Archive for the 'Keratoconus Treatment' Category
Thursday, November 20th, 2008
Here is an article presented in Ophthalmology Times:
Collagen crosslinking shows promise for keratoconus sill more prospective clinical data needed to characterize risks and benefits
Publish date: Oct 15, 2008
By: Cheryl Guttman
Source: Ophthalmology Times
- Research to date involving stress-strain measurements has shown that the collagen crosslinking procedure causes mechanical stiffening of the cornea.
- Dr. Seiler’s current treatment protocol for collagen crosslinking involves a partial corneal abrasion performed over a diameter of 9 mm.
- According to Dr. Seiler collagen crosslinking using ultraviolet A light and the photosensitizer riboflavin has been effective in stopping the progression of keratoconus in almost all eyes, and it has induced regression in about half of treated eyes based on reductions in keratometry readings. However, more prospective clinical data is needed to characterize its risks and benefits and to establish a list of indications and contraindications for this procedure.
Results achieved with corneal collagen crosslinking for the treatment of keratoconus are very encouraging, although the technique still must be considered investigational due to a lack of sufficient data published in the peer-reviewed literature, said Theo Seiler, MD, PhD.
“In our experience, collagen crosslinking using ultraviolet A light and the photosensitizer riboflavin has been effective in stopping the progression of keratoconus in almost all eyes, and it has induced regression in about half of treated eyes based on reductions in keratometry readings,” said Dr. Seiler, professor and chairman, Department of Ophthalmology, University of Zurich, and medical director, Institute for Refractive and Ophthalmic Surgery, Zurich, Switzerland. “However, we clearly need more prospective clinical data to characterize its risks and benefits and to establish a list of indications and contraindications for this procedure.”
Research to date involving stress-strain measurements has shown that the collagen crosslinking procedure causes mechanical stiffening of the cornea. Corneal rigidity, as assessed by Young’s modulus, increased by more than 4-fold after the procedure, Dr. Seiler said.
In addition, experiments performed with porcine corneal buttons show the treatment results in increased resistance of the extracellular matrix to enzymatic digestion compared with native corneal collagen. “The underlying mechanism for this latter effect of the crosslinking procedure is unknown, but it may play a role in the posttreatment reconstruction of the cornea,” he said.
He also said his current treatment protocol for collagen crosslinking involves a partial corneal abrasion performed over a diameter of 9 mm. Then a solution of 0.1% riboflavin in 20% dextran is dropped on the cornea approximately every 3 minutes for 30 minutes. The treated cornea is irradiated for 30 minutes with a 365-nm ultraviolet light source at a distance of 5 cm using an intensity of 3 mW/cm2.
“An alternative technique proposes using topical tetracaine to digest the epithelium and enable diffusion of the riboflavin into the stroma,” Dr. Seiler said. “However, using confocal microscopy, we found there is keratocyte damage to a depth of about 300 to 350 m using our crosslinking technique with corneal abrasion, whereas with the use of tetracaine, normal reflections from keratocyte nuclei can already be seen below the anterior 20 m of stroma. Therefore, it appears there is significantly less free radical formation and crosslinking of collagen fibers using the latter technique.”
He also noted that both the mechanical and biochemical effects of the procedure are very sensitive to the treatment parameters with respect to the concentration of the riboflavin solution used and the duration of application. Therefore, he encouraged that the efficacy of any modified protocol be investigated carefully prior to adoption in clinical use.
To date, Dr. Seiler and colleagues at the Technical University of Dresden, Dresden, Germany, have treated about 700 eyes with collagen crosslinking. Follow-up extending to 4 years shows the benefits are durable. An analysis including 21 patients with bilateral keratoconus who underwent crosslinking in only one eye showed the keratoconus index was increased in the untreated eyes after 1 year and significantly was higher than in the fellow crosslinked eyes.
“Crosslinking was not performed randomly in these patients but rather was used to treat the worse eye,” Dr. Seiler said. “Comparisons in individual patients showed there was a significant difference in the keratoconus index between the treated and untreated eye after 1 year in nearly all patients, and the difference between eyes was highly statistically significant in some cases.”
