New 3D imaging system of surgical field provides benefits

The surgeon does not have to keep refocusing because the system has a large depth of focus (about 25 mm).

San Francisco-State-of-the-art microsurgery has reached a new level with the development of a 3D imaging system for visualization of the surgical field, explained David Miller, MD, who spoke during the Innovator's Session at the American Society of Cataract and Refractive Surgery annual meeting.

The Digital Microsurgical Workstation System by 3D Vision Systems, Irvine, CA, offers ophthalmic surgeons the ability to view a magnified image of the surgical field without bending over a large binocular microscope. This system can eliminate the back and neck pain that some surgeons suffer as a result of working with a traditional microscope.

This new imaging system can also alleviate other problems, such as eye fatigue from looking through eye pieces, too much light in the patient's eye, and limited depth of focus, said Dr. Miller, associate clinical professor of ophthalmology, Harvard Medical School, Boston, and co-inventor of the device.

"Because of the polarizing glasses, each eye gets the different image and then the surgeon's brain puts it together in a 3D impression," said Dr. Miller, who is on the medical advisory board of 3D Vision Systems.

Other advantages of the microsurgical workstation include the ability to enhance the digital image by brightening the image and imposing different templates on the eye during surgery. Because the surgeon is working with a computerized digital image, it can be lightened electronically, avoiding the need to pour more light on the patient. It is also possible to place templates on the image to guide the physician, such as a capsulorhexis circle, a protractor for the limbus, and real-time topography, he said.

The surgeon can also remove imagery from the operative field.

"If the surgeon is faced with some annoying artifacts, such as corneal reflections, blood in the surgical field, or patient movement, you can correct that with the magic of digital imagery," Dr. Miller said.

The surgeon can also obtain intraoperative measurements in the surgical field, such as diameters, K values, and refractive power, he added.

Help from an expert

The system allows for guidance during the surgery with the help of an expert on video performing the same procedure, such as phacoemulsification. It can be shown in a small corner of the screen as the surgeon is performing a case. This feature is especially advantageous for young residents early in their training, he noted. The 3D imaging system is an excellent teaching tool that can be viewed by the surgeon, the assistant surgeon, nurses in the operating room, and students-anyone who is wearing the polarizing glasses.

The idea for 3D imaging of the surgical field was pioneered by Dr. Miller and Roger F. Steinert, MD, more than 20 years ago. Working with professors of engineering from the Massachusetts Institute of Technology, Cambridge, MA, Drs. Miller and Steinert were able to produce the first prototype unit. More recently, Mike Weissman and Phil McKinley have worked to enhance and produce the Digital Microsurgical Workstation, which is now available.

Both Dr. Steinert and Arturo S. Chayet, MD, have used the 3D imaging system to perform cataract surgery. Because the surgeon can increase the surgical field by increasing the size of the screen, surgeons can visualize the patient's eye, surgical instruments, and their own hands holding those instruments. They do not have to keep refocusing because the system has a large depth of focus (about 25 mm).

Showing still 3D photos of cataract surgery performed using the system, Dr. Miller expressed his satisfaction with the 3D effect.

"Notice that everything is in focus," he said. "There is a distance of 15 or 20 mm between the different planes."