Previous Posts
- Got a Pet Tarantula? Better Protect your Eyes
- Contact Lenses Display Information Using LEDs
- Cirrus HD-OCT
- Welcome Dr. Perry Umlauf
- Tears, Idle Tears by Lord Alfred Tennyson
- Dr. Lewis gives Grand Rounds at Rose Medical Cente...
- Crocodile Tears
- Contact Lens Dangers
- Dr. Lewis Honored by the University of Colorado
- Dr. Lewis Appears on Good Morning Colorado Again
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Refractive Surgery Blog
Monday, January 04, 2010
Got a Pet Tarantula? Better Protect your Eyes
Thu Dec 31, 6:31 pm ET
WASHINGTON (Reuters) – Here's some advice stemming from the unusual case of a man who had spider hairs stuck in his cornea: Be sure to cover your eyes when hanging around with your pet tarantula.
Ophthalmologists at St. James's University Hospital in Leeds, England, used high magnification lenses to find out what made the man's eye red, watery and light-sensitive, according to a study reported in the British medical journal The Lancet on Thursday.
They discovered hair-like projections stuck in the man's cornea.
It was a light bulb moment for the patient, who remembered that three weeks earlier he had been cleaning a stubborn stain on the glass tank of his pet, a Chilean Rose tarantula.
"He sensed movement in the terrarium. He turned his head and found that the tarantula, which was in close proximity, had released 'a mist of hairs' which hit his eyes and face," the doctors wrote.
They said the man's condition was rare.
The authors noted that the Chilean Rose tarantula releases the barbed hair on the back of its body to defend against predators.
"We suggest that tarantula keepers be advised to routinely wear eye protection when handling these animals," the doctors said.
(Editing by Mohammad Zargham)
WASHINGTON (Reuters) – Here's some advice stemming from the unusual case of a man who had spider hairs stuck in his cornea: Be sure to cover your eyes when hanging around with your pet tarantula.
Ophthalmologists at St. James's University Hospital in Leeds, England, used high magnification lenses to find out what made the man's eye red, watery and light-sensitive, according to a study reported in the British medical journal The Lancet on Thursday.
They discovered hair-like projections stuck in the man's cornea.
It was a light bulb moment for the patient, who remembered that three weeks earlier he had been cleaning a stubborn stain on the glass tank of his pet, a Chilean Rose tarantula.
"He sensed movement in the terrarium. He turned his head and found that the tarantula, which was in close proximity, had released 'a mist of hairs' which hit his eyes and face," the doctors wrote.
They said the man's condition was rare.
The authors noted that the Chilean Rose tarantula releases the barbed hair on the back of its body to defend against predators.
"We suggest that tarantula keepers be advised to routinely wear eye protection when handling these animals," the doctors said.
(Editing by Mohammad Zargham)
Labels: Spiders
posted by Stuart Lewis, MD at 1:45 PM
Friday, September 18, 2009
Contact Lenses Display Information Using LEDs
From goodideassalon.com
September 1, 2009
Forget sitting too close to the television, its just a matter of time before a screen can literally rest on the eyeball. Scientists at the University of Washington are working on a new breed of contact lenses with embedded LEDs which allow information to be displayed to the wearer. This human machine interface will use custom-built transparent circuitry in a polymer lens that is roughly 1.2 millimeters in diameter.
The technology still faces a few hurdles (the need for custom parts, physical constraints, and user safety) but has already proven itself with single pixel visual cues for both gamers and the hearing impaired.
September 1, 2009
Forget sitting too close to the television, its just a matter of time before a screen can literally rest on the eyeball. Scientists at the University of Washington are working on a new breed of contact lenses with embedded LEDs which allow information to be displayed to the wearer. This human machine interface will use custom-built transparent circuitry in a polymer lens that is roughly 1.2 millimeters in diameter.
The technology still faces a few hurdles (the need for custom parts, physical constraints, and user safety) but has already proven itself with single pixel visual cues for both gamers and the hearing impaired.
Labels: Contact Lenses
posted by Stuart Lewis, MD at 9:30 AM
Tuesday, May 05, 2009
Cirrus HD-OCT
Technology in ophthalmology continues to advance at breakneck speed. At the Cherry Creek Eye Center, we are committed to offering the most technologically advanced therapeutic and diagnostic options for our patients.
We have just purchased the Cirrus HD-OCT (Ocular Coherence Tomograph). This is a clear upgrade from the Stratus OCT 3 that we have had for the past several years in that the images it provides are in high definition. For example, instead of having the capacity to perform 3,072 A-scans with the Stratus OCT 3, we are able to obtain 27,000 A-scans with the new technology. The image quality is markedly enhanced with the Cirrus HD-OCT and the scan patterns provide more viewing options.
The bottom line is that the Cirrus HD-OCT will be a valuable instrument in our armamentarium to help us diagnose macular disorders (macular degeneration) and optic nerve (glaucoma) diseases.
Labels: Technology
posted by Stuart Lewis, MD at 10:02 AM
Monday, May 04, 2009
Welcome Dr. Perry Umlauf
In an attempt to be even more available to our patients, I have hired Dr. Perry Umlauf to work in our office on a regular basis. Dr. Umlauf is both a board certified and fully licensed optometrist who has been in practice since 1989. Due to a job opportunity, he and his wife recently relocated to the Denver area from Central Pennsylvania.
Dr. Umlauf's experience is in the area of medical optometry having worked closely with an ophthalmology practice in Lebanon, PA for the last 20 years. He is also skilled in the fitting of multiple kinds of contact lenses. Dr. Umlauf was voted Central Pennsylvania's Optometrist of the year by the Optometric Society there in 1997 and 2008. He was also voted Optometric Association's optometrist of the year in Pennsylvania in 2009.
We think Dr. Umlauf will be a great addition to our experienced staff.
Dr. Umlauf's experience is in the area of medical optometry having worked closely with an ophthalmology practice in Lebanon, PA for the last 20 years. He is also skilled in the fitting of multiple kinds of contact lenses. Dr. Umlauf was voted Central Pennsylvania's Optometrist of the year by the Optometric Society there in 1997 and 2008. He was also voted Optometric Association's optometrist of the year in Pennsylvania in 2009.
We think Dr. Umlauf will be a great addition to our experienced staff.
Labels: Optometry
posted by Stuart Lewis, MD at 3:11 PM
Friday, February 27, 2009
Tears, Idle Tears by Lord Alfred Tennyson
Tears, idle tears, I know not what they mean,
Tears from the depth of some divine despair
Rise in the heart, and gather to the eyes,
In looking on the happy Autumn-fields,
And thinking of the days that are no more.
Fresh as the first beam glittering on a sail,
That brings our friends up from the underworld,
Sad as the last which reddens over one
That sinks with all we love below the verge;
So sad, so fresh, the days that are no more.
Ah, sad and strange as in dark summer dawns
The earliest pipe of half-awakened birds
To dying ears, when unto dying eyes
The casement slowly grows a glimmering square;
So sad, so strange, the days that are no more.
Dear as remembered kisses after death,
And sweet as those by hopeless fancy feigned
On lips that are for others; deep as love,
Deep as first love, and wild with all regret;
O Death in Life, the days that are no more.
Tears from the depth of some divine despair
Rise in the heart, and gather to the eyes,
In looking on the happy Autumn-fields,
And thinking of the days that are no more.
Fresh as the first beam glittering on a sail,
That brings our friends up from the underworld,
Sad as the last which reddens over one
That sinks with all we love below the verge;
So sad, so fresh, the days that are no more.
Ah, sad and strange as in dark summer dawns
The earliest pipe of half-awakened birds
To dying ears, when unto dying eyes
The casement slowly grows a glimmering square;
So sad, so strange, the days that are no more.
Dear as remembered kisses after death,
And sweet as those by hopeless fancy feigned
On lips that are for others; deep as love,
Deep as first love, and wild with all regret;
O Death in Life, the days that are no more.
Labels: Poetry
posted by Stuart Lewis, MD at 4:06 PM
Sunday, February 15, 2009
Dr. Lewis gives Grand Rounds at Rose Medical Center
On February 10, 2009, Dr. Lewis gave a presentation to the medical staff at Rose Medical Center. The subject of the talk was "Ocular Manifestations of Systemic Diseases." The presentation was well attended, especially by the primary care physicians who were the targeted audience. A question and answer session followed the discussion.
Dr. Lewis has since been asked to give the same presentation to the Rose Medical Center Eye Surgery staff at the Cherry Creek Eye Center and to Rocky Mountain Ophthalmic Personnel members.
