난시 각막굴절교정학 렌즈를 이용한 가장자리 각막난시 교정

Correction of Limbus-to-Limbus Corneal Astigmatism with Toric Orthokeratology Lenses

Purpose: To report the efficacy of toric orthokeratology lenses in a patient with corneal astigmatism within 1.5 D having difficulty wearing spherical orthokeratology lenses because of limbus-to-limbus corneal astigmatism. Case summary: An 11-year-old boy who wanted to wear orthokeratology lenses had a refractive error of -4.75 D sph = -1.00 D cyl 180 in the right eye and -4.50 D sph = -1.25 D cyl 180 in the left eye. The corneal astigmatism was 1.19 D and 1.19 D, respectively, and limbus-to-limbus corneal astigmatism was observed in topography. After wearing spherical orthokeratology lenses, the patient complained of monocular diplopia and both lenses were found to be displaced nasally. Toric orthokeratology lenses were prescribed for centration of lenses and resulted in significant improvement of uncorrected visual acuity of 20/20, refractive error of +0.75 D sph = -0.50 D cyl 170 in the right eye and +0.50 D sph = -0.50 D cyl 160 in the left eye, and centration of lenses for the 12-month follow-up period. Conclusions: Toric orthokeratology lenses should be considered if spherical orthokeratology lenses are not effective even in patients having less than 1.5 D of corneal astigmatism because of limbus-to-limbus corneal astigmatism.