Abstract
Purpose :
Corneal measurements obtained from the physical exam are the gold standard used to monitor the progression of pathological states (for example keratoconus and congenital glaucoma) despite the availability of newer technologies. We tested the hypothesis that structures measured from ultrasound biomicroscopy (UBM) images correlate with related physical exam findings using a prospective comparative clinical study.
Methods :
Ultrasound biomicroscopy (UBM) images were obtained from a total of 181 eyes and 53 patients (mean age 6 years, +/- 12 years, median age to years) who were prospectively enrolled after consent in this study at the University of Maryland, Baltimore, Maryland. Ruler and calipers were used to measure external corneal diameter from color photograph (Figure 1a). ImageJ was used to measure angle to angle width of the anterior chamber (Figure 1b). Correlation coefficient and significance testing for eyes with and without glaucoma were performed.
Results :
Preliminary data suggests a statistically significant correlation between angle to angle (AA) distance and corneal diameter in glaucoma patients (r = 0.6, p = 0.007). Correlation for non glaucoma eyes was weak (r=-0.189) and not significant (p=0.3) (Figure 2). The linear relationship does not hold for angle to angle distances less than 10mm. Bland Altman plots were constructed to evaluate the agreement between image-based and ruler measurements.
Conclusions :
This is the first study identifying relationships between physical exam findings and quantitative features extracted from UBM images in the anterior segment.
This is a 2021 ARVO Annual Meeting abstract.