Abstract
Purpose: :
Diabetic macular edema and proliferative diabetic retinopathy are the leading causes of blindness in the working age population. As the incidence of diabetes increases and the population ages, the burden on the healthcare system will be tremendous. Therapies are available, but they are limited with little visual improvement and frequent and invasive therapies are required. For these reasons, it is imperative to identify cases of macular edema and retinopathy early prior to visual decline. We studied the ability of a retinal acuity meter (RAM) with a brightness acuity meter (BAM) to photostress the macula and identify early macular edema and diabetic retinopathy.
Methods: :
Prospective study of retinal acuity recovery time after a 30 second photostress test using the Retinal Acuity Meter and Brightness Acuity Meter (AMA Optics, Fair Oaks, California, United States of America) was performed on patients with diabetic retinopathy and age matched controls. Macular edema was identified by thickening on optical coherence tomography (OCT) greater than 250 um and the presence of diabetic retinopathy was identified by ophthalmoscopy.
Results: :
One-hundred and forty-three eyes from eighty-four patients were analyzed. Retinal acuity ranged from 20/20 to 20/400 and photostress test recovery time ranged from 22 to 119 seconds. When comparing eyes with macular edema to age matched controls, eyes with macular edema had significantly longer recovery time (p = 0.04) (median recovery time with edema = 34 seconds, mean = 38.9 seconds; median recovery time without edema = 32 seconds, mean = 35.3 seconds; Mann Whitney U test). There was no difference in retinal acuity between the two groups indicating patients with edema had not yet suffered serious visual loss (p = 0.68, Mann Whitney U test).
Conclusions: :
Medical internists may want to consider using the simple and quick Retinal Acuity Meter and Brightness Acuity Meter in their office on all diabetic patients to help identify patients with macular edema who have yet to have visual loss. Patients can then be referred to a retinal specialist in a timely fashion for treatment to prevent irreversible visual loss.
Keywords: diabetic retinopathy • diabetes