Spherical IOL provides a higher CDVA compared to aspheric lens

Fitting a spherical acrylic intraocular lens (IOL) in patients with bilateral cataract improves corrected distance visual acuity (CDVA) more so than fitting an aspheric IOL, claims an investigation featured in Journal of Cataract and Refractive Surgery.

Dr Manickam Thiagarajan and his team, Eye Department, Southampton University Hospital, UK, conducted a randomized, masked, single-centre study on bilateral cataract patients aged 50 years and over. The biometry-predicted IOL power was between 10.0 D and 30.0 D. Patients were fitted with the Akreos Adapt Advanced Optics aspheric IOL and the Sensar AR40e spherical acrylic IOL.

A high-contrast logMAR chart was used to measure CDVA, the Pelli-Robson chart was used to measure contrast sensitivity, range of accommodation was measured using the RAF rule and patient satisfaction was recorded by questionnaire 3 months postoperatively. Pseudoaccommodation, mesopic pupil diameters and scotopic pupil diameters were all measured with a power refractor.

The difference in mean CDVA between the IOLs was 0.015, with the spherical IOL scoring the highest. The differences between contrast sensitivity and range of accommodation were 0.02 and 0.05, respectively. The questionnaire answers produced no differences in dysphotopsia and patient satisfaction.

The spherical IOL demonstrated a statistically significant improvement in CDVA but the findings are not clinically important.