Abstract
Purpose :
Anterior chamber (AC) depth is commonly assessed as part of the ophthalmic examination, as a shallow AC is correlated with risk of acute and chronic angle closure glaucoma. AC depth is typically assessed through gonioscopy or the Van Herick method using a slit lamp. Telemedicine is now being employed to enable screening, diagnosis, and management of ophthalmic conditions. To evaluate the utility of telemedicine to assess AC depth, we implemented a modified slit lamp that can transmit stereoscopic images to remote ophthalmologists. In this study, ophthalmologists viewed and graded images captured on our device and matched the eye being observed with its corresponding anterior segment optical coherence tomography (AS-OCT) image. With binocularity, we hypothesized that graders would accurately identify AS-OCT images that correspond with each anterior limbal angle observed.
Methods :
Limbal AC images and AS-OCTs of 46 eyes were captured. With a VR headset, five ophthalmologists graded images as being shallow or deep, and selected the corresponding AS-OCT from a selection. Cohen kappa, Fleiss kappa, and Youden’s J statistic were used for statistical analysis to find cutoff points at which graders are able to most accurately identify shallow vs deep chambers using the angle opening distance (AOD500) measured on AS-OCT. Paired t-test was used to confirm statistical significance in AOD500 between eyes judged as having a shallow vs deep limbal AC.
Results :
Results showed moderate inter-rater reliability (Fleiss Kappa = 0.476). The reliability of assessments made in-person and remotely by the same grader was fair (Cohen Kappa = 0.242). The mean AOD for our study population was 408um (SD = 176) um. Eyes judged as shallow had a mean of 282 um (SD = 102 um). Eyes judged as deep had a mean of 507 um (SD = 160 um). When using this remote viewing method, the difference in AOD500 between eyes judged as having a shallow vs deep limbal AC was statistically significant (t(32) = 4.7391, p < 0.0001).
Conclusions :
Remote assessment of the AC depth using stereoscopic images is an internally reliable method with moderate inter-rater reliability for examining the anterior chamber. There is a statistically significant difference between AOD500 measurements of shallow versus deep AC, further reinforcing the ability to resolve depth using this remote stereoscopic viewing method.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.