Effect of pseudophakia on standard perimetry parameters

To investigate the effect of monofocal spheric acrylic intraocular lenses (IOL) on the visual field (VF) parameters.

Thirty-six healthy pseudophakics (group 1) and 42 age-matched healthy volunteers (group 2) who had visual acuity of > or = 9/10 Snellen lines underwent central 24-2 threshold VF testing by Humphrey 750i VF analyzer. Subjects of group 1 had undergone VF testing 2 months after cataract surgery. The VFs were divided into three concentric zones for analysis. Age, visual acuity, pupillary size, foveal threshold, mean (MD) and pattern standard deviation (PSD) values, and mean decibel (dB) thresholds. MD and PSD of the three concentric zones were compared between the groups.

There was no significant difference between the groups in regards to age, gender, pupillary size, visual acuity, and mean foveal threshold. Mean MD was -2.4 +/- 2.5 decibel (dB) in the pseudophakics and -1.06 +/- 1.9 dB in the controls (p = 0.01; t = -2.63). Mean PSD values of group 1 and 2 were 2.5 +/- 1.5 dB and 2.06 +/- 1.3 dB, respectively (p = 0.145; t = -1.47). There were statistically significant differences between mean MD values of three concentric zones of both groups (p < 0.003, for all). The reduction of VF sensitivity through peripheral retina was more pronounced in the pseudophakics.

Even monofocal spheric acrylic IOLs have relatively insignificant effect on visual acuity, and foveal threshold may influence global indices such as MD on VF testing. Possible causes of reduction in VF sensitivity should be clarified by further studies in pseudophakics.