Abstract
Purpose:
To evaluate and compare retinal and choroidal morphologic changes, and macular function in center involving diabetic macular edema(C-DME) treated with diode(IR-MPL) and yellow(Y-MPL) subtreshold micropulse laser.
Methods:
Images of 60 eyes(43 diabetics) were evaluated.Inclusion criteria were:previously untreated C-DME, central retinal thickness(CRT) between 300-400µ;color fundus photos, spectral domain optical coherence tomography(SD-OCT),fundus autofluorescence(FAF),fluorescein angiography(FA) and microperimetry(MP1) available before and after treatment;the same treatment parameters:5% duty cycle, spot size(125µ for IR-MPL and 100µ for Y-MPL), power (750mWatt for IR-MPL and 250mWatt for Y-MPL).Two masked retinal specialists independently graded all images before and after IR-MPL or Y-MPL treatment.Grading consisted in evaluation of:retinal thickness and volume, integrity and reflectivity of inner and outer retinal layers and choroidal microstructure on SD-OCT;presence of hyper/hypo autofluorescence on FAF; leakage and laser scars on FA;mean central retinal sensitivity(RS), presence of absolute scotomas, site and stability of fixation on MP1.
Results:
31 eyes treated with IR-MPL and 29 eyes with Y-MPL were evaluated. At baseline mean CRT was 313.68µ+/-4.83µ in the IR-MPL and 323.14µ+/-6.76µ in the Y-MPL group. Six months after treatment CRT was 280.75µ+/-4.43µ in the IR-MPL and 291.74µ+/-6.65µ in the Y-MPL group,(p=0.2).Mean macular volume was not different between the groups:11.28+/-0.18mm3 in the IR-MPL and 11.62+/-0.24mm3 in the Y-MPL group at baseline and 11.10+/-0.16mm3 in the IR-MPL and 11.23+/-0.23mm3 in the Y-MPL at 6 months after treatment.There were no signs of inner or outer retinal and choroidal damage after both treatments on SD-OCT line scans. FAF did not show any changes in both treatment groups. On MP1, mean 4° RS was not different between the two groups:15.4+/-0.6dB in the IR and 14.7+/-0.5dB in the Y-MPL at baseline, and 14.2+/-0.8dB in the IR and 13.2+/-0.7dB in the Y-MPL after treatment. There were no absolute scotoma after treatment. Fixation was always central and stable in all patients.
Conclusions:
No clinically detectable retinal o choroidal signs in the macula were detected after IR-MPL or Y-MPL treatment.Both IR-MPL and Y-MPL with the less aggressive duty cycle(5%) and fixed power parameters appear to be safe in C-DME.
Keywords: 498 diabetes •
505 edema •
578 laser