Diagnostics drive patient education about dysfunctional lens syndrome
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The term “dysfunctional lens syndrome” grew out of improved diagnostics coupled with a need to educate patients about the causes of presbyopia, according to one surgeon.
Jason E. Stahl, MD, said that he uses the term “dysfunctional lens syndrome” as an alternative to “pre-cataract” to educate patients about why a lens-based treatment for presbyopia may be better than a cornea-based approach.
Stahl said he tells patients, particularly those who have had previous laser refractive surgery, that their presbyopia is a symptom of progressive deterioration of the crystalline lens.
“It really came out of just educating patients on where the problem is, which is actually the lens,” Stahl said. “If we do an excimer laser procedure on the cornea, we change the refractive error. Well, that may be able to help in the short term, but this is a progressive change in the lens. The way to treat the patient’s refractive error and also treat presbyopia is to use a presbyopia-correcting lens. We can improve and stabilize the lens optics.”
Before the U.S. Food and Drug Administration approved the Crystalens accommodating IOL (Bausch + Lomb) in 2003, surgeons performed what was then called “clear lens exchange,” Stahl said. Surgeons found that most lenses extracted from relatively young presbyopic patients in their late 40s and early 50s were neither clear nor advanced to cataract, he said.
“We really started thinking, ‘These lenses that we’ve always called clear are not really clear. We know that they’re not accommodating, so they’re presbyopic. But they’re not cataracts, either,’” Stahl said.
Advanced diagnostic imaging technologies, such as Scheimpflug photography with lens densitometry and double-pass technology — which provides an ocular scatter index — enabled clinicians to obtain an objective measurement of forward light scatter through the crystalline lens, according to Stahl.
“We got an objective index of how light scattered. Also, we just looked at the color and clarity of the lens in slit lamp images,” he said. “With our better understanding of how the aging lens progressively degrades the optics, we started using the term ‘refractive lens exchange’ for these procedures. Rarely, we will perform a clear lens exchange in a young, highly hyperopic patient who actually has a clear lens without any characteristics of dysfunctional lens syndrome.”
New diagnostics helped surgeons show patients that dysfunctional lens syndrome progresses slowly.
“We don’t go from being presbyopic to suddenly having a visually significant cataract. We explain what’s happening with this progressive change to help patients understand why we should do a lens-based surgery rather than a corneal-based surgery,” Stahl said.
Stahl said he does not have a desire to make “dysfunctional lens syndrome” the official clinical categorization for the condition.
“It has been very helpful educating our patients so that they understand the reason why we’re recommending a lens surgery vs. a corneal surgery,” he said. “It makes sense for our practice, and many other practices have started using ‘dysfunctional lens syndrome’ to help educate their patients, too.” – by Matt Hasson