A case study is presented that shows the relevance of intraoperative optical coherence tomography (OCT) in complex retinal surgeries, and how better surgical results can be obtained by using this technology.
Complex intraoperative conditions can simulate vitreoretinal changes, which may have fatal consequences and significantly influence the visual outcome of surgery due to poor intraoperative decision-making.
When the eye is filled with air prior to the insertion of silicone oil, light reflexes can significantly disturb the surgeon’s vision. When a patient suffers from one of the rare genetic vitreoretinopathies like Stickler syndrome, there is an added confusion because a sign of vitreoretinopathies may be whitening of the retina, which simulates subretinal fluid, even when it is still attached.
Therefore, it can be unclear whether the retina is detached and needs additional attention or whether the surgeon can move forward with inserting the silicone oil.
Visualising retinal structures in greater detail with intraoperative optical coherence tomography (OCT) can help the surgeon to detect and perform scans during surgery without switching surgical instruments that can interrupt the workflow.
However, intraoperative OCT devices are rare in retinal practices and specific application fields are still under research. OCT technology allows surgeons to view transparent structures in high resolution, which allows better surgical results.
This complex case presentation proves the relevance of intraoperative OCT in complex retinal surgeries.
An 11-year-old boy presented on August 18, 2018, with a history of vision loss in his left eye that he detected 1 week prior.
He suffered from high myopia in both eyes and was wearing spectacles with –10 D correction.
In his right eye, with spectacles, he had 60% vision, and his left eye was counting fingers because of an almost complete rhegmatogenous retinal detachment, resulting from several large retinal breaks. In his right eye, he had peripheral retinal degeneration.
Realising that this was extremely unusual for an 11-year-old boy, we suspected a genetic disease that can cause retinal detachment in children, such as Stickler syndrome. Stickler syndrome is a hereditary condition with many signs and symptoms, one of which is eye abnormalities. These patients can suffer from high myopia, abnormal vitreous, increased intraocular pressure, cataracts and retinal detachment. We know that some of these abnormalities can certainly cause impaired vision or blindness.
Our surgical plan was to perform a 23 G vitrectomy with an encircling band and silicone oil tamponade. We placed the encircling band first, and then started the vitrectomy. Through the viewing system, we could visualise the size of several very large peripheral retinal breaks.
There was one connection in the retina at 11 o’clock and then more at the nasal superior periphery. We filled the eye with heavy liquid, perfluorodecalin, to get the retina re-attached. Prior to performing a direct exchange of silicone oil against heavy liquid, we applied laser coagulation to the retinal breaks.
At this stage of the surgery, we were not sure whether retinal breaks still existed due to the whitening that extended over the macula to the temporal periphery.
Through use of intraoperative OCT (Lumera 700; Carl Zeiss Meditec), we could confirm that the retina was indeed attached and that we could continue with the silicone fill.
The whitening was interpreted as possible intraretinal edema as a reaction of the patient’s vitreoretinopathy to the retinal detachment and not subretinal fluid, which was confirmed on day 1 by OCT.
The patient’s visual acuity increased to 30% at the 4-week postoperative visit. The retina was attached in the silicone oil and we observed scarring of the laser spots.
Eight weeks postoperatively, we planned for silicone oil removal and the retina remained attached. The patient’s vision was 30–40%, which was an excellent result following a complete retinal detachment.
Incorporating intraoperative OCT during vitreoretinal surgery is consistently helpful for decision making during surgery, especially in complex vitreoretinal cases with reduced media transparency.
It can be an essential tool to determine whether the retina is re-attached if the surgeon is clinically suspicious, especially in cases of fresh retinal detachments where timing is essential and re-attaching the retina within 48 hours will increase chances of visual acuity returning to 100%. In those cases, it is important that the macula is attached to get the nutrition from the choroid underneath.
In cases where there is remaining subretinal fluid, the outcome is usually not as good as it is in attached macular situations.
Being able to instantly monitor surgical decisions, progress and outcomes can make the difference between whether a patient has restored vision or not.
Prof. Matthias D. Becker, MD, PhD, MSc
Professor of Ophthalmology and Ophthalmosurgery
Head of Department of Ophthalmology, University of Zurich.
Florian A. Heussen, MD
Chief Physician, Eye Clinic, Triemli City Hospital, Zurich.