Abstract
Purpose: :
To evaluate patients with diabetic macular edema (DME) treated with combination intravitreal bevacizumab and single grid pattern focal laser using a minimum of 900 sub-threshold spots.
Methods: :
A retrospective chart review of patients undergoing combination bevacizumab and sub-threshold single grid pattern macular laser for DME was performed. Inclusion criteria included all patients with DME treated with single-session focal laser using a minimum of 900 sub-threshold spots in combination with intravitreal bevacizumab within 6 weeks. All patients had good quality pre and post-treatment macular thickness imaging by Ocular Coherence Tomography (OCT) and a minimum of 2 months follow-up. Sixteen (n=16) eyes of fourteen patients met the inclusion criteria. Sub-threshold treatment was defined as laser spots with a mild gray or lighter color. The Pascal laser was used for all grid pattern laser and parameters ranged from 100 to 150 mW power, 10 to 20 ms duration, and 100 micron spot size. Outcome measures were change in visual acuity and change in macular thickness as measured by OCT. Macular thickness maps were divided into 9 retinal sectors and pre and post-treatment thicknesses were compared in all 9 sectors. Pre and post-treatment Snellen visual acuities were converted to numerical decimal values to allow for statistical analysis. Statistical analysis of visual acuity and macular thickness was performed using the Wilcoxon matched-pairs test.
Results: :
Mean pre-treatment visual acuity was 0.30+/-0.08 and mean post-treatment visual acuity was 0.4+/-0.08 with a p-value of 0.064. Statistically significant (p<0.05) reduction in macular thickness was observed in 7 of 9 retinal sectors.
Conclusions: :
In a small cohort of 16 eyes with DME, combination intravitreal bevacizumab and single-session grid pattern macular laser using a minimum of 900 sub-threshold spots demonstrated statistically significant improvement in macular thickness in 7 of 9 retinal sectors. A trend towards improvement in visual acuity was observed although this was not statistically significant (p=0.64). We propose that combination sub-threshold grid pattern laser using a minimum of 900 spots and intravitreal bevacizumab is effective in the treatment of DME.
Keywords: diabetes • retina • laser