EyeWorld Asia-Pacific December 2016 Issue

December 2016 EWAP FEATURE 13 Achieving best outcomes with cataract surgery in the post-vitrectomized eye by Liz Hillman EyeWorld Staff Writer Awareness of a few possible complicating factors can result in successful cataract surgeries C ataract surgery in the post-vitrectomized eye has become more common, according to Richard Tipperman, MD , Wills Eye Hospital, Philadelphia. As such, there are certain preop and intraoperative considerations to take into account with these cases to ensure the safest outcomes. “Retina people have gotten much more aggressive about doing vitrectomies for early macular holes and macular puckers when the patient’s vision is dropping a bit,” Dr. Tipperman said. “The other thing is that scleral buckling is falling out of favor and more people are having vitrectomies for retinal detachments, so there are a AT A GLANCE • During a slit lamp investigation, surgeons should look for posterior capsule opacification or puncture. • In surgery, surgeons should be aware of the potential for zonular instability, especially in patients who have had multiple vitrectomies. • Timing of a cataract is something to note; a rapidly progressing cataract days to weeks after an intravitreal injection or vitrectomy could suggest the lens was touched. • Post-vitrectomy patients should be told that their visual outcomes will only be as good as their retinal pathology allows. Upon insertion of the probe, the infusion pressure and lack of vitreous induce a re- verse pupillary block resulting in an overly deep anterior chamber. The chopper is used to temporarily tent up the iris to break the pupillary block and equalize the pressure between the anterior and posterior chambers. The surgeon can now proceed with cataract removal with an anterior chamber that is of normal depth. The cataract is completely removed and the capsular bag is filled with viscoelastic in preparation for IOL insertion Source (all): Uday Devgan, MD lot more vitrectomies.” People who have had a vitrectomy, if they don’t have a cataract already, will eventually form a cataract, Dr. Tipperman added. This could be due to inflammation and/or oxygenation that occurs in the procedure, but in some more rare cases, the lens capsule is punctured from an intravitreal injection needle or a vitrector. Kevin M. Miller, MD , professor of clinical ophthalmology, University of California, Los Angeles, said more intravitreal injections are being done now, leading to a few more lens capsule punctures. “Capsule punctures produce a different cataract than you get in the typical post-vitrectomy cataract eye,” Dr. Miller said. “Even so, they are still the minority of post-vitrectomy cataracts.” In 1998, Dr. Miller was a coauthor of a study that found, for the most part, cataract surgery after pars plana vitrectomy resulted in favorable visual outcomes with “few unplanned intraoperative events or complications … .” 1 Keeping up on subsequent studies that have been published in more than a decade since, Dr. Miller said, aside from some studies citing more anterior chamber depth fluctuation, cataract surgery and its outcomes for the post- vitrectomized eye are “about the same as they would be for an average eye.” Consider timing Timing of a cataract can say a lot in cases with retinal pathology. If a patient received an intravitreal injection for age-related macular degeneration, for example, and 4 days later developed a very mature or rapidly progressing posterior subcapsular cataract, this could indicate that the lens was touched by the needle, Dr. Tipperman said. Uday Devgan, MD , clinical professor of ophthalmology, University of California, Los Angeles, said the typical cataract that forms after an uneventful vitrectomy has central nuclear sclerosis and takes months or longer to develop. “If the patient develops a white cataract within a few weeks of the pars plana vitrectomy, there is almost certainly an iatrogenic break of the posterior capsule, and if this patient undergoes cataract surgery, there is a high risk of the entire lens nucleus falling onto the retina,” he said. Timing is a factor in the scheduling of the cataract surgery itself as well. As a retinal specialist, Ehsan Rahimy, MD , Palo Alto Medical Foundation, Palo Alto, California, says he typically advises patients to wait at least 3 months after routine vitrectomy before proceeding with cataract surgery, unless circumstances warrant sooner intervention (i.e., intraoperative lens touch causing a rapidly progressive white cataract). After that time, most healing from the underlying retinal pathology has usually occurred, and other mitigating visual factors have resolved (i.e., gas bubble has dissolved, scleral buckle has settled into place, intraocular inflammation has been treated) to where an accurate assessment can continued on page 14