TY - JOUR
T1 - Orthokeratology lenses with increased compression factor (OKIC): A 2-year longitudinal clinical trial for myopia control
AU - Lau, Jason K.
AU - Wan, Kin
AU - Cho, Pauline
N1 - Funding Information:
JL. Lau and K. Wan were supported by the Research Residency Scheme of The Hong Kong Polytechnic University. This study was supported by a Collaborative Research Agreement between PolyU and Menicon Co. Ltd., Japan (ZG3Z).
Publisher Copyright:
© 2022 British Contact Lens Association
PY - 2022/8/19
Y1 - 2022/8/19
N2 - Purpose: To investigate the effectiveness of orthokeratology (ortho-k) lenses and corneal changes with increased compression factor for myopia control over a 2-year period. Methods: Young participants (age: 6–<12 years), with low myopia (0.50–4.00 D) and low astigmatism (≤1.25 D), were recruited and allowed to choose to wear either single-vision spectacles or ortho-k lenses (randomly assigned to compression factor of either 0.75 or 1.75 D). Axial length and cycloplegic refraction were measured at six monthly intervals for two years by a masked examiner. The myopia control effectiveness was determined by axial elongation. Results: A significant number of control (63 %) dropped out, mainly due to concern about myopia progression (58 %). A total of 75 participants (mean age: 9.3 ± 1.0 years; control: n = 11, ortho-k [0.75 D]: n = 29, ortho-k [1.75 D]: n = 35) completed the study. Considering ortho-k groups only, the mean axial elongation of participants wearing ortho-k lenses of conventional compression factor (0.75 D) and increased compression factor (1.75 D) were 0.53 ± 0.29 and 0.35 ± 0.29 mm, respectively, over the 2-year study period. The between-group differences in corneal health were not significant at all visits. Conclusion: Participants wearing ortho-k lenses of increased compression factor further slowed axial elongation by 34%, when compared with the conventional compression factor without compromising corneal health. Further investigations are warranted to confirm the potential mechanism of an increased compression factor for improved myopia control effectiveness.
AB - Purpose: To investigate the effectiveness of orthokeratology (ortho-k) lenses and corneal changes with increased compression factor for myopia control over a 2-year period. Methods: Young participants (age: 6–<12 years), with low myopia (0.50–4.00 D) and low astigmatism (≤1.25 D), were recruited and allowed to choose to wear either single-vision spectacles or ortho-k lenses (randomly assigned to compression factor of either 0.75 or 1.75 D). Axial length and cycloplegic refraction were measured at six monthly intervals for two years by a masked examiner. The myopia control effectiveness was determined by axial elongation. Results: A significant number of control (63 %) dropped out, mainly due to concern about myopia progression (58 %). A total of 75 participants (mean age: 9.3 ± 1.0 years; control: n = 11, ortho-k [0.75 D]: n = 29, ortho-k [1.75 D]: n = 35) completed the study. Considering ortho-k groups only, the mean axial elongation of participants wearing ortho-k lenses of conventional compression factor (0.75 D) and increased compression factor (1.75 D) were 0.53 ± 0.29 and 0.35 ± 0.29 mm, respectively, over the 2-year study period. The between-group differences in corneal health were not significant at all visits. Conclusion: Participants wearing ortho-k lenses of increased compression factor further slowed axial elongation by 34%, when compared with the conventional compression factor without compromising corneal health. Further investigations are warranted to confirm the potential mechanism of an increased compression factor for improved myopia control effectiveness.
KW - Orthokeratology
KW - Myopia
UR - http://www.scopus.com/inward/record.url?scp=85136282134&partnerID=8YFLogxK
U2 - 10.1016/j.clae.2022.101745
DO - 10.1016/j.clae.2022.101745
M3 - Journal article
SN - 1367-0484
JO - Contact Lens and Anterior Eye
JF - Contact Lens and Anterior Eye
M1 - 101745
ER -