Purpose:

To assess effect of micropulse diode laser (MPDL) on best corrected visual acuity (BCVA) and central foveal thickness (CFT) in treatment of clinically significant diabetic macular oedema (CSME) as compared to conventional argon green laser (CGL) treatment.

Design:

Single-center, prospective, interventional, comparative study.

Methods:

Twenty four patients (40 eyes) with diabetic CSME were randomly assigned to MPDL (n=20) or CGL (n=40) photocoagulation in CSME less than 400 microns. All eyes had either focal photocoagulation for localized areas of leakage or a grid pattern applied to areas of diffuse macular edema. Treatments were performed after baseline evaluation and follow up is done at 3, 6 and 12 months and re-treatments were allowed at the 3 months visit if necessary. Parameters noted included contrast sensitivity at 5 spatial frequencies and number of cases having macular scars in color fundus photo.

Advantages:

No statistical significant differences in the mean visual acuity value were found at baseline, 3 and 6 months between the CGL and MPDL groups (p= 0.07, 0.45 and 0.46 respectively). There was statistically significant improvement in BCVA over the 2 follow up visits in CGL group and MPDL group (p=0.002 and 0.003 respectively). No statistical significant differences in the mean central macular thickness value were found at baseline, 3 and 6 and 12 months between the CGL and MPDL groups (p= 0.13 and 0.09 respectively). We found that both treatment groups had stability in mean central subfield thickness along 12 month follow up. In MPDL group there was statistical significant improvement in contrast sensitivity at spatial frequencies 6 and 12 (p=0.009 and 0.008 respectively) over the 12 months follow up. Laser scars were identified at color fundus photo in 40% of CGL-treated eyes and not at any of the MPDL-treated. This difference was statistically significant (p=0.04).

Take home message:

Micropulse diode laser photocoagulation is equally effective as CGL treatment for CSME regarding BCVA and central foveal thickness. It is better than convential laser photocoagulation in preserving contrast sensitivity.

Contact Details:

Email: ihabsaad@hotmail.com
Cell Phone: +201001768768

Ihab Saad Othman