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Indications for the multizone bifocal implant.
1Department of Ophthalmology, Scarborough Hospital, England.
Journal of Cataract and Refractive Surgery
|March 1, 1990
Summary
Switching to bifocal implants improves unaided vision for reading small print, but some patients experience reduced clarity. Bifocal implants offer better uncorrected near vision compared to monofocal implants.
Area of Science:
- Ophthalmology
- Biomedical Engineering
Background:
- Monofocal intraocular lenses (IOLs) provide good distance vision but require reading glasses for near tasks.
- Bifocal IOLs aim to restore both distance and near vision without spectacles.
Purpose of the Study:
- To compare the unaided visual performance of patients with 3M diffractive bifocal implants versus monofocal implants.
- To evaluate the impact of bifocal IOLs on uncorrected reading acuity and the need for spectacle correction.
Main Methods:
- Prospective study involving 55 eyes with bifocal implants and 55 eyes with monofocal implants.
- Assessment of uncorrected visual acuity for distance and near tasks, including reading small print (J- அளவு).
Main Results:
- Significantly higher rates of reading J5 and J2 with distance correction in bifocal eyes compared to monofocal eyes.
- 75% of bifocal eyes achieved 20/40 distance and J3 near vision without aid, versus 33% of monofocal eyes.
- 52% of bifocal implant patients required no reading addition, though 17% struggled with J2 vision.
Conclusions:
- 3M diffractive bifocal IOLs offer significant improvements in unaided visual standards, particularly for near tasks.
- While bifocal IOLs reduce spectacle dependence, potential loss of clarity for fine print necessitates careful patient selection.