Antibiotic Improved Diabetic Eye Disease

Diabetic retinopathy may be slowed with low dose doxycycline

(RxWiki News) For those with diabetes, eye diseases like diabetic retinopathy are a concern. One anti-inflammatory agent may offer relief for sore eyes.

Other than controlling blood sugar, blood pressure and cholesterol, there is no established therapy used to fight diabetic retinopathy, which is a leading cause of blindness among adults.

Recent research has found that the anti-inflammatory effects of doxycycline in low doses may improve retina function.

"Get regular eye exams if you have diabetes."

Ingrid Scott, MD, from the Penn State Hershey Eye Center and the Department of Public Health Sciences at Penn State College of Medicine in Hershey, Pennsylvania, and colleagues conducted this small trial with 30 patients who had either type 1 or type 2 diabetes and diabetic retinopathy.

Some patients had severe nonproliferative diabetic retinopathy (NPDR), which is the early stage of the disease. The symptoms of NPDR are mild or non-existent, according to the American Optometric Association. Blood vessels in the retina weaken from this condition and cause tiny bulges called microaneurysms to stick out from the vessel walls.

Other subjects had non-high risk proliferative diabetic retinopathy. With proliferative diabetic retinopathy, blood vessels develop, or proliferate, along the surface of the retina. They bleed and impair vision, and can detach the retina.

Over the course of two years, patients were randomly selected to receive a placebo (mock medication) or doxycycline (brand names Doryx, Doxychel, Monodox).

Doxycycline is a type of tetracycline. Tetracyclines are antibiotics often used to treat bacterial infections such as urinary tract infections, chlamydia and acne. Tetracyclines have been shown to have protective effects on retinal cells.

To evaluate the effectiveness of doxycycline, Dr. Scott and team measured retinal function with the frequency doubling perimetry (FDP) test. This relatively inexpensive method for fast and effective detection of visual field loss gauges sensitivity of fovea, which is in the middle of the retina and is the center of the eye’s sharpest vision.

After two years of treatment, the placebo group experienced a decline in FDP foveal sensitivity, while the doxycycline patients improved. 

In the current study, the researchers noted a higher average foveal sensitivity among the doxycycline patients at six months, 12 months and 24 months.

“Oral doxycycline may be a promising therapeutic strategy targeting the inflammatory component of [diabetic retinopathy],” the authors concluded. “Furthermore, study results suggest that FDP, which primarily measures inner retinal function, is responsive to intervention.”

This study was published recently in JAMA Ophthalmology.

The research was supported in part by a grant from the Juvenile Diabetes Research Foundation, a Research to Prevent Blindness Physician-Scientist Award and the A. Alfred Taubman Medical Research Institute.

Dr. Gregory Jackson, one of the contributing authors, is an investor and employee of MacuLogix, Inc, Hershey, Pennsylvania, the manufacturer of the AdaptDx, a tool to diagnose age-related macular degeneration.

Review Date: 
May 8, 2014