Abstract
Purpose: :
There is extensive drusen deposition and atrophy visible at the retinal periphery in flat-mounted aged donor tissues. Our understanding of the relevance of these peripheral pathologies in Age Related Macular Degeneration (AMD) is limited by the lack of detailed peripheral imaging studies. Imaging retinal periphery in clinical setting is now available; thus the purpose of this study was to develop imaging and grading protocols suited to wide-angle imaging in an aged population.
Methods: :
Conventional digital fundus images (CDI) and ultra wide field (200°) color and autofluorescence (AF) images were taken using Optos P200C AF ultra-wide angle laser scanning ophthalmoscope as part of the 12 year follow-up of the Reykjavik Eye Study. Of the original random population sample, 573 persons of 62 years and older participated. Images were then graded at Moorfields Eye Hospital Reading Centre. Peripheral changes were graded of the 1272 eyes imaged using a standardised grid developed for this imaging modality. Presence or absence of hard and soft drusen, peripheral retinal pigment epithelial changes, atrophy or neovascularisation was graded on the color images and then the presence or absence of hypo-and hyperfluorescence using autofluorescence imaging. All peripheral grading results were tabulated and then the presence of the same changes was examined for the macula and the peripheral grading.
Results: :
Fifty six percent of patients had pathology on the periphery with features that are normally associated with AMD. More Drusen was observed in the superior 2 quadrants compared to the inferior ones. There was no AMD like CNV or PED in the periphery, but 7 patients had atrophy, drusen and RPE changes at the periphery without end-stage disease in the macula. No patient with end-stage disease in the macula had normal periphery.
Conclusions: :
Phenotyping peripheral changes on Optos P200C AF ultra-wide angle laser scanning ophthalmoscope imaging confirmed that there are wide ranging pathological changes in the periphery even in those who have no central pathologies. The predictive values for these paripheral pathological changes are yet to be determined.
Keywords: retina • imaging/image analysis: clinical • clinical (human) or epidemiologic studies: systems/equipment/techniques