Ocular auto-stimulation and its morbidity in stage 5 retinopathy of prematurity

PURPOSE: To evaluate the characteristics and morbidity due to ocular auto-stimulation (OAS) in stage 5 Retinopathy of Prematurity (ROP). METHODS: Stage 5 ROP cases presenting to ROP clinic of a tertiary care centre from January 2017 to December 2017 were recruited. Eye-pressing was elicited on history from parents and categorized as infrequent (performed <50% of waking time) or frequent (≥50% of time). B-scan ultrasonography was performed for configuration of retinal detachment (open or closed funnel). Keratometry was performed in eyes undergoing vitrectomy under general anaesthesia using automated hand-held keratometer. The outcome measures were the presence and characteristics of OAS, enophthalmos, corneal opacity and keratometry values. RESULTS: Out of 93 eyes of 49 babies, 78.5% (n = 73) had OAS. Gestational age, birth weight, sex, retinal funnel configuration, and visual function did not significantly affect OAS. However, post-conceptional age was significantly greater in eyes with OAS (95% CI: 63.1 to 69.9 weeks) than those without OAS (95% CI: 52.4 to 63.4 weeks) (P = 0.018). OAS occurred frequently in 32.8% (n = 24/73) eyes, more commonly in eyes with light followability. Keratometry did not differ significantly with the presence of OAS (P = 0.88). Enophthalmos, corneal opacity, posterior synechiae were noted in 79.5% (58/73), 21.9% (16/73), and 28.8% (21/73) eyes with OAS, respectively. Enophthalmos occurred significantly in eyes with OAS (P = 0.001), while corneal opacity and posterior synechiae did not (P = 0.071 and 0.91, respectively). CONCLUSION: OAS and its resultant morbidity are common occurrences in stage 5 ROP. The post-conceptional age and residual visual function may govern the characteristics of OAS.