Pseudophakic monovision may offer better intermediate vision than multifocal IOLs

This study compared visual function and patient satisfaction in cataract surgery patients who received either bilateral diffractive multifocal intraocular lenses (IOLs) or monofocal IOL monovision. The results indicate that pseudophakic monovision achieved distance vision and near vision comparable to vision achieved with bilateral multifocal IOLs without the inherent risk for the disturbing visual symptoms associated with multifocal IOLs. Monovision patients also had significantly better intermediate vision and less difficulty using computers without glasses. Overall, they expressed a higher level of satisfaction with their vision than multifocal IOL patients.

Subjects in the study were consecutive bilateral cataract patients who underwent implantation of AcrySof ReSTOR SN60D3 multifocal IOLs or AcrySof SN60WF IOLs as monovision between July 2007 and June 2009. The study's 21 multifocal IOL and 22 monovision subjects chose the type of vision they received. They completed the Visual Function Questionnaire-25 preoperatively and three months after surgery.

The authors found that stereo vision was better in the multifocal IOL group. Although fine stereo vision at near without glasses was better with the multifocal IOLs than monovision, the difference between the groups was not statistically significant (P = 0.076). For the gross stereo function of going down steps, stairs or curbs in dim light or at night without glasses, the groups were very similar, with a slightly more favorable mean score in the monovision than the multifocal IOL group (P = 0.716).

I find it surprising that there was no statistical difference in the stereo vision results between the groups. It's too bad that the authors didn't compare monovision with implantation of the AcrySof SN60D1, a later-generation IOL that has supplanted the multifocal IOL used in the study.

The authors conclude that neither bilateral implantation of AcrySof ReSTOR SN60D3 multifocal IOLs nor bilateral implantation of AcrySof SN60WF IOLs for monovision is a perfect solution for presbyopia. However, they say that both are good compromises for patients who desire a good range of vision and high level of spectacle independence. The SN60D3 provides good distance and near vision, although intermediate and computer vision is not very satisfactory. The authors conclude that although glare and halos can be very disturbing to some patients, bilateral implantation of this IOL remains a good option for patients who do not drive much at night but desire good vision and spectacle independence. They say that monovision can provide comparable good distance and near vision and more favorable intermediate and computer vision with less symptomatic glare and halos than with multifocal IOLs.