J Korean Ophthalmol Soc.  2010 Mar;51(3):328-332.

Comparison of Keratometric Values Measured by the Handheld Autokeratometer, On-table Autokeratometer and Manual Keratometer

• Lee KM
• Park SH
• Shin SY

Abstract

PURPOSE
To compare the keratometry measurements by the handheld Nikon Retinomax K-plus2, the on-table Canon RK-5 autokeratometer, and the manual Topcon OM-4 keratometer and to evaluate the degree of agreement among the three instruments.
METHODS
Adults (n=30) and children (n=40) presenting toa tertiary eye hospital clinic were examined by an optometrist. Topcon OM-4 keratometer, Nikon Retinomax and the on-table Canon RK-5 autokeratometer analyses were performed in order. The horizontal and vertical keratometry data were measured. The vector components of astigmatism, mean bias and agreement among the three types of measurements were evaluated.
RESULTS
There were no significant differences among the three keratometers in horizontal or vertical keratometry or in central corneal astigmatism in both the adult and child groups (p-value>0.05). The keratometers which were estimated with Retinomax K-plus2 were highly correlated with those by on-table RK-5 autokeratometer (min. 0.89, max. 0.97) and Topcon OM-4 keratometer (min. 0.67, max. 0.94) in the adult group, while in the child group, the three instruments showed slightly decreased correlation (min. 0.45, max. 0.97 on RK-5, min. 0.36, max. 0.92 on OM-4), especially in the left eyes.
CONCLUSIONS
The handheld Retinomax K-plus2 provided comparable data to that of the conventional on-table Topcon and manual keratometers. This instrument will beuseful in the clinic to measure keratometry in children or immobilized patients who have difficulty sitting during the examination.

Keyword

Autokeratometer; Hand-held keratometer; Manual keratometer; Retinomax K-plus2

MeSH Terms

Adult
Astigmatism
Bias (Epidemiology)
Child
Eye
Humans

Figure

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  Figure 1. Composition of Retimax K-plus2.

Reference

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