Dr. Lewis has since been asked to give the same presentation to the Rose Medical Center Eye Surgery staff at the Cherry Creek Eye Center and to Rocky Mountain Ophthalmic Personnel members.
Labels: Academics
posted by Stuart Lewis, MD at 12:18 PM
Wednesday, October 22, 2008
Crocodile Tears
According to multiple sources including "National Wildlife" and "Science Daily" and Wikipedia, crocodile tears are for real. For centuries, the phrase "crying crocodile tears" has been used to denote insincere grief. According to "National Wildlife" the myth was started in the 15th century when a traveler reported observing a crocodile crying for its prey while consuming it.
Literature through the ages has made references to crying crocodiles including both "The Voyage and Travel of Sir John Mandeville" (published and widely read in 1400) and in Shakespear's "Otello."
University of Florida Zoologist, Kent Vliet, observed and videotaped seven crocodilians while they ate. Five of the seven teared up as they devoured their food. While most mammals produce tears in response to severe pain, crying has been attributed to humans in respnse to both pain and emotional upset. Elephants, gorillas and camels have also been reported to cry according to some studies.
Physiologically, a crocodile's tears are believed to result when they blow air (and tears) through their sinuses while eating. Crocodiles have lacrimal or tear glands that secrete tears but are devoid of tear drainage ducts. The result is that when they eat, the proteinaceous tears bubble up in their eyes. Crocodiles do not cry with remorse.
In humans, "Crocodile Tear Syndrome" is an uncommon consequence of Bell's Palsy. In this condition, the facial or seventh cranial nerve becomes misdirected during regeneration and causes the patient to tear while eating.
Labels: Crocodile Tears
posted by Stuart Lewis, MD at 10:20 AM
Sunday, October 19, 2008
Contact Lens Dangers
Dr. Lewis was again interviewed on Oct. 15 by Shaul Turner on Good Day Colorado. The subject was on the dangers associated with contact lens wear. Specifically, a profile of a typical patient that got into vision-threatening trouble by being lazy in the care of his lenses. The take-home messages that Dr. Lewis gave were:
1. Wash your hands prior to handling your contact lenses.
2. Make sure you rub your contact lenses during cleaning
(despite the "no-rub" advertisement on the bottle.
3. Never "top-off" the lens well with new solution. Empty the
old solution out first.
4. Clean your case out with hot, soapy water regularly and replace
your case monthly.
The vast majority of eye infections related to contact lens wear are caused by poor lens hygiene.
Labels: Corneal Ulcers
posted by Stuart Lewis, MD at 5:21 PM
Monday, June 23, 2008
Dr. Lewis Honored by the University of Colorado
On June 21, 2008, Dr. Lewis was one of two community physicians honored for their years of service to the residency program by the University of Colorado's Department of Ophthalmology. The recognition of Dr. Lewis' twenty-five years of teaching clinical ophthalmology to resident physicians was announced by Naresh Mandava, MD, Chairman of the Department, at the annual Resident's Day Dinner. Dr. Lewis' commitment to the residency program was symbolized by a gift of a buffalo statuette carved from granite.
Labels: Dr. Lewis Honored
posted by Stuart Lewis, MD at 11:52 AM
Tuesday, May 13, 2008
Dr. Lewis Appears on Good Morning Colorado Again
Shaul Turner, anchor of FOX News's Good Morning Colorado, interviewed Dr. Stuart Lewis this morning to "set the record straight" on the latest FDA study on LASIK and to provide an update on the latest technology in refractive surgery. The interview was to some degree a reiteration of the recent press release given by Dr. Lewis (see April 28, 2008 blog entry).
The essence of the FDA study reaffirmed the safety and efficacy of LASIK but did report about up to a 5% complication rate during the period of that study which ended in 2005. Dr. Lewis acknowledged that problems with glare and dry eyes were an issue for a small number of patients in the past. However, with the present state-of-the-art technologies, LASIK can now be performed more predictably and safely than ever before. In fact, the procedure is so stable that it has been approved by the Navy for pilots and by NASA for astronauts.
Technological advances such as the Pentacam that have become available during the past two years have made it easier to predict a patient's candidacy for refractive surgery and make it easier to exclude patients who would be a complication risk. Finally, use of the Intralase in combination with Wavescan Technology makes the procedure more precise and has significantly reduced the number of complications that inspired the FDA study.
To see Good Day Colorado's story on this click here.
posted by Stuart Lewis, MD at 10:10 AM
Tuesday, April 29, 2008
Dr. Lewis Re-Invited to Appear on Good Day Colorado
Earlier this month (April 21), Dr. Lewis appeared on FOX 31's Good Day Colorado to discuss the effects of ultraviolet light on the eye. Due to the success of that broadcast, he has been re-invited to appear on the show on May 13. This time, the conversation is scheduled to be about LASIK and the new advances associated with the evolution of the most common surgical procedure performed today. Specifically, Dr. Lewis will be discussing wave-front technology and the use of the femtosecond laser in this form of refractive surgery.
If you have the opportunity to watch the broadcast, Dr. Lewis is scheduled to be on during the first half hour of the show that begins at 9:00 am, May 13.
To view Dr. Lewis' appearance on April 21st, click here.
If you have the opportunity to watch the broadcast, Dr. Lewis is scheduled to be on during the first half hour of the show that begins at 9:00 am, May 13.
To view Dr. Lewis' appearance on April 21st, click here.
Labels: Good Day Colorado on FOX 31 News
posted by Stuart Lewis, MD at 1:53 PM
Monday, April 28, 2008
LASIK Press Release
According to recent news reports and wire stories, The US Food and Drug Administration (FDA) held a public meeting on Friday, April 25th to discuss patient satisfaction with laser eye surgery, commonly referred to as LASIK (Laser Assisted in-Situ Keratomileusis). Various national print and broadcast media outlets have published this story.
Despite a recent study by the American Academy of Ophthalmology in which 95% of LASIK patients expressed satisfaction with the procedure, the FDA has been prompted to hold these meetings due to complaints received regarding side effects such as dry eye, blurred or double vision, and poor night time vision.
"The FDA has determined that the LASIK procedure is safe and effective for the hundreds of thousands of patients treated every year. Most of these people often have fantastic vision the day after their procedure. However, as with any surgical procedure, there is the potential for an adverse outcome," says Stuart Lewis, MD, the laser eye surgeon at Cherry Creek Eye Physicians & Surgeons, PC.
The number of complaints about LASIK outcomes reported to the FDA from 1998 through 2006 was 140. During this period, between 6 and 7 million patients underwent laser vision correction in the United States. Dr. Lewis elaborated that, "Our patients are concerned about the safety of the procedure, and they are reassured that only 0.002% of the LASIK cases during this time resulted in a complaint to the FDA. This is proof of how successful LASIK is as a surgical procedure. In fact, with the newer technologies available, the complication rate today is significantly lower that that of the past."
Dr. Lewis stated that there are a few patients that experience minor dry eye problems after the procedure, but this is often for a short period of time. "We have known about this particular problem for many years, and we fully inform our patients prior to their surgery via a video and discussions with our staff and physicians that we can alleviate dry eye symptoms with drops and other methods. In addition, we have noted fewer dry eye problems since we have been using the Intralase technology to create the corneal flap."
Dr. Lewis stated that the vast majority of his LASIK patients absolutely love their glasses-free vision. "Once patients learn about how safe and easy LASIK is at Boling Vision Center, they realize that life without glasses or contacts is worth the possibility of a minor complication such as dry eye."
Dr. Lewis reports that he has performed several thousand LASIK procedures since 1996. In fact, Dr. Lewis was one of the first ophthalmologists in the Denver area to perform the procedure. "Patients find that experience reassuring," he said.
Cherry Creek Eye Physicians & Surgeons, PC, is a full service eye care provider that has been in the Denver Community for almost 60 years. With offices in the Cherry Creek Eye Center on East Kentucky Ave. in Denver, Cherry Creek Eye Physicians & Surgeons, PC is one of the leading providers of LASIK in the Denver Metropolitan area. More information can be found at www.cherrycreekeye.com.
Despite a recent study by the American Academy of Ophthalmology in which 95% of LASIK patients expressed satisfaction with the procedure, the FDA has been prompted to hold these meetings due to complaints received regarding side effects such as dry eye, blurred or double vision, and poor night time vision.
"The FDA has determined that the LASIK procedure is safe and effective for the hundreds of thousands of patients treated every year. Most of these people often have fantastic vision the day after their procedure. However, as with any surgical procedure, there is the potential for an adverse outcome," says Stuart Lewis, MD, the laser eye surgeon at Cherry Creek Eye Physicians & Surgeons, PC.
