Abstract
Purpose::
To examine the early changes of retinal sensitivity using fundus-related microperimetry after subthreshold micropulse diode laser photocoagulation (SMDLP) for diabetic macular edema (DME).
Methods::
Nineteen eyes of 17 patients with diffuse DME were treated with SMDLP (cycle 15%, power 380-800 mW, duration 0.2 s, spot size 200 µm). Retinal sensitivity was measured with a fundus-related microperimeter, MP1. The mean retinal sensitivity within the central 2° and 10°, best corrected visual acuity (BCVA) in logMAR units, and optical coherence tomography (OCT)-determined foveal thickness (FT) were determined before and at 3 months after treatment.
Results::
The BCVA improved by >0.2 logMAR units in 5 eyes and remained the same in 14 eyes at 3 months after SMDLP. The FT was reduced by >20% of the pre-treatment FT in 8 eyes and remained the same in the other 11 eyes. The mean retinal sensitivity in the central 2 degrees was improved by >2dB in 9 eyes, remained same in 5 eyes, and worsened in 5 eyes. The mean retinal sensitivity in the central 10 degrees was improved in 6 eyes, remained the same in 7 eyes, and worsened in 6 eyes. In 3 eyes with increased number of hard exudates and 1 eye with exacerbated serous retinal detachment, the retinal sensitivity in the corresponding areas was decreased.
Conclusions::
After SMDLP for diffuse DME, all treated eyes maintained BCVA, however, microperimetry showed a reduction of the mean retinal sensitivity in many of the cases. Microperimetry showed a decrease in sensitivity in focal areas where retinal pathologies developed. From these findings, we conclude that fundus-related microperimetry is a useful tool to evaluate the therapeutic efficacy of SMDLP for diabetic macular edema.
Keywords: edema • diabetic retinopathy • diabetes