Accuracy, Repeatability and Instrument Myopia Induced by a Clinical Aberrometer - The Complete Ophthalmic Analysis System (COAS)
Abstract
Refractive surgery corrects lower-order refractive aberrations (sphere and astigmatism), but in many cases it inadvertently creates large higher-order aberrations that can degrade vision. This has prompted the development of new instruments, aberrometers, which measure higher-order aberrations. We evaluated a new clinical aberrometer, the Complete Ophthalmic Analysis System (COAS) for accuracy, repeatability and instrument myopia. We measured 56 normal eyes (28 subjects) using the COAS, with and without cycloplegia and evaluated its lower-order accuracy in comparison to clinical subjective refraction. We also evaluated lower- and higher-order repeatability and instrument myopia. Data were analyzed for a 5.O-mm diameter pupil. For comparison, some of these analyses were also performed on a conventional auto refractor. Mean COAS accuracy for lower-order aberrations (sphere and astigmatism) was at least as good as clinical subjective refraction. Lower-order repeatability was similar to conventional auto refraction. For higher-order aberrations, repeatability, was in the O.O5-O.O1-um range (95% CI). Instrument myopia was small. On average, the COAS provides accurate, repeatable measurements of the lower-order aberrations (sphere and astigmatism) with little instrument myopia. We quantified repeatability for higher-order aberrations and provided recommendations on how to use the COAS in future refractive surgery-related research.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2006
- Accession Number
- ADA451604
Entities
People
- Corina Van De Pol
- Thomas O. Salmon
Organizations
- United States Army Aeromedical Research Lab