Abstract
Purpose: To assess the long term visual outcomes and refractive status of patients who underwent diode laser for threshold retinopathy of prematurity (ROP) and to investigate the risk factors leading to poor visual outcomes.
Methods: Fifty-seven patients (114 eyes) with threshold ROP who underwent laser therapy were contacted for reassessment. A chart review was performed for all patients to collect data on visual acuity, retinal status and strabismus. A favorable visual outcome was defined as >= 20/160 (Snellen acuity) for young adults (cooperative patients), and >= CSM for children (uncooperative patients) while unfavorable visual outcome was defined as <20/160 or <CSM. Vision in uncooperative children was graded as central, steady, maintain. Descriptive and inferential analyses were conducted. Chi(2) and odds ratios were calculated whenever appropriate. A P value <0.05 was considered as statistically significant.
Results: The mean age at reassessment was 5.2 +/- 2.5 years (range, 1-10 years) where 36 (63.2%) patients were males and 21 (36.8%) were females. Out Of the 114 laser treated eyes, 73 (64%) were myopic, with mean spherical equivalent (SE) of -6.69 (5.9), range (-0.25 to - 21) diaopters, 8 (7%) were emmetrope, while other 33 (29%) were hyperopic with mean SE of +2.43 (3.04), range (+0.25 to +17) diaopters. Strabismus was present in 31 patients (54.4%) of whom 81% (25/31) were esotropic. Retina was found to be normal in 77.1% of the examined eyes, while the remaining eyes had either macular dragging or retinal detachment. Almost 70% of the eyes with a normal retinal examination had favorable visual outcome. Thirteen (11.4%) eyes had zone 1 retinopathy, 83 (72.8%) eyes had zone 2 retinopathy and 2 (1.8%) eyes had zone 3 retinopathy. Vitreous hemorrhage was present in 7 (6.1%) eyes prior to laser treatment. The relationship between final retinal status and visual outcome was statistically significant (P < 0.0001). There was no statistically significant correlation between visual outcome and the zone of the retinopathy (P = 0.448).
Conclusion: The majority of patients who underwent diode laser therapy for threshold ROP had favorable anatomical and visual outcomes. However, high refractive error and strabismus may be clinically the pertinent causes of visual impairment.