New choices in vitreoretinal surgery

November 15, 2007

A new lens-positioning system (Optiflex Surgical Assistant, Volk Optical) for vitreoretinal surgery has a wide field of view and features such as powered and manual controls designed to provide maximum focus capability.

Key Points

A new lens-positioning system (Optiflex Surgical Assistant, Volk Optical) has been introduced for vitreoretinal surgery to improve the surgeon's ability to control position and focus. The system is electromechanical with manual and powered controls designed to provide quick focus capability and precise positioning for clear focus as well as a swing and pivot mechanism that quickly moves the lens out of the surgical field when not in use.

In the early days of vitreoretinal surgery, a contact lens magnifier placed on the eye offered, at most, a 20° to 30° field of view of the center of the retina and was the optimal form of technology, Dr. Wenz said. Viewing the peripheral retina during vitrectomy required use of either a prismatic contact lens, which gave a very limited field of view, or the indirect ophthalmoscope, which is technically difficult to use for vitrectomy work, he said. For the past 15 years, however, most surgeons performing vitrectomies have used some type of wide-field viewing system that enabled them to perform procedures more safely and quickly than the contact lens magnifier. Several of these wide-field viewing systems have been available; the choice of Dr. Wenz and many other surgeons (BIOM, Insight Instruments) provides a view out to about 90°.

A wider field of view allows for less manipulation of the globe and an improved view of the edge of the retina, which is particularly valuable in dealing with cases such as retinal detachments that frequently involve small holes or tears in the extreme edge, he added.

Based on their trial of the new system, Dr. Wenz and Dr. Estafanous said they plan to switch from the wide-field viewing system they currently use to the new lens-positioning system. "The [wide-field viewing system] is a perfectly good system, and I would be quite happy continuing to use it, but I think the [new lens-positioning system] is a notable improvement because it gives a larger field of view. It's not a sea change in technology, but it's an improvement from what we have," Dr. Wenz said.

The new system is compatible with all leading surgical microscopes and can be removed for sterilization. It is made from titanium to withstand numerous autoclave sterilization cycles.

An automated or manual reinverter unit is optional, and lens choices include wide angle, which allows visualization of the retina out past the equator, and high magnification, which allows detailed imaging of the posterior pole.

While testing the new lens-positioning system, Dr. Wenz concluded that the high-magnification lens lacked sufficient depth perception for fine macular work, and he does not use it, preferring to use the contact lens regarded as the gold standard for this type of work. The new lens-positioning system's manufacturer is aware of this evaluation, he noted.