Quantification of Anterior Chamber Cells in Children With Uveitis Using Anterior Segment Optical Coherence Tomography

Abstract

Purpose: To evaluate the feasibility of anterior segment optical coherence tomography (AS-OCT) for measuring anterior chamber (AC) cells in children with uveitis and to compare different AS-OCT acquisition modes.

Design: Validity and reliability analysis.

Methods: We enrolled children younger than 18 years who had uveitis involving the anterior segment and children without eye disease as controls. All underwent clinical grading of AC cells. AC images of each eye were obtained using the Optovue Avanti RTVue XR AS-OCT. Two acquisition modes were used: a single cross-sectional line scan and an 8-line radial scan in an asterisk pattern. Two independent, masked graders counted cells manually on AS-OCT images. Rater agreement was assessed using intraclass correlation (ICC).

Results: Included were 30 children (59 eyes) with uveitis (median age 13.0 years, range 3-17 years) and 20 control children (40 eyes, median age 10.5 years, range 4-17 years). The number of eyes assigned each clinical grade of cells were as follows: none, 32 (54%); 0.5+, 12 (20.3%); 1+, 5 (8.5%); 2+, 8 (13.6%); 3+, 2 (3.4%). ICC of graders for line and radial scan protocols were 0.87 and 0.90. There was no significant difference between acquisition modes for pooled grader results (95% CI for difference: -0.04 to 0.14). ICC of cell counts between line and radial scan protocols was 0.85 (95% CI: 0.69-0.90). No control eyes had cells on AS-OCT images.

Conclusions: Quantification of AC cell in children with uveitis is feasible with AS-OCT and has excellent reliability between different graders and acquisition modes.

Keywords: anterior segment optical coherence tomography; anterior uveitis; optical coherence tomography; pediatrics; uveitis.

Figure 1.

Schematic of a single cross-sectional line AS-OCT scan (A) through the central anterior chamber compared to the eight-line radial scans (B).

Figure 2.

Representative images of AS-OCT single line scans through the central anterior chamber from grades 0 to 3+ using the Standardization of Uveitis Nomenclature (SUN) Working Group criteria. Hyperreflective foci represent cells in the anterior chamber.

Figure 3.

Bland-Altman plot showing the difference in cell counts between Grader 1 and Grader 2 for single line scans (A) and 8-line radial scans (B). The solid red lines show the mean difference. The dotted blue line shows 95% limits of agreement (±1.96 standard deviations).

Figure 4.

Scatterplot demonstrating the number of cells for the AS-OCT 8-line radial scans compared to single line scans. The intraclass correlation between 8-line radial scans and single line scans was 0.85 (95% confidence interval of 0.69 to 0.90). Note that “jitter” was added to the scatterplot display to avoid overlapping dots, thereby demonstrating more effectively the distribution of all data points. As a result, the 8 dots from the radial technique for individual study participants are not in perfect vertical alignment.

Figure 5.

Box and whisker plots demonstrating the number of hyperreflective foci that were counted in AS-OCT (A) single line scans and (B) 8-line radial scans. Lines inside the box represent medians. The lines of the box represent the first and third quartiles. Both single line scans and 8-line radial scans were significantly correlated with SUN grades with p < 0.001 for both imaging modes. SUN: Standardization of Uveitis Nomenclature.