The safety profile of corneal collagen crosslinking has been favorable as well with very few complications recorded. Epithelial healing was delayed in some eyes and resulted in a subepithelial scar. More recently, in some eyes in which the procedure was repeated, a small scar in the anterior segment occurred that persisted for up to 6 months.
Tuesday, November 27th, 2007
Although Dr. Turner has previously been performing Keratoconus Correction in San Jose, Turner Eye Institute has a new location in Campbell, California. Dr. Stephen Turner is well-known throughout California as one of the most experienced Keratoconus surgeons. He is also known for his innovation and excellent results with intacs and other methods of keratoconus correction. Dr. Turner introduced many of todays most successful eye surgery procedures to Northern California, Oakland, San Jose, San Francisco, and Walnut Creek. The advanced Crystalens procedure for improving near vision, the exciting Visian procedure for patients with moderate to high near-sightedness, and the precision of Wavefront LASIK, Intra-Lase, and TF LASIK were all introduced by Dr. Stephen Turner.
The new location in Campbell, CA contains the same advanced technology including the upgraded VISX laser with iris tracking software. San Jose patients can therefore expect the same high level of treatment in Campbell, CA that they had at each of the Turner Eye Institute locations, including San Jose, San Francisco, Walnut Creek, and Oakland. Dr. Turner will perform keratoconus procedures at each of the four locations in Northern California.
Turner Eye Institute performs cataract surgeries and other vision corrective procedures in San Leandro, CA (South of Oakland and north of Fremont). The surgical center provides a sterile environment to provide the highest level of safety for our patients.
Monday, June 11th, 2007
News has been released that British scientists are planning to use embryonic stem cells to cure age related macular degeneration, a common form of blindness. They are hoping to have the first patients receive test treatments within five years. This could be a major improvement in the methods of treating this common form of eye blindness that is experienced by millions of individuals throughout the world.
The pioneering project uses cells derived from human embryonic stem cells to repair damaged retinas. Those who support the research believe the process will involve simple surgery that could one day become as routine as cataract operations. Scientists are suggesting that the technique might be capable of restoring vision in patients with age-related macular degeneration (ARMD), a leading cause of blindness among the elderly that afflicts millions of people worldwide and is the leading cause of blindness in the USA and Europe.
If stem cell research can be used to cure age-related macular degeneration, could it also cure keratoconus? In April 2005, doctors in the UK transplanted corneal stem cells from an organ donor to the cornea of a woman who was blinded in one eye when acid was thrown in her eye at a nightclub. The cornea, which is the transparent window of the eye, is a particularly suitable site for transplants. In fact, the first successful human transplant was carried out in 1905 on a cornea by Dr. Eduard Zirm. The cornea has the remarkable property that it does not contain any blood vessels, making it relatively easy to transplant. The majority of corneal transplants carried out today are due to a degenerative disease called keratoconus which causes vision impairment and has no known cure even after corneal transplant. It is hoped that stem cell research will one day provide a cure to such debilitating corneal disorders.
The first step would be to grow corneas from a living donor. The corneas could then be transplanted into the person’s eyes. The advantage to using a patient’s own tissue would be a reduction in the possibility of rejection and a decrease in medications required to suppress a patient’s immune system.
Later steps might involve injection of healthy corneal cells into a keratoconic cornea in order to increase the strength of the cornea tissue. Stem cells could help reinforce the cornea and prevent the loss of vision that accompanies the progression of keratoconus.
Wednesday, February 7th, 2007
I recently met a lady near Walnut Creek (in Conta Costa County) who was asking for the best corneal transplant surgeon in the San Francisco Bay Area. Her friend was located in the South Bay and San Jose and apparently was suffering from some form of degenerative corneal condition that eventually would require a corneal transplant. She was hoping to find the best surgeon to perform this procedure.