The number of complaints about LASIK outcomes reported to the FDA from 1998 through 2006 was 140. During this period, between 6 and 7 million patients underwent laser vision correction in the United States. Dr. Lewis elaborated that, "Our patients are concerned about the safety of the procedure, and they are reassured that only 0.002% of the LASIK cases during this time resulted in a complaint to the FDA. This is proof of how successful LASIK is as a surgical procedure. In fact, with the newer technologies available, the complication rate today is significantly lower that that of the past."
Dr. Lewis stated that there are a few patients that experience minor dry eye problems after the procedure, but this is often for a short period of time. "We have known about this particular problem for many years, and we fully inform our patients prior to their surgery via a video and discussions with our staff and physicians that we can alleviate dry eye symptoms with drops and other methods. In addition, we have noted fewer dry eye problems since we have been using the Intralase technology to create the corneal flap."
Dr. Lewis stated that the vast majority of his LASIK patients absolutely love their glasses-free vision. "Once patients learn about how safe and easy LASIK is at Boling Vision Center, they realize that life without glasses or contacts is worth the possibility of a minor complication such as dry eye."
Dr. Lewis reports that he has performed several thousand LASIK procedures since 1996. In fact, Dr. Lewis was one of the first ophthalmologists in the Denver area to perform the procedure. "Patients find that experience reassuring," he said.
Cherry Creek Eye Physicians & Surgeons, PC, is a full service eye care provider that has been in the Denver Community for almost 60 years. With offices in the Cherry Creek Eye Center on East Kentucky Ave. in Denver, Cherry Creek Eye Physicians & Surgeons, PC is one of the leading providers of LASIK in the Denver Metropolitan area. More information can be found at www.cherrycreekeye.com.
Labels: LASIK Complications
posted by Stuart Lewis, MD at 11:27 AM
Monday, April 21, 2008
Dr. Lewis Interviewed on Good Day Colorado
This morning Dr. Lewis was interviewed on Good Day Colorado by Shaul Turner. "We are trying to educate Coloradans about the harmful and cumulative effects of ultraviolet (UV) light." The interview was done in response to a new product - Fitovers - non-prescription sunglasses that fit over a standard pair of glasses.
Fitovers have several positive features: They block UV light in the 400nm range and thus help protect the retina/macula, diminish glare because they are polarized, are made of polycarbonate and are, therefore, shatter proof, protect the skin around the eyes due to their size, are fashionable and are inexpensive (~$50.00). The lenses are a great substitute for buying a separate pair of prescription sunglasses and have been particularly well received by fishermen and other sports enthusiasts.
You will be surprised at Fitovers' comfort and convenience. Visit the Cherry Creek Optical located on the first floor of the Cherry Creek Eye Center to look at your Fitover options.
Labels: Ultraviolet Light
posted by Stuart Lewis, MD at 12:26 PM
Wednesday, April 09, 2008
Patient Blog
Recently, while purchasing an item via the Internet, I took the opportunity to read several reviews of other shoppers who had bought and commented on the product in question. Not only did I feel their praise and criticisms to by useful, they were very important in helping me make my shopping decision. I appreciated both the honesty of the reviewers and straight forward business approach of the vendor. I decided that that form of transparency was exactly what my practice needed for patients who wanted another form of information.
At the end of February, I opened a new section on my website - a "Patient Blog." It is a forum where patients are able to candidly express opinions about how they decided to choose us as health care providers, how they were treated and, in general, their experiences in my office. The blog is meant to provide an inside look into the way my office performs from the patient's perspective.
I invite you to read and write reviews about my office.
At the end of February, I opened a new section on my website - a "Patient Blog." It is a forum where patients are able to candidly express opinions about how they decided to choose us as health care providers, how they were treated and, in general, their experiences in my office. The blog is meant to provide an inside look into the way my office performs from the patient's perspective.
I invite you to read and write reviews about my office.
Labels: Patient Blog
posted by Stuart Lewis, MD at 8:24 AM
Monday, April 07, 2008
The "Flomax" Pupil
If you watch sports on television, one of the most common commercials shows a group of men in their fifties or sixties biking, kayaking and generally having a good time. The point of the commercial is that the use of Flomax reduces male urinary symptoms related to an enlarging prostate. At the
posted by Stuart Lewis, MD at 2:08 PM
Tuesday, March 04, 2008
20/20 to being Legally Blind
On a regular basis, I am asked: What does 20/20 actually mean? While the technical answer is complicated, the one most people understand is quite straight forward. Your visual acuity is measured on a Snellen eye chart. The chart contains eleven lines of block letters set up in rows that decrease in their size and increase in number as one looks from the top to bottom of the chart. The thickness of the lines equal the thickness of the white spaces between them and the height and width of each letter is five times the thickness of the line. Only ten letters are used in the chart. 20/20 is considered the smallest line that a person with normal visual acuity can read at a distance of twenty feet. If you had 20/40 vision (or roughly 1/2 normal vision), it means that you would need to be only 20 feet away to read what a normally sighted person can read from 40 feet away.
With regard to "Snellen Vision," many patients report that they are "legally blind" without their glasses. This is a contradiction in terms as legal blindness is defined as being able to see no better than 20/200 (the second largest letter on the eye chart) in the best corrected state. That is much different from being able to see no better than 20/200 in the uncorrected state.
Clearly, there too many causes to cause a deviation from normal vision to discuss here. If you are experiencing a problem with your visual acuity, the best thing you can do is find out the cause. And, if you have other questions about your vision, give my office a call and someone should be able to help you.
Labels: 20/20 Vision
posted by Stuart Lewis, MD at 10:00 AM
Monday, February 04, 2008
"Cheerio" to White Coats and Ties
According to the December 2007 "Anesthesiology News," British physicians will no longer wear white coats or ties. New rules issued by the U.K. Department of Health have mandated a "bare below the elbows" dress code. That code includes jewelry, watches, white coats and neck ties during all clinical activities. The rules are based on a small body of literature that examined the risk for transmission of pathogenic microorganisms. Of particular concern is the transmission of methicillin-resistant Staphylococcus aureus (MRSA), the "superbug" resistant to nearly every available antibiotic.
In the United States, the push has been to maintain professional dress. This difference in approach to dress is because, according to one study, patients "overwhelmingly favor physicians in professional attire with a white coat" and because the link to infections and physician's clothing is not that well studied. There is scant evidence that a physician's attire affects rates of hospital-acquired infections, particularly infections with multifactorial causes like MRSA.
In the United States, the push has been to maintain professional dress. This difference in approach to dress is because, according to one study, patients "overwhelmingly favor physicians in professional attire with a white coat" and because the link to infections and physician's clothing is not that well studied. There is scant evidence that a physician's attire affects rates of hospital-acquired infections, particularly infections with multifactorial causes like MRSA.
Labels: Infection
posted by Stuart Lewis, MD at 9:00 PM
Friday, January 25, 2008
ILASIK (IntraLASIK)
I have been performing IntraLASIK or ILASIK for about a year and a half. A review of the results was just completed and they were impressive. To this point in time, of the first several hundred eyes operated on using this technology, there were no re-treatments needed. All patients had results that either hit or were very close to the target refraction. In addition, there were no flap or other complications.
To put this in perspective, using the "traditional" technology, microkeratome associated LASIK flap complications occurred at a rate of about one percent. While this complication rate does not seem to be high, it can be inconvenient at best and cause the loss of best corrected vision at worst when it occurs. Traditionally performed LASIK (when Customvue technology was not employed) had a re-treatment rate of nearly three percent. And, when the combination of the Intralase femtosecond laser and wavefront technology was used, it was better in almost every case - especially with night vision improvement.
I-LASIK has been a real advancement in both the safety and visual results categories. While the improvements seem to be only incrementally better, we are continuing to strive for refractive visual perfection.
To put this in perspective, using the "traditional" technology, microkeratome associated LASIK flap complications occurred at a rate of about one percent. While this complication rate does not seem to be high, it can be inconvenient at best and cause the loss of best corrected vision at worst when it occurs. Traditionally performed LASIK (when Customvue technology was not employed) had a re-treatment rate of nearly three percent. And, when the combination of the Intralase femtosecond laser and wavefront technology was used, it was better in almost every case - especially with night vision improvement.
I-LASIK has been a real advancement in both the safety and visual results categories. While the improvements seem to be only incrementally better, we are continuing to strive for refractive visual perfection.
