A "hidden" deficit in central vision in diabetic pan-retinal photocoagulation patients

Adaptation ability in the center of vision was tested in diabetic patients treated with pan-retinal photocoagulation for diabetic retinopathy and in normal control subjects. This was accomplished with a specially designed contrast sensitivity testing regimen. Patients with retinopathy showed "hidden" deficits, losses in adaptation ability that could not be measured by standard clinical tests, such as visual acuity. This new test thus quantifies a previously unmeasured visual problem that affects the everyday visual function of these patients.