Structural and functional results of indirect diode laser treatment for retinopathy of prematurity from 1999 to 2003 in Kuwait

Abstract

Purpose: The purpose was to report the structural, visual, and refractive outcomes of infants treated for retinopathy of prematurity (ROP) with laser and to identify the risk factors for unfavorable outcomes.

Materials and methods: The charts of infants with severe ROP treated by diode laser in a tertiary center during the period April 1999 to November 2003 were reviewed. Treated infants were followed up for fundus examination, visual acuity assessment, and cycloplegic refraction. Data regarding ocular risk factors, like zones of ROP and the extent of extraretinal proliferations, and data regarding various systemic risk factors were collected. A minimum follow up of 6 months was needed for inclusion in the study of structural outcome. A minimum follow up of 24 months was needed for the study of visual and refractive outcomes. The outcomes measured were: rate of unfavorable structural outcome, unfavorable visual outcome (visual acuity < 20/40), and high myopia (myopia ≥ 5 diopters). The ocular and systemic risk factors were studied for their significance in the development of unfavorable outcomes.

Results: Two hundred seventy eyes of 148 infants were treated for severe ROP, out of which 20 eyes (7.4%) had unfavorable structural outcome. Visual data were available for 149 eyes of 81 infants, of which 70 eyes (47%) had unfavorable visual outcome. Refractive data were available for 131 eyes of 72 infants, and high myopia was present in 23 (17.6%) eyes. Zone I disease was the significant risk factor for unfavorable structural (P < 0.0001), unfavorable visual outcome (P = 0.03), and for high myopia (P < 0.0001). Lower post-conceptional age at treatment was significant for unfavorable structural outcome (P = 0.03) and high myopia (P < 0.0001). Presence of sepsis (P = 0.029) and extraretinal proliferation ≥ 6 hours were significant for unfavorable structural outcome (P = 0.002).

Conclusion: ROP in zone I was the most significant risk factor for all the unfavorable outcomes. Laser-treated ROP infants need long term follow up.

Keywords: refractive outcome; risk factors for unfavorable outcomes; structural outcome; unfavorable outcome; visual outcome.