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Evaluating the peripheral optical effect of multifocal contact lenses
Author(s) -
Rosén Robert,
Jaeken Bart,
Lindskoog Petterson Anna,
Artal Pablo,
Unsbo Peter,
Lundström Linda
Publication year - 2012
Publication title -
ophthalmic and physiological optics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.147
H-Index - 66
eISSN - 1475-1313
pISSN - 0275-5408
DOI - 10.1111/j.1475-1313.2012.00937.x
Subject(s) - peripheral , dioptre , wavefront , optical transfer function , optics , peripheral vision , image quality , visual field , optometry , ophthalmology , medicine , physics , visual acuity , image (mathematics) , computer science , computer vision
Purpose Multifocal soft contact lenses have been used to decrease the progression of myopia, presumably by inducing relative peripheral myopia at the same time as the central image is focused on the fovea. The aim of this study was to investigate how the peripheral optical effect of commercially available multifocal soft contact lenses can be evaluated from objective wavefront measurements. Methods Two multifocal lenses with high and low add and one monofocal design were measured over the ±40° horizontal field, using a scanning H artmann– S hack wavefront sensor on four subjects. The effect on the refractive shift, the peripheral image quality, and the depth of field of the lenses was evaluated using the area under the modulation transfer function as the image quality metric. Results The multifocal lenses with a centre distance design and 2 dioptres of add induced about 0.50 dioptre of relative peripheral myopia at 30° in the nasal visual field. For larger off‐axis angles the border of the optical zone of the lenses severely degraded image quality. Moreover, these multifocal lenses also significantly reduced the image quality and increased the depth of field for angles as small as 10°–15°. Conclusions The proposed methodology showed that the tested multifocal soft contact lenses gave a very small peripheral myopic shift in these four subjects and that they would need a larger optical zone and a more controlled depth of field to explain a possible treatment effect on myopia progression.