The Effect of +3.00ADD on Myopia Progression in Chinese Children

The Effect of +3.00ADD on Myopia Progression in Chinese Children: A Cluster Randomized Controlled Clinical Trial

The purpose of this study is to evaluate the effect of +3.00ADD vs single vision spectacle on the progression of myopia in children. Many studies applying bifocals or multifocal spectacles to intervene the progression have been carried out based on the idea that myopia was caused by excessive accommodation, however, the effect was limited. The possible reason is that bifocal or multifocal spectacles still not fully adjust the accommodative error in myopia children.

The optical intervention has been extensively explored for the intervention of myopia progression.

Based on the theory that myopia was caused by the excessive accommodative, bifocal or multifocal spectacles for slowing the progression of myopia have been fully studied. Although some studies' results showed statistically significant for slowing myopia progression with multifocal spectacles, few had clinically meaningful, even in children with high accommodative lag or near-point esophoria. The investigators think that the possible reason for this clinical un-meaningful maybe that daily wearing bifocal or multifocal spectacles still not fully adjust the accommodative error in children.

The aim of this randomized clinical trial is to evaluate myopic progression in children using two spectacles (single-vision spectacles for distant vision, and +3.00ADD spectacle for near vision), compared with control subjects wearing one spectacles (single-vision spectacles). Myopia progression quantified by changes in axial length (AL) and cycloplegic spherical equivalent refraction will be monitored for 3 years. The spectacles for intervention group children will be adjusted based on the cycloplegic spherical equivalent and the extent of accommodation lag for schedule time.

Inclusion criteria

1. Children who are aged 8 to 12 years (grade 3 and grade 4) from Huadu district of Guangzhou in China.
2. Refractive error meeting all the following, obtained by cycloplegic autorefraction: spherical equivalent -1.00 to -6.00D in both eyes, astigmatism ≤2.00 D in both eyes, and spherical equivalent anisometropia ≤1.50 D.
3. The best corrected visual acuity is ≥ 6/9.5
4. The parents are willing to provide consent to participation in the study, and the children are willing to wear the only provided spectacles

Exclusion criteria

1. Children who are allergy to tropicamide or topical anesthetic drugs.
2. Children who had other eye diseases that cause the visual impairment including strabismus, amblyopia, ocular surface related disease, cataract, traumas, ocular fundus diseases, and ocular surgery.
3. Children who were wearing rigid gas permeable contact lenses, progressive-addition lenses, bifocal spectacles lens, Peripheral defocus modifying contact lenses;
4. Children who are receiving visual function training.