Damian McNamara

May 14, 2013

SEATTLE, Washington — Predicting which patients with diabetes are more likely to develop macular edema could help clinicians counsel patients about their increased risk and motivate people to keep their diabetes under control.

"The more diabetic complications you have, the higher your risks of developing diabetic macular edema," Nidhi Talwar, MA, from the Department of Ophthalmology and Visual Sciences at the University of Michigan in Ann Arbor, told Medscape Medical News. "Also, race is a factor."

She presented the results of an ambitious longitudinal study during a poster session here at the Association for Research in Vision and Ophthalmology 2013 Annual Meeting.

To identify significant clinical and demographic factors, Talwar and colleagues conducted a study of 447,407 people with diabetes but without macular edema. Patients were 30 years and older, were continuously enrolled in the managed care plan for at least 3 years, and had made at least 1 visit to an eye care provider during that period to rule out diabetic macular edema.

The researchers followed this group for a mean of 5.3 years, and found that 6473 people (1.5%) developed diabetic macular edema, which is a leading cause of blindness in this population.

On multivariable Cox regression analyses, controlled for possible confounders, diabetic nephropathy, diabetic neuropathy, and a higher level of glycated hemoglobin (HbA1c) were found to be significantly associated with increased risk. Black and Latino people with diabetes also are at elevated risk, Talwar noted.

Table. Significant Predictors of Progression to Macular Edema

Predictor Adjusted Hazard Ratio 95% Confidence Interval P Value
Black race 1.14 1.04–1.26 .0074
Latino race 1.28 1.16–1.42 <.0001
Diabetic nephropathy 1.41 1.32–1.50 <.0001
Diabetic neuropathy 1.59 1.50–1.69 <.0001
Type 1 diabetes 1.97 1.85–2.09 <.0001
Higher baseline HbA1c level 1.16 1.09–1.24 <.0001
Hypertension 1.25 1.11–1.40 .0002
Hypertension-associated end-organ damage 1.45 1.28–1.64 <.0001


Hyperlipidemia was associated with a reduced risk for diabetic macular edema (hazard ratio, 0.81; 95% confidence interval, 0.73 - 0.91; P = .0002). "This is just among people who have insurance, so it's not an access-to-care issue," study coauthor Joshua Stein, MD, also from the Department of Ophthalmology at the University of Michigan, told Medscape Medical News.

One message from this study is that if diabetes is not controlled, the risk for diabetic macular edema increases, Dr. Stein said. These findings can be used "to motivate patients to take better care of themselves to prevent blindness."

In the future, Talwar and colleagues would like to use these findings to develop a risk calculator for clinicians. It would incorporate the significant diabetic macular edema predictors, and a patient's total score (above or below a cutoff value) would indicate the risk for diabetic macular edema and the need for any further workup or patient education.

"For all our diabetic patients, regular ophthalmic screening, prompt diagnosis, and early treatment of diabetic retinopathy, especially diabetic macular edema, is essential to maintaining good visual function," said Szilárd Kiss, MD, from the Department of Ophthalmology at Weill Cornell Medical College in New York City, who was asked by Medscape Medical News to comment on the study findings.

"This study elaborates on who is at risk so that we can properly and closely screen those patients," he said. "More important, it adds to our understanding of the underlying risk factors for developing diabetic macular edema — an understanding that we can educate our patients about."

This study was supported by a grant from the National Institute of Diabetes and Digestive and Kidney Diseases; a National Eye Institute K23 Mentored Clinician Scientist Award; a Research to Prevent Blindness "Physician Scientist Award"; an unrestricted grant from Research to Prevent Blindness; and a Taubman Institute RPB Physician-Scholar Award. Ms. Talwar and Dr. Stein have disclosed no relevant financial relationships. Dr. Kiss reports receiving financial support from Alcon, Alimera, Allergan, Genentech, Optos and Regeneron; being a consultant for Alimera, Allergan, Eytech, Genentech, Merge/OIS, Regeneron, and Optos; having a personal financial interest in Merge/OIS; and being a researcher for Alimera, Allergan, Genentech, Optos, and Regeneron.

Association for Research in Vision and Ophthalmology (ARVO) 2013 Annual Meeting: Abstract 1540 - C0030. Presented May 6, 2013.


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