Pneumatic retinopexy provides functionally superior outcomes to pars plana vitrectomy for a range of rhegmatogenous retinal detachment configurations. The technique offers quick visual rehabilitation and minimal cataract morbidity. It’s also highly cost effective.
If you aren’t regularly performing pneumatic retinopexy (PnR), you may wish to consider the best way to incorporate it into your established practice. Here, we provide some guidance on how to do that.
Get started with the right patient
For an experienced vitreoretinal surgeon who’s proficient at detailed peripheral retinal examination with scleral indentation and indirect laser, optimal outcomes with PnR will follow a short initial learning curve.
Nonetheless, we advise you start out by considering PnR in cases with the highest likelihood of success. From an anatomical perspective, these would be eyes with good pupillary dilation, clear ocular media and with RRD morphology meeting PIVOT trial criteria—that is, all breaks in the detached retina within one clock hour, between 8 and 4 o’clock, with breaks or lattice degeneration in attached retina being permissible.1 (PIVOT stands for the Pneumatic Retinopexy vs. Vitrectomy for the Management of Primary Rhegmatogenous Retinal Detachment Outcomes Randomized Trial.)
Strict head posturing is imperative
The ideal patient would have excellent comprehension of the need to comply with a strict head-posturing regime, and would be physically able to carry out the instructions.
Additionally, consider practical factors, such as the patient’s domestic environment and geography, because they may impact on posturing and follow-up compliance: Does the patient live alone? Is she or he a caregiver? Is there home support? Does the patient live locally?
We can’t overemphasize the importance of correct head positioning in ensuring a successful retinal reattachment. Patients’ misunderstanding of this are a common cause of delayed reattachment or failure. They must avoid vigorous activity while the gas remains in situ to reduce the risk of secondary retinal breaks.
A thorough explanation of the need for posturing, and a detailed description and demonstration of the necessary postoperative steps are crucial. In many cases, written or diagrammatic instructions are helpful. A preprinted sheet for your annotation saves time here.
Recognizing signs of success
In most cases, complete subretinal fluid resolution occurs in the early days following gas injection. However, a delay in the complete resolution of SRF isn’t uncommon. It can sometimes linger inferiorly for weeks or even months.
In our experience, this is more often seen in cases of more chronic RRDs, in older patients and in paler fundi, where we suppose that the retinal pigment epithelial pump may be less efficient at SRF clearance. In such cases, the SRF tends to loculate inferiorly, slowly resorbing over time. In these instances, a careful peripheral retinal examination should reveal no open breaks. If the exam does reveal an open break, signs of proliferative vitreoretinopathy developing or SRF increasing, promptly schedule additional surgery.
One way a surgeon can get into trouble with PnR is if she or he waits too long to schedule surgery for a patient who has clearly failed the initial procedure. Such cases should be treated within days. A prolonged delay in getting to the operating room can raise the risk of PVR and failure of the subsequent surgical approach.
If a secondary procedure is needed
A secondary surgical procedure on a failed PnR requires some special considerations. If performing a scleral buckle, exercise great caution with trans-scleral drainage of SRF with gas in situ. Rotating the eye to gain exposure to the drainage site brings the gas bubble to the location of drainage. In this situation, when the posterior sclerotomy is made and drainage starts, the gas bubble can promote retinal incarceration, retinal tear formation and gas egress from the drainage site. Thus, it’s wise to remove all but the smallest gas bubble before drainage.
A further consideration is for phakic patients undergoing subsequent PPV following failed PnR. With gas in situ, the patient must adhere to strict face-down posturing until surgery commences. Supine positioning at home and in the preoperative area results in the gas contacting the lens, and can result in lens opacity, thus complicating the case.
A further advantage of face-down positioning during this period is protection of the macular region. In patients having combined PPV/scleral buckle following failed PnR, lens opacity formation is a particular concern because the SB is generally placed first, allowing enough time for a gas-related lens opacity to form. In this situation, it’s wise to remove the gas as the first step.
Equipment and facilities
The ability to perform a detailed preoperative peripheral retinal examination with scleral indentation is a prerequisite to success in PnR. Therefore, an examination room equipped with a fully reclining chair and indirect ophthalmoscope is essential. We advocate liberal use of indirect laser pre-, intra- and postoperatively for the treatment of all lattice lesions and retinal breaks in the affected eye. For this reason, indirect laser must be on hand for every clinic visit.
