The decentration of a multifocal IOL can cause significant optical aberrations. When the rings of a multifocal IOL are not properly axially aligned with the patient's pupil, their refractive or diffractive pattern becomes asymmetric, and patients therefore may complain of reduced quality of vision in the daytime and asymmetric halos around lights at night.
In a study my colleagues and I presented at the 2007 American Academy of Ophthalmology Annual Meeting in New Orleans, we described the result of argon laser iridoplasty to center the pupil over the multifocal IOL in 14 eyes of 11 patients.1 By 1 month postoperatively, patients' mean BCVA improved from 20/32 to 20/24 (P<.05), and their mean UCVA improved from 20/40 to 20/31 (P<.05). Patients also achieved an improvement in subjective visual quality from 3 to 7.9 on a scale from 1 to 10 (where 10 is excellent). They experienced a statistically significant (P<.05) improvement in photopic and scotopic contrast sensitivity after argon laser iridoplasty. Digital photography showed a mean pupillary shift of 0.55 mm.
We found that decreased quality of vision may occur in some patients following implantationof a multifocal IOL. These patients should be carefully examined for the cause of their visual complaints. The most common reasons for decreased visual quality are residual refractive error, posterior capsular opacity, cystoid macular edema, and ocular surface disease. When these potential problems have been eliminated or treated and the problem remains, pupillary centration over the IOL should be evaluated. When there is decentration, an argon laser iridoplasty is a safe and effective technique for improving quality of vision.
