Ease of use versus accuracy.

摘要

I would like to respond to Baikoff's less than concise reply to my letter to the editor in the August issue. My own letter made 2 basic points: First, that the assertions by Baikoff et al. that the Artemis ultrasound system is difficult to use were overstated; and second, that in contrast to arc scan ultrasound, anterior segment optical coherence tomography (AC-OCT) is very sensitive to refractive "warping," which might lead to inaccuracies in biometry. In his letter, Baikoff states that "we must rely on the engineers" who developed the dewarping algorithms to ensure that biometric values are accurate. I have no reason to doubt the competence of the engineers-my concern is that variability in the physical properties of anterior segment structures responsible for refraction cannot be fully compensated for when they are unknown. In his letter, Baikoff describes AC-OCT findings regarding measurement of anterior chamber depth, which are meant to provide validation of biometric accuracy. Anterior chamber depth measurements, however, would be expected to be almost entirely unaffected by refractive distortion because in this instance, the light rays are of normal incidence to the cornea. Distortion would be expected to mainly affect anterior chamber diameter measurements, where light rays must traverse the cornea at a more oblique angle of incidence as they diverge from the central axis.