Reduced visual sensitivity seen with use of multifocal intraocular lenses
medwireNews: Recent study findings indicate that eyes with multifocal intraocular lenses (MFIOLs) implanted during cataract surgery may develop reduced visual sensitivity.
While the use of MFIOLs may increase distance vision and allow for spectacle independence, they can cause unwanted visual problems and prevent detection of glaucoma.
Nomdo Jansonius (University Medical Center Groningen, The Netherlands) and colleagues designed a study to compare visual sensitivity in 46 people with MFIOLs, monofocal IOLs, or healthy phakic eyes, as assessed with standard automated perimetry (SAP).
As reported in JAMA Ophthalmology, mean deviation (MD) in SAP size III was a significant 2.4 dB lower in the MFIOL group and 0.3 dB lower in the monofocal IOL group compared with healthy phakic controls. Mean sensitivity for SAP size V, adjusted for age and pupil size, was an average of 1.6 dB lower in those with MFIOLs versus controls.
The reduction in sensitivity was not related to eccentricity, and the researchers observe that it "seems to be related to the multifocal design of the IOLs rather than to pseudophakia." In addition, 25% of the people with MFIOLs needed additional correction for near vision.
The authors assessed two different types of diffractive MFIOLs - the Tecnis and Zeiss lenses - but their MD values fell within the interquartile range as a whole. "This tentatively suggests that the reduced visual sensitivity is a generic property of diffractive MFIOLs rather than specific for one type," say Jansonius et al.
Based on these findings, the researchers recommend that a new perimetric baseline be used for all patients with MFIOLs, particularly those who have suspect glaucoma, so that any future visual abnormality can be easily detected and diagnosed. Patients should also be informed that MFIOLs can cause visual sensitivity loss, which may be further exacerbated in the future by advancing age or ocular diseases.
"As a consequence, the originally highly appreciated spectacle independence might be regretted later," they conclude.
By Stephanie Leveene, medwireNews Reporter