Study protocol for prognosis and treatment strategy of peripheral persistent avascular retina after intravitreal anti-VEGF therapy in retinopathy of prematurity

BACKGROUND: Prophylactic peripheral photocoagulation has been proposed to be applied to persistent, peripheral, avascular retina for retinopathy of prematurity (ROP) patients who have received an intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) agents. However, there are doubts regarding the necessity of this prophylactic action regardless of fundus fluorescein angiography (FFA) results. The adverse prognosis for persistent avascular retina after anti-VEGF therapy in ROP patients is not well understood. The relationship between vascular leakage and an adverse prognosis is also unknown. Therefore, it would be of value to study the above issues to shape the treatment strategy of persistent avascular retina after intravitreal anti-VEGF therapy in ROP patients. METHODS/DESIGN: This is a prospective study of ROP patients with persistent avascular retina who have received anti-VEGF intravitreal therapy and have never received laser therapy. All the eyes being studied will be followed up and examined by FFA after anti-VEGF treatment and categorized into two groups, a leakage group and a non-leakage group according to the extent of vascular leakage from FFA results. The eyes being studied in the leakage group will be further randomized into two groups, a laser group and a non-laser group. A cohort study (observational) will be conducted on the non-leakage group and the non-laser group (with leakage) to investigate the incidence of an adverse prognosis for reactivation, retinal tear and retinal detachment; as well as to investigate the relationship between vascular leakage from FFA results and the abovementioned pathological changes. A randomized controlled study (experimental) will be conducted on the leakage group to compare the prognosis between the laser group and the non-laser group. DISCUSSION: The present study aims to investigate the occurrence rates of an adverse prognosis including reactivation, retinal tear and retinal detachment after anti-VEGF therapy in ROP patients with persistent avascular retina; to assess the relationship between vascular leakage from FFA results and the abovementioned pathological changes; to compare the prognosis of persistent avascular retina with or without prophylactic peripheral photocoagulation in these patients; to shape the treatment strategy and provide evidence for the indications of prophylactic photocoagulation. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR), ID: ChiCTR-ROC-17013253. Registered on 5 November 2017. http://www.chictr.org.cn/showproj.aspx?proj=22703