Effect of age and astigmatism on the AMO Array multifocal intraocular lens

Abstract

Multifocal intraocular lenses (MIOLs) have been designed to provide better uncorrected near visual acuity than monofocal IOLs. However, the increase in depth of focus is combined with a significant decrease in contrast sensitivity and glare. We implanted a new zonal-progressive MIOL (AMO Array) in 31 eyes of 25 patients whose mean age was 60.8 +/- 13.5 years. At 12.1 +/- 2.4 months postoperatively, the uncorrected visual acuity averaged 0.56 +/- 0.09 (20/32) for distance and 0.54 +/- 0.12 (20/40) for near focus. Seventy-five percent of patients achieved a best corrected distance visual acuity of > or = 0.9 (20/22). With distance correction only, mean near visual acuity was 0.72 +/- 0.17 (20/25). Best corrected near acuity reached 0.89 +/- 0.11 (20/22), requiring an additional near add of +1.0 to +2.0 diopters (D). We observed an age-dependent difference in the depth of focus. In younger patients (46 +/- 6 years), the pseudoaccommodation range was 6.25 D; acuity attained was > or = 0.4 (20/50). In older patients (71 +/- 7 years), visual acuity at the near focus was substantially reduced (two lines). Regan contrast sensitivity was lower for MIOL patients at all contrast levels, but the difference was statistically significant only at very low contrast (11%). Contrast sensitivity and glare were dependent on the patient's age but did not change with the amount of postoperative astigmatism. Younger patients were very satisfied with the results of MIOL implantation, and the small loss of contrast sensitivity was counterbalanced by the advantage of improved depth of focus and uncorrected near visual acuity.