May 21, 2015
Mini-monovision Versus Multifocal Intraocular Lens Implantation
Labiris G, Giarmoukakis A, Patsiamanidi M, Papadopoulos Z, Kozobolis VP
J Cataract Refract Surg. 2015;41:53-57
This study was performed by a team of investigators from Alexandroupolis, Greece, who compared levels of spectacle independence and visual symptoms in cataract surgical patients.
Two groups of age-matched patients with no ocular abnormality underwent cataract surgery performed by the same surgeon. One group received a refractive multifocal IOL (Isert PY60MV; Hoya Surgical Optics, Inc.) with both eyes targeted for plano, whereas the other comparative mini-monovision group received a monofocal aspheric IOL (SN60WF; Alcon Laboratories, Inc.) targeted for -0.50 D in the dominant eye and for -1.25 D in the other eye.
Pre- and postoperative evaluations were obtained with the Visual Function Index-14 (VF-14) to determine visual symptoms and general visual functionality. Uncorrected binocular near and distance vision were assessed, as well as the proportion of patients who were spectacle-dependent for near and distance vision.
Both the multifocal and mini-monovision groups achieved good binocular uncorrected distance vision. The multifocal lens provided better overall near vision than the -1.25 D target for mini-monovision. There were no differences between the two groups in contrast sensitivity, stereopsis, or VF-14 items pertaining to distance or near vision.
Approximately twice as many multifocal patients (66%) reported being spectacle free compared with mini-monovision patients (34%). However, dysphotopsia (shadows and glare) occurred much more frequently in multifocal patients than in mini-monovision patients.
COMMENTS: William Cuthbertson MD
Although two thirds of the multifocal group was "spectacle-free" in this study, spectacles are not expected to provide relief from dysphotopsias in multifocal emmetropic patients; therefore, patients would be "spectacle-free" no matter what their visual function.
An additional question that could be posed in these studies comparing multifocal IOLs with monovision would be, "Is your vision adequate to do everything that you want to do with ease, including if you wore glasses when you need to?" If the occasional need to wear glasses is included, the excellent vision without dysphotopsias afforded by monofocal monovision would reflect a very high level of visual satisfaction in virtually all patients.
In conclusion, although the term "mini-monovision" could be better defined for study purposes, the concept of providing proximal-range, convenient, and usually spectacle-free vision with simple monofocal IOLs is very appealing. It maintains justifiable advantages over more expensive, and sometimes problematic, multifocal IOLs.