How to optimize 3D visualization for surgery

David R. Chow

FORT LAUDERDALE, Fla. — Several variables can be adjusted on 3D visualization systems to optimize lateral resolution, depth of field and illumination to maximize visualization for surgeons during procedures, according to a speaker here.

“How do we maximize our visual resolution on these systems? When we talk about visual metrics of performance on an NGenuity system, we’re looking at lateral resolution, depth of field, and depth resolution ... specifically, I will look at the effect of surgeon-controlled variables and how they will affect these metrics,” David R. Chow, MD, FRCSC, said at Retina World Congress.

Using real-world data collected from their own NGenuity 3D visualization system (Alcon) hooked up to their Zeiss Lumera, Chow and his colleagues evaluated the best distance needed for the television camera, aperture levels, and magnification levels to optimize lateral resolution, depth of field, and illumination for a surgeon.

To optimize both resolution and depth of field, the television camera should be 1.2 meters away from the surgeon during a procedure and magnification should be set at “high magnification 20x.” The 1.2-meter distance is much closer than most surgeons realize, usually at a patient’s knees, so it requires some finesse to position the camera around the bed, nursing staff, vitrectomy console, and drapes, Chow said.

Depth of field can be optimized with the aperture setting on the NGenuity system set at 30% for procedures. Chow and colleagues collected data from fellows performing three tasks bimanually with two forceps randomized to either 30% aperture first or 75% aperture first. Fellows performed their tasks quicker and with less errors at the 30% aperture setting, he said.

Illumination is optimized at 20% pipe light, which provides enough light for a procedure but does not put the patient at great risk for phototoxicity.

“Bottom line, to maximize visual performance with the NGenuity, you need 1.2 meters, 30% on the aperture, maximum magnification when you’re peeling membranes, and 20% (illumination) gives us a nice compromise for output,” he said.

– by Robert Linnehan

Reference: Chow DR. Science of 3D Visualization Systems. Presented at: Retina World Congress; March 21 to 24, 2019; Fort Lauderdale, Fla.

Disclosure: Chow reports no relevant financial disclosures.