Ocular aberrations and visual function with multifocal versus single vision soft contact lenses

摘要

Purpose: To investigate differences in ocular aberrations induced by centre-near multifocal soft contact lenses (SCL) relative to single vision SCLs and their effect on contrast sensitivity function (CSF). Methods: Ocular aberrometry was measured in 18 cyclopleged subjects (19-24 years) while wearing Ciba Air Optix low (AOlow) and high (AOhigh) add, Bausch & Lomb PureVision low (PVlow) and high (PVhigh) add multifocals, and a Bausch & Lomb PureVision single vision (PVsv) control with the same -3.00. D distance back vertex power. Zernike polynomials were scaled to 4, 5 and 6. mm pupils. CSF was measured at equivalent distances of 6. m, 1. m and 40. cm while fully corrected with spherical trial lenses at 6. m. Results: AOlow, AOhigh and PVhigh induced a negative shift in primary spherical aberration (Z12) from PVsv and all multifocal SCLs induced a positive shift in secondary spherical aberration (Z24) (all p< 0.01), without significantly increasing coma. Area under the CSF (AUCSF) reduced at 40. cm for all multifocals relative to PVsv (p< 0.05), but was not significantly different at 6. m or 1. m. A moderate correlation (r= -0.80, p< 0.005) was found between changes in Z12 and AUCSF at 40. cm for AOhigh, with an increase in negative Z12 reducing multifocal-induced loss of CSF. Conclusions: Centre-near multifocal SCLs induced a negative shift in Z12 and a positive shift in Z24. Although CSF was unaffected at 6. m and 1. m it was reduced at 40. cm, possibly because changes in Z12 and Z24 were not great enough to induce a significant shift in centre of focus and increase in depth of field. ? 2012 British Contact Lens Association.