Effect of pattern scanning laser on macular thickness in diabetic retinopathy.

Purpose: 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).

Methods: 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.

Results: 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.

Conclusion: 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.