Abstract
Abstract: :
Purpose: To compare photopic and scotopic sensitivity of retinal areas with soft drusen, regressed drusen and that of retina of normal appearance in eyes with Age–Related Maculopathy (ARM). Methods: Patients from a large ongoing collection of clinical data of the London ARM Study at Moorfields Eye Hospital, with ARM and both soft and resolved macular drusen, who have serial photographs as clinical records were invited to have sensitivity tests. Phenotyping was performed by grading based on standard 30º stereo color fundus images (SCI), centered on the fovea (Field 2), according to the system defined by the International Classification for ARM carried out by certified graders masked to the main aim of the study. Fundus Autofluorescence (AF, at 488nm) was recorded using a Heidelberg Retina Angiograph 2 (Heidelberg Engineering GmbH, Germany). The retinal location for fixation was determined, and the fixation stability was calculated as a bivariate contour ellipse area (BCEA). Where disappearance of drusen was confirmed by independent grading, the patient was invited for testing by Fine Matrix Mapping (FMM) using a modified Humphrey Field Analyzer. Photopic and scotopic thresholds were obtained at 100 locations on a 9° by 9° matrix of 1° spacing centered at a macular area of regressed drusen. Results: Of 1460 patients enrolled in the London ARM Study, 32 had regression of drusen confirmed by grading of CSI and AF images, 19 patients agreed to be tested, of these 12 had spontaneous regression of drusen, while 7 had regression of drusen following prophylactic laser treatment. Visual acuities ranged between 20/20 and 20/40. All patients had sufficient fixation to carry out the 3–hour FMM test. A greater loss of scotopic than of photopic function was demonstrable, which is consistent with previous work by Scholl and others. Conclusions: FMM allows high spatial resolution comparison of rod and cone mediated sensitivities in relation to observable fundus features from both color and AF images. A greater loss of scotopic function corresponds well with the patients’ usual complaint of night vision disturbances. It is of great interest to further understand how changes in drusen and AF relate to photoreceptor sensitivity loss.
Keywords: age-related macular degeneration • drusen • imaging/image analysis: clinical