Eyeworld

April 2011 by Maxine Lipner Senior EyeWorld Contributing Editor Surveying the diabetic retinopathy landscape Looking at the condition by the numbers A pproximately 28.5% of di- abetic patients in the United States have dia- betic retinopathy, accord- ing to Xinzhi Zhang, M.D., epidemiologist, Center for Disease Control and Prevention, At- lanta. Results from a study published in the August 2010 issue of the Jour- nal of the American Medical Associa- tion indicate that the prevalence of diabetic retinopathy among diabet- ics in the United States is substan- tial. 21st century data While the number of diabetics in the country is certainly consider- able, no one had recently looked at the current prevalence of diabetic retinopathy. This spurred investiga- tors to delve into this. "About 12 million people age 60 years and older have diabetes," Dr. Zhang said. "But for diabetic retinopathy, which is a major complication, the latest estimate is from decades ago—from 1988." In addition, Dr. Zhang pointed out that diagnostic technology has improved considerably in recent years. "We have better technology to identify the estimates using digital photos," he said. He thinks that any resulting estimates would likely be more accurate than those with older film technology. Patients included in the study were culled from participants in the National Health and Nutrition Ex- amination Survey, which ran from 2005-2008. For the recent preva- lence study, investigators only looked at patients age 40 and older who were diabetics and who also had correspondent eye examinations to determine what percentage of them actually had diabetic retinopa- thy. All digital fundus photographs were sent to the University of Wis- consin Fundus Photograph Reading Center, Madison, to be graded for degree of retinopathy. When investigators ran the numbers they found that diabetic retinopathy was all too common. "Mainly, we found that among peo- ple with diabetes age 40 and older, a good percentage of them had dia- betic retinopathy and a certain num- ber had vision-threatening diabetic retinopathy," Dr. Zhang said. Those with diabetic retinopathy accounted for 28.5% of adults with diabetes, and those with vision-threatening disease accounted for 4.4% of pa- tients. Men tended to develop dia- betic retinopathy slightly more often, with the condition affecting 31.6% of men versus 25.7% of women with diabetes. Independent risk factors Investigators also considered a host of other independent risk factors and found some connections. "We found several things that were inde- pendently associated with the pres- ence of diabetic retinopathy including male gender, higher he- moglobin A1 C levels, duration of diabetes, insulin use, and higher sys- tolic pressure," Dr. Zhang said. One of the more major predic- tors was the duration of diabetes. "The longer they have the disease, the more likely it is that they will have eye complications," Dr. Zhang said. In addition, those who were on insulin were more likely to have dia- betic retinopathy. Investigators found that among those who used insulin, 38.1% were likely to have diabetic retinopathy versus 27.1% of 6<0326,$723,&6 &DWDUDFWDQG(QGRWKHOLXP-RLQW6\PSRVLXPZLWK(X&RUQHD )HPWRVHFRQG&DWDUDFW6XUJHU\ 5HIUDFWLYH$GMXVWPHQWVDIWHU2FXODU6XUJHU\ 'HFLVLRQPDNLQJLQ3UHVE\RSLD $SKDNLDDQG$QWHULRU6HJPHQW5HFRQVWUXFWLRQ SUHOLPLQDU\SURJUDPPHRQOLQHDW ZZZHVFUVRUJ 6(37(0%(5 5(('0(66( 9,(11$ $8675,$ (8523($162&,(7<2)&$7$5$&7 5()5$&7,9(685*(216 YLHQQDBH\HZRUOGISDQHZVL]HLQGG A scene as it might be viewed by a person with diabetic retinopathy Source: National Eye Institute, National Institutes of Health continued on page 52

• Cover