The alterations in ocular biometric parameters following short-term discontinuation of long-term orthokeratology and prior to subsequent lens fitting: a preliminary study

Abstract

Purpose: To investigate the alterations in biometric parameters among Chinese adolescents over an extended period of wearing orthokeratology lenses, as well as the subsequent changes after a one-month cessation of lens usage prior to the secondary lens fitting.

Methods: Twenty-four myopic patients aged 7-14 were enrolled in this 37-month prospective observational study. Ocular biometric parameters were measured in the study. Ocular biometric parameters were assessed, and the utilization of Generalized Estimating Equations (GEE) was employed in the analysis to address the correlation between the two eyes of each participant.

Results: The axial length (AL) increased by 0.55 mm after 36 months of lens wearing and further increased to 0.62 mm at the 37-month follow-up compared to the initial measurement. The differences in AL elongation per month between the 37-month time point and the 12-, 24-, and 36-month marks of lens wearing were found to be statistically significant (p_12-month = 0.001; p_24-month = 0.003; p_36-month = 0.001). Following the cessation of lens wear for 1 month, there was no significant complete recovery observed in the flat and steep keratometry values. However, the intraocular pressure and anterior chamber depth returned to their baseline levels.

Conclusions: The AL elongation undergoes alterations during temporary discontinuation of lenses, with the flat and steep keratometry measurements remaining significantly flatter compared to the baseline. However, the intraocular pressure and anterior chamber depth return to their initial levels after one month of lens cessation.

Keywords: Ocular biometry; adolescents; anterior chamber depth; axial length; keratometry; orthokeratology.

Figure 1.

The corneal keratometry (a). Flat keretyometry; (b). Steep keratometry; (c). Corneal astigmatism) in both eyes of participants in the follow-up time, including the 37-month time point following 1 month of lens cessation.

Figure 2.

The change in axial length and the axial length elongation per month in both eyes of participants in the follow-up time, including the 37-month time point following 1 month of lens cessation. Bars represent the mean value; error bars represent the standard deviations (SD) of the mean.

Figure 3.

Ocular axial length elongation per month in each year compared with the previous year during the 37-month follow-up period. Bars represent the mean value; error bars represent the standard deviations (SD) of the mean.

Figure 4.

Intraocular pressure and anterior chamber depth in both eyes of the participants during the 37-month follow-up period. Bars represent the mean value; error bars represent the standard deviations (SD) of the mean.