Dysfunctional lens syndrome as a term has been around for more than 15 years. It was first introduced by Harvey Carter, MD, as a way to talk to patients about using IOLs to improve their vision before they developed cataracts. When patients older than 48 years of age desire better vision, more and more surgeons are recommending refractive lens exchange (RLE) as a way to address issues that refractive surgery alone cannot.
THE STAGES OF DYSFUNCTIONAL LENS SYNDROME
Surgeons are beginning to divide dysfunctional lens syndrome into three stages, each with its own potential surgical treatment.
Stage 1 occurs when patients are in their 40s and becoming presbyopic. The crystalline lens loses its focusing power but is still clear and colorless. Patients' dislike of reading glasses and bifocals prompts them to seek an eye examination. At Durrie Vision, this is usually when my colleagues and I begin having discussions with our patients about their overall vision goals—not just for the present but also what they want in 15 or 20 years.
In stage 2, nuclear sclerosis begins, and patients start complaining that their night vision is deteriorating and they need more light to read. Typically, they are in their 50s and 60s.
Stage 3 occurs when the patient has a visually significant cataract. Treatment for this condition is well understood and will not be addressed in this article.
Stage 1 now has several treatment options, most of which are familiar to patients. They include blended vision, monovision, and LASIK or PRK. Plus, the FDA recently approved the first corneal inlay (Kamra; AcuFocus), which I find has made patients more interested in looking for solutions to stage 1 dysfunctional lens syndrome.
In my experience, the treatment of stage 2 dysfunctional lens syndrome requires a longer conversation with patients (see Why Multiple Tests Are Necessary). Most of them are unaware of RLE. It is therefore my goal to ensure that patients understand their lens and its anatomy (my practice uses eye models and Eyemaginations software to this end). Once they fully understand the natural course of vision as people age, many of my patients choose to have their lenses replaced in stage 2 rather than wait for a cataract.
In my experience, patients with stage 2 dysfunctional lens syndrome are often best treated with RLE rather than other options. A corneal inlay is not going to perform to its best capability in an eye with nuclear sclerosis and a lot of ocular scatter. LASIK monovision will only work for a couple of years before the patient returns with vision complaints. In contrast, RLE prevents cataracts and stabilizes the vision system. (Obviously, the patient has to be vetted as a viable candidate first.)
A LONG-TERM COMMITMENT
For the surgeon, the RLE conversation and education are a long-term commitment that, in my experience, will grow a practice but not immediately. Patients frequently go home and mull over RLE for a few months or even years. As a reminder, they came to my office expecting LASIK, not something that would address their vision problems for years to come. I would say that approximately 20% to 25% of people opt for RLE during their first discussion.
Offering RLE to patients with stage 2 dysfunctional lens syndrome makes good sense, but it requires a practice to invest time and effort into educating people. n
Daniel S. Durrie, MD
• director of Durrie Vision, Overland Park, Kansas
• (913) 491-3330; email@example.com
• financial disclosure: clinical investigator for Abbott Medical Optics, AcuFocus, and Alcon