Abstract
BACKGROUND: Anterior segment neovascularisation (ASNV), including neovascularisation of the iris (NVI) and angle (NVA), is a known complication of proliferative diabetic retinopathy (PDR), but outcomes specific to this group remain poorly characterised. We aimed to evaluate visual and intraocular pressure (IOP) outcomes in patients with ASNV secondary to PDR, stratified by anatomical stage, and to assess the incidence of neovascular glaucoma (NVG). METHODS: This retrospective cohort study included 116 eyes from 72 patients with treated PDR and ASNV treated between 1/1/2017 and 31/12/2023. Eyes were stratified into three groups: NVI only; NVI and/or NVA without peripheral anterior synechiae (PAS); and eyes with PAS. Data on visual acuity (VA), IOP, treatment, and disease progression were collected. Median follow-up was 42.5 months. RESULTS: Visual outcomes and IOP control were significantly worse in eyes with PAS. Final median logMAR VA was 0.36 in the NVI group, 0.44 in the NVI/NVA group, and 2.30 in the PAS group (p = 0.009). Vision loss ≥3 lines occurred in 34%, 31%, and 71% of eyes, respectively (p = 0.010). Final VA ≥ 1.0 logMAR was recorded in 71% of PAS eyes, compared to 18.2% in the other groups (p < 0.001). NVG developed in 9/116 eyes (7.8%) overall, exclusively in the PAS subgroup (9/17 eyes, 53%). Glaucoma surgery was required in 41% of eyes with PAS. CONCLUSIONS: In treated PDR, NVI or NVA alone was generally compatible with visual stability, whereas PAS were associated with high NVG incidence and poor vision. Early gonioscopic detection and aggressive treatment are critical to prevent synechial angle closure.