Comparison Of Non-Mydriatic Ultra-Widefield Fundus Photography To Standard Early Treatment of Diabetic Retinopathy Study 7- Fields In Diabetic Retinopathy Screening.

Abstract

Purpose: To assess the effectiveness of non-mydriatic ultra-widefield fundus photography (UWFFP) in detecting peripheral vascular lesions and to compare it to the Early Treatment of Diabetic Retinopathy Study (ETDRS) 7-fields for screening of diabetic retinopathy.

Methods: A retrospective review of Optos® camera ultra-widefield fundus photography obtained during diabetic retinopathy screening. Two independent reviewers screened each photograph for quality based on preset paramaters. Then microaneurysms (MA), intraretinal hemorrhages (IRH), venous beading (VB), intraretinal microvascular abnormalities (IRMA), cotton wool spots (CWS), hard exudates (HE), neovascularization on the disc (NVD), neovascularization elsewhere in the retina (NVE), preretinal hemorrhage (PRH), vitreous hemorrhage (VH) were counted within and outside ETDRS 7-field areas and divided into four quadrants. Statistical analyses were performed to compare retinal abnormalities in respective regions.

Results: 193 eyes from 100 patients were included in this study. Significant number of outer quadrants (N = 433) had greater than 50% of its area covered by obscurations and artifacts when compared to inner quadrants (N = 76, p = 10^-64). Full ETDRS 7-fields without significant artifacts were captured in 149 eyes (77.8%). Most commonly affected outer quadrants were inferonasal and inferotemporal quadrants (89% and 64% respectively). MA and IRH were significantly more frequent within EDTRS 7-field quadrants than outer quadrants (MA N_in vs. N_out = 116 vs. 20, p = 10^-102 and IRH N_in vs. N_out = 115 vs. 58, p = 10^-14 respectively). VB, CWS, and HE were exclusively present within ETDRS 7-field quadrants. One case of NVD was seen. No NVE, PRH, or VH were identified. Incidental findings included macular and peripheral drusen (N = 44), central retinal vein occlusion (N = 3), and choroidal rupture (N = 1).

Conclusions: Optos non-mydriatic UWFFP is a potentially useful method to screen for diabetic retinopathy since it allows imaging of the peripheral retina and ETDRS 7-fields even without dilation. While the peripheral retina outside of ETDRS 7- field are frequently obscured by artifacts, especially in inferior quadrants, the majority of pathology was within the ETDRS 7 fields. Additional peripheral pathologies were found outside the ETDRS 7-fields that otherwise would have been missed.