Predictive factors associated with anatomical and functional outcomes after panretinal photocoagulation in people with proliferative diabetic retinopathy

Purpose:To determine effects of baseline characteristics and laser type performed on outcomes in people with proliferative diabetic retinopathy (PDR) undergoing panretinal photocoagulation (PRP).Methods:Medical records of all consecutive patients with PDR naïve to PRP, identified using an electronic database, evaluated at the Macula Clinic, Belfast Health and Social Care Trust, receiving their first PRP between January 1, 2016, and June 30, 2017, and followed for a minimum of 6 months after stabilization of PDR, were retrospectively reviewed. Outcomes included time to stabilization after PRP, progression of PDR, and mean change in the best-corrected visual acuity from baseline to the last follow-up. Cox regression was used to estimate hazard ratios (HRs) for the effect of baseline characteristics and type of laser on outcomes after treatment.Results:One hundred and fourteen patients (135 eyes) with a mean age of 56.9 (SD: 12.9) years were included, 67% males. People receiving pattern or mixed laser had a statistically significantly delayed stabilization (HR: 0.57, P = 0.020; and HR: 0.44, P ≤ 0.001, respectively) and increased risk of progression (HR: 1.87, P = 0.045; and HR: 1.96, P = 0.028, respectively) when compared with those receiving standard laser. Among other potential predictors in multivariable regression analysis, only vitreous hemorrhage and fibrosis or traction at baseline increased the risk of progression (HR: 1.58, P = 0.047; and HR: 4.29, P ≤ 0.001, respectively). Baseline characteristics and type of laser had no statistically significant effect on vision.Conclusion:These findings should be considered when selecting laser treatment, planning surveillance, and counselling patients with PDR undergoing PRP.