I began to quest the lady regarding the condition, which I had begun to suspect might be keratoconus. Apparently, her friend’s vision was fine until arriving into adulthood. At this time the vision deteriorated and needed to be corrected with hard contact lenses. I guess that soft contact lenses were not providing adequate vision. Her friend’s vision, however, was now becoming unsatisfactory even with hard contact lenses and she believed that a corneal transplant might be the only option now.
Her description of the patient’s symptoms sounded very much like keratoconus. I described to her the effects of keratoconus and told her that if her friend had keratoconus there was very likely to be a better option than a corneal transplant. While corneal transplants might still be performed, in the vast majority of cases, another option can either delay or prevent the need for a corneal transplant.
Many patients with keratoconus under intacs treatment. This requires placing a plastic band within the cornea which helps reinforce the cornea and can generally allow a patient with keratoconus to avoid needing a complete cornea transplant. The reinforced cornea can then often wear a hybrid contact lens designed to correct vision in a keratoconic patient. These contact lenses are part hard and part soft and are better for treating keratoconus because they provide the clear vision of a hard contact lens and the comfort of a soft contact lens.
The lady was grateful for the information a told me she would contact her friend. I am hoping that I was able to help. Keratoconus can often be a very painful and debilitating condition that requires long term care. Keratoconus patients often feel that they are not given the treatment that they require. Luckily, intacs and hybrid contact lenses have significantly improved the vision and comfort of patients with keratoconus.
If you have keratoconus or know someone who does, please contact Turner Eye Institute so that we can provide the best quality care and give them the chance to avoid a cornea transplant. There are option that exist that can provide better vision and greater comfort for patients suffering from keratoconus.
Tuesday, January 16th, 2007
Frequently patients with keratoconus are choosing between wearing contact lenses and having intacs surgery. Hard contact lenses can improve vision much better than glasses for patients with keratoconus but some studies show that long term contact lens wear causes a deterioration in the cornea for keratoconus patients. This results in worsening vision that eventually can no longer be treated with contact lenses and requires surgery. Too often patients postpone surgery leading to a drop in vision and a loss in end visual acuity.
We recommend that patients with keratoconus be treated with intacs surgery as soon as the best corrected vision with glasses becomes inadequate. We do not recommend waiting until contact lenses can no longer correct the loss of vision due to keratoconus. We are finding that patients who wait until contact lenses can no longer correct keratoconus end up with significantly worse results after intacs surgery than those who are treated earlier.
Oftentimes, contact lenses (specialty lenses for patients with keratoconus) are still necessary following intacs surgery. In fact, the majority of intacs surgery patients must still wear contacts to see clearly. The difference is that long term visual prognosis is generally better for someone whose cornea is strengthened through intacs surgery.
If you are interested in learning more about treatments for keratoconus contact one of our refractive coordinators. Turner Eye Institute is located in San Leandro (near Oakland), San Francisco, San Jose, and Concord (near Walnut Creek). We are happy to evaluate your options and offer the best possible treatments to you.
Tuesday, January 2nd, 2007
Patients with keratoconus are constantly seeking the best treatment for their eyes. Many of those dealing with keratoconus feel that the treatment they have received thus far has been unsatisfactory. What can keratoconus patients expect for 2007?
FDA trials are already underway and past the early stages in a variety of vision related trials. Early results for C3-R treatment have been promising but this treatment has not yet been FDA approved. There are several surgeons who perform C3-R treatment off-label but thus far it is not yet endorsed by the US FDA. We will likely see further results at Ophthalmological Seminars regarding the efficacy of this treatment.
Contact lens treatments for keratoconus are also advancing and increased research in this area can be expected in 2007. Synergeyes offers a new hybrid lens for keratoconus patients and so far results with this treatment have been excellent. We can expect more keratoconus patients to be fit with the newer hybrid lenses (a blend of hard and soft lenses). As practitioners gain more skill in fitting these lenses, we can expect results to continue to improve.
The Help Keratoconus blog will continue to offer new information in 2007 and continue to provide new findings concerning keratoconus as well as offer new options in treatment. Continue to visit the blog on a monthly or biweekly basis as new blogs try to offer the newest insights into keratoconus.
