Mixed Reality (MR) Based Slit Lamp: The First Step Toward XR-Ophthalmology.

This study demonstrates the concept of Mixed Reality (MR) based slit lamp (MR-SLP), which can display real-time stereoscopic diagnostic images of the eye both locally and remotely, making it suitable for stereoscopic tele-ophthalmology applications. In MR-SLP, two high-resolution video cameras were mounted on the left and right viewing channels of a conventional slit lamp to capture corresponding diagnostic images in real time, which were then transmitted to multiple MR headsets via a broadcast network. The operator wears the MR headset to see the stereoscopic diagnostic images and operates the slit lamp using the MR's see-through function. The system's depth perception, a key feature inherited from the slit lamp, was quantitatively tested using a tube-threading task. The feasibility of tele-ophthalmology was evaluated across multiple sites with subjective feedback from participants. The results showed no observable differences in image quality or depth perception between local and remote sites, and ophthalmologists participated in this study reported a user experience with the MR-SLP that was comparable to a conventional slit lamp. Furthermore, the tube-threading test indicated that the time taken to complete the task was similar when using the MR-SLP compared to the direct view through the eyepieces. This study successfully demonstrates the feasibility of the MR-SLP for transmitting high-quality stereoscopic slit lamp images to multiple MR devices in real-time, without distance limitations, wherever an internet connection is available.