METHODS: This was a prospective clinical study. From January 2017 to March 2018, 35 patients(52 eyes)with severe NPDR diagnosed in our hospital were selected as photocoagulation group(conventional therapy combined with PRP)and 35 patients(52 eyes)with severe NPDR matched with age and gender in the same period were selected as the control group(conventional therapy, use difrarel, ginkgo leaves tablets, mecobalamin and other drugs to protect blood vessels, improve microcirculation and nourish nerves). The best corrected visual acuity(BCVA), RNFL thickness and visual field of the two groups were compared after 1a after treatment.

RESULTS: There was no significant difference in BCVA before and after treatment in the photocoagulation group(P>0.05), but the BCVA of the control group decreased(P<0.05). There was no significant difference in temporal RNFL thickness(74.5±13.7μm vs 70.8±11.3μm, P>0.05)in the photocoagulation group, and the thickness of RNFL in the other quadrants and the mean RNFL were thinner than those before treatment(P<0.05); there was no significant change in the MS of the corresponding field of vision of the temporal nerve fiber(22.5±8.7dB vs 20.8±7.2dB, P>0.05), the other quadrants and the mean MS were lower than those before treatment(P<0.05). Before and after treatment, the change of RNFL thickness of the patients in the photocoagulation group showed weak positive correlation or no correlation with the change of visual field MS corresponding to the RNFL at nasal, nasal superior, temporal superior, temporal, temporal superior, temporal inferior and average RNFL.

CONCLUSION: PRP can effectively control the further development of severe NPDR and maintain the visual acuity of patients, but the damage of PRP to RNFL and visual field cannot be ignored.