Figure 1. George Hilton, MD, presenting at one of the 12 consecutive AAO courses on pneumatic retinopexy.

Although pneumatic retinopexy was first performed more than a century ago¹ and resurrected in the 1930s,² it was not refined and seriously brought to the attention of the retinal community until George Hilton and W. Sanderson Grizzard published their experience in 1986.³ D. A. Domiguez from Spain, Ingrid Kreissig from Germany and Harvey Lincoff from New York played major roles in modern-day pneumatic retinopexy.^4,5  Dr. Lincoff was the first to report how an intravitreal gas bubble with proper positioning over a retinal break could result in complete resolution of subretinal fluid in his classic paper, using rapidly resorbing Xenon gas to locate a retina break.⁶ Had he placed a spot of cryopexy on the break (revealed as the gas bubble receded), pneumatic retinopexy would have been credited to him alone. 

I was chief resident at Pacific Medical Center in San Francisco at the time Dr. Grizzard did his fellowship with George Hilton across the bay in Oakland. I had the privilege of spending time with Dr. Hilton in the OR during that year. He always operated in the evening, after office hours, when things quieted down. He was very methodical; every detail was placed in a cubbyhole. “Paul, there are 13 causes of cystoid macular edema,” he would say, reciting them in the same order every time he gave “the sermon.” He also said there are 10 steps to retinal detachment surgery (scleral buckling), and he demonstrated how one step followed the other. He made retinal surgery appear very simple. He sparked my interest in retinal disease and helped me obtain a retina fellowship at Barnes Hospital in St. Louis with Ed Okun, MD. After I completed my retina fellowship, I hung my shingle in San Diego but kept in touch with Dr. Hilton, a mentor, and I frequently asked his advice in the early days of my practice.

Figure 2. W.S. Grizzard, MD, presenting at the AAO pneumatic retinopexy course.

The concept of pneumatic retinopexy came to light at an alumni meeting of the 1979 Paul Cibis Club shortly after my fellowship. Dr. Ed Boldrey, MD, gave a paper describing a bedside injection of air to salvage a failing scleral buckle (patients were admitted to the hospital in those days for scleral buckling).⁷ Dr. Boldrey’s talk was followed by the guest lecturer, Robert Machemer, MD, who made a very profound statement, “The retina wants to heal itself and if you don’t do too much to it, it probably will.” I recall sitting next to Dr. Okun and at the conclusion of Dr. Machemer’s talk, I turned to him and said, “Ed, why don’t we try the bubble first and if it doesn’t work, we can always insert the buckle.” He very politely told me I was nuts. I returned to San Diego and tried this technique on two patients with no insurance and no means of otherwise regaining their sight. Both cases worked! However, I was in practice just a few years and was not anxious to let anyone know just how far I deviated from the standard of care.

Howard Shatz, MD, started the West Coast Retina Study Club in the early 1980s and I attended a meeting in San Francisco where Dr. Hilton presented five cases of pneumatic retinopexy. I told him I had done two cases and asked where he got the idea. To my amazement he said he heard Ed Boldry’s talk at UCSF. At that meeting Neil Kelly said he also independently did a few cases. 

Dr. Hilton subsequently presented his experience with 20 cases to the AAO and on the audiotape, which I cherish to this day, he magnanimously stated that Dr. Kelly in Sacramento and myself were also doing this procedure. We then put all our data together and published our experience in several papers.^8-10 We subsequently shared our experience with others in an AAO instruction course consecutively for more than a decade (See Figures 1 & 2).

Figure 3. Drs. Hilton (left), Tornambe and Grizzard (right). Taken at the 1988 American Academy of Ophthalmology Meeting, Las Vegas, when the Pneumatic Retinopexy Clinical Trial results were first presented.

Dr. Hilton decided that the only way this new procedure would be accepted in the retinal community would be with a prospective, randomized, controlled clinical trial. He invited seven groups of fellowship-trained retina surgeons from across the country who had experience with pneumatic retinopexy and scleral buckling to participate in the trial. He outlined how pneumatic retinopexy would be performed, but told the participants to perform whatever scleral buckling operation they normally used. This trial could not be done today. We did not have IRB approval (I don’t think there was an IRB at that time); we used a gas that was not approved for intraocular use (the cost of the gas and lecture bottle was $14); and we funded the project internally, paying for the biostatistician who provided randomization envelopes. We did not charge the patient for the pneumatic operation. It was a very exciting time. Then, one day Dr. Hilton called me. He was a bishop in the Mormon Church and told me he had been called for a mission to Tahiti. He asked if I would take over the trial and, in a moment of weakness and complete ignorance what that meant, I said yes. 