Labels: ILASIK (IntraLASIK)
posted by Stuart Lewis, MD at 12:07 PM
Tuesday, January 22, 2008
PRK and LASIK after RK
A patient I have followed over the past twenty years recently came in with an all too common problem - his vision had deteriorated gradually after having had radial keratotomy (RK) in the 1980s. Allan had a multiple cut RK along with an AK (astigmatic keratotomy) about twenty-five years ago when living in California. Through the years I have fit him with a variety of different contact lenses to improve his vision but even a rigid lens was difficult to fit as his cornea was so flat. The result was that his vision was inconsistent and he was never entirely happy with his compromised vision. Now, Allan's vision had become so abnormal due to the shifting of his cornea that he was no longer correctable with glasses or contact lenses. The question was: Now what?
RK was the first popular surgical approach used to correct both myopia and astigmatism. It was the rage in the 1980s and into the early 1990s before LASIK became available in the United States. The way it worked was partial thickness radial cuts were made into the cornea. The effect was to weaken the peripheral cornea so that the normal intraocular pressure that was constantly pushing out, preferentially influenced the weakened area of the cornea that provided the least resistance. The result was the peripheral cornea bulged and the central cornea flattened to give the desired effect. The problem was that over the years, the central cornea continued to gradually flatten and patients gradually became farsighted.
Over the past several years I have has success treating these refractive problems by performing either hyperoptic LASIK under the RK cuts or PRK over the cuts in an attempt to even out the corneal curvature. In this case I recommended LASIK to Allan with special emphasis on treating the large amount of astigmatism that had developed. Allan was nervous about this but decided to proceed as he felt he had little to lose. The procedure went perfectly and Allan had 20/20 vision on the first post-operative day.
Post-RK refractive surgery works. If your having farsighted problems years after your RK, give us a call.
RK was the first popular surgical approach used to correct both myopia and astigmatism. It was the rage in the 1980s and into the early 1990s before LASIK became available in the United States. The way it worked was partial thickness radial cuts were made into the cornea. The effect was to weaken the peripheral cornea so that the normal intraocular pressure that was constantly pushing out, preferentially influenced the weakened area of the cornea that provided the least resistance. The result was the peripheral cornea bulged and the central cornea flattened to give the desired effect. The problem was that over the years, the central cornea continued to gradually flatten and patients gradually became farsighted.
Over the past several years I have has success treating these refractive problems by performing either hyperoptic LASIK under the RK cuts or PRK over the cuts in an attempt to even out the corneal curvature. In this case I recommended LASIK to Allan with special emphasis on treating the large amount of astigmatism that had developed. Allan was nervous about this but decided to proceed as he felt he had little to lose. The procedure went perfectly and Allan had 20/20 vision on the first post-operative day.
Post-RK refractive surgery works. If your having farsighted problems years after your RK, give us a call.
posted by Stuart Lewis, MD at 2:06 PM
Thursday, January 03, 2008
Pentacam - More Advanced Technology
In addition to the upgraded IOLMaster discussed in my last blog entry, my practice has also acquired a Pentacam Comprehensive Eye Scanner. It is a rotating camera that photographs both the anterior and posterior surfaces of the cornea as well as other parts of the front of the eye. The main advantage to this technology is that this unique camera provides precise measurements of the central cornea better than any other instrument available.
The Pentacam has improved my ability to diagnose ocular conditions (especially keratoconus) more accurately than ever before. Equally important is that with this camera I have the confidence to rule out "false keratoconus positives" from traditional topographers and offer LASIK and other refractive procedures to many patients who have been denied them in the past. The Pentacam is also extremely helpful in determining the intraocular lens(IOL) power for cataract patients who have previously had a refractive procedure. Finally, it is very helpful in understanding the positioning of phakic and piggyback IOLs.
With the the use of the IOLMaster and Pentacam both LASIK and intraocular refractive procedures are safer and and more precise than ever before.
Labels: Pentacam
posted by Stuart Lewis, MD at 4:24 PM
Tuesday, January 01, 2008
The IOLMaster - Advanced Diagnostics for the Cherry Creek Eye Center
Happy New Year from the Cherry Creek Eye Physicians and Surgeons! Since 1982 when I entered into private practice, I have been committed to providing the very best options for treating our patients. That commitment began with the development of the Cherry Creek Eye Center in 1985 and has continued without interruption until today. The Cherry Creek Eye Center is now the most frequented eye only facility in East Denver and continues to grow in both numbers of patients and in the quality of care offered. We are trying to provide not just the community standard of care but rather the state-of-the-art.
An example of this commitment to excellence is the recent purchase of the IOLMaster, version 5 software. The IOLMaster is an optical device used to make multiple, critical measurements of the eye that can then be used to calculate the intraocular lens (IOL) power used when replacing the crystalline lens of the eye (cataract or clear lens replacement surgery). This instrument uses non-contact, optical methods to measure the length of the eye, the depth of the front chamber of the eye and the curvature of the cornea. The IOLMaster is accurate to +/- 0.02 mm or better giving an increase in accuracy of five fold over traditional measurement methods. While we have had the IOLMaster for years, the new software enhances both the accuracy and reproducibility of measurements by analyzing them individually and as a series. And, with the new software, the IOLMaster can be used on an expanded population of patients who could not enjoy it's benefits in the past. The data obtained with this instrument takes us to the next level of precision in cataract and clear lens replacement surgery.
With the increasing technology of the newest replacement lenses available such as the multifocal IOLs (ReZoom and ReStor), precision measurements are more important than ever. Good vision is no longer good enough after cataract surgery - great vision is our interest and goal.
At the Cherry Creek Eye Center, we are invested in your visual results.
Labels: IOLMaster
posted by Stuart Lewis, MD at 8:58 PM
Thursday, December 06, 2007
SynergEyes Hybrid Contact Lenses are Available
When 9News at 10pm spot-lighted my practice in their feature story "The Eyes Have It" earlier this year, they spent one segment on a high-tech, alternative to laser vision correction. Specifically, the SynergEyes contact lens was discussed in detail. After months of testing in my office, we are now offering this lens for patients with myopia, regular astigmatism, farsightedness and keratoconus. The lens will soon be available for patients who have post-surgical irregular astigmatism and for patients suffering from presbyopia.
The SynergEyes lens is similar in design to the older Softperm contact lens in that it is a hybrid lens - a rigid, gas-permeable lens with a soft lens skirt fused to its edges. But, that is where the similarities end. The SynergEyes lens is a much improved lens in that it is highly permeable to oxygen and the patented Hyperbond technology solves the durability issue that plagued previous hybrid lenses. In addition, this lens is offered with a large number of fitting parameters allowing almost any patient to obtain their best potential vision.
While this high-tech hybrid lens is not inexpensive, it is a lens of "last resort." If you have been unable to wear contact lenses due to poor or fluctuating vision or poor centration of the lens, you owe it to yourself to explore the SynergEyes option. Give us a call to see if this lens is right for you.
Labels: Contact Lenses
posted by Stuart Lewis, MD at 9:00 PM
Wednesday, November 28, 2007
Dr. Lewis Named Chief of Ophthalmology at Rose Medical Center
At the most recent meeting of the Department of Ophthalmolgy at Rose Medical Center, Stuart Lewis, MD, FACS was named Chairman of the Department for a two year term. While Dr. Lewis has served in the capacity of Department Chair in the past, he agreed to another term and has plans to continue to improve and re-vitalize the department with additional equipment and services.
The Cherry Creek Eye Center has been the base of operations for Rose Medical Center ophthalmologists since 1986. The Eye Center is composed of private physician offices, the Rose Medical Center dedicated out-patient eye surgery operating rooms, the Cherry Creek Optical and an out-patient ophthalmic lab. The idea of an out-patient eye surgery center was developed by six Rose Medical Center ophthalmologists (Drs. Lewis, Frankel, Goldstein, Kadler, Meltzer and Barmatz) in 1985 and was the first such center in the Denver metropolitan area. The ground-breaking concept of private practice physicians working together with a hospital in such a manner was unique at the time but has proven to be the blueprint for many successful out-patient surgery centers (Midtown/HealthOne, Harvard Park/Porter, Lowry/HealthOne) in Denver.
It is Dr. Lewis' plan to continue to offer state-of-the-art services rather than just the community standard at the Cherry Creek Eye Center. If you have questions regarding the Ophthalmology Department at Rose or constructive suggestions, please call us at 303 691-2228.
