Laser Diopexy for Peripheral Retinal Ablation in Proliferative Diabetic Retinopathy

Aim: To assess the effect and efficacy of the diopexy (contact transscleral retinal photocoagulation with a diode laser) in the peripheral areas of the retina not accessible by standard slit-lamp laser, after full scatter PRP ± macular treatment in eyes with PDR. The objective is to induce regres¬sion of neovascularization in cases with persistent new vessels as an alternative to anterior retinal cryoablation.Methods: Diopexy was performed on 35 eyes in patients with PDR associated with NVD ± NVE s ± subtotal localized subhyaloid hemorrhage ± rubeosis irides.Results: Out of the 35 eyes that underwent diopexy, 4 had initial subtotal vitreous hemorrhage, 3 initial rubeosis. In 21/35 eyes stabilization of the neovascularization occurred after diopexy. 7/36 eyes developed vitreous hemorrhage after diopexy (9ms, 3ms, 1 week, 5ms, 2 weeks, 10ms and 3 l^ms later). 3 underwent vitrectomy, and in 4 vitreous hemorrhage absorbed, 1/35 eye developed increase in lenticular changes 1 week after diopexy .Out of the 4 eyes with initial subtotal hemorrhage, 2/4 had recurrent vitreous hemorrhage attacks (1 month and 4 months later), but ultimately vitreous hemorrhage absorbed in all cases within 4 months.Out of the 3 eyes with initial rubeosis, in 2/3 rubeosis regressed 1 week later, and 1/3 rubeosis regressed 1 month later then recurrent rubeosis occurred after another month and later needed vitrectomy for the initial unabsorbed total vitreous hemorrhage.Conclusion: Results showed that diopexy is useful in stabilizing the PDR eyes, help in regression of rubeosis, and in cases of recurrent vitreous hemorrhage, help reabsorption of hemorrhage. Patients with persistent vitreous hemorrhage who underwent vitrectomy later had a better prognosis than those who did not have diopexy.To conclude, diopexy is an intermediate option between laser treatment and vitrectomy in the sequence of PDR treatment.