Comparation of Bevacizumab Intravitreal Injection Effects with and without Yellow Subthreshold Micropulse Laser (577-nm) Combination on Central Macular Thickness and Best Corrected Visual Acuity of Mild-Moderate Diabetic Macular Edema Patients

Abstract

Introduction & Objectives
The management of macular edema is constantly evaluated, with anti-VEGF therapy being the first
line. Subthreshold micropulse laser (SML) has been proposed as alternative adjuvant. Previous
retrospective studies demonstrated the effectiveness of 577-nm SML as monotherapy in macular
edema with CMT below 400 ?m. However, prospective data on the effectiveness of SML as adjuvant
is lacking. The aim is to assess the effect of the combination of bevacizumab and 577-nm SML laser
compared to bevacizumab monotherapy on central macular thickness and visual acuity in mildmoderate
diabetic macular edema patients.

Methods
A prospective randomized clinical trial was performed on diabetic macular edema patients with
macular thickness range of 300-600 ?m. Subjects are divided into two groups. The control group
received a standard protocol and the study group received a yellow SML laser adjuvant one week
after injection. Patients underwent follow-up assessment of visual acuity and central macular
thickness at 28 and 35 days post-injection.

Results
26 subjects were equally divided into study and control groups. Significant decrease in CMT were
found in study group (p=0.011 and 0.014) and the control group (p=0.006 and p=0.001). However,
there was no significant difference in ?CMT values between the two groups in the 28-day (p=0.317)
and 35-day controls (p=0.84). There was no difference in ?BCVA ETDRS between the study and
control groups at 28 days (p=0.568) and 35 days (p=0.128) after injection.

Conclusion
The combination of SML and intravitreal bevacizumab can reduce central macular thickness and
improve visual acuity but there was no significant difference with standard monotherapy.