The Cherry Creek Eye Center has been the base of operations for Rose Medical Center ophthalmologists since 1986. The Eye Center is composed of private physician offices, the Rose Medical Center dedicated out-patient eye surgery operating rooms, the Cherry Creek Optical and an out-patient ophthalmic lab. The idea of an out-patient eye surgery center was developed by six Rose Medical Center ophthalmologists (Drs. Lewis, Frankel, Goldstein, Kadler, Meltzer and Barmatz) in 1985 and was the first such center in the Denver metropolitan area. The ground-breaking concept of private practice physicians working together with a hospital in such a manner was unique at the time but has proven to be the blueprint for many successful out-patient surgery centers (Midtown/HealthOne, Harvard Park/Porter, Lowry/HealthOne) in Denver.
It is Dr. Lewis' plan to continue to offer state-of-the-art services rather than just the community standard at the Cherry Creek Eye Center. If you have questions regarding the Ophthalmology Department at Rose or constructive suggestions, please call us at 303 691-2228.
posted by Stuart Lewis, MD at 10:29 AM
Monday, September 24, 2007
NASA Approves Wave-Front Guided Intralasik
On September 21, 2007 wave-front Guided IntraLASIK received further validation when the National Aeronautics and Space Agency (NASA) approved all-laser LASIK technologies for use on U.S. astronauts. This approval follows the U. S. Navy's recent decision that approved the same procedure (see blog entry August 10, 2007). While this advanced refractive technology has been performed in the United States for about two years, it has taken NASA that long to review extensive military Clinical data and determine that this technology provides superior safety and vision.
The excimer laser was approved by the FDA in October 1995 for use in refractive eye surgery. Since that time, over eleven million LASIK procedures have been performed making it the most common (and successful) elective procedure performed in the United States. However, it was not until the development of an all laser technique that both the U.S. Navy and now NASA approved it for their pilots. It was approved because the visual results and post-operative stability of the cornea following LASIK were able to withstand even the most extreme rigors of warfare and flight.
I have been performing exactly the procedure described with exactly the same equipment as Navy and NASA ophthalmologists. In the past year, there is no doubt that the visual results and stability of vision are superior to the first rendition of this surgery. In addition, complications related to the procedure have become rare. While the wave-front guided LASIKusing an all-laser platform is more expensive, I have not had a single patient who has felt it was not worth the price.
Stuart Lewis, MD
Labels: Wave-Front Guided Intralasik
posted by Stuart Lewis, MD at 3:59 PM
Monday, August 27, 2007
We're Watching
On August 24, 2007, NASA released newly expanded images of the Helix nebula taken by the Spitzer Space Telescope. The spectacular image that looks like a large eye is actually that of a dying star unraveling into space. Using the Spitzer Space Telescope, scientists have been able to map the six-light-year-wide nebula and have found what appears to be a planetary system that survived the explosion that created the above image. The Spitzer Space Telescope image was released on the fourth anniversary of its' launch in 2003.
Ophthalmologists have been very interested in the space telescopes because many of the optical challenges faced and overcome by NASA scientists have been applied to modern refractive surgery. The Hubble and Spitzer Space Telescopes are considered to be NASA's "Great Observatories."
posted by Stuart Lewis, MD at 10:54 AM
Thursday, August 16, 2007
Ophthalmology Increases in Popularity
Earlier this year, "Match Day" was held for the almost 20,000 medical students across the country. This was the day when graduating fourth year medical students chose and were chosen for one of the various medical specialty residencies programs. In the past, ophthalmology was always the first or second most difficult residencies to obtain but that position was supplanted by dermatology in recent years. Well, history is repeating itself with a resurgence of interest in ophthalmology.
According to Wired magazine, ophthalmology has become one of the most popular medical specialties. Residency choices broke down like this: 23% chose internal medicine followed by pediatrics with 12%. Radiology was chosen 8% of the time and ophthalmology and emergency room programs weighed in at 7%.
While it seems to me that primary care specialties like internal medicine, family practice, pediatrics and OBGyn would best serve our growing population's medical needs, sub-specialty programs are growing in popularity.
Stuart Lewis, MD
According to Wired magazine, ophthalmology has become one of the most popular medical specialties. Residency choices broke down like this: 23% chose internal medicine followed by pediatrics with 12%. Radiology was chosen 8% of the time and ophthalmology and emergency room programs weighed in at 7%.
While it seems to me that primary care specialties like internal medicine, family practice, pediatrics and OBGyn would best serve our growing population's medical needs, sub-specialty programs are growing in popularity.
Stuart Lewis, MD
Labels: Ophthalmology Residencies
posted by Stuart Lewis, MD at 3:48 PM
Friday, August 10, 2007
Wavefront-guided LASIK and Intralase (SBK)
In a recent report, the U.S. Navy has mandated that all pilots undergoing laser corrective surgery have it done with Wavefront-guided Technology and with the use of the IntraLase to create the corneal flap. This approach is also known as sub-Bowman's keratomileusis (SBK). I have been an advocate of exactly this surgical approach for the past year and have used it on 99% of all LASIK patients. In fact, I use identical equipment to that used on Navy pilots. The reasons for my recommending this approach is that I believe the risks of this procedure are greatly reduced and that the visual results are as good or better than those seen after traditional LASIK.
Navy Physicians found that Wavefront-guided LASIK with the IntraLase Method provided improved contrast sensitivity. They also found that femtosecond (IntraLase FS laser) flaps led to faster visual recovery and better contrast sensitivity compared with mechanical microkeratomes. In an evaluation of night driving vision, naval aviators who were treated with IntraLase plus wavefront-guided LASIK showed an above average improvement in performance.
The U.S. Navy now performs LASIK with a flap created by a femtosecond laser (IntraLase FS laser) and corrects the refractive error with a wavefront-guided ablation (VISX STAR S4 laser). IntraLase was awarded a contract from the Defense Logistics Agency for IntraLase FS lasers, procedures, maintenance and support for the U.S. Army, Navy, Air Force, Marine Corps and Federal civilian agencies.
Stuart Lewis, MD
posted by Stuart Lewis, MD at 5:00 PM
Friday, July 20, 2007
Avast you Scurvy Dogs
In my last blog posting (July 13, 2007), I mentioned that monovision correction had been around since the Johnson Administration. I have since learned that a form of monovision has been around since around the 13th century B.C. Pirates or Sea Peoples apparently used a form of monovision when they threatened the Aegean Sea during ancient times.
When you think of a pirate, the image of a peg-legged, hook-armed eye-patched sailor comes to mind. While one can understand how loss of a limb might have been very common on the high seas, it is hard to conceive of that many pirates losing an eye. In fact, according to pirate folklore, pirates covered one eye on purpose to keep it dark adapted for night vision. When a sailor went from being in the bright sun into the dark hold below, the patch would be switched to the fellow eye and there would be no delay in the time it took to recover his vision. Pirates moved about their ship freely and efficiently but did so with poor depth perception.
If you are interested in finding out more on this topic, an episode of Mythbusters recently aired on the discovery channel addressing this very subject. Part of the pirate episode is posted on the Internet. Check it out on YouTube.
Stuart Lewis, MD
Labels: Monovision
posted by Stuart Lewis, MD at 12:21 PM
Friday, July 13, 2007
FDA Approves VISX S4 for Monovision LASIK
The US Food and Drug Administration (FDA) finally approved a refractive technique that eye surgeons have commonly used to help presbyopic patients deal with their visual challenges at both distance and near (See my Blog entry "LASIK for Presbyopia," Feb. 13, 2007). Monovision, or the concept of correcting one eye for distance and the other (usually non-dominant eye) for near vision, was approved on July 12, 2007. I have been performing monovision laser refractive surgery on an off-label basis since 1996 and have been correcting patients that way with contact lenses and with intraocular lenses following cataract surgery since 1982. This approach has been widely utilized since the Johnson Administration.
"Monovision has been available off-label since approval of the first laser used for conventional laser eye surgery" according to the Executive Director of the Council for Refractive Surgery Quality Assurance. "This FDA approval is not likely to have any practical effect on the availability of monovision lasik in the United States."
According to the FDA, patients should have a contact lens trial of monovision correction prior to having surgical correction to make sure they tolerate having their eyes corrected to different focal points. The main draw back to to monovision correction is that depth perception may not be as acute as having both eyes corrected equally. Other problem areas arise in driving at night or reading extensively for long periods of time. Some patients elect to wear glasses for those tasks but don't use any additional correction for most daily activities. While we take care to make sure the decision to have monovision correction is the correct one, occasionally a patient will decide it is not what they really wanted. In those rare cases, additional laser treatment can be used to equalize the vision.
