Development of the refraction and axial length of the eye in preterm infants with retinopathy of prematurity after retinal laser coagulation depending on the age

Aim of the study
To estimate dynamics of the state of refraction and axial length of eye (ALE) in preterm infants with retinopathy of prematurity (ROP) after laser coagulation of the retina (LCR) in relation to age.

Material and methods
The material for our study was data of ophthalmological examinations of 84 premature babies at the age of 6 months to 3 years (average age 1.1 years) and from 3 to 8 years (average age 5.4 years) in group of children without ROP; a group with ROP self-regression; and a group with ROP, who underwent LCR. The ophthalmological examination included a standard assessment of the anterior and posterior sections of the eye, strabismus and clinical refraction; eye ultrasound (A and B scans) through eyelids; assessment of visual acuity (from 3 years).

Results
It was found out, that the axial length of eye in premature babies after laser coagulation of the retina does not differ at the age of 6 months – 3 years and 3-8 years (p > 0.05). At the age of 6 months – 3 years, the axial length of the right and left eyes in premature babies after laser coagulation of retina was 19.65 mm and 19.52 mm; at the age of 3-8 years – 22.52 ±1.28 mm and 22.61 ±1.19 mm. A refractive shift in the magnitude of the spherical equivalent towards myopia was established in premature babies after laser coagulation of the retina at the age of 6 months – 3 years and 3-8 years (from –0.5 ±3.72 to –1.91 ±4.87 in the right eye; from +0.07 ±3.54 to –2.3 ±4.9 in the left eye). In children after laser coagulation of retina at the age of 6 months – 3 years in the right eye, hyperopic refraction was recorded in 59.1%, myopic – in 31.8%, in the left eye – in 59.1% and 18.2%, respectively; at the age of 3-8 years in the right eye hyperopic refraction in 50.0%, myopic – in 36.4%, in the left eye – in 50.0% and 40.9%, respectively. A significant difference in the magnitude of myopic refraction among premature children after laser coagulation of the retina and children without ROP/ROP self-regression at the age of 6 months – 3 years and 3-8 years (p < 0.05) was established. Astigmatism < 2 D and ≥ 2 D after laser coagulation of retina at the age of 6 months – 3 years occurred in the right eye in 22.7% and 0.0%, in the left eye – in 22.7% and 4.6%; at the age of 3-8 years in the right eye in 36.4% and 18.2%, in the left eye – in 36.4% and 22.7%, respectively.There was a difference in astigmatism ≥ 2 D in the right and left eyes in premature infants after laser coagulation of the retina and children without ROP/ROP self-regression at the age of 3-8 years (p = 0.016; p = 0.004). For the first time, a more frequent occurrence of anisometropia among children after laser coagulation of the retina was established (22.7% and 18.2%).