Astigmatism and biometric optic components of diode laser-treated threshold retinopathy of prematurity at 9 years of age

• Published in: Eye (London) Vol. 27; no. 3; pp. 374 - 381
• Main Authors: Yang, C-S, Wang, A-G, Shih, Y-F, Hsu, W-M
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.03.2013; Nature Publishing Group
• Subjects: 692/699; 692/700/1720; 692/700/565; Astigmatism - epidemiology; Astigmatism - physiopathology; Biometry; Child; Clinical Study; Cornea - pathology; Cross-Sectional Studies; Female; Gestational Age; Humans; Infant, Newborn; Laboratory Medicine; Laser Coagulation; Lasers, Semiconductor - therapeutic use; Male; Medicine; Medicine & Public Health; Microscopy, Acoustic; Myopia - epidemiology; Myopia - physiopathology; Ophthalmology; Pharmaceutical Sciences/Technology; Premature Birth; Prevalence; Prospective Studies; Refraction, Ocular - physiology; Retinopathy of Prematurity - surgery; Surgery; Surgical Oncology; Taiwan - epidemiology; Visual Acuity - physiology; Taiwan; biometry; astigmatism; diode laser; optic components; retinopathy of prematurity
• ISSN: 0950-222X; 1476-5454
• DOI: 10.1038/eye.2012.263

Purpose To assess the prevalence of astigmatism and its relationship with biometric optic components in preterm school children with diode laser-treated threshold retinopathy of prematurity (ROP). Methods A prospective, cross-sectional study in which cycloplegic keratometry, refraction, and ultrasound biometric measurement of optic components were performed on 24 consecutive preterm children with diode laser-treated threshold ROP at the age of 9 years. The study results were compared with data on 1021 age-matched full-term control children from a national survey. Results The laser-treated eyes had a mean astigmatism of 3.47 D, with a mean spherical equivalent of −4.49 D. Of the 46 eyes studied, 98% of eyes showed astigmatism ≥0.5 D and 50% had high astigmatism (>3.0 D). Most astigmatic eyes (97.7%) showed with-the-rule astigmatism, with the mean plus cylinder axis at 89.30 o . Further correlation analysis showed the astigmatism in refraction was highly correlated with the corneal astigmatism ( r =0.921, P <0.001) and the vertical corneal curvature ( r =0.405, P =0.005). There was significantly steeper vertical corneal curvature ( P =0.003) and flatter horizontal corneal curvature ( P =0.031) in eyes with laser-treated ROP when compared with age-matched full-term controls. The eyes with laser-treated ROP also show significantly thicker lens (3.93 mm) and shallower anterior chamber depth (ACD; 2.92 mm) than full-term controls ( P <0.001). Conclusions There is significantly higher prevalence and greater magnitude of astigmatism in eyes with laser-treated threshold ROP compared with full-term controls. The steeper vertical corneal curvature component contributes to the increased astigmatism in eyes with laser-treated ROP.