AIM: To evaluate the efficacy and safety of panretinal photocoagulation(PRP)and sub-panretinal photocoagulation(sub-PRP)for pre-proliferative diabetic retinopathy(PPDR)and its effect for macular.

METHODS: From January to December 2014, 61 patients with PPDR were divided into observation group(24 patients with 43 eyes who received sub-PRP)and control group(37 patients with 66 eyes who received PRP). Their clinical data and follow-up results were reviewed.

RESULTS: The efficiency rate of visual acuity and of retinopathy were 77% and 81% in observation group at 6mo after treatments. The two indicators in control group were 76% and 80% and the difference on the two indicators between the two groups were not statistically significant(P>0.05).The central macular thickness and volume of macula reached peak in both group at 1mo after photocoagulation and compared to those before treatments, the differences were statistically significant(P<0.05). The central macular thickness and volume of macula in observation group was significantly lower than those of control group(P<0.05). At 3mo after treatments, the central macular thickness and volume of macula in sub-panretinal photocoagulation group had returned to the level before treatments(P>0.05), while those of panretinal photocoagulation group were higher than those before treatments and those of observation group(P<0.05). At 6mo after photocoagulation, the central macular thickness and volume of macula were lower in both groups compared to those before treatments(P<0.05).

CONCLUSION: The effect of sub-PRP on PPDR is comparable to that of PRP, while the effect on the macula is smaller.