Interchangeability of corneal curvature and asphericity measurements provided by three different devices

Session Details

Session Title: Presented Poster Session: Keratorefractive Surgery Results II

Venue: Poster Village: Pod 2

First Author: : D.Piñero Llorens SPAIN

Co Author(s): :    P. Ruiz-Fortes   H. Fukumitsu   R. Soto-Negro                 

Abstract Details

Purpose:

To evaluate the interchangeability of keratometric and asphericity measurements provided by three measurement systems based on different optical principles

Setting:

Department of Optics, Pharmacology and Anatomy of University of Alicante and Department of Ophthalmology of Vithas Medimar International Hospital

Methods:

A total of 40 eyes of 40 patients with a mean age of 34.1 years were included. In all cases, a corneal curvature analysis was performed with IOL-Master (Carl Zeiss Meditec) (IOLM), iDesign 2 (Johnson & Johnson Surgical Vision) (ID2), and Sirius systems (CSO) (SIR). Differences between instruments for flattest (K1) and steepest keratometric readings (K2), as well as for magnitude (Ast) and axis (Ax) of corneal astigmatism were analyzed using the Bland-Altman method and calculating the ranges of agreement (RoA). Likewise, differences in asphericity (Q) between SIR and ID2 were also evaluated.

Results:

Mean differences between devices for K1 were 0.20±0.21 (p<0.001), -0.12±0.36 (p=0.046) and -0.32±0.36 D (p<0.001) for the comparisons IOLM-SIR, IOLM-ID2 and SIR-ID2, respectively (RoA: 0.41, 0.70, and 0.70 D). For K2, mean differences were 0.31±0.33 (p<0.001), -0.08±0.43 (p=0.265) and -0.39±0.38 D (p<0.001) (RoA: 0.65, 0.84, and 0.74 D). Concerning Ast, RoA were in the limit of clinical relevance (0.49 D, p=0.011; 0.55 D, p=0.386; 0.43 D, p=0.05). In contrast, RoA were clinically relevant for Ax (26.68º, 33.83º and 18.37º, p≥0.121) and Q between SIR and ID2 (0.16, p<0.001).

Conclusions:

The keratometric corneal power, astigmatic axis and asphericity measurements provided by the three systems evaluated cannot be considered as interchangeable, whereas measurements of corneal astigmatism obtained with SIR and iD2 can be considered as interchangeable for clinical purposes

Financial Disclosure:

... research is funded, fully or partially, by a company producing, developing or supplying the product or procedure presented