Initial results of trifocal diffractive IOL implantation

Abstract

Background: Bifocal intraocular lenses (IOL) are designed to reduce dependence on eyeglasses after surgery, but they cannot provide full range of vision, and have a drop of visual acuity in the intermediate distance. This problem may be solved with a trifocal lens, which produces three useful focal points. This study was conducted to evaluate clinical outcomes, functional vision and spectacle independence in patients with trifocal diffractive IOLs.

Methods: Thirty-six eyes after implantation of diffractive intraocular lens MIOL-Record were evaluated. This IOL has a diffractive lens profile binary in phase and produces three useful foci. Outcome measures recorded 6 months postoperatively were uncorrected and distance-corrected (far, near, intermediate) visual acuities, contrast sensitivity (under photopic and mesopic condition), root-mean-square (RMS) of higher order aberrations (HOA), patients' quality of life (visual function questionnaire VFQ-25, halos and glare presence, overall satisfaction), and spectacle independence.

Results: Postoperatively, monocularly, the uncorrected (UDVA) and the corrected distance visual acuity (CDVA) were 0.74 +/- 0.21 and 0.86 +/- 0.23 respectively (P < 0.05). No differences were found between uncorrected (UNVA)-0.85 +/- 0.13 and best distance-corrected near visual acuity (CNVA) 0.89 +/- 0.12 (P > 0.05). The uncorrected (UIVA) and best distance-corrected acuities of intermediate vision (CIVA) at 50 cm were 0.58 +/- 0.16 and 0.6 +/- 0.2 respectively. The photopic contrast sensitivity was within the standard normal range. But under dim light conditions it was inferior at all spatial frequencies by more than 0.2 logarithmic units. The mean aberration values were: total HOA RMS-0.816 +/- 0.362 mum, spherical aberration (SA)-0.207 +/- 0.136 mum, coma-0.335 +/- 0.206 mum. The percentage of patients achieving spectacle freedom was 94%. On the questionnaire, 25% of patient noted nighttime halos; glare difficulty was reported by 16.7% of patients, difficulties with night vision persisted in 22.3% of cases.

Conclusion: Diffractive trifocal intraocular lens MIOL-Record provided good uncorrected distance, intermediate and near vision, gave high rates of spectacle freedom and overall patient satisfaction.