OCT systems provide repeatable measurements of soft contact lens thickness

Both swept-source and spectral-domain optical coherence tomography (OCT) systems provide reliable and comparable measurements of soft contact lens central thickness, with good repeatability and close agreement with the electronic thickness gauge, according to a study.

The randomized, controlled, investigator-masked trial included 120 soft contact lenses made from 8 different materials. Three examiners measured lens thickness using a swept-source OCT system and a spectral-domain OCT system, with a spherical support to ensure proper lens centration. Intra- and inter-examiner repeatability were assessed, and results from both OCT systems were compared with those from an electronic thickness gauge, considered the gold standard.

Both OCT systems showed strong intra-examiner repeatability, with 95% confidence intervals below 10 micrometers for most lens materials. Inter-examiner repeatability was lower and exceeded 10 micrometers for some materials. The mean differences between OCT measurements and the electronic thickness gauge were under 10 micrometers. Swept-source OCT produced slightly lower thickness values than spectral-domain OCT, though most differences fell within plus or minus 10 micrometers.

Reference
Romaguera M, Valdes-Soria G, Sierra-Buitrago LX, et al. Validation and comparison of two commercial OCT systems for in vitro measurement of soft contact lens thickness. J Optom. 2026;19(2):100607. doi: 10.1016/j.optom.2025.100607. Epub ahead of print. PMID: 41579490.