Combined photic and nonphotic electro-oculographic responses in the clinical evaluation of the retinal pigment epithelium.

In an attempt to simplify the recording technique in electrophysiologic evaluation of the retinal pigment epithelium, we combined the electro-oculographic light rise, hyperosmolarity and acetazolamide responses in a single recording session. Recordings were performed in six normal subjects and in seven patients with diabetic retinopathy or retinitis pigmentosa. In the patients with background diabetic retinopathy, the hyperosmolarity responses were slightly reduced, while the acetazolamide response and the light rise was normal. In the patients with proliferative diabetic retinopathy, the hyperosmolarity response and light rise were remarkably reduced, while the acetazolamide response was normal. In the patients with retinitis pigmentosa, the hyperosmolarity response and light rise were decreased, while the acetazolamide response was normal. Despite a small study population, we concluded that the clinical results from our combined recording protocol were essentially the same as those reported for each response separately. Because this recording technique simplifies electrophysiologic evaluation of the retinal pigment epithelium, it may help clarify the mechanisms or localization of retinochoroidal and pigment epithelial diseases.