Long-term visual outcomes of laser-treated threshold retinopathy of prematurity: a study of refractive status at 7 years

Abstract

Purpose: To assess the long-term visual outcomes and refractive status in patients with diode laser-treated threshold retinopathy of prematurity (ROP), and to investigate the causes of impaired visual function.

Method: A total of 60 eyes of 30 consecutive patients with diode laser-treated threshold ROP were recalled for assessment at the age of 7 years or more.

Results: There were 38 eyes (65.5%) achieving 6/12 or better vision, however, an unfavourable visual outcome (6/60 or worse) occurred in four eyes (6.9%). One eye (1.7%) had unfavourable structural outcome. Of these 60 laser-treated eyes, 46 eyes (77.0%) were myopic, the overall mean spherical equivalent was -3.87 D. Anisometropia (>or=1.5 D) was also noted in 14 patients (46.7%). Strabismus was present in nine patients (30.0%). Perinatal neurological events of intraventricular haemorrhage (IVH) were identified in eight children (26.7%), periventricular leucomalacia (PVL) in eight children (26.7%), and cerebral palsy (CP) in four children (13.3%). There was a statistically significant association of the presence of strabismus with PVL (P=0.002). The presence of anisometropia was a significant risk factor associated with poor visual outcome of 6/15 or worse in laser-treated ROP (P=0.002).

Conclusion: The majority of patients with diode laser-treated threshold ROP had favourable anatomical and visual outcomes. However, anisometropia, advanced refractive error, strabismus, and perinatal neurological events remain important causes of impaired visual function. Long-term follow-up is very important for early detection and timely treatment of these ocular morbidities.