personalEYES BLOG
Aspheric Intraocular lenses
In recent times asphericity has been regarded as an important consideration for refractive and lens surgery. Positive spherical aberration occurs when marginal rays of light come into focus in front of paraxial rays.
Pseudophakic eyes implanted with spherical IOL’s have significantly higher spherical aberration compared to age matched phakic eyes. An aspheric lens counteracts the positive spherical aberration of the cornea.
Clinical observation suggests that preserving some amount of spherical aberration may enhance overall image quality.
The major lens companies have addressed this in different ways: The Alcon model has counteracted some of the positive corneal spherical aberration with negative spherical aberration in its IQ lens, leaving a small amount of residual spherical aberration.
AMO tries to counteract all of the positive spherical aberration with its Tecnis lens, working on average readings. This leaves zero spherical aberrations as the final result.
B&L’s Akreos lens is a zero aspheric lens, it does not alter the eyes natural spherical aberrations.
The Acrysof® IQ comes preloaded in the specifically designed Acrysert® Delivery System. This means easy preparation, no forceps required & also no handling of the lens. Due to this there is less chance of contamination.
However the wound size for this system needs to be 3.2mm which is slightly larger than the average wound size. An increased wound size is going in a different direction than the current trend of small incisional lens surgery.
Some of the lens companies e.g.; Alcon (Restor), AMO (Tecnis) and Zeiss (AcriLisa) make an aspheric multifocal IOL.
At personalEYES we have noted a definite improvement in quality of vision and patient satisfaction, particularly for distance vision with these multifocal intraocular lenses.
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