A retrospective study included reviewing of medical records of preterm babies who were admitted in neonatal intensive care unit (NICU) of Mansoura University children hospital (MUCH) or referred from nearby hospitals for ROP screening during the period from March 2013 to February 2020.

Retinopathy of prematurity was diagnosed and classified according to the International Classification of ROP. Data of the patients who received IVR for type 1 ROP or aggressive posterior ROP (AP-ROP) according to early treatment ROP study (ETROP) were collected. Intravitreal ranibizumab injection was performed as follows; topical anesthetic drop was applied, standard aseptic eye preparation with 5% betadine was performed, a lid speculum was inserted and intravitreal injection of 0.25 mg/0.025 ml ranibizumab with a 30-gauge needle 1.5mm from limbus was given. In case of bilateral ROP, both eyes are injected in the same session. Infants were examined a day after the procedure and weekly thereafter until full vascularization of the retina was observed.

ROP reactivation was defined as any of the following: recurrent plus disease, recurrent neovascularization, or reformation of ridge despite treatment . Once recurrence was determined, second injection of IVR (0.25mg/0.025mL) was given to patients or surgery was performed if progressed to stage 4 or 5. All treated infants were examined until complete regression of ROP and full retinal vascularization.

Inclusion Criteria:

• patients received IVR for type 1 ROP or aggressive posterior ROP (AP-ROP) according to early treatment ROP study (ETROP) and developed recurrence of ROP

Exclusion Criteria:

-

ROP reactivation was defined as any of the following: recurrent plus disease, recurrent neovascularization, or reformation of ridge despite treatment