Intraoperative Spectrally Encoded Coherence Tomography and Reflectometry (iSECTR) for Ophthalmic Surgical Guidance.

PURPOSE

We present an optimized intraoperative spectrally encoded coherence tomography and reflectometry (iSECTR) system integrated with a Zeiss OPMI VISU 200 ophthalmic surgical microscope (Zeiss, Oberkochen, Germany).

METHODS

An iSECTR scan-head was designed to overcome previous barriers to clinical translation by improving system stability, optimizing optical throughput, reducing reflection artifacts, and adding motorized focus-adjust functionality. The iSECTR imaging performance was demonstrated in in vivo human eyes and during simulated ophthalmic surgical maneuvers in ex vivo porcine eyes.

RESULTS

The optimized iSECTR scan-head achieved a footprint of 19.67 × 30.2 cm (width × length) and a surgical microscope stack height increase of only 6.06 cm. Motorized focusing was able to accommodate for ±10 D of focal shift to accommodate refractive power differences across surgeons. In vivo and ex vivo iSECTR imaging was able to resolve clinically relevant retinal and corneal tissue features and tissue deformation from conventional surgical instruments during simulated ophthalmic surgical maneuvers.

CONCLUSIONS

This work demonstrates the performance of our iSECTR scan-head for ophthalmic intraoperative optical coherence tomography (iOCT). Our robust modular design allows for stable performance that is suitable for clinical translation. The improved spectrally encoded reflectometry (SER) imaging performance allowed for reproducible anterior and posterior eye imaging in both in vivo and ex vivo eyes, and independent iSECTR focus-adjust further enhances clinical ergonomics. Clinical translation of iSECTR technologies will provide a research platform for automated retinal- and instrument-tracking and four-dimensional visualization of surgical dynamics.

TRANSLATIONAL RELEVANCE

Design considerations for minimizing footprint, microscope stack height, and integration of motorized focus-adjust were emphasized to benefit surgical ergonomics and clinical translation.