Perfluoro-n-octane (PFO) is FDA approved for use during surgery in patients with retinal detachment. But at the Retina Subspecialty Day on Friday, Steven Charles, MD, described the advantages of using it off label as a medium-term tamponade for 14 days.
Dr. Charles has applied the technique to more than 1,000 consecutive cases over 19 years, he said, and has garnered benefits in phakic, pseudophakic, and aphakic eyes with minimal negative effects. “The notion that there’s toxicity is simply nonsense,” he stated.
Benefits. In patients with inferior retinal detachments, PFO eliminates the need for prone positioning and allows patients to sit, stand, fly, drive, and work. Unlike scleral buckles, PFO does not induce myopia and is ideal after refractive or cataract surgery. Moreover, PFO does not cause strabismus, pain, ocular surface disorder, or corneal damage or put patients at risk for conjunctival damage.
Medium-term use is also beneficial in patients with inferior, nasal or temporal giant retinal tears. PFO can be injected over the optic nerve, on the anterior surface of the retina, using a dual-bore cannula and viscous fluid control (VFC) at 8 psi. The tip should be retracted during injection and kept at the interface of the PFO and balanced salt solution (BSS) to ensure a single bubble.
Surgical pearls. “Keep the tip of the cannula in contact with the initial bubble, carefully focus, and follow that path upward. If you do that, you’ll make a single bubble every time,” he noted. Patients with inferior tears can assume seated, supine, or upright positions during recuperation, while those with temporal or nasal tears must lie on their side.
Dr. Charles recommends a PFO-gas exchange or PFO-silicone oil exchange in patients with a superior giant retinal tear, but silicone oil in those with proliferative vitreoretinopathy. In this setting, VFC should be at 80 psi to inject oil through a short, thin-walled, low-resistance supratemporal cannula. An infusion cannula is too slow, he noted. The extrusion cannula should be kept at the oil or gas interface, with PFO in the periphery during the exchange. He recommends removing any BSS, SRF, and liquid vitreous before PFO to avoid slippage.
New macular patch technique. Finally, Dr. Charles described a technique for autologous macular patch graft that was recently developed by Tamer Mahmoud, MD, PhD. In this technique, the graft is moved from the donor location to the macular hole under PFO, with a DSP ILM forceps to prevent scrolling and inversion. Do not lift the leading edge of graft, Dr. Charles noted.
The advantage of using this technique on grafts, he said, is that PFO offers better graft oxygenation than silicone oil and allows oxygenation from the anterior surface rather than only the choriocapillaris. When the PFO is removed after seven days, take care to keep the backflush cannula away from the graft, he cautioned. — Anni Delfaro, PhD
Financial disclosures. Dr. Charles: Alcon Laboratories: C,P.
Disclosure key. C = Consultant/Advisor; E = Employee; L = Speakers bureau; O = Equity owner; P = Patents/Royalty; S = Grant support.
Read more news from AAO 2019 and the Subspecialty Day meetings.