Abstract
Purpose To examine post-operative visual outcomes when using micro-incision surgery and a three-piece, foldable acrylic intraocular lens (IOL) and when using small-incision surgery and a one-piece, rigid polymethyl-methacrylate (PMMA) IOL.
Methods Phacoemulsification and IOL implantation was conducted by one surgeon on 86 subjects (aged 50-89 years) with cataracts. Of these subjects, 67 completed the study. Subjects were implanted either with a foldable IOL (n = 38) or a rigid IOL (n = 29). Best corrected Snellen visual acuity and contrast sensitivity (2-28 cycles/degree) were measured approximately 2 months post-operatively. Comparisons were made between the pseudophakic groups and an additional group of 28 age-matched, normal subjects (aged 58-81 years). Non-parametric (Kruskal-Wallis and Mann-Whitney u) as well as parametric (ANOVA and Pearson) statistics tests were used in the analysis of results.
Results All pseudophakes had corrected visual acuity of 6/9 or better. There were no significant differences in visual acuity (Kruskal-Wallis, p = 0.61) or contrast sensitivity (ANOVA, p = 0.33) between the three groups. The mean residual refractive error of the foldable IOL group was hypermetropic in comparison with the rigid IOL group but not significant at the 99% level of probability (Mann-Whitney u, p = 0.02). There was no significant difference in astigmatism between the groups.
Conclusions Implanting a foldable acrylic IOL gave no post-operative benefit in visual acuity and contrast sensitivity to pseudophakes over a less expensive rigid PMMA IOL, within this post-operative period. This study did not provide a comparison between the two lenses regarding post-operative complications, in particular the important long-term complication of posterior capsular opacification (PCO). Until and if any particular advantage of a given IOL in reduced incidence of PCO is confirmed, it appears more economical to implant the conventional rigid PMMA IOL using small-incision surgery.
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This study was reported, in part, at the annual meeting of the American Academy of Optometry, Orlando, Florida, USA, 9 December 1996; at the annual meeting of the Association for Research in Vision and Ophthalmology, Fort Lauderdale, Florida, USA, 13 May 1997; and at the annual meeting of the British Congress of Optometry and Visual Science, City University, London, UK, 11 September 1997
Miss Afsar was supported by a research scholarship provided by the College of Optometrists, London, UK. Alcon Laboratories (UK) supplied the foldable acrylic intraocular lenses to the Southern General Hospital, Glasgow, UK
Proprietary and financial interest: none
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Afsar, A., Patel, S., Woods, R. et al. A comparison of visual performance between a rigid PMMA and a foldable acrylic intraocular lens. Eye 13, 329–335 (1999). https://doi.org/10.1038/eye.1999.84
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DOI: https://doi.org/10.1038/eye.1999.84
