Abstract
Purpose :
Ophthalmic microsurgery is typically performed through a stereoscopic operating microscope which provides limited depth perception. Microscope integrated OCT (MIOCT) can augment the surgeon’s view by providing high resolution, depth resolved imaging. However, most previously reported MIOCT systems use 100 kHz or slower OCT engines, limiting these systems to B-scan imaging or slow (~3 Hz) volumetric imaging. This limits their utility for surgical guidance as the former lacks lateral context and the latter is too slow to capture dynamic surgical maneuvers. In order to facilitate real time, 4D guidance of surgery we have developed a new, high speed 4D MIOCT system based on a 400 kHz laser.
Methods :
A commercially available Enfocus MIOCT scanner was modified for high speed swept source OCT. The OCT engine used a 400 kHz, 1050 nm swept frequency laser. Light from the laser was introduced into modified scanner and illuminated a transmissive Mach-Zender interferometer. A Truevision (Goleta, CA) 3D visualization system was used to provide heads up, stereoscopic visualization of both the surgical field and OCT data on a 3D TV. Optical power on the sample was below 5.5 mW in accordance with ANSI Z80.36 standard for 1050 nm light.
Results :
High Speed MIOCT imaging was performed using a 300 A-scan/B-scan, 180 inactive lines per B-scan, and 96 B-scans/volume scanning protocol (8.68 Hz volume rate). MIOCT images were acquired during mock surgical maneuvers performed with a membrane scraper in ex-vivo porcine eyes. The increased volume rate enables the surgeon to monitor the tool tissue interaction and manipulate the pockets of sub-retinal fluid using 4D MIOCT guidance only.
Conclusions :
We have demonstrated a real time 4D MIOCT system for visualization of mock surgical maneuvers. Based on these results we believe this system will be readily translated into human surgery.
This is a 2020 ARVO Annual Meeting abstract.