Hyperosmolarity response of ocular standing potential as a clinical test for retinal pigment epithelium activity diabetic retinopathy.

The hyperosmolarity response, a drug-induced response from the retinal pigment epithelium, was recorded in diabetic retinopathy. The hyperosmolarity response was occasionally abnormal at the pre-retinopathic stage and at the first stage of retinopathy by Scott classification. The response was frequently abnormal at the second and third stages of retinopathy. The hyperosmolarity response is useful for early diagnosis of pigment epitheliopathy in diabetes.