Five Questions About Microscope-integrated Intrasurgical OCT

Learn more about the common uses and future promise of this emerging modality.

By Justis P. Ehlers, MD

Intrasurgical OCT provides access to a tremendous amount of information during surgery that we have never had in the past. In this exciting field, new developments are emerging rapidly. One key area of advancement is microscope integration. Intrasurgical OCT is now available integrated into the ophthalmic microscope, along with high-definition displays for viewing intrasurgical OCT images. This technology has the potential to revolutionize the approach to ophthalmic surgery with real-time feedback on surgical objectives. Below, I discuss four common questions about this emerging modality.

What is microscope-integrated intrasurgical OCT?

The initial approach to intrasurgical OCT was to utilize an OCT system external to the microscope that required surgeons to stop surgery to perform imaging. Microscope-integrated intrasurgical OCT devices are OCT systems that utilize the optical path of the microscope to allow surgeons to take OCT images seamlessly during surgery. Leica’s EnFocus is a new intrasurgical OCT device that can be used with many existing microscopes.

There are two different EnFocus models available: the Ultra-HD and the Ultra-Deep. The Ultra-HD system delivers resolution at 4 μm or better with 2.5 mm of range. The Ultra-Deep system provides up to 11 mm range with resolution of appoximately 9 μm.

How do surgeons use intrasurgical OCT?

Using intrasurgical OCT enables surgeons to perform OCT imaging immediately prior to surgery as well as to get updated real-time information during surgery.

Microscope integration facilitates directing the intrasurgical OCT to specific areas of interest during surgery. The speed of acquisition is also optimized compared with external systems, given that a pause in surgery is no longer required.

What are intrasurgical OCT’s retina applications?

Both posterior and anterior uses are being investigated for intrasurgical OCT. To date, its value has been noted in several retina applications, including macular hole, epiretinal membrane, proliferative diabetic retinopathy, and retinal detachment.¹

When surgeons perform epiretinal peeling, for example, intrasurgical OCT enables surgeons to see if they have completed the peel or if residual membranes remain. In one study, surgeons reported that intrasurgical OCT helped them evaluate patients in 43% of epiretinal peeling cases; occult residual membrane was identified in 13% of cases.¹

Can intrasurgical OCT play a role in anterior segment procedures?

There is a tremendous opportunity to use intrasurgical OCT during anterior segment surgery as well. For example, surgeons can use intrasurgical OCT during DMEK and DSAEK to evaluate for persistent interface fluid and graft orientation.^2-4

In cataract surgery, intrasurgical OCT can be used to establish IOL position.^1,2 In the future, intrasurgical OCT may be utilized to optimize IOL calculations and effective IOL positioning.^5,6 •

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