Stereo vision based optic nerve head 3D reconstruction using a slit lamp fitted with cameras: performance trial with an eye phantom

Preventing vision loss from glaucoma, the second leading cause of blindness globally, relies on early detection and intervention. A key clinical indicator for early detection is structural change of the optic nerve head (ONH), which impacts the ONHs three-dimensional footprint on the retina. Clinically, such footprint is commonly assessed by subjective observation through a slit lamp, with significant inter- and intra-observer variability. Objective devices that rely on 3D imaging show promise in increasing diagnostic accuracy within clinics but are prohibitively expensive for many. In previous work, we demonstrated the initial feasibility of obtaining 3D surface images by applying stereo vision techniques to a slit lamp fitted with low-cost cameras. In this paper, we present the assessment of the precision and accuracy of our system with ONH targets in an eye phantom. Quantitative reconstructions, referenced to ground truth data, were obtained. Current results, albeit promising, suggest that more work is likely needed to improve accuracy and precision to a clinically significant level.