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

Abstract

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 agematched 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 À 4.49 D. Of the 46 eyes studied, 98% of eyes showed astigmatism Z0.5 D and 50% had high astigmatism (43.0 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 ¼ 0.921, Po0.001) and the vertical corneal curvature (r ¼ 0.405, P ¼ 0.005). There was significantly steeper vertical corneal curvature (P ¼ 0.003) and flatter horizontal corneal curvature (P ¼ 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 (Po0.001). 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.

Refractive errors in premature infants with retinopathy of prematurity after anti-vascular endothelial growth factor (anti-VEGF) therapy

“…Also in both groups, the most common type of astigmatism was with-the-rule (WTR). These results agree with the results of other authors [29][30][31] . Astigmatism has been known to be associated with ROP, but the exact mechanism of this astigmatism in prematurity and ROP is not completely understood.…”

The long‐term outcome of extremely preterm (<28 weeks’ gestational age) infants with and without severe retinopathy of prematurity

“…Severe ROP is likely to affect ocular structures more so than subcortical or cortical structures; however, if ROP affects the initial processing of visual information, which in turn affects the development of the eye, then these changes may ultimately affect the way subcortical and cortical pathways develop such as ocular dominance columns or other visual pathway networks. Unsurprisingly, visual acuity remained significant after controlling for important confounders, given the reported relationship between ROP and refractive errors in this population (Kushner, ; Nissenkorn et al ., ; Quinn et al ., ; Snir et al ., ; Wani et al ., ; Yang et al ., ). Several studies have discussed the possible relationship between preterm birth, ROP, ocular growth, and development, with several mechanisms proposed as contributing factors (Fielder & Moseley, ; Fielder et al ., ).…”

“…Future studies may endeavour to determine the long-term effect of severe ROP following the most recent treatment options as laser surgery has largely replaced cryotherapy which was the treatment of choice at the time this cohort were born. Cryotherapy is reported to be more traumatic with diffuse tissue destruction of choroid and sclera compared with eyes treated with laser therapy (Yang et al, 2013). However, several studies have compared the refractive outcome of threshold ROP after different treatments; the results showed no difference in the prevalence of astigmatism between cryotherapy and laser-treated eyes (Yang et al, 2013).…”

“…Cryotherapy is reported to be more traumatic with diffuse tissue destruction of choroid and sclera compared with eyes treated with laser therapy (Yang et al, 2013). However, several studies have compared the refractive outcome of threshold ROP after different treatments; the results showed no difference in the prevalence of astigmatism between cryotherapy and laser-treated eyes (Yang et al, 2013). Although there has been a move away from high levels of ambient illumination in the NICU and a shift towards lighting cycling regimens (Fielder & Moseley, 2000), the NICU environment deserves closer scrutiny and long-term follow-up is warranted.…”

“…Despite improvements in care, long-term follow-up of children with regressed ROP has shown that there is an increased incidence of strabismus, amblyopia and refractive errors, in particular myopia, compared with preterm infants without ROP and with fullterm infants (Kushner, 1982;Nissenkorn, Yassur, Mashkowski, Sherf, & Ben-Sira, 1983;Quinn et al, 1998;Snir, Nissenkorn, Sherf, Cohen, & Ben Sira, 1988;Wani et al, 2013;Yang, Wang, Shih, & Hsu, 2013). For example, Nissenkorn et al (1983) found that 50% of preterm children between 2 and 8 years of age who had any stage of ROP were myopic, compared with 16% of preterm children without ROP.…”