Visualization of Cataract Surgery Steps With 4D Microscope-Integrated Swept-Source Optical Coherence Tomography in Ex Vivo Porcine Eyes

Abstract

Purpose: To investigate the visualization capabilities of high-speed swept-source optical coherence tomography (SS-OCT) in cataract surgery.

Methods: Cataract surgery was simulated in wet labs with ex vivo porcine eyes. Each phase of the surgery was visualized with a novel surgical microscope-integrated SS-OCT with a variable imaging speed of over 1 million A-scans per second. It was designed to provide four-dimensional (4D) live-volumetric videos, live B-scans, and volume capture scans.

Results: Four-dimensional videos, B-scans, and volume capture scans of corneal incision, ophthalmic viscosurgical device injection, capsulorrhexis, phacoemulsification, intraocular lens (IOL) injection, and position of unfolded IOL in the capsular bag were recorded. The flexibility of the SS-OCT system allowed us to tailor the scanning parameters to meet the specific demands of dynamic surgical steps and static pauses. The entire length of the eye was recorded in a single scan, and unfolding of the IOL was visualized dynamically.

Conclusions: The presented novel visualization method for fast ophthalmic surgical microscope-integrated intraoperative OCT imaging in cataract surgery allowed the visualization of all major steps of the procedure by achieving large imaging depths covering the entire eye and high acquisition speeds enabling live volumetric 4D-OCT imaging. This promising technology may become an integral part of routine and advanced robotic-assisted cataract surgery in the future.

Translational relevance: We demonstrate the visualization capabilities of a cutting edge swept-source OCT system integrated into an ophthalmic surgical microscope during cataract surgery.

Figure 1.

Clear corneal incision (A–D) and OVD injection (E–H) imaged with 4D-OCT. (A) Knife tip above cornea. (B–D) Corneal incision. (E–H) OVD injection. Black and white arrows indicate the knife in A–C. In E–H, black and white arrows refer to the cannula.

Figure 2.

The 4D visualization of capsulorrhexis. (A) Initial punctuation of the anterior capsule performed with a slit-angled knife. (B) Deformation of initial cut is indicated by the blue arrow. (C) Forceps inserted through the corneal incision and approaching puncture. (D) Forceps grasping initial puncture to create flap.

Figure 3.

B-scan series of phacoemulsification (A–D) and IOL unfolding process (E–G). (A) Nucleus emulsification has just started. (B) A central groove was sculpted in the nucleus with a depth of approximately 50% of the natural lens height. (C) The groove was advanced towards posterior. (D) The nucleus was removed with a small lens fragment remaining in the anterior chamber. (E) IOL is injected in the capsular bag. The IOL unfolding started and the injector is visible. (F) IOL unfolding continues. (G) Position of IOL in the capsular bag after unfolding.

Figure 4.

Different perspectives of IOL position in the capsular bag. The entire length of the eye, from cornea to retina, is shown in each scan. Images were averaged five times. (A) Rendered raster capture scan demonstrating the IOL position in the capsular bag. (B) Iris and capsulorrhexis from the anterior view. (B) Capsulorrhexis from the posterior view. The white arrow indicates an edge of the flap. (D) B-scan of IOL position in the capsular bag. For A–C, scanner amplitude is scaled to 1.5 to cover a larger FOV of 18.6 mm.