Focus On

The Merlin surgical viewing system


Merlin Brings Tricky Cases Into Focus

Samantha Stahl, Assistant Editor

As retinal procedures increase in sophistication and use of small-gauge instruments becomes commonplace, it's more crucial than ever to have a crystal-clear view of the surgical field. The Merlin non-contact surgical system from Volk Optical enhances the viewing experience even for challenging cases, aiding efficient procedures and better outcomes.


Merlin has two platform options: The rotational assembly (RA) or a condensing lens assembly (CLA). The CLA has an automated and manual version, and conveniently reduces the working height of the microscope without losing any workspace underneath. Both platforms hold the lens positioning unit (LPU) and lens in alignment with the microscope optical pathway. The 360 degrees of rotational movement made possible by this set-up gives surgeons the opportunity for precise lens positioning.

Brandon Busbee, MD, of Clarksville, Tenn., a long-time fan of the RA platform, says the 360-degree rotational design “allows me to always have the lens out of the way. If there is pathology in different parts of the eye, I can rotate it so the lens is not impeding my view.”

The design also fosters a more efficient operating room workflow. “The system allows me to work independently—doing things like shaving of the vitreous base—without the need for an assistant. The flexibility of the system can free up other hands.”


Each Merlin system gives you a choice of two of the three available lens options (the third can be purchased separately): The mid field, wide angle, or wide angle small diameter lenses.

The Merlin allows 360 degrees of rotational lens positioning.

Dr. Busbee, who uses all three, believes that each lens has its own advantages. The wide angle lens, which allows visualization of the retina all the way to the ora serrata, is particularly advantageous when peripheral pathology needs to be well visualized. He says the quality of the wide-field view far into the periphery is essential when working near the vitreous base.

The wide angle small diameter lens maintains 94% of the field of view of the wide angle lens. At 13 mm in diameter, versus the 19 mm diameter of the other lenses, this option increases space for instrument manipulation. Dr. Busbee says this option is great for deep-set eyes and potentially tighter spaces that still need an excellent view of the periphery.

Finally, the mid field lens provides a higher magnification view (0.74x) for detailed imaging of the posterior pole to the equator.

“This is a really wonderful lens for diabetics and bimanual surgery, especially diabetic tractional retinal detachments. They usually develop around the posterior pole, and you want to have a wider view to make sure you're removing scar tissue without creating breaks in the mid-peripheral retina,” he says.

With diabetic tractional detachments, he says the Merlin is great for its ability to view and monitor the mid-periphery retina. “Before this lens, I would go back and forth between a very magnified view to peel membranes and a minified view to evaluate the peripheral retina. The mid-field lens gives you both a magnified view along with a consistent view beyond the equator. This allows for much easier bimanual surgery, which leads to better outcomes.”

Another optional feature is the Rols Infinity reinverter, which has the capability for custom alignment with any microscope to minimize image shift and vignetting, according to Volk.

Dr. Busbee calls Merlin “an exceptional optical system that really gives you clarity of view that is comparable to any contact lens system.”

He adds that one of the primary benefits of a non-contact system is the cost savings—an especially big deal for those at ASCs. The reusable lenses and mounting that can be autoclaved are a huge advantage.

“This is a more economical approach to a viewing system,” says Dr. Busbee. “What makes the Merlin unique is its ability to provide quality viewing at a reasonable price.” RP

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