A randomized non-inferiority trial of adjustable glasses versus standard and ready-made spectacles among Chinese school children: WEAR (Wearability and Evaluation of Adjustable Refraction) III

Abstract

Purpose : To study the acceptance and durability of adjustable children’s glasses under conditions of actual day-to-day wear.

Methods : This randomized trial was carried out among junior high school students aged 11-16 years in Maoming city, southern China, with presenting visual acuity=<6/12 in both eyes, correctable to =>6/7.5; subjective spherical equivalent refractive error (SER) =<-1.00D; astigmatism and anisometropia both <2.00D and no other ocular abnormalities. Participants were randomized (1:1:1) to conventional standard glasses, ready-made glasses (spherical equivalent power of worse-seeing eye) or adjustable glasses based on self-refraction. Rate of glasses wear on twice-weekly covert evaluation by head teachers was the primary outcome. Self-reported and observed wear, best-corrected visual acuity (BCVA, not pre-specified), children’s satisfaction and value attributed to glasses were also recorded and compared. Results were modelled using linear regression.

Results : Among 379 eligible participants, 127 were allocated to standard glasses (mean age 13.7±1.00 years, 54.3% male), 125 to ready-made (mean age 13.6± 0.83 years, 45.6% male) and 127 to adjustable (mean age 13.4± 0.85 years, 54.3% male). Mean teacher-observed wear rate of adjustable glasses was lower than for standard glasses (45% vs 58%; p=0.011), and the unadjusted, but not the adjusted, difference met the pre-specified definition for inferiority. Self-reported and investigator-observed wear did not differ by study group, nor did satisfaction with or value attributed to study glasses or change in quality of life. BCVA with adjustable glasses was better (P<0.001) than with standard glasses. Change in power of study lenses at the end of the study (Adjustable: 0.65D, 95%CI, 0.52-0.79; Standard: 0.012D, 95% CI, -0.0056, 0.029, P<0.001) was greater for adjustable glasses, though greater inter-observer variation in power measurements appears to have explained this. Lens scratches and frame damage were more common with adjustable than standard glasses, while lens breakage was less common.

Conclusions : Rates of wear were lower with adjustable glasses, though visual acuity was better and measures of satisfaction and quality of life were not inferior to standard glasses.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.