Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Multicenter Study
. 2018 Jun;44(6):701-708.
doi: 10.1016/j.jcrs.2018.03.027. Epub 2018 Jun 1.

Refractive outcomes of intraocular lens power calculation using different corneal power measurements with a new optical biometer

Affiliations
Multicenter Study

Refractive outcomes of intraocular lens power calculation using different corneal power measurements with a new optical biometer

Giacomo Savini et al. J Cataract Refract Surg. 2018 Jun.

Abstract

Purpose: To evaluate the results of intraocular lens (IOL) power calculation using different corneal power measurements provided by an optical biometer combined with a dual Scheimpflug analyzer and a Placido disk topographer (Galilei G6).

Setting: G.B. Bietti Foundation, Rome, Italy, and Keio University Hospital, Tokyo, Japan.

Design: Evaluation of diagnostic technology.

Methods: Consecutive patients having cataract surgery were enrolled. The IOL power was calculated with the Barrett Universal II, Haigis, Hoffer Q, Holladay 1, and SRK/T formulas. Different options were used to calculate the corneal power: simulated keratometry (K) based on anterior corneal surface measurements only and total corneal power (TCP) based on ray tracing through both corneal surfaces. Three TCP measurements (TCP1, TCP2, and TCP-IOL) were evaluated.

Results: The study analyzed 118 eyes. The mean values of simulated K (43.74 diopters [D] ± 1.40 [SD]), TCP1 (43.13 ± 1.35 D), TCP2 (41.87 ± 1.30 D), and TCP-IOL (42.62 ± 1.35 D) were significantly different (P < .0001). The best results were obtained using simulated K: the median absolute error ranged between 0.22 D and 0.29 D and the percentage of eyes with a prediction error of ±0.50 D or less, between 76.2% and 84.7%, depending on the formula. After constant optimization, the results using any TCP value and simulated K were similar with no statistically significant differences.

Conclusions: Biometric measurements provided by the Scheimpflug-Placido optical biometer can be used to accurately calculate the IOL power. Simulated K and TCP led to similar outcomes after constant optimization.

PubMed Disclaimer

Publication types