Influence of induced decentered orthokeratology lens on ocular higher-order wavefront aberrations and contrast sensitivity function

Purpose

To quantitatively evaluate the effect of overnight orthokeratology lenses intentionally left decentered after 3 months of wear and assess the influence on clinical outcomes such as ocular higher-order wavefront aberrations and contrast sensitivity function.

Setting

Department of Ophthalmology, Tsukuba University Hospital, Ibaraki, Japan.

Methods

This prospective study assessed refraction, visual acuity, corneal topography, wavefront aberration, and contrast sensitivity function before and 3 months after overnight orthokeratology treatment. Decentration of the treatment zone from the center of the entrance pupil was determined using computerized videokeratography (TMS-4) and data-analysis software (MatLab). The relationship between decentration and the clinical parameters was analyzed.

Results

The mean age of the 23 patients (46 eyes) was 24.2 years±3.3 (SD) and the mean spherical equivalent refraction before treatment, −2.38±0.98 diopters. The mean magnitude of decentration (0.85±0.51 mm) was statistically significantly correlated with the amount of myopic correction (P<.05), increases in coma-like aberration (P<.01), increases in spherical-like aberration (P<.01), and reductions in contrast sensitivity function (P<.0001). Changes in contrast sensitivity function were also statistically significantly correlated with the amount of myopic correction (P<.05), changes in coma-like aberration (P<.01), and changes in spherical-like aberration (P<.01). Stepwise multiple regression analysis showed that the magnitude of decentration was the only explanatory variable related to contrast sensitivity function (P<.0001).

Conclusion

Decentered treatment of orthokeratology resulted in decreased contrast sensitivity after treatment, showing that centration of the procedure is crucial to good outcomes.