Abstract:

Objective To compare the effects of multi-point scanning laser and traditional single-point krypton laser in the treatment of diabetic retinopathy (DR). Design Case-control study. Participants A total of 117patients (220 eyes) with clinically diagnosed DR from January 2013 to June 2015. Methods Patients were randomly divided into two groups including the experimental group (58patients, 112 eyes) and the control group (59 patients,108 eyes).The experimental group received pan-retinal photocoagulation (PRP) with multi-point scanning laser, and the control group received PRP with single-point krypton laser. Fundus fluorescein angiography (FFA) was performed 3 months after laser therapy. On the day after laser treatment, we scored the pain according to the Numerical Rating Scale (NRS), recorded the energy index of laser therapy, and calculated the energy density. Best-corrected visual acuity (BCVA), central macular thickness (CMT), mean deviation of perimetry were measured at 1, 3 and 6 months after laser therapy. Main Outcome Measures BCVA, CMT and mean deviation of perimetry before and after treatment, the pain score on the day of laser therapy, the laser energy and laser energy density. Results The laser time in the experimental group (39.07±5.10 min) was shorter than that in the control group (52.36±7.47 min) (t=5.63, P<0.01). The laser energy density of the experimental group (68.23±12.16 mw*ms/μm2) were lower than those of the control group (157.64±31.63 mw*ms/μm2)(t=7.75，P<0.01). The pain score after laser treatment in the experimental group (1.46±0.633) was significantly lower than that in the control group (2.43± 0.95) (t=6.61, P<0.01). There were 30 eyes (26.78%) with improved visual acuity in the experimental group, compared to 32 eyes (29.62%) in the control group (χ2=1.85, P=0.39). Compare to the pre-treatment measurement, the average BCVA were both improved in the two groups (2.43± 0.95 vs. 2.70±2.62) (t=0.27, P=0.82), but the reduction of MCT was significantly (t=-1.02, P=0.03) smaller in experimental group (27.66±46.87 μm) than in the control group (34.47±51.77 μm). The reduction of average threshold sensitivity was significantly smaller (t=9.55, P<0.01) in experimental group (1.22±0.50 dB) than in control group (2.32±1.10 dB). The vitreous hemorrhage rate of experimental group 2.67% (3/112) was similar to that of control group (1.85% (2/118), χ2=0.17, P=0.68). There were 28 eyes (25%) in the experimental group received supplemental laser therapy compared to 20 eyes (18.51%) in the control group(χ2=1.35, P=0.24). Conclusions Multi-point scanning laser achieves the same therapeutic outcomes as the single-point mode with relatively minor functional damage. (Ophthalmol CHN, 2019, 28: 345-349)

Key words: diabetic retinopathy, laser photocoagulation