Corneal thickness evaluation using ultrasonic technique

Abstract

The dog eye was used to compare different methods of cornea ultrasonic investigation and evaluate the changes of corneal thickness of canine eye after death. The corneal thickness was measured using ultrasonic pachymeter (frequency of transducer 16 MHz), the signals have been fixed in the digital oscilloscope, the real signals have been transmitted into PC and processed by program pack Matlab. The corneal thickness was counted from the signal, spectrum and cepstrum.

The twenty mixed-breed adult dogs were used in this study. Results of the different ultrasonic investigations showed that the counting of corneal thickness from spectrum was the most precise: average square deviation and dispersion was the least. Immediately after death cornea thickness decreased because of changes of dehydration state especially reduced tear production. After enucleation corneal thickness progressively increased; corneal thickness similar as in vivo 55 min. after enucleation, 2 hours after enucleation cornea was thicker that in vivo and the cornea was the thickest 24 hours after death.