Stuart Lewis, MD
"Monovision has been available off-label since approval of the first laser used for conventional laser eye surgery" according to the Executive Director of the Council for Refractive Surgery Quality Assurance. "This FDA approval is not likely to have any practical effect on the availability of monovision lasik in the United States."
According to the FDA, patients should have a contact lens trial of monovision correction prior to having surgical correction to make sure they tolerate having their eyes corrected to different focal points. The main draw back to to monovision correction is that depth perception may not be as acute as having both eyes corrected equally. Other problem areas arise in driving at night or reading extensively for long periods of time. Some patients elect to wear glasses for those tasks but don't use any additional correction for most daily activities. While we take care to make sure the decision to have monovision correction is the correct one, occasionally a patient will decide it is not what they really wanted. In those rare cases, additional laser treatment can be used to equalize the vision.
Stuart Lewis, MD
Labels: Monovision LASIK
posted by Stuart Lewis, MD at 10:58 AM
Sunday, July 08, 2007
Dr. Lewis is Elected as a Fellow of the American College of Surgeons
Last month (June 2007), I was approved for fellowship in the American College of Surgeons. After the convocation ceremony later this year in New Orleans, my formal title will be Stuart A. Lewis, M.D., F.A.C.S. I am honored to be accepted into this prestigious organization and look forward to being involved in carrying out its mandate.
The American College of Surgeons is a scientific and educational association of surgeons that was founded in 1913 to improve the quality of care for the surgical patient by setting high standards for surgical education and practice.
Members of the American College of Surgeons are referred to as "Fellows." The letters FACS (Fellow, American College of Surgeons) after a surgeon's name mean that the surgeon's education and training, professional qualifications, surgical competence, and ethical conduct have passed a rigorous evaluation, and have been found to be consistent with the high standards established and demanded by the College.
It will be my goal to continue providing not only excellence in eye care as has been the tradition in my office for over 50 years, but, to provide care in a state-of the-art, ethical manner in accordance with the American College of Surgeons.
Labels: American College of Surgeons
posted by Stuart Lewis, MD at 5:21 PM
Tuesday, June 12, 2007
LASIK Approved by the U.S. Air Force
The Air Force News recently reported that effective May 21, 2007 Air Force officials reversed their long-standing policy that prevented pilots and others who have had lasik from applying for aviation and aviation-related jobs. The new policy also removed the altitude and high-performance aircraft restrictions for people who have had lasik. All applicants to aviation-related career fields still must meet the vision standards prescribed in AFI-48-123 (Medical Examination and Standards for entrance into the Air Force and aviation and special-duty positions).
The decision to make this change was based on studies that showed there was little if any difference between lasik-treated as compared to untreated eyes when subjected to the wind blast experienced during aircraft ejection or exposure to high altitude.
Of the various options for refractive surgery, the Air Force has recommended two particular types of lasik for aviation candidates: Wave Front Guided Photorefractive Keratectomy (WFG-PRK) and Wave Front Guided laser In-Situ Keratomileusis (WFG-LASIK) using the femtosecond laser for the creation of the corneal flap. It was the feeling of the Air Force that eyes treated by one of these methods would be more trauma resistant after surgery compared to other forms of refractive surgery.
At the Cherry Creek Eye Center, I have been performing both of the above procedures for a lengthy period and have had excellent results. As of this date, I have had no complications in patients who have had the WFG-PRK or WFG-LASIK.
Stuart Lewis, MD
Labels: Cataract Surgery after LASIK
posted by Stuart Lewis, MD at 2:35 PM
Wednesday, May 30, 2007
Complete MoisturePlus Multipurpose Contact Lens Solution Recalled
On May 25, 2007, Advanced Medical Optics (AMO) decided to voluntarily recall Complete MoisturePlus contact lens solution. The decision was made in response to information received from the Center for Disease Control (CDC) regarding eye infections from the microorganism Acanthamoeba. The report was based upon interviews with 46 patients who had developed Acanthamoeba keratitis (AK) since January 2005. A total of 39 of these patients were wearing soft contact lenses and 21 of them were using the solution in question.
AMO is working closely with the CDC and has recalled the contact lens solution acting out of caution. There has been no evidence of contamination of the product and none of the other AMO products have been implicated in this inquiry.
Acanthamoeba is a naturally occurring organism that can cause a serious eye infection known as Acanthamoeba Keratitis (AK). The organism can be found in water, soil, sewage systems, cooling towers and heating/ventilation/air conditioning (HVAC) systems. The incidence of AK has been estimated to be one to two cases per million contact lens users. It is usually associated with contact lens wearers who improperly store/handle/disinfect their contact lenses. For example, many patients use tap water to clean their lenses. It is also found in those who swim, use hot tubs, or those who over-use their disposable contact lenses without properly disinfecting them while trying to extend their life and save money.
Please contact us if you experience any of the following symptoms: eye pain, eye redness, blurred vision, sensitivity to light, a foreign body sensation in the eye and/or excessive tearing. Symptoms can last for weeks to months and are not uniform in their presentation. Early infections with Acanthamoeba can be similar to other eye infections but advanced AK causes severe pain with possible loss of vision that could require corneal transplant.
Please discontinue the use of this product immediately and call 1-888-899-9183 for more information. You can report adverse reactions related to this product to the FDA at 1-FDA-1088.
http://www.cherrycreekeye.com/eye_care.html%20On
AMO is working closely with the CDC and has recalled the contact lens solution acting out of caution. There has been no evidence of contamination of the product and none of the other AMO products have been implicated in this inquiry.
Acanthamoeba is a naturally occurring organism that can cause a serious eye infection known as Acanthamoeba Keratitis (AK). The organism can be found in water, soil, sewage systems, cooling towers and heating/ventilation/air conditioning (HVAC) systems. The incidence of AK has been estimated to be one to two cases per million contact lens users. It is usually associated with contact lens wearers who improperly store/handle/disinfect their contact lenses. For example, many patients use tap water to clean their lenses. It is also found in those who swim, use hot tubs, or those who over-use their disposable contact lenses without properly disinfecting them while trying to extend their life and save money.
Please contact us if you experience any of the following symptoms: eye pain, eye redness, blurred vision, sensitivity to light, a foreign body sensation in the eye and/or excessive tearing. Symptoms can last for weeks to months and are not uniform in their presentation. Early infections with Acanthamoeba can be similar to other eye infections but advanced AK causes severe pain with possible loss of vision that could require corneal transplant.
Please discontinue the use of this product immediately and call 1-888-899-9183 for more information. You can report adverse reactions related to this product to the FDA at 1-FDA-1088.
http://www.cherrycreekeye.com/eye_care.html%20On
Labels: Contact Lenses
posted by Stuart Lewis, MD at 3:59 PM
Tuesday, May 22, 2007
Orangutan Undergoes Cataract Surgery in Sarawak
According to a recent report by the Associated Press, a 19-year-old, 330 pound orangutan named Aman underwent bilateral cataract surgery last week on the Island of Borneo. The procedure took about two-and-a-half hours and was performed by a veterinarian ophthalmologist from South Africa. Aman had apparently been suffering from poor vision for about seven years. While cataract surgery has been performed on many other animals, this was the first performed on an orangutan. Orangutans live upwards of 45 years and this surgery was seen as a benevolent act.
Details of the surgery were not reported and it was not clear whether intraocular implants were used to replace the great ape's cloudy lenses.
Stuart Lewis, MD
http://www.cherrycreekeye.com/cataracts.html
Details of the surgery were not reported and it was not clear whether intraocular implants were used to replace the great ape's cloudy lenses.
Stuart Lewis, MD
http://www.cherrycreekeye.com/cataracts.html
Labels: Cataract Surgery in Animals
posted by Stuart Lewis, MD at 10:15 AM
Monday, May 14, 2007
Cataract Surgery after LASIK
Now that corneal refractive surgery is well established and has been deemed safe and effective by the FDA, more and more patients are feeling comfortable enough to consider one of the available refractive surgical options. In particular, baby boomers in their 40s, 50s and even 60s are having LASIK performed on themselves in greater numbers in an attempt to safely, simplify their lives. But, a percentage of these patients will develop cataracts over the next ten years and will need to have them removed. These patients will expect the same excellent post-operative visual result they experienced with their refractive surgery years before. The question is: How will the refractive surgery done in years past impact your cataract surgery result?
The truth of the matter is that the calculation for the intraocular lens (IOL) that is placed in the eye after removing the cataract is trickier than was originally expected. And therefore, achieving the predicted result is not routine in patients who have had LASIK or PRK or other procedures as compared to those who have not had prior corneal refractive procedures. This is because the true power of the cornea after refractive surgery is actually less than measured by conventional instruments. Unless this is understood, post-LASIK cataract patients will end up under-corrected and farsighted following their surgery.
