Biyue Guo

The primary outcome of the study is the change in OSDI score after a 2-week visit. Secondary outcomes include first-NITBUT and meibography assessments conducted at the 2-week and 3-month visits. Additionally, other exploratory outcomes evaluated include changes in average Lipid Layer Thickness (LLT) from baseline, tear meniscus height (TMH), and the results of Schirmer’s test without anesthesia.

Measurement procedures Subjects who achieved a successful lens fit7 were required to attend cycloplegic examinations (two drops of 1% cyclopentolate) at the first month (±2 days), and then six monthly (±2 weeks) thereafter, for data collection. All the procedures were conducted at the Optometry Clinic, School of Optometry of PolyU. All subsequent visits were conducted within ±2 h of the time at the baseline visit to minimise diurnal differences in the measurements.

To compare changes in ocular aberrations in children wearing orthokeratology (ortho-k) lenses with a back optic zone diameter (BOZD) of 6 mm (6-MM group) or 5 mm (5-MM group) and their associations with axial elongation (AE) over two years. Seventy Chinese children, aged 6 to < 11 years, with myopia between - 4.00 to - 0.75 D, were randomly allocated to 5-MM and 6-MM groups. Ocular aberrations were measured, rescaled to a 4-mm pupil, and fitted with a 6th order Zernike expansion.