EyeWorld India December 2014 Issue

December 2014 8 EWAP FEATURE Cataract surgery in pseudoexfoliation syndrome cases by Lauren Lipuma EyeWorld Staff Writer AT A GLANCE • If phacodonesis or lens subluxation is present at the slit lamp exam, experts recommend sending the patient to a retina specialist for pars plana vitrectomy and lensectomy. • Three-piece IOLs are easier to refixate than 1-piece IOLs. • Accommodating, toric, multifocal, and aspheric monofocal IOLs are contraindicated in patients with pseudoexfoliation. Unique challenges presented by pseudoexfoliation can be managed with the appropriate surgical tools and techniques, experts say T he deposition of extracellular protein on the structures of the anterior segment puts patients with pseudoexfoliation syndrome at a higher risk for complications both during and after cataract surgery. Zonular weakness, due to deposition of pseudoexfoliative material on the zonular fibers, and poor pupil dilation, due to infiltration of material into the iris stroma, are the factors that most increase patients’ risk for complications. Steven Gedde, MD , professor of ophthalmology, Bascom Palmer Eye Institute, Miami, Fla., U.S., stressed the importance of assessing for zonular weakness and poor pupil dilation preoperatively to guide intraoperative management. Iridodonesis, phacodonesis, asymmetry of anterior chamber depth, and lens subluxation are manifestations of zonular weakness, but these Figure 1. Pseudoexfoliation material vis- ible on the anterior lens capsule Figure 2. Close-up of Figure 1 Figure 3. Pseudoexfoliative material adherent to the corneal endothelium Figure 4. Low power photo of the lens against the red re ex showing the pseu- doexfoliation material on the anterior lens capsule and transillumintion defects in the peripheral iris margin Figure 5. Photo of the lens against the red re ex, highlighting the pattern of pseudoexfoliation material on the anterior lens capsule (close-up of Figure 4) Source (all): David G. Heidemann, MD signs may or may not be present preoperatively depending on the severity of the disease. Observing phacodonesis or lens subluxation at the slit lamp is a sign of severe zonular weakness, indicating that “all the zonules are near death or pretty much gone,” said John Hart, MD, FACS, co- chief of anterior segment surgery, William Beaumont Hospital, West Bloomfield, Mich., U.S. In those cases, Drs. Hart and Gedde send the patient directly to a vitreoretinal specialist for a pars plana lensectomy and vitrectomy with a sclerally fixated IOL. If zonular weakness is mild, signs of it can be subtle, but the fact that pseudoexfoliation tends to be asymmetric helps produce these signs, said JoAnn Giaconi, MD , associate clinical professor of ophthalmology, Jules Stein Eye Institute, Los Angeles, Calif., U.S. Poor pupillary dilation in one eye indicates a greater risk for zonular weakness on that side, as well as a shallow or deep anterior chamber or a depth that fluctuates based on patient position. Gonioscopy and ultrasound microscopy are useful techniques for assessing asymmetry of anterior chamber depth prior to surgery, said Drs. Gedde and Giaconi. Intraoperative management Poor pupillary dilation can be managed with mechanical pupil expanders, such as iris retractors or a Malyugin ring (MST, MicroSurgical Technology, Redmond, Wash., U.S.). Drs. Hart and Gedde prefer iris retractor hooks because they can be repositioned to the edge of the capsulorhexis to provide support for the capsule and counter tension for the capsulorhexis. “I like MST iris retractors for supporting the capsule because they’re double-stranded, so the part that contacts the capsule is very smooth and won’t break it,” Dr. Hart said. Once the pupil has been sufficiently expanded, minimizing stress on the zonules is the main objective during surgery.