October 2017

COVER FEATURE

Challenging cataract cases
Complications of cataract surgery in AMD patients


by Rich Daly EyeWorld Contributing Writer




Dry AMD (left) and wet AMD (right). The features of AMD can be more effectively detected in the absence of media opacities including optically significant cataracts.
Source: Mohammad Rafieetary, OD

Age-related macular degeneration can complicate cataract surgery in several
key ways

Patients with age-related macular degeneration (AMD) need different clinical approaches and special reassurance when they approach cataract surgery, according to surgeons.
When AMD patients say that they read that their macular disease may worsen after cataract surgery, Steve Charles, MD, Germantown, Tennessee, refers them to the Age-Related Eye Disease Study (AREDS), which was a long-term multicenter, prospective study of the clinical course of AMD and age-related cataract.
An assessment of 8,050 eyes of the AREDS population looking specifically at the risk of advanced AMD developing after cataract surgery showed no clear effect of cataract surgery on the risk of progression to advanced AMD.1
The authors of that study noted that concerns were raised in earlier research—including population-based epidemiological studies—about the potential of cataract surgery to accelerate progression to advanced, vision-threatening forms of AMD. However, AREDS was the only prospective study in which the severity of AMD was documented prior to and following cataract surgery in a large number of cases with more than 5 years of regular follow-up.
“These data, that are contrary to previously reported results, may provide some reassurance to patients with AMD who are considering cataract surgery,” the authors wrote.

Injection timing

Dr. Charles underscored that cataract surgery patients who are receiving ongoing intravitreal injections need to not deviate from the injection cycle.
Injections of anti-VEGF agents for wet AMD and cataract surgery can proceed in parallel; there is no need to delay cataract surgery until AMD is inactive or stop injections in the perioperative period, Dr. Charles said. In general, wet AMD patients who have more injections have better outcomes; treat and extend is the best injection protocol.
Dr. Charles said the procedure should be synchronized with the injection schedule so that the cataract surgery is midway between injections.

Capsular eye damage

Cataract surgeons operating on AMD patients need to watch for the clinical signs that may indicate capsular or zonular injury from repeated intravitreal injections, said Robert Osher, MD, professor of ophthalmology, University of Cincinnati College of Medicine, and medical director emeritus, Cincinnati Eye Institute.
In the case of capsular rupture, often the first sign a surgeon sees is a focal cataract, such as a white linear opacity in the peripheral lens. That would be the most obvious sign that the needle has gone through the lens, Dr. Osher said.
Another sign of capsular rupture is a visible tear in the capsule, which is unlikely, but can happen with a needle.
When there is a tear in the posterior capsule, there may be fluffed up adjacent cortex and lens material in the vitreous.
Any cortical material behind the posterior capsule would indicate that the lens has been ruptured. These signs are better seen in the operating room with the pupil widely dilated.

Zonular damage

When zonular damage occurs, the entire lens can be decentered. One might see subtle focal iridodonesis where the vitreous herniates forward, through the dialysis, poking the back of the iris, Dr. Osher said.
Another subtle sign is where you have decentration of the lens nucleus, Dr. Osher said. Normally when you sweep a slit beam across the nucleus, the fetal nucleus is central rather than displaced.
A third subtle sign of zonular damage is what Dr. Osher calls a “gap sign.” The juxtapapillary edge of the iris normally abuts against the anterior capsule, but a focal gap may indicate microluxation.
Dr. Osher noted that retinal injections with a needle in the hands of a retinal specialist generally do not cause these complications. Improper angulation of the needle is responsible for inadvertent lens damage, Dr. Osher said. Ophthalmologists performing such injections should always be knowledgeable, and they almost always are, he noted. “But we have seen rare complications ranging from a small rupture of the posterior capsule to a dramatic intralenticular cylinder of injected steroid,” he said.
A surgeon should always be prepared for a lens rupture from previous injections similar to a lens rupture from a previous vitrectomy, Dr. Osher said. Always anticipate a complication even though it almost never occurs. It’s always good to expect the worst and to be pleasantly surprised, he said.

Reference

1. Chew EY, et al. Risk of advanced age-related macular degeneration after cataract surgery in the Age-Related Eye Disease Study: AREDS report 25. Ophthalmology. 2009;116:297–303.

Editors’ note: Dr. Charles has financial interests with Alcon (Fort Worth, Texas). Dr. Osher has no financial interests related to his comments.

Contact information

Charles: scharles@att.net
Osher: rhosher@cincinnatieye.com

Complications of cataract surgery in AMD patients Complications of cataract surgery in AMD patients
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