Session Title: Imaging II
Session Date/Time: Friday 18/09/2015 | 16:30-18:00
Paper Time: 16:46
First Author: : S.Sadda -0
Co Author(s): : M. Sagong J. van Hemert M. Singer
PURPOSE:To establish the extent and morphology of the peripheral retinal vasculature in normal individuals for use in comparison to studies of retinal disease.
Tertiary care retina practice and academic image reading center
This IRB-approved study enrolled 61 eyes of 31 normal subjects. Ultrawidefield pseudocolor and fluorescein angiographic images were captured centrally and with peripheral steering using the Optos 200Tx. Images taken at different gaze angles were montaged and corrected for peripheral distortion using a stereographic projection method to provide a single image for grading of the peripheral most edge of the visible vasculature. The border of the vascularized retina was expressed as a radial surface distance from the center of the optic disc at each meridian. Qualitative features of the peripheral vasculature, including capillary dropout, tortuosity, vessel staining were also tabulated.
In normal eyes, the mean radial surface distance (mm) from the optic nerve to the periphery was 20.32±1.37mm and the mean area of normal “perfused” retina was 979.99 mm2. There was no significant difference between right and left eyes or between males and females. The distance (in mm) to the periphery was different, however, depending on the quadrant with temporal (22.45±0.91) greater than inferior (20.42±1.65), greater than superior (19.22±1.47), greater than nasal (17.37±0.88); p=0.0001 for all inter-comparisons. Interestingly, the distances to the perfused vascular border were significantly shorter in individuals older than 60 compared with younger subjects. The frequency of the qualitative peripheral vascular findings of capillary dropout, tortuosity, vascular staining, and circumferential vessels were 26.2%, 13.1%, 19.7%, and 11.5%, respectively.
Ultrawidefield angiography is an important tool for studying the peripheral retinal vasculature. Given the increasing use of ultrawidefield imaging in the evaluation and management of patients with retinal vascular disease, the normative data from our study may provide a useful reference when assessing the pathologic significance of findings in the setting of disease.