Visual fields in patients with multifocal intraocular lens implants and monovision: an exploratory study

To assess the difference in binocular visual fields (VFs) in patients who underwent bilateral cataract surgery with either multifocal (MF; Tecnis ZM900, AMO) intraocular lenses (IOLs) or monofocal IOLs with powers adjusted to give monovision (MV; Akreos AO, Bausch&Lomb).

St George's & Moorfields Eye Hospital, London.

Prospective exploratory study. Binocular Esterman VFs (Humphrey Field Analyser II) were compared between 10 participants with MV and 16 participants with MF IOLs. The dominant eye in MV participants had 0 to -0.50DS and the non-dominant eye had between -1.0DS and -1.5DS. Best-corrected Snellen visual acuity for all 52 eyes was six out of nine or better. The main outcome measure was Esterman Efficiency Score. Incidence of suboptimal VF results (≥1 Unseen Locations--ULs) and mean testing times in the two groups were compared.

There was no statistically significant difference in the incidence of suboptimal VF results in these two groups (P=0.662). Test durations in the two groups were not significantly different (P=0.650). However, 3/10 MV plots (33%) had markedly suboptimal right hemi-fields (distance-dominant eye) compared with 0/15 MF plots. Additionally, the MV group accounted for 79% of total ULs (20/29) and all these ULs were distributed in areas outside or bordering the true binocular VFs.

All included VFs met the UK driving standards criteria. The pattern of VF defects encountered in the MV group is of interest because the majority of ULs (13/20; 65%) corresponded to the monocular VFs of the distance-dominant eye.