Accuracy of optical biometry combined with Placido disc corneal topography for intraocular lens power calculation

PLoS One. 2017 Feb 23;12(2):e0172634. doi: 10.1371/journal.pone.0172634. eCollection 2017.


Purpose: To investigate the accuracy of a new optical biometer for intraocular lens (IOL) power calculation in eyes undergoing cataract surgery.

Methods: Consecutive eyes of patients undergoing cataract surgery with the same IOL model were enrolled in a prospective cohort study. Axial length (AL) and corneal power were measured with an optical biometer based on optical low-coherence interferometry and Placido-disc corneal topography. IOL power was calculated with the Hoffer Q, Holladay 1 and SRK/T formulas. For each formula the lens constant was optimized in retrospect in order to achieve a mean prediction error (PE) of zero (difference between the predicted and the postoperative refraction). Median absolute error (MedAE) and percentage of eyes with PE ±0.50 D were calculated.

Results: Seventy-four eyes of 74 cataract patients were enrolled. The MedAE was 0.25 D with all formulas. A PE within ±0.50 D was obtained in 89.04% of cases with the Hoffer Q and SRK/T formulas, and in 87.67% of cases with the Holladay 1 formula.

Conclusions: The optical biometer investigated in the present study provides accurate measurements for IOL power calculation.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Biometry / methods*
  • Cataract / diagnostic imaging*
  • Cataract Extraction*
  • Corneal Topography / methods*
  • Female
  • Humans
  • Male
  • Prospective Studies

Grant support

The contribution of GB Bietti Foundation IRCCS was supported by the Italian Ministry of Health and Fondazione Roma.