AIM: To investigate the timing of using anti-VEGF drugs in severe non-proliferative diabetic retinopathy(SNPDR)patients with diabetic macular edema(DME)treated with intravitreal injection of Conbercept(IVC)combined with panretinal photocoagulation(PRP).

METHODS: Totally 85 SNPDR patients(85 eyes)with DME diagnosed in our hospital from May 2017 to October 2018 were randomly divided into control group(n=29 cases), IVC group(n=28 cases), PRP group(n=28 cases). The control group was treated with PRP only; the IVC group was given PRP 1wk after IVC; the PRP group was given IVC 1wk after PRP. The follow-up time was 12mo. Changes of the best corrected visual acuity(BCVA)and central macular thickness(CMT)were observed before and 1, 3, 6, 12mo after treatment, and the frequency of IVC were recorded.

RESULTS: Compared with before treatment, the BCVA of the three groups after treatment improved, and the CMT decreased(P<0.05). after treatment, the BCVA of the IVC group and the PRP group was better than the control group, and the CMT was lower than the control group(P<0.05). 3mo after treatment, BCVA(0.24±0.18, LogMAR)in the ICV group decreased more than that in the PRP group(0.38±0.29, LogMAR)(P<0.05). At 1 and 3mo after treatment, CMT in the ICV group(1mo 313.89±61.69um, 3mo 287.64±43.94μm)decreased more than that in the PRP group(1mo 347.50±56.55μm, 3mo 318.04±49.334μm), and the difference was significant difference(P<0.05). The frequency of IVC was(3.07±1.33)times in the IVC group and(3.93±1.60)times in the PRP group(P<0.05).

CONCLUSION: In SNPDR patients with DME, IVC combined with PRP is better than PRP alone. Anti-VEGF drugs before PRP can obtain better BCVA, reduce macular edema in the short-term observation. In long-term observation, it can also reduce the frequency of IVC, the risk of infection and the financial burden.