I have been studying this problem for several years and have performed hundreds of cataract procedures on post- LASIK, PRK, and RK patients. There are a few important features to obtaining consistent results. First, it is critical that accurate measurements of the length of the eye are obtained. We use the newest version of the IOLMaster. This device measures the length of the eye by having the patient fixate on a target and then bouncing a beam of light off of the center of the retina (macula). This is different and more accurate than measuring the length of the eye with the traditional method of using ultrasound. Secondly, the calculations become more predictable if both the pre and post LASIK corneal curvatures are known. The latter can be easily measured but the former need to be obtained from old medical records. Finally, it is important that the correct formula is used in the calculation.
What you should do now is obtain your old records before they get lost or are destroyed. Keep them in a safe place or have them copied and give them to your present ophthalmologist for safe keeping in his/her records. That way you will allow yourself the best chance for accurate calculations prior to future procedures.
http://www.cherrycreekeye.com/cataracts.html
Stuart Lewis, M.D.
The truth of the matter is that the calculation for the intraocular lens (IOL) that is placed in the eye after removing the cataract is trickier than was originally expected. And therefore, achieving the predicted result is not routine in patients who have had LASIK or PRK or other procedures as compared to those who have not had prior corneal refractive procedures. This is because the true power of the cornea after refractive surgery is actually less than measured by conventional instruments. Unless this is understood, post-LASIK cataract patients will end up under-corrected and farsighted following their surgery.
I have been studying this problem for several years and have performed hundreds of cataract procedures on post- LASIK, PRK, and RK patients. There are a few important features to obtaining consistent results. First, it is critical that accurate measurements of the length of the eye are obtained. We use the newest version of the IOLMaster. This device measures the length of the eye by having the patient fixate on a target and then bouncing a beam of light off of the center of the retina (macula). This is different and more accurate than measuring the length of the eye with the traditional method of using ultrasound. Secondly, the calculations become more predictable if both the pre and post LASIK corneal curvatures are known. The latter can be easily measured but the former need to be obtained from old medical records. Finally, it is important that the correct formula is used in the calculation.
What you should do now is obtain your old records before they get lost or are destroyed. Keep them in a safe place or have them copied and give them to your present ophthalmologist for safe keeping in his/her records. That way you will allow yourself the best chance for accurate calculations prior to future procedures.
http://www.cherrycreekeye.com/cataracts.html
Stuart Lewis, M.D.
Labels: Cataract Surgery after LASIK
posted by Stuart Lewis, MD at 3:50 PM
Tuesday, March 06, 2007
Keratoconus (Corneal Ectasia)
Now that laser surgery for vision correction has been around for over a decade, patients who previously were hesitant to consider LASIK have accepted the procedure to be safe and effective and are being evaluated in ophthalmologist's offices with increasing frequency. Fortunately, the technology we now have for this screening process has improved to the level that we are able to determine good candidates from bad ones almost all of the time. The interesting thing is this; we are finding that the number of patients with underlying corneal abnormalities (and thus not LASIK candidates) is greater than we thought. Specifically, the condition known as keratoconus or corneal ectasia was previously thought to occur in 1/2,000 Americans but now reports are finding this condition to be occurring as commonly as 1/500 according the the National Eye Institute.
Keratoconus is a condition that usually begins to develop in the late teenage years and can progress until the age of about 40 when it slows down or stops. The condition occurs in both genders and all ethnicities but has a higher prevalence among females and in those with Asian heritage. The symptoms vary from those of just needing a glasses prescription to see more clearly to diminished vision and/or double or triple vision that is uncorrectable with glasses. The classic complaint of the keratoconus patient is seeing multiple ghost images out of the affected eye(s) or monocular polyplopia. There are many theories as to the cause of this conditions but its cause(s) still remains a mystery. Keratoconus is associated with certain allergic and arthritic disorders, Down's syndrome, chronic eye rubbing, corneal surgery and chronic contact lens wear. And, it has a recessive genetic component that can run in families.
While many keratoconus patients are unaware that they have an underlying corneal condition or dystrophy, others complain of severe visual difficulty. If patients with keratoconus cannot be corrected with glasses or soft contact lenses, there are now a number of innovative rigid lenses that can be used quite successfully to correct the myopia and astigmatism that is common in this corneal disorder.
In the most severe cases of corneal ectasia, surgical options can be used. Corneal transplantation has traditionally been the final answer for keratoconus patients. But now, other choices exist. Corneal ring inserts (Intacs or Ferrara rings) are being used more commonly today. They work by bolstering the thinned, bulging corneal tissue and tend to reduce the irregular corneal astigmatism that commonly occurs with keratoconus. While corneal ring inserts have not been widely used at this point in time, the results of using them have been encouraging. Another option that has shown promise is the use of riboflavin eye drops followed by exposure to UV-A light. This treatment increases the cross-linking of collogen in the cornea and improves its over-all strength. This option can be used in conjunction with corneal ring inserts or with conductive keratoplasty. Read more about CK.
Read more about General Eye Care.
Stuart Lewis, MD
Keratoconus is a condition that usually begins to develop in the late teenage years and can progress until the age of about 40 when it slows down or stops. The condition occurs in both genders and all ethnicities but has a higher prevalence among females and in those with Asian heritage. The symptoms vary from those of just needing a glasses prescription to see more clearly to diminished vision and/or double or triple vision that is uncorrectable with glasses. The classic complaint of the keratoconus patient is seeing multiple ghost images out of the affected eye(s) or monocular polyplopia. There are many theories as to the cause of this conditions but its cause(s) still remains a mystery. Keratoconus is associated with certain allergic and arthritic disorders, Down's syndrome, chronic eye rubbing, corneal surgery and chronic contact lens wear. And, it has a recessive genetic component that can run in families.
While many keratoconus patients are unaware that they have an underlying corneal condition or dystrophy, others complain of severe visual difficulty. If patients with keratoconus cannot be corrected with glasses or soft contact lenses, there are now a number of innovative rigid lenses that can be used quite successfully to correct the myopia and astigmatism that is common in this corneal disorder.
In the most severe cases of corneal ectasia, surgical options can be used. Corneal transplantation has traditionally been the final answer for keratoconus patients. But now, other choices exist. Corneal ring inserts (Intacs or Ferrara rings) are being used more commonly today. They work by bolstering the thinned, bulging corneal tissue and tend to reduce the irregular corneal astigmatism that commonly occurs with keratoconus. While corneal ring inserts have not been widely used at this point in time, the results of using them have been encouraging. Another option that has shown promise is the use of riboflavin eye drops followed by exposure to UV-A light. This treatment increases the cross-linking of collogen in the cornea and improves its over-all strength. This option can be used in conjunction with corneal ring inserts or with conductive keratoplasty. Read more about CK.
Read more about General Eye Care.
Stuart Lewis, MD
Labels: Keratoconus
posted by Stuart Lewis, MD at 4:42 PM
Monday, March 05, 2007
Viagra, Levitra, Cialis and Your Vision
I receive questions regularly from patients and colleagues about the safety of Viagra, Levitra and Cialis usage. Specifically, many patients have heard about the possible effects on one's vision and want to know if there is any truth to the "rumor." The answer, in a word, is yes. I will try to outline some of the well documented information about these drugs.
Since receiving approval by the FDA in 1998, Viagra (Pfizer Labs) has been prescribed well over 23 million times in the United States alone. The way this drug works is by inhibiting an enzyme (phosphodiesterase 5 or PDE-5) and enhances the effects of nitric oxide in the body. Nitric oxide stimulates the smooth muscle which facilitates blood flow and causes the desired effects. However, this class of medications can also affect arteries elsewhere in the body and the results are unwanted side effects. In addition, Viagra-like drugs also inhibit the effect of PDE-6, a closely related enzyme to PDE-5. This enzyme is present in retinal photoreceptors and when blocked, causes light sensitivity (photophobia) and/or blue tinged vision.
Systemic side effects of this class of drugs include:
A rarer and poorly understood eye disorder called nonarteritic anterior ischemic optic neuropathy (NAION) has been reported in several men and is presently being investigated. NAION is the most common acute optic nerve disease in adults over age 50 and shares a number of common risk factors with erectile dysfunction (ED): age over 50, high blood pressure, high cholesterol, and diabetes. "Most of the cases in which NAION has occurred in men taking Viagra have involved patients with underlying anatomic or vascular risk factors associated with the development of NAION" according to Pfizer. In other words, it is not clear that there is a cause and effect relationship between Viagra use and NAION.
