Choroidal Response to the Modified Defocus Incorporated Multiple Segments Spectacle Lenses

The goal of this study is to investigate the short-term changes in choroidal thickness and efficacy of the study spectacle lenses in children. Participants will be prescribed with a pair of study spectacle lenses for daily use and visit the clinic once every week for the first month for checkup and tests. After the first month of follow-up, participants will visit at 1 month, 6- and 12-month for checkup. Choroidal thickness, axial length and refractive errors will be monitored.

Optical interventions have been widely used for myopia control in children, however, the effectiveness varied between individuals. The current study spectacle lenses are modified based on DIMS technology. Participants will be randomly allocated to single vision (SV) lens group (control), D1 or D2 group (treatment). The weekly choroidal thickness changes will be monitored in the first month of lens wear. Their cycloplegic refraction and axial length will be monitored every 6 months for 1 year.

Inclusion Criteria: * Hong Kong Chinese * Age at enrolment: 6 - 13 years * Myopia in spherical power: -1.00D to -5.00D in both eyes * Astigmatism: equal or less than 2.00D * The sum of spherical power and astigmatism: equal or less than -7.00D * Anisometropia (spherical equivalent refraction (SER)): equal or less than 1.50D * Previous myopia progression (valid documentation dated within 2 years before screening): * -0.50D (SER) per year or more in both eyes OR Axial length elongation: 0.27mm/year in both eyes * If myopia is initially detected during screening, eligibility requires myopia (in SER) below the 3rd percentile curve of refraction in both eyes.12 * Best corrected visual acuity: LogMAR 0.04 or better in both eyes * Ocular health: no abnormalities in both internal and external ocular health * Binocular vision: no strabismus and other binocular abnormalities * Normal colour vision * Willing to wear the study spectacles all the time (10 hours per day, for 7 days per week) Exclusion Criteria: * Previous or current treatment for myopia control (e.g., red-light therapy, atropine, orthokeratology, specialized spectacle lenses and contact lenses and oral supplements for myopic control) * Existing or past eye diseases or surgeries (e.g., strabismus surgery, amblyopia, oculomotor nerve palsies, corneal disease, intraocular disease, etc.) that may have an impact on vision or visual development * Long-term medication (intake at least 3 days/week) or medication/supplements that affect eye health * Systemic diseases that may have an impact on vision or visual development (e.g., endocrine, cardiac and respiratory diseases, diabetes, Down syndrome, etc.) * Allergic to cyclopentolate eye drops * Individuals who, in the judgment of the Investigator, are unable to cooperate and follow instructions during eye examination.