Bubble and corneal dimple formation after the first overnight wear of an orthokeratology lens: a case series

Choroidal Thickness Changes after Orthokeratology Lens Wearing in Young Adults with Myopia

INTRODUCTION

Recently in South Korea, there are increasing number of young adults undergoing orthokeratology treatment for myopia control. They prefer orthokeratology treatment more than wearing spectacles or having a refractive surgery for several reasons. However, there is little research on the effect of orthokeratology treatment on choroids.

OBJECTIVE

The aim of this study was to analyze the change in choroidal thickness (CT) in the horizontal axis in young myopic adults after orthokeratology treatment.

METHODS

This was a retrospective research among young myopic patients (-1.0 to -5.0 diopters) aged 19-29 years (n = 36; 23.6 ± 2.5 years). We selected patients who were treated with orthokeratology for 12 months. CT values of the horizontal axis near the fovea before and after orthokeratology treatment were analyzed using optical coherence tomography. The value was measured at the beginning of treatment and at 3, 6, and 12 months after orthokeratology treatment. Three regional areas of choroid on the horizontal plane including fovea were analyzed.

RESULT AND CONCLUSIONS

In the beginning of orthokeratology treatment, CT of the horizontal axis was 248.9 ± 45.7 μm in the temporal region, 259.9 ± 55.3 μm in the macular region, and 219.2 ± 46.4 μm in the nasal region. Three months after orthokeratology treatment, thickness values of choroids in the 3 divided areas increased significantly (p < 0.05). Mean CT at 6 or 12 months after orthokeratology treatment was greater than before ortho<X00_Del_TrennDivis>--</X00_Del_TrennDivis>keratology treatment. CT increased after 3 months of orthokeratology treatment in each regional area. In young myopic adults, CT in nasal area was thinner than that in foveal or temporal area before treatment. CT recovered to near baseline when it was observed for more than 6 months after orthokeratology treatment.

Predictive role of corneal Q-value differences between nasal-temporal and superior-inferior quadrants in orthokeratology lens decentration

BACKGROUND

To investigate the association between pretreatment corneal parameters and orthokeratology lens decentration.

METHODS

This retrospective study included a total of 108 eyes in 60 myopia patients, who were divided into a lens-decentration and a control group. Various pretreatment corneal parameters were analyzed by receiver operating characteristic curves (ROC curves), including corneal horizontal and vertical curvatures, diopter, corneal eccentricity (E-value), asphericity (Q-value), diameter, and astigmatism, to establish a reliable predictive model for orthokeratology lens decentration.

RESULTS

The temporal and inferior quadrants are preferential sides for lens decentration, which was associated with the occurrence of complications such as ghosting and corneal epithelial staining. By further analysis, we revealed lower corneal horizontal curvature and much higher corneal Q-value differences between the nasal-temporal and superior-inferior quadrants in the lens-decentration group compared to the control group (P < 0.05). ROC curve analysis showed that the sum of Q-value differences between the nasal-temporal and superior-inferior quadrants was more sensitive than any other corneal parameters in predicting lens decentration, with an area under the curve of 0.778 and a truncation point of 0.3 (P < 0.001).

CONCLUSION

The sum of pretreatment corneal Q-value differences between nasal-temporal and superior-inferior quadrants is a convenient and reliable predictor for orthokeratology lens decentration.

The Safety of Orthokeratology--A Systematic Review

Objectives:

The aim of this review is to evaluate the ocular safety of orthokeratology (OrthoK) treatment of myopia correction and retardation.

Data Sources:

Clinical studies published in English and Chinese were identified from MEDLINE, EMBASE CNKI, CQVIP, and WANFANG DATA (all from 1980 to April 2015). The reference lists of the studies and the Science Citation Index were also searched.

Selection Criteria:

Relevant clinical studies including case series, case reports, patient/practitioner surveys, retrospective and prospective cohort studies, and clinical trials were all included in the review. The material of OrthoK lenses was limited to gas-permeable lens.

Main Results:

This review incorporated a total of 170 publications, including 58 English and 112 Chinese literature. The risk of microbial keratitis in overnight OrthoK was similar to that of other overnight modality. The most common complication was corneal staining. Other clinically insignificant side effects included epithelial iron deposit, prominent fribrillary lines, and transient changes of corneal biomechanical properties. There was no long-term effect of OrthoK on corneal endothelium.

Conclusions:

There is sufficient evidence to suggest that OrthoK is a safe option for myopia correction and retardation. Long-term success of OrthoK treatment requires a combination of proper lens fitting, rigorous compliance to lens care regimen, good adherence to routine follow-ups, and timely treatment of complications.