Orthokeratology for High Myopia (OHM) Study

Myopia Clinical Trial

Official title:

Orthokeratology for High Myopia (OHM) Study

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT03881358
• Other study ID #: HSEARS20180322002
• Status: Recruiting
• Phase: N/A
• Start date: August 4, 2018
• Est. completion date: January 2024

Study information

• Verified date: February 2021
• Source: The Hong Kong Polytechnic University
• Contact: Pauline Cho, PhD
• Phone: (+852) 2766 6100
• Email: pauline.cho[@]polyu.edu.hk
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

This project aims to investigate/examine high myopic subjects on full correction ortho-k (using Topaz ortho-k lenses for high myopia) compared to subjects undergoing partial reduction ortho-k and their relationship with myopia and myopic progression.

Description:

For many years, commercially-available ortho-k lenses aim to reduce low - moderate myopia. Attempts to use these lenses for reduction of high myopia have been shown to give rise to complications such as corneal staining and lens decentration. Thus, practitioners may choose a more conservative way for high myopic children, that is, offering partial reduction ortho-k. Partial reduction ortho-k is target for 4.00-5.00D reduction and the residual refractive errors will be corrected with single vision spectacles to allow good visual acuity in the daytime. Partial reduction ortho-k has been shown to slow axial elongation in high myopic children, however, the main disadvantage is that the children have to wear spectacles in the daytime to correct residual refraction. Euclid has recently designed a new lens, Euclid's Topaz, for high myopic children. It is currently commercially available to correct myopia for up to 10 D. However, evidence of its effectiveness for visual correction and slowing AL growth is lacking. While numerous studies have shown that orthokeratology is an effective clinical treatment to slow axial eye growth in children, the exact mechanism underlying this reduction in myopia progression associated with orthokeratology remains unclear.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 66
• Est. completion date: January 2024
• Est. primary completion date: November 2023
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 7 Years to 13 Years

Eligibility

Inclusion Criteria:

• Myopia: at least 5.00D in one eye or in both eyes
• Astigmatism: =1.50D; with-the-rule astigmatism (axes 180 ± 30) =1.25D; astigmatism of other axes =0.50D in both eyes
• Anisometropia: not be more than 1.00D in the former and not more than 2.00D in the latter.
• Best-corrected Monocular Snellen visual acuity 6/7.5 or better

Exclusion Criteria:

• Strabismus at distance or near
• Previous experience in contact lens wear or myopia control treatment (e.g. refractive therapy or progressive spectacles)
• Contraindication for contact lens wear and orthokeratology (e.g. limbus to limbus corneal cylinder and dislocated corneal apex)
• Previous history of ocular surgery, trauma, or chronic ocular disease
• Concurrent use of medications that may affect tear quality or contact lens wear
• Systemic or ocular conditions that may affect tear quality or contact lens wear (e.g allergy and concurrent medication) or that may affect refractive development (e.g Down syndrome, ptosis)
• Poor compliance to tests (e.g poor fixation in noncontact tonometry or intolerance of lens wear)
• Not willing to comply with the allocated treatment, use and care of lenses and follow-up schedule

Related Conditions & MeSH terms

• High Myopia
• Myopia

Intervention

Device:
• ortho-k lenses and thinner spectacles
Conventinally designed (Emerald) ortho-k lenses (target for -4.00D) and thinner specs during day time
• newly designed ortho-k lenses
Newly designed (Topaz) ortho-k lenses for high myopia (target for full correction)

Locations

Country	Name	City	State
Hong Kong	School of Optometry, The Hong Kong Polytechnic University	Kowloon

Sponsors (3)

Lead Sponsor	Collaborator
The Hong Kong Polytechnic University	Aston University, Queensland University of Technology

Country where clinical trial is conducted

Hong Kong, 

References & Publications (12)

Atchison DA, Li SM, Li H, Li SY, Liu LR, Kang MT, Meng B, Sun YY, Zhan SY, Mitchell P, Wang N. Relative Peripheral Hyperopia Does Not Predict Development and Progression of Myopia in Children. Invest Ophthalmol Vis Sci. 2015 Sep 1;56(10):6162-70. doi: 10.1167/iovs.15-17200. — View Citation

Charm J, Cho P. High myopia-partial reduction orthokeratology (HM-PRO): study design. Cont Lens Anterior Eye. 2013 Aug;36(4):164-70. doi: 10.1016/j.clae.2013.02.012. Epub 2013 Mar 18. — View 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. — View Citation

Cho P, Cheung SW, Edwards MH. Practice of orthokeratology by a group of contact lens practitioners in Hong Kong. Part 2: orthokeratology lenses. Clin Exp Optom. 2003 Jan;86(1):42-6. — View Citation

González-Méijome JM, Villa-Collar C, Queirós 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. — View Citation

Hiraoka T, Matsumoto Y, Okamoto F, Yamaguchi T, Hirohara Y, Mihashi T, Oshika T. Corneal higher-order aberrations induced by overnight orthokeratology. Am J Ophthalmol. 2005 Mar;139(3):429-36. — View Citation

Kakita T, Hiraoka T, Oshika T. Influence of overnight orthokeratology on axial elongation in childhood myopia. Invest Ophthalmol Vis Sci. 2011 Apr 6;52(5):2170-4. doi: 10.1167/iovs.10-5485. — View Citation

Lam CS, Goldschmidt E, Edwards MH. Prevalence of myopia in local and international schools in Hong Kong. Optom Vis Sci. 2004 May;81(5):317-22. — View Citation

Lee TT, Cho P. Relative peripheral refraction in children: twelve-month changes in eyes with different ametropias. Ophthalmic Physiol Opt. 2013 May;33(3):283-93. doi: 10.1111/opo.12057. — View Citation

Swarbrick HA. Orthokeratology review and update. Clin Exp Optom. 2006 May;89(3):124-43. Review. — View Citation

Walline JJ, Jones LA, Sinnott LT. Corneal reshaping and myopia progression. Br J Ophthalmol. 2009 Sep;93(9):1181-5. doi: 10.1136/bjo.2008.151365. Epub 2009 May 4. — View Citation

Walline JJ, Lindsley K, Vedula SS, Cotter SA, Mutti DO, Twelker JD. Interventions to slow progression of myopia in children. Cochrane Database Syst Rev. 2011 Dec 7;(12):CD004916. doi: 10.1002/14651858.CD004916.pub3. Review. Update in: Cochrane Database Syst Rev. 2020 Jan 13;1:CD004916. — View Citation

* Note: There are 12 references in all — Click here to view all references

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in axial length elongation over 24 months.	To determine the change in axial length measured at baseline and two years after lens wear using IOLMaster	2 years
Secondary	First fit success rate of a newly designed ortho-k lens for high myopic children	The success rate in using the first pair of lenses to achieve target refractive correction will be determined	1 month
Secondary	Quality of life (questionnaire)	Quality of life will be determined by questionnaires (using revised Pediatric Refractive Error Profile (PREP) 1 in traditional Chinese version) before and after ortho-k in the two groups of subjects	3 months
Secondary	Ocular aberration	Ocular aberration will be measured by Complete Ophthalmic Analysis System (COAS) aberrometer	2 years