Reduced Fluence Decreases Pain Caused by Panretinal Photocoagulation for Diabetic Retinopathy

Abstract

Purpose: : To measure pain perceived by diabetic patients receiving panretinal photocoagulation using reduced fluence parameters (RFP), compared to traditional parameters (TP).

Methods: : Diabetic patients scheduled for panretinal photocoagulation who accepted to participate in the study were included. All eyes received at least 500 burns, using a 532 nm laser. The right eye was treated with RFP (time 20-50 msec, power 400-700 mW), while the left eye was treated with TP (time 100-200 msec, power 200-400 mW). Parameters were adjusted in both cases to obtain a gray-whitish burn. The eye to be treated first was assigned in an alternate fashion. After each eye received treatment, patients were questioned about the perceived pain using the NRS-11 scale (0 = no pain; 10 = most painful experience).

Results: : Twenty-five patients were included. Fluence per burn using RFP was 16.7 ± 10.5 J/cm², and using TP was 35 ± 15.1 J/cm² (p=0.000001). Pain score was 5 ± 2.19 for RFP and 7.7 ± 1.5 for TP (p=0.000058). There was a positive correlation (R²=0.4) between fluence per burn and pain perceived. No complications were observed secondary to treatment.

Conclusions: : Using RFP seems to reduce pain secondary to photocoagulation compared to TP.

Clinical Trial: : www.clinicaltrials.gov NCT00802269

Keywords: diabetic retinopathy • laser