COMFORT MATTERS The binocular head should be flexible enough to provide ergonomic sitting positions for all surgeons.

An ophthalmic microscope is a big-ticket purchase you're going to have to live with for years to come. The microscope you choose not only has to meet your surgeons' needs, it also has to promote efficient workflow for your OR staff. Keeping those considerations in mind, here are 5 questions you should ask before you write the check.

1. What's its illumination source?
Light sources are typically either halogen or xenon. Halogen illumination appears more yellow than the white high-contrast light produced by xenon sources. Some microscopes have an interchangeable system that provides both. Microscopes with high-intensity transmission optics let you use a lower light level for retinal procedures, thereby lowering the risk of macular phototoxicity. Another useful feature is the presence of an additional oblique beam with a separate adjustment control. The beam can be used to illuminate features of the ocular surface and can be dimmed to better visualize intraocular structures. A slit beam illuminator to improve visualization of delicate structures such as epiretinal membranes or the posterior lens capsule is useful for both posterior and anterior segment surgeons. From a workflow standpoint, ask about the cost of bulbs and the average bulb lifespan for each microscope. The standard range of magnification for ophthalmic microscopes is 6X to 25X. Does the microscope have programmable magnification presets that can be individualized for each surgeon?

2. How will the optics help your docs?
Unless you have a degree in physics, comprehending the designs of optical systems built into ophthalmic microscopes can be daunting. Some microscopes boast optical systems that generate collimated, non-focused light; others promote focused, coaxial, double-beam, stereo illumination or apochromatic optics that reduce chromatic aberration, which results in improved contrast and resolution. From a practical surgical perspective, it's crucial to have a microscope that maintains a bright and stable red reflex, high resolution and long depth of focus. Another optical feature to consider is the availability of a viewing system that integrates with the microscope to let retinal surgeons view all areas of the fundus without the aid of a contact lens or endoilluminator.

3. What about scope ergonomics?
There are many ergonomic features to look for in an ophthalmic microscope. It's helpful to have a small footprint of the base and long arm reach, both of which limit intrusion into the surgical field and the area near the surgeon's feet. Likewise, a wireless, rechargeable, waterproof foot control pad that incorporates the on-off switch, dimming switch, focus control and magnification control allows for hands-free adjustment and prevents excess wires from hindering the foot controls of other instruments. A small base footprint also lets OR staff quickly move the microscope between cases. The same is true of electromagnetic brakes that engage with the push of a button, as opposed to mechanical brakes that have to be manipulated individually. To help with sterility and prevent tangling with other equipment during setup and positioning, all cables should be internalized within the support housing. Bulbs should be easily accessible and easy to replace, and the microscope should either automatically switch to a back-up bulb during surgery or let you make the change with a simple hand switch.

Correct settings are paramount for efficient and accurate operation. For the staff, parameters such as pupillary distance, initial magnification, speed of both focus and magnification and focus point should be programmable and preset so the microscope can be reset quickly between cases or surgeons.

The binocular head of the microscope should have a free range of positions to provide for an ergonomic sitting position. Individualized, programmable head positioning presets help staff prepare the scope for each surgeon. The head should also contain manual overrides with sterile covers to allow you to change the parameters, microscope position or angle during the case.

Ergonomics is also crucial for the surgical assistant. Incorporating a rotating beam splitter lets the surgical technician have a stereoscopic view through the assistant scope, allowing for greater dexterity and efficiency. Additionally, independent zoom and focus controls on the assistant scope are useful. For the support staff, having an assistant scope that can be quickly and easily readjusted between left and right eye positions improves turnover time.

NEW OR USED? Depends. Do refractive cataract and retinal procedures account for a high percentage of your cases?

4. Are high-tech additions available?
With the advent of premium intraocular lenses and refractive cataract surgery, patients have high expectations. Fortunately, there are high-tech additions for ophthalmic microscopes that increase surgeon efficiency, shorten case times and improve patient outcomes. These include intraoperative displays of individualized patient templates for performing limbal-relaxing incisions, scalable rings to aid in capsulorhexis creation, a keratoscope for visualizing corneal curvature, and reference and target axes for more accurate positioning of toric intraocular lenses. You can see these displays either through the microscope oculars or on a separate monitor.

From an imaging standpoint, digital cameras and monitors are also available. A technician who's uncomfortable using an assistant scope can provide effective surgical assistance by viewing a monitor in real time. Live video in 1 or more ORs allows support staff to constantly be aware of the status of the case in progress. That lets them know when to start preparing for the next case or whether technical or equipment assistance is needed in another OR. Family members can also view the patient's surgery in real time. With a DICOM module, you can also save images and video to a patient's record in compatible EMR systems, allowing you to produce high-quality academic presentations and publications.