In March, I had the pleasure of attending a continuing education class at the Southern California College of Optometry (SCCO). This was a one-day seminar dedicated to the fitting of large-diameter lenses, and the emphasis of the presentation focused on scleral lenses.
I would be hard pressed to find a better group of presenters on these topics. Tim Edrington, O.D., professor at SCCO, talked about large-diameter corneal lenses. As always, Dr. Edrington’s approach is very clinical, (i.e., he shows the participants how to fit lenses when they return to their offices the next day.)
Christine Sindt, O.D., Associate Professor at the University of Iowa Department of Ophthalmology & Visual Sciences, Gloria Chu, O.D., Chief Optometrist at the Perry Rosenthal Clinic Doheny Eye Institute and Brett Larson, O.D., SCCO contact lens resident, also shared their expertise on fitting techniques for scleral lenses.
Most of the time, when we fit very large lenses (including scleral lenses), we note that the corneas are quite irregular as a result of trauma or disease. In these cases, topography is always of value. However, in the case of greatly distorted corneas, topography may not provide the best information to fit these lenses without diagnostic lenses.
Dr. Edrington’s recommendation on the initial fitting: “Just put a lens on the eye.” This was perhaps the best technique I have ever heard in more than 30 years of contact lens fitting.
The best “topographer” for irregular corneas is a diagnostic lens. So, as Dr. Edrington mentioned, put a lens on the eye, and then evaluate the fit. If the lens appears too flat or too steep, make a change of 1.00D to 2.00D in the base curve, and reevaluate the fit.
On a grossly irregular cornea, do not expect to see an “ideal” fluorescein pattern. A well-fit scleral lens should rest lightly on the sclera, not restrict the flow in the underlying blood vessels, and effectively clear the cornea. However, it is not unusual if one part of the lens does not clear the entire cornea. When the edge of this “touch” shows a feathered fluorescein pattern, it may be acceptable. If the edge of the “touch” is very sharp and distinct, more clearance is needed to avoid corneal irritation.
Scleral Lens Fitting
It is not my intention to provide you with the vast amount of knowledge needed to fit scleral lenses, but to let you know there are resources available to help you learn how to use this very valuable tool.
Recently, the Scleral Lens Education Society (
www.sclerallens.org) was formed by a small group of experienced scleral lens fitters. The society’s mission is to teach contact lens practitioners the science and art of fitting all designs of scleral contact lenses for the purpose of managing corneal irregularity and ocular surface disease.
SLS, a non-profit organization, also supports public education that highlights the benefits and availability of scleral contact lenses.
By the end of June, the Gas Permeable Lens Institute ( www.gpli.info) should have a new module available. According to their executive director, Ed Bennett, O.D., a PowerPoint presentation on GP management of keratoconus will include information on design, fitting and problem solving for sclerals.
As the co-chair of the Bronstein Contact Lens and Cornea Seminar, we will have a minimum of four lecture hours on large corneal and scleral lenses at our January 14-16, 2011 meeting in Scottsdale, Arizona. This meeting is sponsored by the Arizona Optometric Association, and further information can be obtained at
Scleral lenses could very likely be the wave of the near future for fitting unusual eyes. Contact the Scleral Lens Education Society, the Gas Permeable Lens Institute, a nearby College of Optometry or any of the great continuing education programs available across the country for the availability of educational opportunities on this topic. Additionally, you can ask your state associations or local societies to bring in some of the very talented people who are willing to share their knowledge on scleral lenses.