ESCRS - PO064 - Characterization And Prediction Model Of The Short-Term Effect Of Myopic Orthokeratology

Characterization And Prediction Model Of The Short-Term Effect Of Myopic Orthokeratology

Published 2022 - 40th Congress of the ESCRS

Reference: PO064 | Type: ESCRS 2022 - Posters | DOI: 10.82333/rhvp-3v80

Authors: Alicia Sanchez Garcia* 1 , Ainhoa Molina Martin 1 , Sidi Mohmamed Hamida Abdelkader 2 , Miguel Angel Ariza Gracia 3 , David P Piñero Llorens 4

1Department of Optics, Pharmacology and Anatomy,University of Alicante,Alicante,Spain, 2Department of Ophthalmology,Torrecárdenas Hospital Complex,Almeria,Spain, 3University of Bern,Bern,Switzerland, 4Vithas Medimar International Hospital,Alicante,Spain

Purpose

To establish a pattern of corneal epithelial thickness modifications correlated with topographic and refractive changes after orthokeratology (OK) for myopia, and to propose a predicting equation of the OK effect according to the wearing time, and changes in refraction and corneal shape.

Setting

Department of Optics, Pharmacology and Anatomy, University of Alicante, Spain; Vithas Medimar International Hospital, Alicante, Spain; Department of Ophthalmology, Torrecárdenas Hospital Complex, Almería, Spain; University of Bern, Bern, Switzerland.

Methods

Prospective study including 50 myopic eyes undergoing orthokeratology. Refractive, corneal topographic and aberrometric, and corneal epithelium thickness were evaluated since the first 20 minutes of contact lens wear to 1 week of OK use. Central epithelium thickness (CET), para-central epithelium thickness (PCET) at 2 mm from the center, and mid-periphery epithelium thickness (MPET) at 4 mm from the center were measured by a spectral domain optical coherence tomography (OCT). To establish a predicting equation of such OK effect, a multiple linear regression analysis was used relating baseline data and the change in refraction and the other parameters evaluated during these first 60 minutes with the OK effect at 1 week.

Results

All clinical parameters evaluated showed a statistically significant change (p<0.001) in all visits, except the coefficient of coma aberration which showed a statistically significant change only after one week of use (p<0.05). CET thinned from first 40 minutes of OK use with statistical significance (p<0.001), with difference in means at one week of use of 8.06 ± 0.78. PCET showed only a significant thinning after 1 week (4.53±1.03, p<0.001). MPET did not show a statistical significant change. With multiple linear regression analysis, a predicting model of the effect of OK at 1 week was obtained (R2= 0.718) which was based on baseline refraction, baseline keratometry, age, and refractive change after one hour of lens use.

Conclusions

Orthokeratology for myopia induces a significant thinning of CET from the first 40 min of contact lens wear. This thinning remained constant for one week, including the paracentral area of the cornea. The refraction change achieved with OK in the short term can be predicted from baseline spherical equivalent and keratometry, age and the refractive changes occurring after 1 hour of OK use.