Refractive Status in Children with Laser-Treated Retinopathy of Prematurity: Our Experience in Bulgaria

With the establishment of laser photocoagulation as a standard treatment modality for prethreshold retinopathy of prematurity (ROP), a dramatic reduction of cases with ROP blindness and severe visual impairment have been reported. In the same time, high refractive errors, a common complication in ROP cases and especially in ROP treated infants, have become the main cause of visual and often severe visual impairment.

The purpose of our study was to analyse the long-term refractive status in children at 3.5 years after laser-treatment for type 1 prethreshold ROP.

A retrospective, one centre study of refractive status of 18 children with laser-treated type 1 prethreshold ROP was conducted. The refraction after cycloplegia with 1% cyclopentolate was measured at a mean age of 3.56 years (SD ± 0.34). Hyperopia was subdivided into two groups - low hyperopia (SE < +5.0 D) and high hyperopia (SE ≥ +5.0 D). Myopia was classified as myopia (SE ≥ -0.25D) and high myopia (SE ≥ -5.0 D). Astigmatism was divided into low astigmatism (plus CD ≥ +1.0 D) and high astigmatism (plus CD ≥ +2.0 D).

Thirty-three eyes of 18 children were recruited in the study. Three eyes were excluded because of unfavourable anatomical results. The mean gestational age at birth was 27.3 weeks (24-31 weeks, SD ± 1.78), and the mean birth weight - 928.9 g (550-1500 g, SD ± 252.8). The mean spherical equivalent for the whole group was -1.82 D and ranged from -9.00 D to +4.50 D (SD ± 3.48). Hyperopia was observed in 12 (36.4%) eyes. Myopic refraction had 21 (63.6%) eyes. Astigmatism was detected in 18 (54.5%) eyes. Anisometropia had 3 (16.7%) children. Six children (33.4%) had strabismus (4 esotropia; 2 exotropia).

High per cent of treated infants for vision-threatening ROP have visual significant refractive errors and strabismus that can cause serious visual impairment if not treated properly and on time.