Abstract
Purpose :
The current abstract focuses on the technical aspects and capabilities of the novel cell-resolution anterior eye imaging technology, Optical transmission tomography (OTT). This technology will be presented for the first time at ARVO 2024.
Methods :
In vivo ophthalmic OTT was inspired by the two scientific directions: 1) OTT in ex vivo microscopy (https://doi.org/10.1364/BOE.453586) as well as the 2) Asymmetric retroillumination microscopy. OTT relies on the back-illumination from the fundus of the eye and common-path interference with Gouy effect to highlight the anterior eye structures with high contrast. Unlike the majority of imaging methods working in ‘reflection’, OTT provides unique ’transmission’ contrast that can help uncover new understanding about the structural organization of the ocular layers. The interference nature of OTT makes it capable of optical sectioning - rejection of the out-of-focus light for improved contrast (Fig. 1).
Early conceptual imaging study involved 2 young healthy subjects (25-40 y/o, 1 female and 1 male) and fast non-contact examination (1-5 minutes with 10 ms exposure time per image).
Results :
OTT revealed cell-resolution corneal and lenticular structures with 1 µm resolution across the field of view (FOV) of 2.5 mm × 1.5 mm (Fig. 2). This field was 25× larger in area than that of the confocal and specular microscopies and 3× larger than that of the advanced research system (e.g. Curved-field OCT). Even larger FOV of 4 mm × 2.5 is possible in the future at the expense of reduced resolution. Precise endothelial cell counts across large FOV can improve selection of candidates for cataract surgeries and reduce the number of post-surgical corneal failures, while the precise sub-basal nerve measurements can help to identify patients with early dry eye and weigh the risks of performing refractive surgery.
Conclusions :
Optical transmission tomography is a new anterior eye imaging tool that bridges the micro and macro worlds. Cell-resolution view on global scale can help in improving the diagnosis, follow-up and understanding of the complex corneal and lenticular conditions.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.