Contrast sensitivity and retinal disease.

A new and practical test for contrast sensitivity (Arden gratings) was evaluated in retinal diseases and found to be a more sensitive indicator of dysfunction than Snellen acuity. Most patients with acuity of 20/30 or better (e.g., with retinitis pigmentosa or toxic retinopathy) showed diminished sensitivity to finely spaced gratings, while patients with poor acuity (e.g., with cone dystrophy) showed normal sensitivity to coarsely spaced gratings. Grating tests may allow earlier diagnosis and more precise follow-up of retinal disease, but their specificity for particular disorders remains to be established.