For a few years now, it has been possible to implant a special lens during cataract surgery that enables patients to obtain good near and distance vision (multifocal lenses) without the need for glasses. The use of special lenses to correct astigmatism is also on the increase. New study results from the Department of Ophthalmology and Optometrics of MedUni Vienna und Vienna General Hospital demonstrate the stability of these lenses in the eye and facilitate the correct choice of implant for each individual patient.
Cataracts are a common eye condition most prevalent in people over the age of 50 and result in clouding of the otherwise clear lens. For some time now it has been possible to treat other existing eye problems during the outpatient cataract procedure, for example to correct presbyopia by implanting multifocal lenses or astigmatism by implanting special intraocular lenses.
Customised implantation of toric intraocular lens in the first procedure
It is becoming increasingly common practise to fit intraocular lenses to correct astigmatism during cataract surgery. If these special lenses are to provide patients with better vision, it is essential that they sit stably in the eye.
"The full effect of these lenses is very dependent upon their stable seating. Optimal rotational stability is essential if patients are to have good vision and are to be spared the need for a follow-up operation," reports Christina Leydolt from the Department of Ophthalmology and Optometrics of MedUni Vienna and Vienna General Hospital.
The Department of Ophthalmology and Optometrics has conducted several studies on the rotational stability of toric intraocular lenses to ensure that, in future, once cataract surgery has been done, no further eye surgery is required to correct astigmatism.
"We have developed a very precise method for measuring and assessing the stability of toric lenses. The results of the study help us to choose the correct lens implant for the eye and to achieve the best possible astigmatism correction during the cataract operation. This means that patients are able to see really well without glasses after cataract surgery and do not require any further corrective surgery," reports Leydolt.
Recent study investigates the improvement in intermediate vision produced by new multifocal lenses
As well as removing cataracts, cataract surgery also provides an opportunity to implant multifocal lenses to correct presbyopia, which affects everybody over the age of about 40. Multifocal lenses largely enable people to do without glasses for near and distance vision. A new generation of special lenses now promises to improve intermediate (middle-distance) vision as well.
"The offering of different multifocal lenses is constantly increasing in response to the increasing needs of patients," reports Leydolt. "Intermediate vision at a distance of between 50 and 80 cm is becoming increasingly important, as that is the distance from which you view the screen of a PC or laptop."
An ongoing study led by Christina Leydolt is investigating to what extent the new multifocal lenses actually improve intermediate vision. The preliminary results are expected early in 2021.
American Journal of Ophthalmology: „Comparison of long-term rotational stability of three commonly implanted intraocular lenses.“ Schartmüller D, Schwarzenbacher L, Meyer EL, Schriefl S, Leydolt C, Menapace R.;
https://www.ajo.com/article/S0002-9394(20)30376-7/fulltext DOI: 10.1016/j.ajo.2020.07.019
British Journal of Ophthalmology: „True rotational stability of a single-piece hydrophobic intraocular lens.“ Schartmüller D, Schriefl S, Schwarzenbacher L, Leydolt C, Menapace R.;
https://bjo.bmj.com/content/103/2/186 DOI: 10.1136/bjophthalmol-2017-311797