Ultrasound Research Today is a free monthly online journal that collates and summarizes the latest research about Ultrasound, including details on screening, diagnosis, pregnancy, detection.

Meridional differences in internal dimensions of the anterior segment in human eyes evaluated with 2 imaging systems.

Werner L, Lovisolo C, Chew J, Tetz M, Müller M

John A. Moran Eye Center, University of Utah, Salt Lake City, Utah 84132, USA. liliana.werner@hsc.utah.edu

PURPOSE: To evaluate meridional differences in angle-to-angle (A-A) and sulcus-to-sulcus (S-S) dimensions in human eyes using very high frequency ultrasound (VHF US) and anterior segment optical coherence tomography (AS-OCT). SETTING: John A. Moran Eye Center, University of Utah, USA; Berlin Eye Research Institute, Germany; Quattroelle Centri Oftalmochirurgici, Italy. METHODS: Human autopsy eyes were fixated to special eye holders and had anterior segment scanning using 50 MHz ultrasound (Artemis, Ultralink) (20 eyes) and AS-OCT (SL-OCT, Heidelberg Engineering) (24 eyes). Seventy-three eyes (58 patients) also had anterior segment scanning using the same systems (Artemis, 50 eyes; SL-OCT, 23 eyes). Four meridians were evaluated in each eye. The A-A dimensions were measured by VHF US and AS-OCT. The S-S dimensions were also measured by VHF US. Statistical analyses were done with the Huynh-Feldt test. RESULTS: In the autopsy-eye study, the differences in A-A and S-S dimensions between the 4 meridians in eyes analyzed with VHF US were statistically significant (P=.002 and P=.009, respectively). The differences in A-A dimensions in eyes analyzed with the AS-OCT were also significant (P=.005). The same findings were observed in the clinical study (VHF US, P=.001 for A-A and P<.001 for S-S; AS-OCT, P<.001 for A-A). CONCLUSIONS: This study suggests that the internal geometry of the anterior segment of human eyes does not constitute a circle. This may have significant relevance for the accurate sizing of phakic intraocular lenses.

Published 23 June 2008 in J Cataract Refract Surg, 34(7): 1125-32.
Full-text of this article is available online (may require subscription).

© 2004-2008 Ultrasound Research Today. All Rights Reserved.