Clinical trial NCT02643342: A 2-year Longitudinal Study on the Structural and Optical Effects of Orthokeratology Treatment on Eye
Official title: A 2-year Longitudinal Study on the Structural and Optical Effects of Orthokeratology Treatment on Eye
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Myopic Progression
Keywords: myopia control
orthokeratology
Lead sponsor: The Hong Kong Polytechnic University
Sponsor class: OTHER
Collaborators: name: Menicon Co., Ltd.
name: Queensland University of Technology
name: Aston University
First posted: 2015-12-31
Enrollment: 99
Sex: ALL
Minimum age (years): 6
Maximum age (years): 10
Standard ages: CHILD
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: This is a two-year longitudinal study investigating the optical and structural effects of increased compression factor of orthokeratology lens on eyes and the corresponding effect on change in choroidal thickness and therefore myopic control.


Eligibility criteria: Inclusion Criteria:

* 6 to 10 years old
* Myopia: between 0.50 D and 4.00 D in both eyes
* Astigmatism: \<1.50 D; ≤ 1.25 D for with-the-rule astigmatism (axes 180 ± 30); ≤ 0.50 D for astigmatism of other axes in both eyes
* Anisometropia: ≤ 1.50 D
* Symmetrical corneal topography with corneal toricity \<2.00 D in both eyes
* Agree for randomization

Exclusion Criteria:

* Contraindications for orthokeratology wear (e.g. limbus-to-limbus corneal cylinder and dislocated corneal apex)
* Any type of strabismus or amblyopia
* Myopic treatment (e.g. refractive surgery and progressive lens wear for myopic control) before and during the study period
* Rigid contact lenses (including orthokeratology lenses) experience
* Systemic condition which might affect refractive development (for example, Down syndrome, Marfan's syndrome)
* Ocular conditions which might affect the refractive error (for example, cataract, ptosis)
* Poor compliance for lens wear or follow-up

Primary outcomes:
measure: Axial length
timeFrame: every 6 monthly in 2 years
Secondary outcomes:
measure: Ocular aberration measured by Complete Ophthalmic Analysis System (COAS) aberrometer
timeFrame: every 6 monthly in 2 years
measure: Corneal biomechanics (corneal response using ocular response)
timeFrame: every 6 monthly in 2 years
measure: Accommodation lag measured by Complete Ophthalmic Analysis System (COAS) aberrometer
timeFrame: every 6 monthly in 2 years
measure: Choroidal thickness captured by Optical Coherent Tomographer (OCT)
timeFrame: every 6 monthly in 2 years
Other outcomes:
Locations:
city: Hong Kong
country: China
facility: School of Optometry, The Hong KOng Polytechnic University
Study officials:
affiliation: The Hong Kong Polytechnic University
name: Pauline Cho, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Lam CS, Lam CH, Cheng SC, Chan LY. Prevalence of myopia among Hong Kong Chinese schoolchildren: changes over two decades. Ophthalmic Physiol Opt. 2012 Jan;32(1):17-24. doi: 10.1111/j.1475-1313.2011.00886.x.
citation: Cho P, Cheung SW, Edwards M. The longitudinal orthokeratology research in children (LORIC) in Hong Kong: a pilot study on refractive changes and myopic control. Curr Eye Res. 2005 Jan;30(1):71-80. doi: 10.1080/02713680590907256.
citation: Cho P, Cheung SW. Retardation of myopia in Orthokeratology (ROMIO) study: a 2-year randomized clinical trial. Invest Ophthalmol Vis Sci. 2012 Oct 11;53(11):7077-85. doi: 10.1167/iovs.12-10565.
citation: Chen C, Cheung SW, Cho P. Myopia control using toric orthokeratology (TO-SEE study). Invest Ophthalmol Vis Sci. 2013 Oct 3;54(10):6510-7. doi: 10.1167/iovs.13-12527.
citation: Gonzalez-Meijome JM, Villa-Collar C, Queiros A, Jorge J, Parafita MA. Pilot study on the influence of corneal biomechanical properties over the short term in response to corneal refractive therapy for myopia. Cornea. 2008 May;27(4):421-6. doi: 10.1097/ICO.0b013e318164e49d.
citation: Wolffsohn JS, Safeen S, Shah S, Laiquzzaman M. Changes of corneal biomechanics with keratoconus. Cornea. 2012 Aug;31(8):849-54. doi: 10.1097/ICO.0b013e318243e42d.
citation: Tse DY, Lam CS, Guggenheim JA, Lam C, Li KK, Liu Q, To CH. Simultaneous defocus integration during refractive development. Invest Ophthalmol Vis Sci. 2007 Dec;48(12):5352-9. doi: 10.1167/iovs.07-0383.
citation: Chan B, Cho P, Mountford J. The validity of the Jessen formula in overnight orthokeratology: a retrospective study. Ophthalmic Physiol Opt. 2008 May;28(3):265-8. doi: 10.1111/j.1475-1313.2008.00545.x.
citation: Wan K, Lau JK, Cheung SW, Cho P. Orthokeratology with increased compression factor (OKIC): study design and preliminary results. BMJ Open Ophthalmol. 2020 May 4;5(1):e000345. doi: 10.1136/bmjophth-2019-000345. eCollection 2020.