AIM: To observe the efficacy of different dosage regimens of ranibizumab in the treatment of choroid neovascularization secondary to pathological myopia(PM-CNV), and to explore the related factors affecting retreatment.

METHODS: The medical records of 42 patients(43 eyes)diagnosed with PM-CNV in our hospital from January 2015 to January 2020 and treated with intravitreal injection of ranibizumab were retrospectively analyzed. According to different dosage regimens, they were divided into group A(3+PRN, 22 cases with 22 eyes)and group B(1+PRN, 20 cases with 21 eyes). Followed up for 12mo, the changes of best corrected visual acuity(BCVA), central macular thickness(CMT)and choroidal neovascularization(CNV)were observed and compared between the two groups. The times of intravitreal injection, retreatment rate and recurrence rate after initial treatment were compared between the two groups, and the related factors affecting retreatment were analyzed.

RESULTS: At 1,3,6 and 12mo, the BCVA(LogMAR), CMT and CNV thickness in the two groups were significantly improved compared with those before treatment(P<0.05). During the 12mo follow-up, the times of intravitreal injection in group A and group B were 3(3, 4)and 2(1, 3), respectively(P<0.001), and the times of reinjection after the initial treatment were 0(0, 1)and 1(0, 2), respectively(P=0.061). There was no difference in retreatment rate(32% vs 57%)and recurrence rate(14% vs 29%)between the two groups(P=0.095, 0.281). In addition, 1+PRN treatment regimen, female, baseline CMT>300μm and baseline CNV area >1.0mm² were all related factors affecting retreatment.

CONCLUSION: Intravitreal injection of ranibizumab 1+PRN and 3+PRN can both effectively improve the visual prognosis and anatomical structure of PM-CNV patients, but the 1+PRN treatment has less injection times than the 3+PRN treatment, which reduces the risk and cost of treatment.