Skip to main content
Article thumbnail
Location of Repository

Comparing methods to estimate the human lens power

By Jos J. Rozema, David A. Atchison and Marie¬José Tassignon

Abstract

Purpose: To compare accuracies of different methods for calculating human lens power when lens thickness is not available. \ud \ud Methods: Lens power was calculated by four methods. Three methods were used with previously published biometry and refraction data of 184 emmetropic and myopic eyes of 184 subjects (age range [18, 63] years, spherical equivalent range [–12.38, +0.75] D). These three methods consist of the Bennett method, which uses lens thickness, our modification of the Stenström method and the Bennett¬Rabbetts method, both of which do not require knowledge of lens thickness. These methods include c constants, which represent distances from lens surfaces to principal planes. Lens powers calculated with these methods were compared with those calculated using phakometry data available for a subgroup of 66 emmetropic eyes (66 subjects). \ud \ud Results: Lens powers obtained from the Bennett method corresponded well with those obtained by phakometry for emmetropic eyes, although individual differences up to 3.5D occurred. Lens powers obtained from the modified¬Stenström and Bennett¬Rabbetts methods deviated significantly from those obtained with either the Bennett method or phakometry. Customizing the c constants improved this agreement, but applying these constants to the entire group gave mean lens power differences of 0.71 ± 0.56D compared with the Bennett method. By further optimizing the c constants, the agreement with the Bennett method was within ± 1D for 95% of the eyes. \ud \ud Conclusion: With appropriate constants, the modified¬Stenström and Bennett¬Rabbetts methods provide a good approximation of the Bennett lens power in emmetropic and myopic eyes. \u

Topics: Lens power, phakometry, lens thickness
Publisher: Association for Research in Vision and Ophthalmology
Year: 2011
DOI identifier: 10.1167/iovs.11-7899
OAI identifier: oai:eprints.qut.edu.au:49223

Suggested articles


To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.