Korean J Ophthalmol.  2011 Jun;25(3):151-155. 10.3341/kjo.2011.25.3.151.

Intraocular Lens Power Calculation Using IOLMaster and Various Formulas in Short Eyes

• Roh YR
• Lee SM
• Han YK
• Kim MK
• Wee WR
• Lee JH

• KMID: 1010020
• DOI: http://doi.org/10.3341/kjo.2011.25.3.151

Abstract

PURPOSE
To evaluate the predictability of intraocular lens (IOL) power calculations using the IOLMaster and four different IOL power calculation formulas (Haigis, Hoffer Q, SRK II, and SRK/T) for cataract surgery in eyes with a short axial length (AL).
METHODS
The present study was a retrospective comparative analysis which included 25 eyes with an AL shorter than 22.0 mm that underwent uneventful phacoemulsification with IOL implantation from July 2007 to December 2008 at Seoul National University Boramae Hospital. Preoperative AL and keratometric power were measured by the IOLMaster, and power of the implanted IOL was determined using Haigis, Hoffer Q, SRK II, and SRK/T formulas. Postoperative refractive errors two months after surgery were measured using automatic refracto-keratometry (Nidek) and were compared with the predicted postoperative power. The mean absolute error (MAE) was defined as the average of the absolute value of the difference between actual and predicted spherical equivalences of postoperative refractive error.
RESULTS
The MAE was smallest with the Haigis formula (0.37 +/- 0.26 diopter [D]), followed by those of SRK/T (0.53 +/- 0.25 D), SRK II (0.56 +/- 0.20 D), and Hoffer Q (0.62 +/- 0.16 D) in 25 eyes with an AL shorter than 22.0 mm. The proportion with an absolute error (AE) of less than 1 D was greatest in the Haigis formula (96%), followed by those in the SRK II (88%), SRK-T (84%), and Hoffer Q (80%).
CONCLUSIONS
The MAE was less than 0.7 D and the proportion of AE less than 1 D was more than 80% in all formulas. The IOL power calculation using the Haigis formula showed the best results for postoperative power prediction in short eyes.

Keyword

Intraocular lens power calculation; IOLMaster; Short eyes

MeSH Terms

Aged
Aged, 80 and over
Female
Humans
Lens Implantation, Intraocular
*Lenses, Intraocular
Male
Middle Aged
*Optics and Photonics
Phacoemulsification
Postoperative Period
Refractive Errors/diagnosis/physiopathology
Retrospective Studies

Figure

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  Fig. 1 Means and standard deviations of the absolute errors the four intraocular lens calculation formulas.

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  Fig. 2 Proportion of the absolute errors (AE) less than 1 diopter (D) according to the intraocular lens formulas.

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  Fig. 3 Relationships between axial length and anterior chamber depth (ACD). Dots represent data points (linear regression analysis).

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  Fig. 4 Means and standard deviations of the mean errors of the four intraocular lens calculation formulas.

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