Likewise, for certain cases, cryotherapy is effective and convenient for intraoperative retinopexy and should be available. A potential major advantage of PnR is the accessibility of the technique, free from the need for complex equipment, scrub staff, neurolept analgesia/general anesthesia or, indeed, an operating room. Ready access to a suitably equipped treatment room is highly desirable and allows for swift intervention.
Again, a fully reclining chair or stretcher is preferable, and an operating microscope is useful (although not essential) for performing anterior chamber paracentesis in phakic patients. Postprocedure, it may be helpful to provide an observation area to ensure patient safety and comfort. Such an area would allow for a period of face-down positioning on site to aid in normalization of intraocular pressure and, in some instances, to await for reperfusion of the optic nerve following gas injection.
Nuances of scheduling
Patients undergoing PnR generally need review at 24 to 48 hours post-gas injection. At the first follow-up visit after PnR, patients require more time than the usual retinal clinic consultation if you anticipate indirect laser retinopexy. Furthermore, a second gas injection may occasionally be appropriate, so it’s important to schedule these patients with sufficient time. We suggest scheduling them toward the end of the day to help with smooth clinic flow.
Patients who have had pre-PnR cryopexy are more predictable to manage because the responsible break has already been treated. Once retinopexy is complete, PnR patients may be accommodated routinely in the clinic around two weeks later. The vast majority of PnR failures occur in the early weeks, and late redetachments are rare. Therefore, patients may be safely discharged at two to three months post-procedure.
PnR is ideal for fellowship programs that can use a team approach. Fellows at any stage can participate in the procedure and assume more responsibility over time.
Tips for fellows
Vitreoretinal fellows should gain proficiency in PnR because it’s an important tool in our armamentarium for repairing RRD. The clinical exam is critical, because missed breaks in detached and attached retina lead to procedural failure. Scleral indentation is always necessary and is the only way to identify smaller breaks.
Before starting the exam, inform the patient about possible discomfort. Topical anesthetic should be instilled and the patient reclined for maximum visualization in all quadrants. Indentation can be done over the eyelids or directly on anesthetized conjunctiva using a cotton tip applicator or (ideally) a clean metallic scleral depressor.
During the initial examination, take special notice of landmarks that will help identify the break at a later stage, with gas in situ (a distinctive vessel or lattice lesion, for example). For fellows who haven’t yet mastered scleral indentation, we advise performing this exam on every retinal patient to gain proficiency.
Explaining the desired postprocedure head positioning to every patient is essential. We suggest giving printed instructions along with a verbal explanation. Patients routinely underestimate the importance of adherence to precise head positioning instructions. They usually comprehend the positioning necessary for breaks at 12, 9 or 3 o’clock pretty well. However, for breaks at around 10:30 and 1:30, where a 45-degree position is warranted, we prefer to ask that patients lie on their side with three pillows rather than have them attempt to sit up with a head tilt at 45 degrees—because they invariably end up more upright than intended.
The most challenging aspect of PnR for the fellow in training is indirect laser. You may administer subconjunctival anesthetic in the vicinity of the anticipated treatment, especially when you’re early in the learning curve. Another tip is to irrigate povidone iodine from the conjunctival sac with balanced salt solution after the gas injection to preserve the clarity of the ocular surface for the laser a day or two later. If the ocular surface remains irritated at that stage, BSS or artificial tears may be applied. Laser can be applied either through the gas bubble or through the vitreous, by tilting the head to divert the gas away from the break—but avoid the meniscus. Scleral indentation under the retinal break can help to bring it into view and aid with laser uptake.
Early on, close senior guidance is needed to maximize anatomical success rates. Fellows should communicate with the staff vitreoretinal surgeon at each visit about the evolution of their PnR cases. Such close communication will maintain good outcomes while offering the best learning experience. RS
1. Hillier RJ, Felfeli T, Berger AR, et al. The Pneumatic Retinopexy vs. Vitrectomy for the Management of Primary Rhegmatogenous Retinal Detachment Outcomes Randomized Trial (PIVOT). Ophthalmology. 2019;126:531-539.