Children with retinopathy of prematurity (ROP) who were managed with laser treatments develop more pronounced corneal steepness and higher anterior corneal astigmatism, making them suboptimal candidates for later refractive surgery, according to a study published in Eye.
Children who were born with ROP (n=176; mean age, 6.97 years; 52.8% boys; 26.48 weeks gestation; birth weight, 867.79 g), born premature without ROP (n=178; 7.57 years; 59.7% boys; 38.93 weeks gestation; 3160.79 g), or born at term (n=77) were recruited for this study at the Chang Gung Memorial Hospital in Taiwan between 2019 to 2021. Every 6 months, participants underwent corneal topography evaluation and researchers compared differences between cohorts.
Among the ROP cohort, 131 received laser or and/or anti-vascular endothelial growth factor (VEGF) intravitreal injection (IVI) and 45 were untreated. Most untreated ROP eyes had zone 2, stage 1 or 2 ROP without plus disease and most treated eyes had zone 2, stage 3 ROP with plus disease.
Compared with full-term controls, patients who were born premature had higher cylindrical power (P =.022) and posterior corneal astigmatism (P =.036) and both patients who were born premature and who had untreated ROP had higher mean keratometry (P =.007), steep keratometry (P =.007), steep keratometry of the anterior corneal surface (P =.008), flat keratometry (P =.014), mean keratometry of the anterior corneal surface (P =.016), and anterior corneal astigmatism (P =.036).
Compared with untreated ROP, treatment with laser alone associated with higher mean and steep keratometry of the anterior surface and lower corneal diameter, anterior chamber death, and the ratio of anterior chamber depth to axial length whereas both laser and IVI with lower cylindrical power, anterior chamber death, and the ratio of anterior chamber depth to axial length and higher anterior corneal astigmatism (all P ≤.043).
In the generalized estimating equation, birth weight affected mean (β, -0.711 D; P <.001), flat (β, -0.650 D; P <.001), and steep (β, -0.756 D; P <.001) keratometry of the anterior corneal surface, pachymetry (β, 13.415 μm; P <.001), corneal diameter (β, 0.174 mm; P <.001), and anterior chamber depth (β, 0.061 mm; P <.001); laser treatment for ROP affected mean (β, 0.652 D; P =.041) and steep (β, 0.873 D; P =.018) keratometry of the anterior corneal surface, anterior corneal astigmatism (β, 0.488 D; P =.001), and anterior chamber depth (β, -0.154 mm; P =.001); and age affected anterior chamber depth (β, 0.026 mm; P <.001). No significant effects of ROP or anti-VEGF IVI treatment for ROP were found.
“Premature status led to greater corneal ectasia (steeper anterior corneal curvature and thinner thinnest pachymetry), whereas laser treatment for ROP caused further corneal steepness and higher anterior corneal astigmatism,” explain the researchers. “ROP pathology and IVI anti-VEGF treatment exerted a marginal effect on corneal topography. Ophthalmologists should carefully evaluate the corneal topography before laser refractive surgery in preterm patients, particularly in those treated with laser for ROP.”
The major limitation of this study was that ophthalmic examinations were not performed at uniform ages.
Wu P-Y, Chen H-C, Hsueh Y-J, et al. Corneal topography in preterm children aged 2 years to 12 years with or without retinopathy of prematurity. Eye. Published online January 2, 2023. doi:10.1038/s41433-022-02375-x