Effect of panretinal photocoagulation on retinal nerve fiber layer thickness and vision-related quality of life in proliferative diabetic retinopathy patients

The purpose of this study is to evaluate the retinal nerve fiber layer (RNFL) thickness and vision-related quality of life (VRQoL) in type 2 diabetes mellitus (T2DM) patients with proliferative diabetic retinopathy (PDR) following panretinal photocoagulation (PRP). A prospective cohort study was conducted from June 2012 until December 2013. Visual acuity was evaluated using Snellen chart (converted to LogMAR decimal notation), RNFL thickness using optical coherence tomography and VRQoL using Visual Function Questionnaire-25 (VFQ-25) before and at three months after completed PRP. A total of 44 PDR patients were enrolled into this study. There was significant reduction of mean visual acuity at three months post PRP (p < 0.001). Both mean global RNFL thickness and mean composite score of VFQ-25 showed significant reduction at three months post PRP (p < 0.001 and p < 0.001 respectively). There was significant fair negative correlation between VFQ-25 composite score and LogMAR visual acuity post PRP (r = -0.425, p = 0.004). PRP was associated with reduction of RNFL thickness and VFQ-25 composite score in T2DM patient with PDR at three months post PRP. Longer duration of follow-up is recommended to look for the long-term effect of VRQoL from laser therapy.