Eyeworld

EW FEATURE 66 by Michelle Dalton EyeWorld Contributing Editor Pterygia and cataract When patients present with both, surgeons need to de- termine a treatment plan based on the severity and placement of the pterygia P terygium—a conjunctival thickening that grows onto the cornea—used to be more common in the southern parts of the coun- try compared to the northern areas. But as the population has become much more transient and mobile, it is almost as likely to have patients present with a primary outburst in Boston as Boca Raton. When those same patients present with simulta- neous cataract, however, the chal- lenge for ophthalmologists is to determine a proper course of treat- ment. Experts agree that the size of the pterygium will be the primary deter- minant for treatment, coupled with the pterygium's location and its abil- ity to distort K readings. "If the pterygium is large, in- duces a lot of astigmatism, or causes distortion for the K readings, then I'll treat the pterygium first," said Rick Palmon, M.D., partner, Southwest Florida Eye Care, Fort Myers, Fla. "Corneal topography is key, looking at curvature change and in- duced astigmatism. In addition, ac- tive, elevated, and inflamed pterygia are the ones that are most likely to cause corneal shape change. Small inactive lesions may be ignored," said Robert Nasser, M.D., in prac- tice, Napa, Calif. If the pterygia does not prevent reliable K readings, "consider com- bined cataract and pterygium re- moval to save the patient an additional surgery," said Scheffer C.G. Tseng, M.D., director, Ocular Surface Center, Miami; medical di- rector, Ocular Surface Research & Education Foundation, Miami; and director, research and development, Tissue Tech, Miami. If, however, the astigmatism is along the axis of the pterygium, "it's much better to do pterygium removal first," he added. Although not a steadfast rule, Dr. Palmon said pterygia that are 1-2 mm usually do not induce signifi- cant astigmatism, and those 3 mm or more "can cause distortion into the Ks." He said when the pterygium is "not grossly elevated off the sur- face," when vascularity is minimal, and when it's quiet, "it usually won't cause any problems for the patient and won't interfere with cataract surgery." February 2011 Challenging cataract cases September 2011 Dr. Tseng's pterygium severity grading guide: mild (top photo), with fully visible episcleral blood vessels; moderate (middle photo), with partially obscured episcleral blood vessels; and severe (bottom photo), with non-visible episcleral blood vessels Source: Scheffer C.G. Tseng, M.D. continued on page 68 AT A GLANCE • If pterygia are small and do not impact K readings, they can be left alone, removed during cataract surgery, or removed on their own • If pterygia are large enough to adversely affect K readings, remove the pterygia first and then plan for cataract extraction • Wait at least a month between pterygium removal and new keratometry readings • Be meticulous about the wound closing during pterygium removal

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