Central retinal thickness following panretinal photocoagulation using a multispot semi-automated pattern-scanning laser to treat ischaemic diabetic retinopathy: Treatment in one session compared with four monthly sessions.

PURPOSE To compare central retinal thickness (CRT) after panretinal photocoagulation (PRP) with a multispot semi-automated PAttern-SCAnning Laser (PASCAL) in one session (SS-PRP) versus four monthly sessions (MS-PRP) in diabetic retinopathy. METHODS Multicentre, prospective, randomized, single-blinded, controlled trial evaluating the noninferiority of SS-PRP versus MS-PRP for CRT measured with macular spectral-domain optical coherence tomography (SD-OCT), with a 9-month follow-up in patients presenting severe nonproliferative diabetic retinopathy (DR) or mild proliferative DR without macular oedema (ME) at baseline. RESULTS Ninety-seven eyes of 97 participants with a mean age of 57.0 ± 14.2 years were included. The mean change of CRT from baseline to 9 months was not statistically different in SS-PRP or in MS-PRP: +16.9 ± 28.3 μm versus +24.7 ± 31.8 μm, respectively (p = 0.224). The variation in mean best-corrected visual acuity (BCVA) from baseline to 9 months was similar in both groups: -1.1 ± 6.5 letters versus -0.6 ± 6.2 letters (p = 0.684). The number of patients with stabilization of DR was not statistically different between the two groups. No severe complication was recorded in either group. CONCLUSION This study showed the noninferiority of PRP performed in one session versus four monthly sessions with a PASCAL concerning central retinal thickness for treating mild proliferative or severe nonproliferative DR without ME at baseline.