Abstract: 【Abstract】 Objective To assess the effectiveness of long-term orthokeratology (Orhto-K, OK)  for myopia  treatment in youth. Design Retrospective case series. Participants 30 young myopia patients. Methods During 2000 to 2005, 30 patients (60 eyes) in the BeiYi Optometry & Ophthalmology Center had been  prescribed with  the Ortho-K contact lens and wore it more than seven years. The refraction, visual acuity, corneal curvature, axial length, anterior chamber depth and lens thickness were examined pre-wearing and post-wearing OK lens at six months, one year, three years, five years and seven years. Main Outcome Measures Refraction (spherical and cylinelrical), uncorrected visual acuity (UCVA), corrected visual acuity (CVA), average K value, axial length, anterior chamber depth, lens thickness. Results At post-wearing OK lens six months, UCVA had been significantly improved from 4.26±0.28 to 4.71±0.36 (P=0.00), and average K value of corneal curvature had been apparently flattened from 43.66±1.85 D to 42.41±1.66 D(P=0.00). Refraction had been significantly decreased from -4.76±2.20 D to -2.06±2.90 D (P=0.00). From six months to seven years, the UCVA, refraction and average K value maintained stable (4.70, -2.80 D, 42.40 D). During the entire seven years, the axial length had slowly increased from 25.59±1.07 mm to 26.28±1.44 mm. Conclusions In generally, scientific and standardized long-term Orthokeratology wearing would be effective for controlling myopia and increase of axial length and  improving naked vision. (Ophthalmol CHN, 2012, 21: 371-374)

Key words: myopia, adolescent, long-term care, orthokeratology