These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: New bi-sign aspheric IOL and its application.
    Author: Portney V.
    Journal: Optom Vis Sci; 2012 Jan; 89(1):80-9. PubMed ID: 22041588.
    Abstract:
    PURPOSE: To present a bi-sign aspheric intraocular lens (IOL) and make theoretical comparisons with spherical and one-sign aspheric IOLs for retinal image quality in mesopic conditions and intermediate image capability in photopic conditions. METHODS: Using ray-tracing in pseudophakic eye models, retinal image quality in terms of modulation transfer function was analyzed between the bi-sign aspheric and three types of one-sign aspheric IOLs and the spherical IOL for the range of corneal asphericities and different lens misalignments at 5 mm pupil diameter; comparison is made with the spherical IOL at defocus conditions characterized by negative refractive errors at 3 mm pupil diameter. RESULTS: Retinal image quality of the bi-sign aspheric lens was equal to or exceeded the one-sign aspheric and spherical IOLs in the majority of anterior cornea asphericities and lens misalignments within the spatial frequencies of 6 to 15 c/deg. Intermediate image capability of the bi-sign aspheric exceeded the spherical IOL. CONCLUSIONS: A new bi-sign aspheric lens produces regions of opposite spherical aberrations in the eye model with pupil diameters above 3 mm to balance out aberrations within the lens itself in addition to compensating corneal aberration as with a one-sign aspheric lens. This allows reduction in the variability of the retinal image quality at different anterior cornea asphericities and lens misalignments, when compared with a one-sign aspheric and spherical lens. The bi-sign aspheric produces positive longitudinal spherical aberration in the eye model within 3 mm pupil diameter that improves intermediate image capability when compared with the spherical IOL.
    [Abstract] [Full Text] [Related] [New Search]