Abstract
Purpose::
To compare subthreshold diode laser photocoagulation (SDL) with conventional argon laser photocoagulation (CAL) in the treatment of mild clinically significant diabetic macular edema (CSDME).
Methods::
This interventional case series included 21 patients with bilateral CSDME. One eye received SDL and the other CAL. The choice of treatment for the right and left eye in each patient was given by a randomization table. The main outcome measure was best corrected visual acuity (BCVA). Secondary endpoints were change in central retinal thickness using optical coherence tomography (OCT), vision contrast sensitivity with Pelli Robson charts and white-on-white perimetry (central 10º). The examinations were performed at baseline and 4 and 12 months after laser treatments.
Results::
All patients completed 12 months of follow-up after treatment. Initial mean (SD) best corrected visual acuity (BCVA) was 78.8 (9.5) in SDL eyes and 77.1 (8.9) in CAL eyes. The mean visual acuity decreased at 4 and 12 months to 77.5 (10.4) and 73.7 (15.6), respectively, in SDL eyes and to 73.2 (16.1) and 69.3 (22.1), respectively, in CAL eyes. Vision was better preserved in SDL eyes but the difference was not statistically significant. There were also no significant differences in contrast sensitivity and retinal thickness between the two modalities of laser photocoagulation, either at 0, 4 or 12 months. White-on-white perimetry revealed, however, in the perifovea, that the SDL treatment eyes had a better outcome than the CAL treated eyes (p=0.035). The CAL group showed from baseline to V12 a decrease of (1.0 ± 2.3 dB, while the SDL group showed an increase of 0.7 ± 2.0 dB).
Conclusions::
Subthreshold diode laser photocoagulation compared well with conventional argon laser photocoagulation for the treatment of CSDME showing no significant differences at 12 months for BCVA, retinal thickness and contrast sensitivity but with less functional damage to the central macula as demonstrated by white-on-white perimetry.
Clinical Trial::
AIBILI-CE39
Keywords: edema • laser • macula/fovea