Purpose: To measure the ciliary sulcus-to-sulcus (STS) diameter in 4 axes in emmetropic and myopic eyes using ultrasound biomicroscopy (UBM) and compare the measurements with automated horizontal white-to-white (WTW) diameter measurements.
Setting: University Eye Hospital Freiburg, Freiburg im Breisgau, Germany.
Design: Evaluation of diagnostic technology.
Methods: The STS diameter was measured at 0, 45, 90, and 135 degrees using 35 MHz UBM. The 0-degree WTW diameters were obtained using scanning-slit topography (Orbscan) and partial coherence interferometry (PCI) biometry (IOLMaster). The 0-degree STS and 90-degree STS were compared using the paired t test; the Pearson correlation was used to assess whether the 0-degree STS diameter could be predicted from the 0-degree WTW diameter.
Results: The mean SE refraction was -0.48 diopter (D) ± 0.35 (SD) in emmetropic eyes and -9.55 ± 3.70 D in myopic eyes. In 35 of 37 eyes, 90-degree STS was greater than 0-degree STS. The mean 90-degree STS was 12.51 ± 0.43 mm. The mean 0-degree STS was 12.19 ± 0.47 mm (P<.01). The mean 0-degree WTW diameters were 11.73 ± 0.37 mm (scanning-slit topography) and 12.20 ± 0.42 mm (PCI biometry). The correlations were good between 0-degree STS and 0-degree WTW with PCI biometry (r(2) = 0.82) and scanning-slit topography (r(2) = 0.86) in emmetropic eyes but weak between 0-degree STS and 0-degree WTW in myopic eyes (r(2) = 0.36 and r(2) = 0.40, respectively).
Conclusions: Sulcus diameter measurements were most precise using UBM. The ciliary sulcus is vertically oval. The WTW diameter is not suitable for calculating a PC pIOL diameter, particularly in myopic eyes.
Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.