Eyeworld

P seudoexfoliation (PEX) is a telltale sign of other ocu- lar problems, including cataract and glaucoma, and new research suggests it is also linked to a serious systemic condition: peripheral vascular dis- ease (PVD). "Based on the results of current study, we strongly recommend eval- uating for PVD in all subjects with PEX," reported study co-author Abhay R. Vasavada, F.R.C.S., Iladevi Cataract & IOL Research Center, Raghudeep Eye Clinic, Ahmedabad, India. "To the best of our knowl- edge, this is the first reported associ- ation between PEX and low ABI [ankle brachial index], which indi- cates the presence of a PVD." Study participants with cataract and PEX had a significantly lower ABI compared to those with cataracts without PEX. The study was published online in December 2010 in Eye. The systemic link Dr. Vasavada and colleagues ana- lyzed 40 subjects with PEX and cataract compared to 120 subjects with cataract but without PEX. ABI measurements for subjects were taken. The lowest mean ABI found in controls was 0.98 +/–0.03. In PEX cases, it was 0.88 +/–0.02. "The odds ratio of abnormal ABI in cases as compared with controls was 58.50," Dr. Vasavada reported. Both in the presence and in the absence of systemic illnesses, PEX cases had a lower mean ABI com- pared to controls. "ABI was found to be significantly lower in cases as compared with controls irrespective of the state of systemic illness," Dr. Vasavada reported. "After adjusting for other factors, in the presence of PEX the odds/chances of abnormal ABI was increased by 150 times." It's understandable that PEX has a systemic link. "Extraocular de- posits of PEX have been localized to the connective tissues or septa tra- versing the organ tissue," Dr. Vasavada noted in the study. "These deposits are associated with the pres- ence of elastic fibres, collagen fibres, fibroblasts, and the walls of small blood vessels, suggesting the sys- temic nature of PEX." Already, PEX has been linked to Alzheimer's disease and stroke. "However, to the best of our knowl- edge, the possible association be- tween ocular PEX and PVD has not been reported," Dr. Vasavada noted. The low ABI linked to PEX in this study establishes the relation- ship to PVD. "The ABI is the best 'non-invasive' test for PVD; and the measurement of ABI is a sensitive and specific diagnostic test for PVD," Dr. Vasavada noted. "ABI can be performed quickly and has high validity and good reproducibility." Meanwhile, PVD prevalence is substantial. The prevalence in Eu- rope and the United States is about 10.9%, 12.2%, 18%, and 39% in people older than 50, 60, 65, and 85 years old, respectively. "A slit-lamp examination of the eye could help in identifying an im- portant marker that indicates the risk of a systemic vascular disease," Dr. Vasavada observed, referring to PEX as the important marker. How- ever, PEX itself is potentially less common, with a reported prevalence of 1.8 to 13.5%, Dr. Vasavada noted. Diagnosing PVD is important, as the disease is a serious one. "There is a fourfold to sixfold increase in car- diovascular mortality rate among pa- tients with objectively documented PVD as compared with healthy, age- matched individuals," Dr. Vasavada noted. Some local limitations may apply to this study, which evaluated Indian patients. "In our previous study while evaluating intraopera- tive performance of Indian eyes with PEX, we found that the results were comparable to that in normal eyes in contrast to reports from other parts of world, which indicated more intraoperative difficulties and complications," Dr. Vasavada noted. "From the current study, it would be justifiable to add that the results of current study may not be applicable to patients with PEX from other parts of the world." Bjorn Johansson, M.D., Linkoping University Hospital, Linkoping, Sweden, noted his uncer- tainty about whether the study de- finitively links PEX to PVD. On the one hand, PEX is not purely an ocular disease, but a con- dition that concerns various systems in the body. On the other hand, there are many other risk factors for systemic diseases like cardiovascular disease to be concerned about, Dr. Johansson said. "There are more serious risk fac- tors such as hereditary factors, lifestyle, smoking, drinking, and diet," Dr. Johansson said. In his opinion, PEX is a piece of the sys- temic disease puzzle, but not a big piece. "We do not take precautions with PEX patients," Dr. Johansson April 2011 by Matt Young EyeWorld Contributing Editor Study links PEX to PVD with the understanding that they should not be so quick to correct surgically induced astigmatism in this population. "Physicians need to be aware that surgically induced astigmatism typically resolves, and thus they should be hesitant to do any surgical procedure after cataract surgery," he said. "There may also be the same response in other sur- geries performed on children." With this in mind, he urges practitioners who find astigmatism in such chil- dren after surgery to be patient be- fore either cutting sutures or pre- scribing glasses. Overall, Dr. Bothun sees the findings as bolstering clinical obser- vations and other investigations. "We were pleased that our findings paralleled our clinical observations and also paralleled what we have found in other types of smaller-inci- sion cataract surgery in children," he said. "I think that this gives con- tinued support for the understand- ing of how children heal after in- traocular techniques." He hopes that these results will help surgeons as they deal with these issues no matter what technique or type of incision they are using in children. EW Editors' note: Dr. Bothun has no finan- cial interests related to his comments. Contact information Bothun: 612-328-2128, bothu003@umn.edu Through continued from page 14 672062PI_2_23x12_5.pgs - Thu Feb 10 11:21:06 PST 2011 continued on page 18

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