Relationship of Retinal Zone and Plus Severity with the Requirement of Re-Treatment in Bevacizumab-Treated Eyes for Retinopathy of Prematurity.

Abstract

Introduction: The aim of this study was to investigate the relationship between the location of retinal vascularization and plus severity with re-treatment rates in intravitreal bevacizumab (IVB)-treated eyes.

Methods: For this retrospective, observational study, 200 eyes treated with IVB for type 1 retinopathy of prematurity (ROP) and aggressive-ROP were included. The pretreatment retinal vascularization was evaluated by analyzing quantitative measurements of optic disc-to-fovea distance (DFD), disc diameter, and shortest and longest distance between the optic disc and ridge of wide-field fundus photographs (WFPs). Plus severity was qualified in five grades such as normal, pre-plus, mild plus, moderate plus, and severe plus by evaluating WFPs. Re-treatments up to 60 weeks of postmenstrual age (PMA) were evaluated. Re-treated eyes up to first month after initial treatment were labeled as early re-treatment group and re-treated eyes after the first month of initial treatment up to 60 weeks of PMA were labeled as middle-term re-treated group.

Results: Thirty-six percentage of eyes had zone I, 64% of eyes had zone II disease, and 42% eyes had mild plus disease. Forty-three (21.5%) eyes of 23 infants underwent re-treatment prior to 60 weeks of PMA. Thirteen eyes and 30 eyes were in the early- and middle-term re-treated groups, respectively. In middle-term re-treated group, 27 (13.5%) eyes re-treated for progressive reactivated disease, and 3 (1.5%) eyes re-treated for prophylactic purposes. Advanced pretreatment retinal vascularization and high birth weight were negatively associated with the re-treatment rate (p = 0.016, odds ratio = 0.774; p = 0.041, odds ratio = 0.999, respectively). There was a positive association between the re-treatment rate and pretreatment plus severity (p = 0.044, odds ratio = 1.449). The lower ratio of shortest distance between the optic disc and ridge to DFD was considered as an independent predictive variable for higher rate of re-treatment (p = 0.002; odds ratio: 0.450).

Conclusion: The location of retinal vascularization and plus disease showed a wide distribution in bevacizumab-treated eyes. Graded evaluation of retinal vascularization and plus severity may help predict the need for additional treatment. Unresponsiveness to the initial treatment, increased fibrotic activity, progressive reactivated stage 2-3 ROP, extraretinal new vessels, and prophylactic purposes were the main re-treatment indications.