Visual function after correction of distance refractive error with ready-made and custom spectacles: a randomized clinical trial

Abstract

Purpose: To evaluate patient-reported outcome measures with the use of ready-made spectacles (RMS) and custom spectacles (CS) in an adult population in India with uncorrected refractive error (URE).

Design: Prospective, double-masked, randomized trial with 1-month follow-up.

Participants: A total of 363 adults aged 18 to 45 years with ≥1 diopter (D) of URE (RMS, n = 183; CS, n = 180).

Intervention: All participants received complete refraction and were randomized to receive CS (full sphero-cylindrical correction) or RMS based on the spherical equivalent for the eye with lower refractive error but limited to the powers in the RMS inventory.

Main outcome measures: Visual function and quality of life (VFQoL) instrument and participant satisfaction.

Results: Rasch scores for VFQoL increased from 1.14 to 4.37 logits in the RMS group and from 1.11 to 4.72 logits in the CS group: respective mean changes of 3.23 (95% confidence interval [CI], 2.90-3.56) vs. 3.61 (95% CI, 3.34-3.88), respectively. Mean patient satisfaction also increased by 1.83 points (95% CI, 1.60-2.06) on a 5-point Likert scale in the RMS group and by 2.04 points (95% CI, 1.83-2.24) in the CS group. In bivariate analyses, CS was not associated with increased VFQoL or patient satisfaction compared with the RMS group. In the full multivariable linear regression, the CS group had greater improvement when compared with those receiving RMS (+0.45 logits; 95% CI, 0.02-0.88), and subjects with astigmatism >2.00 D had significantly less improvement (-0.99 logits; 95% CI, -1.68 to -0.30) after controlling for demographic and vision-related characteristics. In multivariable analysis, increased change in patient satisfaction was related to demographic and optical characteristics, but not spectacle group.

Conclusions: Ready-made spectacles produce large but slightly smaller improvements in VFQoL and similar satisfaction with vision at 1-month follow-up when compared with CS. Ready-made spectacles are suitable for the majority of individuals with URE in our study population, although those with high degrees of astigmatism may benefit from a trial of CS. This study provides further evidence for the use of RMS in settings where CS are unavailable or unaffordable, or refractive services are inaccessible to those in need.