Estimation of the effective lens position using a rotating Scheimpflug camera

Jau Der Ho, Shiow Wen Liou, Jui-Fang Tsai, Ching Yao Tsai

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Purpose: To describe a no-history method of estimating the effective lens position (ELP) for double-K intraocular lens (IOL) power calculation in eyes that had previous refractive surgery. Setting: Departments of Ophthalmology, Taipei Medical University Hospital and Taipei City Hospital, Taipei, Taiwan. Methods: The corneal height (H m) and anterior chamber diameter (AG m) in 106 unoperated eyes were measured using a rotating Scheimpflug camera. The theoretical anterior corneal radius (R rt) was then derived from H m and AG m by regression and rearrangement of the Fyodorov equation. The ELP estimate was then calculated from R rt. The performance of this ELP estimation method in double-K IOL power calculation and the performance of other methods were compared retrospectively in 11 eyes having cataract surgery that had previous refractive surgery. The refractive results 9 to 12 weeks after cataract surgery were selected for data analysis. Results: The new ELP estimation method, combined with the BESSt formula or the Savini et al. method for estimating post refractive-surgery corneal power (K post) in the double-K SRK/T formula, provided the best IOL power prediction results. The mean arithmetic and absolute IOL prediction errors were -0.05 ± 0.62 diopters (D) and 0.49 ± 0.34 D, respectively, when combined with the BESSt formula and 0.03 ± 0.73 D and 0.60 ± 0.36 D, respectively, when combined with the Savini et al. method. With either combination, all 11 eyes were within ±1.00 D of the refractive prediction error. Conclusion: This ELP estimation method may be helpful for IOL power calculation in post refractive-surgery eyes when historical data are unavailable.

Original languageEnglish
Pages (from-to)2119-2127
Number of pages9
JournalJournal of Cataract and Refractive Surgery
Volume34
Issue number12
DOIs
Publication statusPublished - Dec 2008

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Lenses
Intraocular Lenses
Refractive Surgical Procedures
Cataract
Refractive Errors
Urban Hospitals
Anterior Chamber
Ophthalmology
Taiwan
History

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems
  • Surgery

Cite this

Estimation of the effective lens position using a rotating Scheimpflug camera. / Ho, Jau Der; Liou, Shiow Wen; Tsai, Jui-Fang; Tsai, Ching Yao.

In: Journal of Cataract and Refractive Surgery, Vol. 34, No. 12, 12.2008, p. 2119-2127.

Research output: Contribution to journalArticle

Ho, Jau Der ; Liou, Shiow Wen ; Tsai, Jui-Fang ; Tsai, Ching Yao. / Estimation of the effective lens position using a rotating Scheimpflug camera. In: Journal of Cataract and Refractive Surgery. 2008 ; Vol. 34, No. 12. pp. 2119-2127.
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