Is surgery useful for addressing optic pit cases? Not everybody is convinced—in fact, over a third of Ophthalmic Medical Education Summit attendees said that they don’t believe surgery helps. However, Gaurav K. Shah, MD, FASRS cautions practitioners against writing it off so quickly. “Surgery performed at the right time is definitely the right option,” he says. “Optic pits aren’t that common—most of us will likely only see a handful of these cases over the course of our careers. Because of this, surgeons may not have a specific technique that they consistently use, opening the door to things going wrong.” Imaging before, during, and after surgery has significantly improved his surgical process and reduced unintended outcomes. “The developments in intraoperative imaging have been really important; it leads you away from things you don’t intend to do during surgery, as much as it helps in other areas.”
Real-time guidance
Imaging is key to each stage of Dr. Singh’s approach to retinal surgery. When a 35-year-old patient presented with a visual acuity of 20/200, Dr. Singh first turned to color fundus photography, through which he saw a very visible optic pit and a large area of macular detachment with subretinal fluid, followed by additional advanced imaging. “Fundus autofluorescence imaging highlighted an area of atrophy or potential fluid, which may not improve,” he explains. “That opens up a conversation to have with the patient about the perioperative outcome and assessments, and what he might expect to see over time. The preoperative OCT highlighted a membranous change, providing extra information for approaching surgery. We also saw that the retina right above the area in question was very thin.”
Having acquired this knowledge, Dr. Singh proceeded with the surgery, first elevating the hyaloid, after which he assessed the macula using intraoperative OCT. “I could see the tissue draped over the retina,” he recalls. “After placing indocyanine green down, I was able to evaluate it with the finesse loop, monitoring in real-time how deep it was going to ensure the retinal areas weren’t penetrated.”
Dr. Singh continued using the intraoperative OCT as he performed an internal limiting membrane (ILM) peel in and around the optic nerve. “The retina was extremely thin—only around 20-40µm dead-center. We avoided causing an inadvertent macular hole, a kiss of death in such scenarios.” And the result spoke for itself—even six days post-op, there was improvement of the subretinal fluid, which resolved a month later, in conjunction with the closure of the optic pit.
Finding the optimal approach
The complications practitioners face when approaching retinal surgery can be multifaceted. When Dr. Shah first saw a 39-year-old patient with a right eye visual field defect, he used fundus photography to observe a giant retinal tear extending almost 180 degrees. “This patient had come in believing, apart from this visual defect, that there wasn’t anything massively wrong because his central acuity was still 20/20,” he says. “On the OCT, we observed Schaffer’s sign—a large amount of pigment was in the eye, alongside blood.”
Adding further complexity to this already complex case were the patient’s other medical issues and the social barriers to follow-up. “The initial injury that had led to this patient being hospitalized had happened about a month prior,” Dr. Shah recalls. “He had bilateral test tubes—which was a first for me in terms of performing surgery. Although we had an incredibly capable anesthetist who allowed us to perform the surgery as we needed, we were still left with the question of the optimal approach to take.” Alongside considerations regarding positioning and which technique to use during the surgery, the patient also made it clear that he had no intention of returning once discharged.
Ultimately, Dr. Shah opted to perform a vitrectomy with a 41-band scleral buckle and then maintained the intraocular pressure (IOP) using a fluid-perfluoro-n-octane (PFO) exchange, which was left in the eye for a week—something possible because Dr. Shah knew the patient would remain in the hospital. The PFO was removed from the eye under passive extrusion, using balanced salt solution (BSS) to make this process easier without the risk of hitting the retina. After this, Dr. Shah applied endolaser to the anterior margin of the tear and then filled the patient with air. “I used to use a PFO-oil exchange, but it’s been my experience that once long-acting tamponade oil is put into the eye, especially in a 20/20 eye like this, it’s just never the same,” Dr. Shah explains. Despite the difficulties of the case, the patient’s outcomes were great, having a visual acuity of 20/30 at the last follow-up before he left for good.
Closing the gap
Intraoperative imaging isn’t just useful for preventing the occurrence of serious complications, but also for their surgical correction, as Dr. Talcott demonstrates through a number of complex macular hole cases. “Usually, performing a standard ILM peel works really well for most macular hole patients, but in cases of more challenging presentation, there are other approaches we can take.” In some cases, where Dr. Talcott feels an ILM peel alone isn’t enough, she creates an ILM flap and positions it over the hole.
“I like this technique as it gives patients a better chance of their macular hole closing,” she explains. This approach may not be feasible for patients who have already had surgery. However, approaches such as encouraging macular tissue mobilization can still be taken by creating subretinal blebs. “I’ve found this technique helpful in cases where there’s not a lot of ILM left, which makes making a hinge flap, or other alternatives, difficult.” In a final patient without a lot of ILM to scrape, Dr. Talcott created a ribbon using the ILM she could obtain and repositioned it over the hole using viscoelastics.
These patients all experienced good post-operative anatomical results; however, the amount of vision regained varied and isn’t necessarily related to the surgical procedure. Instead, in Dr. Talcott’s experience, factors such as how long the macular hole has been present, its constitution prior to surgery, and the ellipsoid zone (EZ) makeup after the hole has closed are more indicative of the final visual outcome.
“Evaluating these identifiers, through pre- and postoperative imaging, gives me a sense of whether a patient might continue to experience improvements to vision over time, or whether I need to prepare them for the likelihood that this may not happen.”
Additionally, working in an academic institution, Dr. Talcott has found that intraoperative OCT helps her fellows by guiding their maneuvers. “One question that our fellows often have in complex retinal detachment cases is when to stop,” she explains. “Intraoperative OCT is really helpful in determining when we’ve achieved our goals, when it’s safe to do more, and when it isn’t.” Although the large monitors of heads-up imaging systems can be useful for teaching and engaging with students, Dr. Talcott has found the color and views of ZEISS’s ARTEVO system provide a more beneficial experience. “One of the criticisms sometimes raised against heads-up systems is that some of the peripheral views can be challenging; the ARTEVO nicely balances an excellent macular view with its peripheral view,” she explains. “Intraoperative OCT is definitely a step forward; looking towards this new era of operating room viewing systems, they’ll need to continue to offer us things standard scopes don’t—but where we’re at right now is so exciting!”
In conclusion, intraoperative imaging techniques enhance surgical outcomes by providing real-time guidance and enabling surgeons to make more informed decisions during procedures. As demonstrated in various complex cases, advanced imaging methods such as color fundus photography, fundus autofluorescence, and intraoperative OCT assist in minimizing complications and enhancing patient visual acuity after surgery.
