Safety and efficacy of panretinal photocoagulation in patients with high-risk proliferative diabetic retinopathy using pattern scan laser versus conventional YAG laser

The purpose of the study was to compare the results of panretinal photocoagulation (PRP) using the pattern scan laser (PASCAL) in a single setting versus multiple sessions of standard YAG laser in patients with proliferative diabetic retinopathy. Charts of 35 eyes that were treated with the PASCAL and an equal number of eyes that were treated with conventional laser were retrospectively reviewed. The whole PRP treatment was performed in one session in the PASCAL group, whereas all the patients in the conventional-laser group completed the entire PRP treatment in two or three sessions. Persistence and/or recurrence of neovascularization, complications encountered, total number of laser spots, and mean power used were compared. Patients treated with the PASCAL received significantly higher number of laser spots than those treated with conventional laser (2885 vs. 1642, p < 0.001). The PASCAL and conventional-laser systems required an average power of 650 mW and 330 mW, respectively (p < 0.001). Patients treated with the PASCAL showed similar rates of treatment failure within 12 months of follow-up compared with patients treated with conventional laser (14% vs. 11%, p > 0.05). In the PASCAL group, vitreous hemorrhage, neovascular glaucoma, retinal hemorrhage, and choroidal detachment were reported in two, two, one, and two patients, respectively, whereas only one each vitreous hemorrhage and neovascular glaucoma were encountered in the conventional-laser group. Our study reports that single-session PRP with the PASCAL has similar efficacy compared with conventional laser, and has a favorable side-effect profile.