Abstract
Purpose:
There are increasing numbers of studies using ultra wide field imaging for peripheral retinal pathologies. Wepreviously graded images of the retinal periphery in Reykjavik Eye Study 12-year follow up participants for age-related macular degeneration (AMD)-like pathologies. We had reported a specific spatial distribution for AMD-like pathologies favouring the superior-nasal quadrant. We also observed some intriguing features that are associated with large areas but showed no association with single quadrants. In this study we assessed the prevalence of these phenotypes and assessed their ease of use and reproducibility to grade peripheral retinal changes.
Methods:
Ultra wide field (200°) colour and autofluorescence (AF) images were taken using OPTOMAP P200C AF ultra-wide field laser scanning ophthalmoscope as part of the 12-year follow-up of the Reykjavik Eye Study, a random population sample. Images were graded based on the presence of: 1) peripheral hard drusen field, that was defined as large areas covered by well distinguishable and numerous hard drusen outside the macular area; 2) soft drusen fields, that was defined by the presence of large areas covered by numerous soft drusen outside the macula; 3) arcade drusen, that was defined as drusen fields immediately exterior of the arcade vessels and 4) peripheral reticular degeneration, characteristic hyper-pigmentation streaks exterior to the peripheral retina. Images were graded by 2 independent observers to obtain inter-grader agreement.
Results:
In this study, 1158 eyes of 579 subjects were assessed. Overall 10.6% of all eyes had peripheral hard drusen field. Peripheral soft drusen field were present in 2.5% of the eyes while arcade drusen were present in 5.7% of the eyes. The most prevalent peripheral pathology was the peripheral reticular degeneration that was associated with 18.3% of the eyes. Overall 28.5% of the eyes had one and 7.7% had more than one of the new peripheral grading categories. Grading by two independent observers showed no significant disagreement using these new categories (kappa> 0.95; p<0.05 for all categories).
Conclusions:
The advantage of these periphery-only grading categories is that these were easily, quickly and reliably identifiable by graders. Given the large area the peripheral retina covers, these phenotypes might provide meaningful categories for phenotyping large populations based studies.
Keywords: 464 clinical (human) or epidemiologic studies: risk factor assessment •
550 imaging/image analysis: clinical •
638 pathology: human