Competing/conflicts of interest: No stated conflict of interest.
Accuracy of intraocular lens power calculations in eyes with axial length <22.00 mm
Version of Record online: 11 JUL 2012
© 2012 The Authors. Clinical and Experimental Ophthalmology © 2012 Royal Australian and New Zealand College of Ophthalmologists
Clinical & Experimental Ophthalmology
Volume 40, Issue 9, pages 855–862, December 2012
How to Cite
Day, A. C., Foster, P. J. and Stevens, J. D. (2012), Accuracy of intraocular lens power calculations in eyes with axial length <22.00 mm. Clinical & Experimental Ophthalmology, 40: 855–862. doi: 10.1111/j.1442-9071.2012.02810.x
Funding sources: Funding for this project was provided by The RD Crusaders Charitable Trust (via Fight for Sight, London; grant reference 1956). Dr Day and Prof Foster acknowledge a proportion of their financial support from the Department of Health through the award made by the National Institute for Health Research for The NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology.
- Issue online: 6 DEC 2012
- Version of Record online: 11 JUL 2012
- Accepted manuscript online: 18 MAY 2012 03:46AM EST
- Received 7 October 2011; accepted 4 April 2012.
- intraocular lens;
Background: To assess the accuracy of Haigis, Holladay 1, Hoffer Q and SRK/T formulae in eyes with axial length of <22.00 mm.
Design: Retrospective comparative analysis.
Participants: 163 eyes of 97 patients undergoing phacoemulsification and intraocular lens (IOL) implantation.
Methods: Ocular biometry was performed using IOLMaster laser interferometry. Predicted refractive outcomes before and after lens constant adjustment were compared to actual refractive outcomes.
Main Outcome Measures: Mean prediction (ME) and mean absolute errors (MAE) with standard deviations (±SD).
Results: Mean preoperative spherical equivalent was +5.44D ± 1.97D. Mean axial length was 21.20 mm ± 0.60 mm. Using standard IOL constants the MAE for Hoffer Q (0.62D, ±0.52D) and Holladay 1 (0.66D ± 0.52D) were significantly lower than SRK/T (MAE 0.91D ± 0.64D; P = <0.0005 and P = 0.001 respectively), but not Haigis (MAE 0.82D ± 0.83D, P = 0.071 and 0.22 respectively). MAEs for all formulae were significantly reduced by IOL constant adjustment (all P = <0.001). Following this there was no statistically significant difference in MAEs between formulae (range 0.50–0.57D, P = 0.57). Increasing MAE was significantly associated with reducing axial length and increasing IOL power for all formulae. For bilateral cases, prediction errors between eyes were significantly correlated across all formulae (all P = <0.0001) and explained 32–42% of the variance in prediction error between eyes.
Conclusions: Prediction of postoperative refraction in patients with short axial lengths is challenging and at the limit of current, popular IOL formulae. There is now a clear need for prospective studies to assess latest generation IOL formulae such as Holladay 2 or Olsen in small eyes.