Peripheral refraction for distance and near vision in emmetropes and myopes.
We investigated the relationship between myopia and peripheral refraction for distance and near vision by measuring peripheral refractive errors in 10 myopic and 10 emmetropic participants at viewing distances of 2.5 and 0.4 m. Measurements were made at the fovea, and at eccentricities of 10 degrees , 20 degrees and 30 degrees in the temporal and nasal hemispheres of the horizontal visual field. Our results showed that peripheral astigmatism increased with increasing eccentricity, but there was no significant difference between refractive error groups except at 30 degrees eccentricity in the temporal retina. Considering the Mean Spherical Equivalent errors, emmetropes became relatively myopic at peripheral eccentricities, but there was little change in myopes. The effect of viewing distance on astigmatism or Mean Spherical Equivalent error was not significant. Our results do not support the view that myopia is associated with changes in peripheral refraction during distance or near vision.
Calver
Richard
R
Department of Optometry & Ophthalmic Dispensing, Anglia Ruskin University, East Road, Cambridge CB1 1PT, UK. r.i.calver@anglia.ac.uk
Radhakrishnan
Hema
H
Osuobeni
Ebi
E
O'Leary
Daniel
D
D000328:Adult; D001251:Astigmatism / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D009216:Myopia / Q000503:physiopathology*; D012016:Reference Values; D012029:Refraction, Ocular; D012030:Refractive Errors / Q000503:physiopathology; D013223:Statistics as Topic; D014787:Vision Tests / Q000379:methods*