Wednesday, December 13th, 2006
Keratoconus patients are often difficult fits for contact lenses. The steepness of the cornea and the need to avoid contact with the apex of the cone requires that a specialized fitting or procedure be provided that not only allows for good vision but also prevents future deterioration of the cornea.
Keratoconus is a progressive thinning of the cornea. Hard contact lenses can hasten the corneal degredation if they rub against the steepest portion of the cornea. Many keratoconus patients have in the past experienced faster progression of keratoconus due to poor fitting contact lenses.
Dr. Turner has has significant experience in treating keratoconus with surgical methods, such as intacs and corneal transplants. He suggests that most keratoconus patients should be treated with intacs before the condition progresses significantly. Intacs treatments are more effective when used earlier. Once the keratoconus has cause a significant degree of vision loss and steepening of the cornea, intacs provide lesser results than if treated early.
Following intacs treatment, keratoconus patients will generally require continued contact lens care. The new hybrid lens, Synergeyes, has been very effective in fitting patients comfortably while providing much improved vision. Often a keratoconus patient’s best corrected acuity can be improved several lines with a good hybrid lens fitting.
Keratoconus patients are receiving much better care with these new technological advances. Intacs stabilizes the cornea and slows or stops keratoconus progression. Synergeyes allows for the comfort of a soft contact and the improved vision of a hard contact lens.
Tuesday, December 5th, 2006
Medical Device may restore visual function for patients with keratoconus and could defer the need for corneal transplant for moderate to severe keratoconus
DES PLAINES, Ill. Aug. 4, 2004 Addition Technology, Inc., the manufacturer of Intacs prescription inserts for surgical vision correction, announced today that it has received approval from the U.S. Food and Drug Administration (FDA) for a Humanitarian Device Exemption (HDE) to market Intacs inserts for the treatment of keratoconus. Keratoconus causes a progressive thinning of the cornea and affects up to 300,000 people in the United States.
The FDA approval is based on Intacs excellent safety record, the relatively low number of U.S. patients affected by keratoconus, and the fact that no other treatment options exist for patients with keratoconus other than an invasive corneal transplant procedure. The approval allows Intacs inserts to be marketed for the reduction or elimination of myopia and astigmatism in patients with keratoconus, where functional vision is no longer achievable with their contact lenses or eyeglasses. In addition, Intacs inserts may defer the need for a corneal transplant for some keratoconus patients.
The FDA approval will allow Addition Technology to educate keratoconus patients about the potential advantages of Intacs inserts and is expected to help facilitate expanded health insurance coverage for the procedure in the United States.
“Keratoconus sufferers now have a new option when it comes to restoring and improving their vision,” said William M. Flynn, president and chief executive officer of Addition Technology. “Intacs inserts fill a significant gap between rigid contact lenses and corneal transplantation for these patients.”
“For many of my patients, Intacs provide a solution to obtaining functional vision where contact lenses no longer suffice,” said Yaron Rabinowitz, M.D., of Cedars Sinai Medical Center in Los Angeles, Calif. “Before Intacs inserts, the only option was a corneal transplant, which I prefer to be a last resort for these patients.”
“In the past few years my condition caused my astigmatism to increase to the point where I couldn’t wear contact lenses comfortably and my best corrected spectacle correction was deteriorating each year. Even though the morbidity risk was low, I was reluctant to consider corneal transplantation, since the convalescent period was lengthy and as an ophthalmic surgeon, I needed good binocular vision to continue to operate,” said ophthalmologist Leslie A. Eisner, M.D. of Stamford, Conn. “Intacs in my right eye has improved and stabilized my vision, allowing me to resume my normal activities without undergoing a highly invasive transplant procedure. I can now wear soft toric contact lenses comfortably and with good vision. I’m so pleased with the results that I plan to have the left eye done this winter.”
