Abstract | BACKGROUND: Several clinical studies indicate, that the visual function of multifocal IOLs ( MIOL) is impaired by corneal astigmatism. To assess the influence of uncorrected corneal astigmatism on the contrast sensitivity function (CSF) of mono- and multifocal IOLs, an "optical implantation" of physical eyes with astigmatic corneas and IOLs was performed in younger subjects. METHODS: The virtual image of physical eyes with a 40 dpt achromate as artificial cornea and the (M)IOL in a water bath was projected on the retina of the observer by means of an exactly adjusted video objective. Silicone lenses with defined astigmatisms (+1; +2; +4; +6 dpt) were put in front of the achromate to produce an artificial corneal astigmatism. We compared results of a standard monofocal IOL (Pharmacia 811B), a multizone progressive MIOL (AMO Array SSM-26NB) and a diffractive MIOL (Pharmacia 811E). CSF through these IOLs in the physical eyes was measured in ten healthy subjects (mean age: 27.4 y.) with the B-VAT II-SG Video Acuity Tester (Mentor O&O), which uses sine wave gratings of five different spatial frequencies (1.5; 3; 6; 12; 20 cpd). RESULTS: Without astigmatic lenses, all IOLs showed a mean CSF within the age-related norm, but the monofocal IOL yielded significantly better results than both MIOLs at three spatial frequencies (3; 6; 12 cpd). With additional astigmatic lenses of 2 dpt and more, mean CSF of all IOLs was below normal range, but there was no difference in the performance of the three lens styles. CONCLUSION: CSF of MIOLs seems to be less sensitive to uncorrected corneal astigmatism than CSF of the monofocal IOL. This suggests, that a higher preoperative astigmatism does not severely affect the image quality through a multifocal IOL.
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Authors | D Eisenmann, R Wagner, B Dick, K W Jacobi |
Journal | Klinische Monatsblatter fur Augenheilkunde
(Klin Monbl Augenheilkd)
1996 Aug-Sep
Vol. 209
Issue 2-3
Pg. 125-31
ISSN: 0023-2165 [Print] Germany |
Vernacular Title | Einfluss des Hornhautastigmatismus auf die Kontrastempfindlichkeit bei mono- und multifokaler Pseudophakie--eine theoretische Studie am physikalischen Auge. |
PMID | 8992072
(Publication Type: English Abstract, Journal Article)
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Topics |
- Adult
- Astigmatism
(physiopathology)
- Contrast Sensitivity
(physiology)
- Cornea
(physiopathology)
- Eyeglasses
- Female
- Humans
- Lenses, Intraocular
- Male
- Reference Values
- Visual Acuity
(physiology)
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