OCT can assist in surgery in numerous retinal surgical cases, including pars plana vitrectomy with membrane peeling, a study found.
PARIS Intrasurgical optical coherence tomography improves
intraoperative evaluation of vitreoretinal conditions, facilitates surgery and
supports the surgeons decision-making process, thus improving surgical
outcome, according to a specialist.
Intraoperative imaging provides immediate information about
structural changes during surgery, such as tissue movements, the influence of
fluid dynamics and the amount of surgical trauma, Susanne Binder, MD,
said at the Euretina meeting. All this in a perfectly safe way, without
loss of sterility. It also allows examination of patients who are unable to sit
upright, such as ROP babies.
In order to clarify indications for intraoperative OCT, 512 × 128
macular cube scans of 50 eyes of 50 patients were acquired at various stages of
surgery, using the Carl Zeiss Meditec Cirrus HD-OCT system adapted to the
optical pathway of a Zeiss OPMI VISU 200 surgical microscope with 60D BIOM
OCT guided our surgery in a variety of situations, such as pars
plana vitrectomy with membrane peeling (35 cases), combined or not with
cataract surgery and IOL implantation, macular pucker (23 cases), penetrating
macular hole (12 cases), retinal detachment (three cases), silicone oil removal
(two cases) and cataract surgery alone (12 cases). We were able to acquire
intraretinal scans of sufficiently good quality for all the patients, Dr.
Dr. Binder and her colleagues sought answers to questions such as
whether the quality of intrasurgical OCT is comparable to that of preoperative
OCT, whether surgical manipulation can be observed and whether the amount of
surgical trauma can be estimated.In addition, they sought to verify how
precisely we could visualize the outcomes: whether membrane peeling was
complete, how was the retina at the end of surgery, whether or not there was a
foveal involvement and whether there was any residual subretinal fluid under
Dr. Binder and colleagues found that intrasurgical OCT was comparable to
preoperative OCT in terms of image quality.
Image quality was excellent and we could visualize details with
extreme clarity, she said.
Benefits of OCT
Surgical maneuvers could be closely observed as they were performed, and
this helped in calibrating manipulation and controlling the immediate effects
of maneuvers on the eye structures.
In one case of stage 2 macular hole with a traction, I was able to
control the traction force. I decided to remove the membrane with scissors at
the end, so I did not de-roof the macular hole. The amount of surgical trauma
could be estimated immediately at the beginning, during and at the end of
membrane peeling, Dr. Binder said.
In another case, it was possible to see how complete membrane peeling
was. The extension of the membranes and the loss of foveal contours could be
seen at the beginning of surgery. At the end of the procedure, a second look
was taken in the nasal contour for residual membrane. The 3-D scan of the
postoperative processing confirmed some wrinkling of the retina, but the retina
itself was clean.
The condition of the retina can be continuously watched during the
entire process of membrane peeling.
Again, at the end of surgery you can double-check, in 3-D, the
membrane you have removed and the retinal condition you have left when you have
removed the tissue. You will be surprised to see that what you leave is a
totally nice flat retina that looks very different, Dr. Binder said.
Intrasurgical OCT can also visualize features that are not detected
clinically, she said.
In a myopic patient with a nasally superior retinal detachment, a dry
macula was diagnosed by clinical observation.
Visual acuity was 20/40, so, why not? He also had a little bit of
a cataract. But what we could see at the beginning of surgery was that he had a
detached macula when he was in the lying position. I strongly believe we will
no longer be able to differentiate macula on and off by clinical observation
only, Dr. Binder said.
The 3-D scan also showed a retinal detachment up to the fovea and only a
partial vitreous detachment. This explained why primary vitrectomy was
difficult, due to the large parts of attached vitreous.
Future of OCT use
Intrasurgical OCT is a promising examination method that can help
greatly during surgery, Dr. Binder said.
The instrument needs further improvement. The scan line indicator
will need to be implemented into the visual field of the surgeon. Now we have
to look into two different screens. We also need tracking systems, she
said. by Michela Cimberle
- Susanne Binder, MD, can be reached at Department of Ophthalmology,
Ludwig Boltzmann Institute for Retinology and Biomicroscopic Laser Surgery,
Rudolph Foundation Clinic, Juchgasse 25, 1030 Vienna, Austria;
+43-1-71165-4607; fax: +43-1-71165-4609; e-mail:
- Disclosure: Dr. Binder has no financial interest in the products
discussed in this article, nor is she a paid consultant for any companies
Intraoperative OCT is a promising and exciting new imaging procedure
that is in the early stages of development and refinement. Currently, the only
commercially available units that can be feasibly used in the operating room
are handheld units or modified table-top systems. Various intraoperative OCT
prototypes are currently being studied. The development of a seamlessly
integrated OCT system into the operating theater is the ultimate goal that will
hopefully impact our understanding of vitreoretinal surgical diseases and
improve our clinical outcomes. We are just beginning to describe some of the
findings associated with various surgical vitreoretinal diseases and the impact
of our surgical maneuvers on these conditions. Intraoperative OCT has also
begun to reveal important new information regarding the pathophysiology of
certain retinal diseases. Extensive research is still needed to further
understand the role for intraoperative OCT and its impact on clinical outcomes.
Areas of important future research include rapid scan targeting, OCT-friendly
instrumentation, heads-up display systems, imaging protocols for dynamic
intraoperative imaging and identification of critical feedback information to
Finally, studies are needed to verify the utility of this technology,
not only in providing more information regarding pathophysiology, but also in
improving functional and anatomic outcomes.
Justis P. Ehlers, MD
Service, Cole Eye Institute, Cleveland Clinic, Cleveland, USA
Dr Ehlers has no financial interest in the products discussed in this article.