Frequency of myopia development after congenital cataract extraction in infancy with different keratometric and biometric parameters in pseudophakic eyes

Aim. In most children, unplanned myopia develops after the extraction of congenital cataracts (CC) with t he implantation of intraocular lenses (IOLs) in infancy; thus, it is necessary to analyze the mechanisms of its development.

The study aimed to investigate the role of keratometric and biometric indicators of eyes in pediatric patients with pseudophakia in the formation of myopia.

Material and methods. Analysis of refraction indices, degree of postoperative astigmatism, and length of the anteroposterior axis (APO) was performed in 40 pediatric patients (56 eyes) with bilateral (29 children, 45 eyes) and unilateral (11 children) pseudophakia at the age of 4 to 8 years after CC extraction with IOL implantation in infancy.

Results. Myopia was detected in 67.9% (38 eyes, 28 children) of cases, including 41.1% (23 eyes, 16 children) with moderate (12 eyes) and high (11 eyes) myopia. The study revealed a direct average correlation between the magnitude of astigmatism and the degree of developing myopia. Astigmatism of >3.25 diopters was detected frequently in moderate and high myopia. For eyes with astigmatism of >3.25 diopters, the APO length was 22.6 ± 1.9 mm (21.8–23.5 mm), whereas for those with astigmatism of <3.0 diopters, it was 20.9 ± 1.8 mm (20.3–21.5 mm). With the initial APO length of <20.0 mm, less eye growth was registered in the postoperative period.

Conclusion. In the majority of pediatric patients with pseudophakia, myopic refraction develops after CC extraction in infancy, which is influenced by the degree of astigmatism and the initial values of the APO length. Astigmatism of >3.0 diopters causes irregular peripheral defocus on the retina, which contributes to the overgrowth of the eye with pseudophakia after early CC extraction, leading to axial myopia. In CC eyes, the risk of myopia is lower with an initial APO length of <20.0 mm.