Effect of pattern scanning laser on macular thickness in diabetic retinopathy

This study investigates the effect of pattern scanning laser (PASCAL) panretinal photocoagulation (PRP) on central macular thickness (CMT) and visual acuity (VA) in patients with proliferative diabetic retinopathy (PDR).

This retrospective non-randomized comparative case series included 262 eyes (163 with macular edema) of 177 patients with PDR. Treatment was PRP alone (137), PRP + anti-vascular endothelial growth factor (VEGF) (69), PRP + focal laser (28), or all three (89). CMT and central macular volume 3 and 6 mm from fovea were analyzed before and 1, 3, and 6 months after PRP. Spot number was plotted against CMT, and linear regression analysis was performed.

For each treatment group and time point, there was a non-significant relationship between spot number and CMT. In eyes receiving all three treatment modalities, a significant negative relationship was found between spot number and 3-mm volume at 6 months (p = 0.04) and 6-mm volume at 1 month (p = 0.002) and 6 months (p = 0.011). There was no significant change in VA in any treatment group at the 6-month time point.

PASCAL PRP ± focal laser or anti-VEGF was not associated with increased development of macular edema or change in VA. PASCAL PRP with focal laser and anti-VEGF may result in a decrease in macular edema.