The bottom line is that one should not take these medications unless they are needed as there are serious health and visual risks associated with them. Patients with the following conditions should check with their ophthalmologist prior to taking any ED drug:
Read more about General Eye Care.
Stuart Lewis
Since receiving approval by the FDA in 1998, Viagra (Pfizer Labs) has been prescribed well over 23 million times in the United States alone. The way this drug works is by inhibiting an enzyme (phosphodiesterase 5 or PDE-5) and enhances the effects of nitric oxide in the body. Nitric oxide stimulates the smooth muscle which facilitates blood flow and causes the desired effects. However, this class of medications can also affect arteries elsewhere in the body and the results are unwanted side effects. In addition, Viagra-like drugs also inhibit the effect of PDE-6, a closely related enzyme to PDE-5. This enzyme is present in retinal photoreceptors and when blocked, causes light sensitivity (photophobia) and/or blue tinged vision.
Systemic side effects of this class of drugs include:
- Headache
- Facial flushing
- Nasal congestion
- Nausea
- Other gastrointestinal problems
- Pulmonary hypertension
A rarer and poorly understood eye disorder called nonarteritic anterior ischemic optic neuropathy (NAION) has been reported in several men and is presently being investigated. NAION is the most common acute optic nerve disease in adults over age 50 and shares a number of common risk factors with erectile dysfunction (ED): age over 50, high blood pressure, high cholesterol, and diabetes. "Most of the cases in which NAION has occurred in men taking Viagra have involved patients with underlying anatomic or vascular risk factors associated with the development of NAION" according to Pfizer. In other words, it is not clear that there is a cause and effect relationship between Viagra use and NAION.
The bottom line is that one should not take these medications unless they are needed as there are serious health and visual risks associated with them. Patients with the following conditions should check with their ophthalmologist prior to taking any ED drug:
- Retinitis pigmentosa
- Diabetes
- Retinal pathology - including macular degeneration and optic nerve disorders
Read more about General Eye Care.
Stuart Lewis
Labels: Medications
posted by Stuart Lewis, MD at 5:47 PM
Friday, February 16, 2007
Selective Laser Trabeculoplasty (SLT) Study
Selective laser trabeculoplasty (SLT) is a treatment modality for both glaucoma and ocular hypertension that has been gaining popularity in recent years. The procedure works by targeting only pigmented cells inside the drainage area (trabecular meshwork) of the eye. By treating these cells, the normal "scavenger" cells of the body kick into action and clean out the drainage meshwork. With this form of treatment there is no thermal injury to the structures inside the eye.
Advantages of this form of Glaucoma treatment are associated with fewer side effects from medications, less expense for patients and third-party payers and compliance becomes a non-issue. And, since there is no thermal injury with this type of laser (frequency-doubled Nd:YAG), it can be repeated if the effects wear off.
While in the community of ophthalmologists the positive effects of SLT treatment are well known and accepted, a recent multi-center study was performed to compare SLT treatment to the traditional pharmacological approach to controlling intraocular pressure (IOP). In that study, 72 participants (136 eyes) who were randomly assigned to receive either the SLT or medical (eye drops) treatment. After eight months of follow-up, the target intraocular pressure was reached in the majority of eyes in each group and the pressure lowering effects of SLT and medical therapy were essentially equal.
I am now offering SLT as a first-line therapy in the treatment of open-angle glaucoma. It is my hope that side effects associated with drug therapy, adherence issues and cost can be reduced for patients with this chronic disease.
Read more about the the latest technologies used in our office.
Stuart Lewis, MD
Advantages of this form of Glaucoma treatment are associated with fewer side effects from medications, less expense for patients and third-party payers and compliance becomes a non-issue. And, since there is no thermal injury with this type of laser (frequency-doubled Nd:YAG), it can be repeated if the effects wear off.
While in the community of ophthalmologists the positive effects of SLT treatment are well known and accepted, a recent multi-center study was performed to compare SLT treatment to the traditional pharmacological approach to controlling intraocular pressure (IOP). In that study, 72 participants (136 eyes) who were randomly assigned to receive either the SLT or medical (eye drops) treatment. After eight months of follow-up, the target intraocular pressure was reached in the majority of eyes in each group and the pressure lowering effects of SLT and medical therapy were essentially equal.
I am now offering SLT as a first-line therapy in the treatment of open-angle glaucoma. It is my hope that side effects associated with drug therapy, adherence issues and cost can be reduced for patients with this chronic disease.
Read more about the the latest technologies used in our office.
Stuart Lewis, MD
posted by Stuart Lewis, MD at 1:38 PM
Tuesday, February 13, 2007
LASIK for Presbyopia
Presbyopic patients outside the U.S. are now being successfully treated with aspheric multifocal ablations which strongly suggests we will have that treatment here in the near future. However, before that will happen, the FDA is requiring a clinical trial of monovision LASIK to be performed. Monovision LASIK is already widely used in the U.S. and is already a standard procedure for many surgeons.
AMO-Visx is proceeding with the monovision trial to prove the safety and efficacy of monovision for presbyopic patients and is leading the way for the multifocal ablation study. The six month results are encouraging. At least 80% of patients have achieved 20/20 uncorrected vision at both distance and near and 92% were 20/25 or better at distance and near simultaneously. And, 95% of patients reported being less dependent on on glasses with 97% of patients reporting they would undergo monovision correction again if given the opportunity. The downside of monovision were the visual symptoms of seeing halos (~10%) or glare (~3%).
We have been providing the monovision LASIK option for over ten years. But, before I offer monovision to patients, they must undergo a contact lens monovision trial. Interestingly, I have found women prefer this treatment as compared to men but both genders appear to do quite well when they make the the monovision choice.
Stuart Lewis, MD
AMO-Visx is proceeding with the monovision trial to prove the safety and efficacy of monovision for presbyopic patients and is leading the way for the multifocal ablation study. The six month results are encouraging. At least 80% of patients have achieved 20/20 uncorrected vision at both distance and near and 92% were 20/25 or better at distance and near simultaneously. And, 95% of patients reported being less dependent on on glasses with 97% of patients reporting they would undergo monovision correction again if given the opportunity. The downside of monovision were the visual symptoms of seeing halos (~10%) or glare (~3%).
We have been providing the monovision LASIK option for over ten years. But, before I offer monovision to patients, they must undergo a contact lens monovision trial. Interestingly, I have found women prefer this treatment as compared to men but both genders appear to do quite well when they make the the monovision choice.
Stuart Lewis, MD
Labels: Presbyopic LASIK
posted by Stuart Lewis, MD at 2:44 PM
Monday, February 05, 2007
We are Featured on 9News at Ten
Channel 9 News approached me several weeks ago with interest in a story about the newest types of refractive surgery. I agreed and found about three patients who agreed to be interviewed and to have their procedures taped. Last night on the 10:00 pm news, we were one of the two featured surgeons interviewed. I am grateful to the patients who agreed to go along with this idea. The reporters at 9News were very discrete and professional. If you are interested in viewing the news report, click here to see "The Eyes Have It." The report gives a very quick overview of some of the new procedures we offer.
Stuart Lewis, MD
Stuart Lewis, MD
Labels: Intralase
posted by Stuart Lewis, MD at 5:14 PM
Sunday, February 04, 2007
Welcome to the New cherrycreekeye.com Blog
About The Cherry Creek Eye Physicians and Surgeons, P.C.
Welcome to my refractive surgery blog. The purpose of having this part of the cherrycreekeye.com website is to better communicate with both patients and potential patients of this practice. The emphasis of this site is to provide accurate information to you about my practice and be as much as a community resource in the area of ophthalmology as possible. In the process, you will be able to get to know about my practice, Cherry Creek Eye Physicians and Surgeons, P.C., and the way I think about and approach various medical and refractive issues.
The plan is not only to keep you updated on the latest news and technology, but also to provide answers to common questions that patients ask on a regular basis. Needless to say, in course of seeing patients interested in refractive surgery, the same topics and concerns are common to many and not uncommonly misunderstood. It is my hope to post these questions and concerns and discuss them in a less formal manner with you. Feel free to email or call us with questions and/or to give us feedback on the practice and website. I look forward to using this new method of communication to reach many of you in a meaningful way.
Stuart Lewis, MD
Labels: Welcome
posted by Stuart Lewis, MD at 12:51 PM
Cherry Creek Eye Physicians and Surgeons, P.C.
(303) 691-2228Uncompromised Excellence in Eye Care
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