TOPOGRAPHIC PATTERNS OF PERIPHERAL DIABETIC NEOVASCULARIZATION ON ULTRA-WIDEFIELD FLUORESCEIN ANGIOGRAPHY

Purpose: To investigate the prevalence, patterns, and topographic distribution of peripheral retinal neovascularization in treatment-naïve patients with proliferative diabetic retinopathy (PDR) using ultra-widefield fluorescein angiography. Methods: A retrospective cross-sectional observational study conducted in a single center. An overlay grid outlining the 7-field ETDRS and five peripheral fields was applied on ultra-widefield fluorescein angiography images. Neovascular lesions were classified as neovascularization of the disk within one disk diameter of the optic disc, neovascularization elsewhere within the ETDRS 7-field area, and peripheral neovascularization (PNV) within the five peripheral fields. The study evaluated the prevalence and distribution of PNV in the extended ETDRS fields and examined its associations with other forms of retinal neovascularization. Results: Ninety seven eyes of 61 patients with were included. PNV was identified in 56 eyes (57.7%) and solely present in only three eyes (3.1%). PNV was most associated with both neovascularization of the disk and neovascularization elsewhere in 34 eyes (35.1%), followed by its coassociation with neovascularization elsewhere only in 17 eyes (17.5%) and was observed alongside neovascularization of the disk alone in two eyes (2.1%). PNV demonstrated the highest prevalence in Extended Field 6 (43.3%) and showed a significant association with younger patients (50 years and younger; P = 0.012). Conclusion: Retinal neovascularization frequently develops outside the ETDRS 7-field area in treatment-naïve eyes with PDR, particularly among younger patients, underscoring the need for vigilant monitoring and tailored management. Nevertheless, peripheral neovascularization (PNV) often coexists with posterior neovascularization, reinforcing the continued relevance of standard ETDRS 7-field imaging for PDR grading.