Korean J Ophthalmol.  2018 Jun;32(3):241-248. 10.3341/kjo.2017.0063.

Comparative Efficacy of the New Optical Biometer on Intraocular Lens Power Calculation (AL-Scan versus IOLMaster)

Affiliations
  • 1Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea. kmk9@snu.ac.kr
  • 2Laboratory of Ocular Regenerative Medicine and Immunology, Seoul Artificial Eye Center, Seoul National University Hospital Biomedical Research Institute, Seoul, Korea.

Abstract

PURPOSE
To evaluate the agreement in axial length (AL), keratometry, and anterior chamber depth measurements between AL-Scan and IOLMaster biometers and to compare the efficacy of the AL-Scan on intraocular lens (IOL) power calculations and refractive outcomes with those obtained by the IOLMaster.
METHODS
Medical records of 48 eyes from 48 patients who underwent uneventful phacoemulsification and IOL insertion were retrospectively reviewed. One of the two types of monofocal aspheric IOLs were implanted (Tecnis ZCB00 [n = 34] or CT Asphina 509M [n = 14]). Two different partial coherence interferometers measured and compared AL, keratometry (2.4 mm), anterior chamber depth, and IOL power calculations with SRK/T, Hoffer Q, Holladay2, and Haigis formulas. The difference between expected and actual final refractive error was compared as refractive mean error (ME), refractive mean absolute error (MAE), and median absolute error (MedAE).
RESULTS
AL measured by the AL-Scan was shorter than that measured by the IOLMaster (p = 0.029). The IOL power of Tecnis did not differ between the four formulas; however, the Asphina measurement calculated using Hoffer Q for the AL-Scan was lower (0.28 diopters, p = 0.015) than that calculated by the IOLMaster. There were no statistically significant differences between the calculations by MAE and MedAE for the four formulas in either IOL. In SRK/T, ME in Tecnis-inserted eyes measured by AL-Scan showed a tendency toward myopia (p = 0.032).
CONCLUSIONS
Measurement by AL-Scan provides reliable biometry data and power calculations compared to the IOLMaster; however, refractive outcomes of Tecnis-inserted eyes by AL-Scan calculated using SRK/T can show a slight myopic tendency.

Keyword

AL-Scan; Intraocular power calculation; IOLMaster; Optical biometer

MeSH Terms

Anterior Chamber
Biometry
Cimetidine*
Humans
Lenses, Intraocular*
Medical Records
Myopia
Phacoemulsification
Refractive Errors
Retrospective Studies
Cimetidine

Figure

  • Fig. 1 Bland-Altman plots of biometric measurements from the AL-Scan and IOLMaster. (A) Mean axial length (AL), (B) mean keratometry 1 (K1), (C) mean K2, and (D) mean anterior chamber depth (ACD) with both biometers. D = diopters.


Reference

1. Fontes BM, Fontes BM, Castro E. Intraocular lens power calculation by measuring axial length with partial optical coherence and ultrasonic biometry. Arq Bras Oftalmol. 2011; 74:166–170.
Article
2. Olsen T. Calculation of intraocular lens power: a review. Acta Ophthalmol Scand. 2007; 85:472–485.
Article
3. Shammas HJ, Chan S. Precision of biometry, keratometry, and refractive measurements with a partial coherence interferometry-keratometry device. J Cataract Refract Surg. 2010; 36:1474–1478.
Article
4. Santodomingo-Rubido J, Mallen EA, Gilmartin B, Wolffsohn JS. A new non-contact optical device for ocular biometry. Br J Ophthalmol. 2002; 86:458–462.
Article
5. Drexler W, Findl O, Menapace R, et al. Partial coherence interferometry: a novel approach to biometry in cataract surgery. Am J Ophthalmol. 1998; 126:524–534.
Article
6. Huang J, Savini G, Li J, et al. Evaluation of a new optical biometry device for measurements of ocular components and its comparison with IOLMaster. Br J Ophthalmol. 2014; 98:1277–1281.
Article
7. Kaswin G, Rousseau A, Mgarrech M, et al. Biometry and intraocular lens power calculation results with a new optical biometry device: comparison with the gold standard. J Cataract Refract Surg. 2014; 40:593–600.
Article
8. Olsen T, Thorwest M. Calibration of axial length measurements with the Zeiss IOLMaster. J Cataract Refract Surg. 2005; 31:1345–1350.
Article
9. Bland JM, Altman DG. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet. 1986; 1:307–310.
Article
10. Kola M, Duran H, Turk A, et al. Evaluation of the repeatability and the reproducibility of AL-Scan measurements obtained by residents. J Ophthalmol. 2014; 2014:739652.
Article
11. Freeman G, Pesudovs K. The impact of cataract severity on measurement acquisition with the IOLMaster. Acta Ophthalmol Scand. 2005; 83:439–442.
Article
12. Eleftheriadis H. IOLMaster biometry: refractive results of 100 consecutive cases. Br J Ophthalmol. 2003; 87:960–963.
Article
13. Prinz A, Neumayer T, Buehl W, et al. Influence of severity of nuclear cataract on optical biometry. J Cataract Refract Surg. 2006; 32:1161–1165.
Article
14. Faria-Ribeiro M, Lopes-Ferreira D, Lopez-Gil N, et al. Errors associated with IOLMaster biometry as a function of internal ocular dimensions. J Optom. 2014; 7:75–78.
Article
15. Drexler W, Hitzenberger CK, Baumgartner A, et al. Investigation of dispersion effects in ocular media by multiple wavelength partial coherence interferometry. Exp Eye Res. 1998; 66:25–33.
Article
16. Olsen T. Sources of error in intraocular lens power calculation. J Cataract Refract Surg. 1992; 18:125–129.
Article
17. Holladay JT, Prager TC, Chandler TY, et al. A three-part system for refining intraocular lens power calculations. J Cataract Refract Surg. 1988; 14:17–24.
Article
18. Sheard R. Optimising biometry for best outcomes in cataract surgery. Eye (Lond). 2014; 28:118–125.
Article
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