Related Experiment Video
Updated: Jan 22, 2026

Comparison of Agreement and Accuracy using Binocular Wavefront Optometer with Autorefractor and Phoropter
Published on: September 16, 2025
Agreement of ocular biometry measurements between 2 biometers
1Virginia Eye Consultants, Norfolk, Virginia, USA.
Purpose:
To establish the agreement of routine measurements taken before cataract surgery between the Aladdin biometer, which is based on optical low-coherence interferometry (OLCI), and the Lenstar biometer, which is based on optical low-coherence reflectometry (OLCR).
Setting:
Virginia Eye Consultants, Norfolk, Virginia, USA.
Design:
Prospective case series.
Methods:
Biometry parameters in the same eye were measured using the OLCI biometer and the OLCR biometer at separate preoperative visits. Measured parameters included axial length (AL), anterior chamber depth (ACD), keratometry (K) values (flat K, steep K, steep K axis), lens thickness, central corneal thickness (CCT), and the white-to-white (WTW) distance. Adverse events were monitored.
Results:
Data were collected for 101 eyes (65 right eyes) of 101 patients (mean age 67.9 years ± 7.2 [SD]). The mean values measured by the OLCI biometer and OLCR biometer, respectively, were as follows: AL, 23.88 ± 1.23 mm and 23.89 ± 1.23 mm; ACD, 3.24 ± 0.36 mm and 3.25 ± 0.37 mm; flat K, 43.63 ± 1.65 diopters (D) and 43.61 ± 1.67 D; steep K, 44.59 ± 1.76 D and 44.61 ± 1.77 D; lens thickness, 4.61 ± 0.39 mm and 4.45 ± 0.45 mm; CCT, 0.55 ± 0.04 mm and 0.55 ± 0.04 mm; and WTW distance, 11.63 ± 0.41 and 12.03 ± 0.49 mm. There was a high correlation between all parameter measurements obtained by the 2 devices. No adverse events occurred.
Conclusion:
The measurements of the OLCI biometer were as reliable and reproducible as those of a leading biometer on the market, with the former having the advantage of an incorporated full corneal topographer.
Related Concept Videos
meta-Directing Deactivators: –NO2, –CN, –CHO, –⁠CO2R, –COR, –CO2H
2° Amines to N-Nitrosamines: Reaction with NaNO2
SN2 Reaction: Kinetics
In a chemical reaction, a relationship exists between the concentration of reactants and the rate at which the reaction proceeds. The study to measure this relationship is known as the kinetics of a chemical reaction. Kinetic studies are used to deduce the rate law of a chemical reaction, which provides information about the species involved during the transition state of the rate-determining step. Thus, kinetic studies help to derive the mechanism of a...
SN2 Reaction: Mechanism
The presence of the more electronegative halogen in the substrate creates a polarized carbon-halide bond. The halide pulls the electron cloud generating an electrophilic center at the carbon atom. Thus, the carbon atom carries a partial positive charge while the halide has a...
SN2 Reaction: Transition State
When the nucleophile approaches the electrophilic carbon with its lone pairs, the halide acts as a leaving group and moves away with the electron-pair bonded to the carbon. Dotted partial bonds represent the bonds being formed or broken...
SN2 Reaction: Stereochemistry
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not...

