Efficacy of a Novel Myopia Defocus Spectacle Lens in School-Aged Children

Optical strategies have been shown to be effective for slowing myopia progression. The design of the BLMCL patented spectacle lens is based on existing myopic control theory of peripheral defocus spectacle lenses. This prospective, observational cohort study aims to evaluate the short-term efficacy and safety of the BLMCL lens in school-aged children. Forty participants, aged 6 to 15 years with SER between -6.00D to -0.75D and astigmatism not more than -2.00D, will be fitted with the BLMCL Lens and followed for six months. They will be required to return for five scheduled visits: baseline, delivery, 1 month, 3 months, and 6 months after lens delivery visits. The primary endpoint is the change in subfoveal choroidal thickness (SfChT) for potential effective myopia control via SfChT thickening. The secondary endpoints are the changes in AL and refraction after cycloplegia which allow comparison with other myopia control studies. Subjective symptoms will be assessed using the PREP2 and QoV questionnaires.

• BCMC lens (Other): BLMC spectacle lens is a spectacle lens that corrects the distance refraction and provides defocus in peripheral region

Primary outcomes

• Change in subfoveal choroidal thickness (SfChT) [Delivery and 1, 3, and 6 months after delivery]: SfChT will be measured using Swept-Source OCT (SS-OCT) without cycloplegia. It will be measured at the delivery visit before dispensing, and 1, 3 and 6 months after delivery. In order to minimize the effect of diurnal variation, it will be measured within two hours hours from the first measurement at the delivery visit. Two good quality images will be captured for each eye. Segmentation of the images will be performed by a masked examiner. Changes in SfChT after using the lenses for 1, 3, and 6 months will be determined.

Sex: All, ages: 6 Years to 15 Years, accepts healthy volunteers

Inclusion Criteria:

* Age 6 to 15 years (Chinese), inclusive
* Cycloplegic SER between -0.75 D and -6.00 D in both eyes
* Astigmatism ≤ 2.00 D in both eyes
* Anisometropia ≤ 1.50 D
* BCVA of 0.04 logMAR or better in each eye

Exclusion Criteria:

* Previous or current use of any myopia control intervention within 6 months
* Presence of any ocular pathology, amblyopia, colour vision deficiency or strabismus that could affect refractive development or visual function
* History of ocular surgery or significant ocular trauma
* Known systemic diseases or use of medications that could affect vision or ocular growth