Threshold retinopathy of prematurity: ocular changes and sequelae following cryotherapy.

ABSTRACT

PURPOSE: To determine ocular changes and sequelae following cryotherapy for threshold retinopathy of prematurity (ROP). METHODS: This is a retrospective study of 49 eyes of 26 premature babies with threshold ROP treated with cryotherapy between 1995 and 1998. All eyes included in the study had favourable structural outcome after cryotherapy. Follow-up examination of all babies was done 12 - 62 months (average 28 months) after cryotherapy. Visual axis, fixation pattern, anterior segment examination, cycloplegic refraction and dilated fundus examination with indirect ophthalmoscopy were undertaken in all eyes during follow-up. RESULTS: Posterior pole retinal residuae observed following cryotherapy were tortousity of blood vessels in 32 (65.3%), narrow temporal arcade in 22 (44.89%), temporal crescent in 17 (34.69%), disc drag in 13 (26.53%) and macular heterotopia in 7 (14.28%) eyes. Myopia was observed in 20 (40.82%) eyes and strabismus in 5 (19.23%) babies. The significant risk factor for ocular changes was ROP with more clock hours of involvement (p < 0.05). Higher period of gestation was associated with posterior pole changes (p< 0.05). CONCLUSIONS: All premature babies with threshold ROP treated with cryotherapy require frequent and long-term follow up to look for retinal residuae, refractive status, and ocular motility disorders.