Involution patterns of retinopathy of prematurity after treatment with intravitreal bevacizumab: implications for follow-up.

PURPOSE: To describe involution patterns following monotherapy with intravitreal bevacizumab injection (IVB) for type 1 retinopathy of prematurity (ROP) in zone I or zone II posterior.

METHODS: A retrospective chart review of infants treated with IVB from January 2010-April 2014. Infants with minimum of 82 weeks postmenstrual age at last follow-up were included. Primary outcome was timing of involution of type 1 ROP for the first 12 weeks post treatment. Secondary outcomes were development of any recurrence and structural outcome at last follow-up. Retinal examination records, fundus, and flourescein angiography images were reviewed.

RESULTS: Twenty-eight eyes were included. Average follow-up post treatment was 33.9±9.7 months (range 21.4-61.9). Cumulative frequency of regression of plus disease was seen in 73.3, 86.7, and 100% of eyes by days 3, 5, and 8, respectively. Regression of both stage 3 and plus disease was observed in 29, 82, 88, and 100% by weeks 1, 2, 3, and 4, respectively. Within the first 3 months, 17/28 eyes developed recurrence to stage 1 or 2 after regression. None developed recurrence of plus disease. By the end of 3 months 18% of eyes vascularized into zone III. At a mean of 24±17.3 months, 39% of eyes were not vascularized into zone III as seen on flourescein angiography with scleral indentation.

CONCLUSION: Our experience suggests regression of plus disease and stage 3 are expected within the first 4 weeks after bevacizumab treatment. Recurrence may occur despite initial regression and requires careful follow-up.