Addition Technology, Inc., a privately held company, is the manufacturer of Intacs prescription inserts, the only corneal implant approved by the FDA. Intacs inserts are also approved for distribution in Europe, Asia, and Latin American countries that include Mexico. For more information on Intacs prescription inserts, visit www.helpkeratoconus.com or call 1.800.339.2733.
Tuesday, November 28th, 2006
Stephen Turner, M.D. has been helping Bay Area residents see for 30 years now. Even more impressive than the length of time that Dr. Turner has been in practice is the level at which he has been practicing. Consistently, Dr. Turner has been on the leading edge of the newest advancements in medical and surgical eye care, including advancements in the treatment of keratoconus.
Recently, Dr. Turner performed a live training for ophthalmologists from around the world to teach them the newest techniques and procedures available in eye surgery.
Dr. Turner is a pioneer in the field of LASIK eye surgery and as an FDA investigator was the first surgeon to perform LASIK in the Bay Area after its FDA approval. In addition, Dr. Turner introduced Wavefront LASIK and Intralase (also known as bladeless LASIK) to the San Francisco Bay Area. These technologies have increased the accuracy and safety of LASIK surgery. Dr. Turner also patented a technique known as TF LASIK and is currently the only surgeon in the world to perform this procedure. Dr. Turner also performs the newest treatments for keratoconus patients, including intacs for keratoconus patients.
With constant advancements in medicine it is often difficult for surgeons to stay updated. Dr. Turner has managed to remain at the forefront of research and was the first surgeon in the Bay Area to provide new treatments such as Visian, and Verisyse. These treatments allow very near-sighted patients to enjoy the benefits of good vision without glasses or contact lenses. Dr. Turner was also the first surgeon to perform Crystalens surgery, the first FDA approved cataract surgery that provides good vision restoration at both distance and near focus.
Dr. Turner’s experience is well-known in the ophthalmology and eye care community. He has performed over 30,000 laser eye treatments and over 15,000 cataract surgeries, allowing him to specialize in multiple treatments to provide the needed solution for a wide variety of vision needs. He has treated hundreds of cases of keratoconus as well.
Despite the restrictions in medical care imposed by HMOs and managed care approaches, Dr. Turner remains upbeat about the future of medicine and says that “with medical advances increasing in frequency the future is exciting.” He is looking forward to his next 10 years and plans to continue enjoying his practice in the San Francisco Bay Area.
Dr. Turner has practices in San Leandro, San Jose, San Francisco, and Concord. You can find more about his practice at www.turnereye.com or by calling Turner Eye Institute at 1-800-339-2733.
Monday, November 13th, 2006
There is now a hybrid contact lens specifically developed for patients with keratoconus SynergEyes® KC. It is a cross between a hard and soft lens to provide the advantages of both in helping to treat patients with keratoconus.
The SynergEyes KC lens provides enhanced comfort and wearability and is expected to be a primary contact lens solution for patients with keratoconus. Every lens is custom made to provide the best lens to cornea match for optimized vision. The highly oxygen permeable rigid center of the SynergEyes KC lens promotes corneal health and optimizes vision while the soft outer skirt holds the lens in place better than a rigid lens and provides desired comfort throughout the day.
The best eye care practitioners go to great lengths to try any type of lens and combinations of lenses for highly irregular keratoconus eyes. Rigid lenses have been the method of choice for challenging keratoconic eyes. Practitioners also use “Piggy-back” systems comprised of a soft lens applied first and a rigid lens applied over the soft lens.
SynergEyes KC lenses offer good lens centration and freedom from lenses dislodging and debris under the lens that often occurs with rigid lenses. SynergEyes lenses also offer simplicity when compared to piggy-back systems.
Ultimately many patients with keratoconus consider surgery to allow them to obtain better vision. The surgical options include Intacts for Keratoconus or a corneal transplant (penetrating keratoplasty).
The SynergEyes KC lens may be an excellent alternative if your keratoconus has progressed to the point that you and your eye care professional are considering surgery. Your eye care professional will be able to tell if the SynergEyes KC lens is right for your specific prescription.