Abstract
Purpose :
To demonstrate the clinical performance of a novel imaging system for standardized, high-resolution external eye photography. To highlight the importance of imaging standardization for high throughput ocular surface photography for improving the management of ocular surface diseases (OSD).
Methods :
An imaging prototype was used to capture ocular surface photographs from healthy subjects and patients with various OSDs consulting an ophthalmic outpatient clinic. The system is equipped with a custom-made objective with a convex focal surface, which was parametrized by the external ocular curvature. As a result, the camera can capture the entire visible ocular surface in focus with a single shot. In addition, an integrated fixation target, an automated iris tracker, a single illumination setting and an auto-focus mode complete the set of standardized imaging parameters. The prototype's performance was evaluated in a prospective clinical trial and compared to slit-lamp photography.
Results :
An exemplary image of a healthy volunteer is shown in Fig. 1A. High-resolution imaging, which allows the visualization of limbal capillaries, can be obtained for the entire visible ocular surface. Automated eye tracking guarantees imaging with a centralized iris in a primary gaze direction, which is an essential requirement for longitudinal observation and documentation of OSDs. Exemplary longitudinal series of patients with pinguecula and pterygium are shown in Fig. 1B and 1C imaged at intervals of 20 and 14 weeks, respectively. Additionally, eyes with various ocular surface pathologies were imaged, including penetrating corneal grafts, corneal foreign bodies, superficial punctate keratitis, and microbial conjunctivitis. Images of three example cases are shown in Fig. 2, including a comparison to images acquired with a slit-lamp camera. Conjunctival vasculature can be observed in greater detail when compared to slit-lamp photography. Imaging standardization minimized gaze-dependent image decentration and lightness variability. Slit-lamp photographs, however, showed a clearer appearance of the central cornea with currently used illumination settings tailored for conjunctival imaging.
Conclusions :
The novel external eye photography system is able to capture high quality images with details of OSDs, as required for clinical and research purposes, thus standardizing the process.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.