One complication of diabetes is the damage to the eyes' retina which can lead to vision loss.

Study in mouse models at Medical College Georgia revealed that a drug known for it pain-relieving power and believed to stimulate memory appears to prevent this retinal damage.

The said drug is pentazocine.

"The effects of this drug on retinal health are phenomenal," says Dr. Sylvia Smith, retinal cell biologist and co-director of the Vision Discovery Institute in the Medical College of Georgia School of Medicine. She's comparing retinal images from a diabetic mouse model treated with (+)- pentazocine to one that wasn't. Even to the untrained eye, the differences are dramatic.

Sigma receptors are ubiquitous in the body, but their role and what naturally activates them are unknowns. Recent research suggests sigma receptors help protect cells from stress by ensuring an adequate level of the properly folded proteins they need for normal function. Dr. Smith and others have shown that sigma receptors are located within the endoplasmic reticulum of cells, which controls protein synthesis and regulates calcium levels. When needed, the receptors appear to chaperone these proteins to the cell powerhouse, or mitochondria. Dr. Smith suspects sigma receptors help manage this hotbed of cell stress. In fact, sigma receptor binding with pentazocine increases with cellular stress.

Published in the September issue of Investigative Ophthalmology & Visual Science, the findings suggest that compounds like pentazocine that bind with the sigma receptor in the eye may be good treatments for the top two causes of vision loss: diabetic retinopathy and glaucoma.

Read more from Medical College Georgia.