Objective: To evaluate functional, anatomical and clinical efficacy, and safety of the pattern scanning laser (PASCAL®) photocoagulation in patients with diabetic macular edema and absence of proliferative diabetic retinopathy.
Methods: From 2008 to 2013 84 eyes of 58 patients (30 men, 28 women) were treated with pattern laser photocoagulation at the Ophthalmology Department at University Hospital Ostrava. Average age at the baseline visit was 65 years. The inclusion criteria included nonproliferative diabetic retinopathy (84 eyes), focal DME (14 eyes), diffuse exudative DME (70 eyes). All the eyes were „treatment naive“. The average duration of diabetes was 18 years, average baseline HbA1c value was 8,4%. Either focal laser photocoagulation or grid photocoagulation was performed with the PASCAL photocoagulator. Best corrected visual acuity (BCVA), central retinal thickness (CRT), fundus photography, biomicroscopy and complications were evaluated during the minimum 12months follow-up period. Statistical analysis using parametrical and nonparametrical tests with p less han 0,05 was done.
Results: Mean baseline BCVA was 0,43 logMAR. Values 0,38, 0,37, 0,38 a 0,38 logMAR were observed in the follow-up intervals in the 4th, 6th, 12th and 18th month. In 4 eyes (5%) improvement of more than 3 lines was observed, in 26 eyes (31%) improvement from 0 to 3 lines was observed, in 52 eyes (62%) decrease from 0 to 3 lines was observed and in 2 eyes (2%) decrease of more than 3 lines was observed. Mean baseline CRT was 398 µm, values 370 µm, 362 µm, 349 µm and 338 µm were observed in the follow-up intervals in the 4th, 6th, 12th and 18th month. At the 12th month visit 76 eyes (90%) were stabilized, and in 8 eyes (10%) progression of the disease was observed. No complications were observed during the first 12 monhts follow up.
Conclusion: Pattern scanning laser photocoagulation of DME lead to BCVA and clinical stabilization. In addition to this, it lead to decrease of the CRT. The efficacy was comparable to traditional laser systems with no apparent benefit to the traditional systems. The efficacy was inferior to modern intraocular anti-VEGF (vascular endothelial growth factor) drugs.