Abstract
Adaptive optics (AO) imaging of the human cone mosaic has shown that a visible stimulus can induce intrinsic changes in cone infrared reflectivity. We studied this intrinsic response as a function of stimulus irradiance and duration. Five subjects were imaged using a previously described AO scanning light ophthalmoscope. Following 2 minutes of dark adaptation, image sequences were obtained 0.65° from the fovea using a 790 nm imaging light. Four seconds after the start of each sequence, a 680 nm stimulus of variable irradiance (0.037 to 18.9 μW/deg^2) and duration (0.2 to 2 secs) was delivered to one half of the imaging field. Reflectance signals were extracted from each cone and standardized to their pre-stimulus values. The difference in the standard deviation of the reflectance of stimulated and control (unstimulated) cones was determined at each time point. The peak was extracted from the resultant time-varying response. Peak response increased with both stimulus irradiance and duration, qualitatively consistent with a dependence of the response on photoreceptor function.
Meeting abstract presented at the 2016 OSA Fall Vision Meeting