Orthokeratology lens for management of myopia in anisometropic children: A contralateral study

Purpose To investigate the effect of overnight orthokeratology (OK) lens wear on axial growth in anisometropic children. Methods The study involved 17 males and 12 females with an average age of 11.4 ± 2.9 years. Cycloplegic spherical equivalent error (SER) was −0.50D to −6.00D, and anisometropia ≥1.00D. The eyes with greater myopia were assigned to the G eye group and the fellow eyes with less myopia to the L eye group. All eyes were fitted with OK lenses. Axial length (AL) was measured at the beginning of the study and at 6-, 12-, 18-, and 24-month follow-up visits. Refractive error was measured at the beginning and at the 24-month visit. Linear mixed model analysis was used to evaluate the effect of time, group, and time*group on axial growth. Paired t test was used to compare the myopia increase over 24 months between the two groups. Results:The mean baseline AL was 25.06 ± 0.61 mm for the G eyes and 24.48 ± 0.61 mm for the L eyes. After 24 months, AL had increased by 0.31 ± 0.23 mm in the G eye group and by 0.41 ± 0.31 mm in the L eye group. Axial growth of the L eyes was significantly greater than that of the G eyes (p = 0.006). The mean baseline myopia of the G eye and the L eye was −3.62 ± 1.27D [−5.75D to −1.75D] and −1.93 ± 1.02D [−4.00D to −0.50D] respectively. At 24 months, the increase in myopia in the G eyes was significantly less than that in the L eyes (−0.84 ± 0.63D vs, −1.21 ± 0.89D, p < 0.001). Conclusions: In anisometropic children who wore OK lenses, axial growth was greater in the eye with less baseline myopia than in the fellow eye with greater baseline myopia after 2 years.