Effect Of Decentration On Quality Of Vision In Two Aspheric Posterior Chamber Intraocular Lenses: A Contralateral Eye Study

To perform an intraindividual comparison of quality of vision and the effect of decentration between two aspheric intraocular lenses: aspheric balanced curve (ABC) design Vivinex iSert XY1 (Hoya Surgical Optics, Singapore)  and anterior aspheric design Tecnis ZCB00 (Abbott Medical Optics, CA).

Advanced Eye Centre, PGIMER, Chandigarh, India.

In this prospective, randomized comparative study 30 patients were randomized to implantation of Vivinex iSert XY1 in one eye and Tecnis ZCB00 in the contralateral eye. 12 weeks post-operatively, a laser ray-tracing aberrometer was used to evaluate the visual Strehl ratio, higher-order aberrations (HOA), decentration of IOL from the visual axis and geometric axis, angle alpha, and angle kappa. Contrast sensitivity was measured using the Functional visual analyzer.

The visual internal Strehl ratio was higher (p<0.05) at all pupil sizes and the spherical aberrations values were lower (p<0.05) at larger pupil sizes (5mm, 6mm) in the Vivinex group. Mean decentration from the visual axis in the Vivinex group is significantly more than that in the Tecnis group (p<0.01). With an increase in angle alpha, there is a decline in the visual Strehl ratio for both lenses but there is a statically significant decline at 3mm pupil size for Tecnis ZCB00 (p=0.028). The contrast sensitivity was similar for both IOLs.

In comparison to an anterior aspheric design IOL, the ABC design IOL yielded better quality of vision, neutralized spherical aberrations to a larger extent, and provided a relatively superior quality of vision with decentration.