Dr. Grizzard and I subsequently put on a seminal meeting in San Diego. We invited anyone who was performing the operation to present his or her data, which we eventually published.¹¹ All the presentations were similar, with about the same positive results and complications. We realized we were onto something good.

The Pneumatic Retinopexy Clinical Trial enrolled about 100 patients into the scleral buckle group and another 100 into the pneumatic retinopexy group. The process of randomization remarkably produced two very similar groups. After following the patients for six months, the data showed that pneumatic retinopexy reattached the retina almost at the same frequency as scleral buckling, but most importantly, quickly improved vision to the pre-detachment level more often than scleral buckling. It also showed that a failed pneumatic did not harm the eye. Writing the manuscript was quite challenging, for there was no Internet and no one was really using a computer.

Pneumatic Retinopexy My Way. A Dozen Pearls I once gave a lecture to a group of retina specialists from a very prestigious Northeastern university. One of the junior faculty members approached me at the end of the lecture and said, “My results are not as good as yours, but I don’t do the procedure exactly the way you do,” My technique is published in detail in the Transactions of the AOS.27 Here are some bullet pearls: 1. Most patients, if they meet the criteria, can undergo pneumatic retinopexy in the office exam chair. There are very few who cannot be gently and confidently talked through the operation. Don’t do the procedure in the middle of a busy office day. Bring the patient back at the end of the day for your relaxed and undivided attention. 2. If you can’t examine the entire retina well, don’t do the operation. A minor vitreous hemorrhage does not disqualify the eye. But if you have a small pupil, cataract or pseudophakic opacities that prevent you from seeing the periphery well, don’t do the operation. 3. Pseudophakia is absolutely not a contraindication to pneumatic retinopexy, assuming the intraocular lens is stable and the periphery can be examined. 4. Retrobulbar anesthesia is never needed. SubTenon’s xylocaine is all that is necessary. 5. Breaks at 12, 3 and 9 o’clock are easy to close. Breaks in the superior oblique meridians are harder to close. Inferior breaks are very hard to close but are possible in a limber, motivated patient. A positioning device such as the Escalon pneumo-level will greatly help with compliance. 6. If the break is not highly elevated, I do the procedure in one sitting with light cryopexy. I always use cryopexy, if possible, on breaks at 3 and 9 o’clock for if there is no pexy, the breaks tend to reopen on the trip back to the office for the first postop visit. If the break is so elevated that a large ice ball must grow from the probe to the break (liberating retinal pigment epithelial cells), I stage the operation and apply laser the next day. Beware that once the break flattens, it will be very difficult to find. Sometimes a laser spot (delivered with the laser indirect ophthalmoscope) can be applied to the ora to mark the meridian of the break. A careful drawing of the blood vessel network or an Optos wide-angle photo can be very helpful. 7. C3F8 is overkill. Ninety-five percent of detachments can be repaired with 0.5 to 0.6 ml 100% SF6. I use C3F8 only if the eye is large, or the break is large or extends over a few clock hours, or is posterior or inferior. I’m more concerned about not penetrating the anterior hyaloid and injecting into the space of Petit than I’m worried about fish eggs going under the retina. If a small amount of gas does get under the retina and a larger bubble covers the tear, no rescue procedure is needed. Subretinal gas goes away faster than the vitreous bubble. If gas does enter the space of Petit, no treatment is needed; the bubble usually breaks through the next day. 8. I’m comfortable treating eyes with less than three clock hours of lattice. If there is lattice or there are several breaks, I consider 360 peripheral equator plus laser. These eyes have abnormal peripheral vitreoretinal adhesions and tend to form new breaks. 9. I always do a paracentesis before injecting gas with a TB syringe without the plunger and a #30 needle. If you pump up the eye with gas before doing a paracentesis, gas may enter the anterior chamber (even if phakic), and iris incarceration is more likely during the paracentesis. 10. I always use 5% povodine iodine; always use a speculum; always give 0.2 ml of subTenon’s gentamycin away from the injection and paracentesis site; and now always use a mask and almost never wear gloves. 11. I always examine the patient on the first postoperative day. 12. If the break is still open on day three, a rescue operation will likely be needed. If the break is closed and there is inferior subretinal fluid, no treatment is needed as long as the macula is attached. Sometimes subretinal fluid can linger for months. If the macula is off, there is likely an inferior break. The rescue operation should be performed by day five, especially if cryopexy was used. Pneumatic retinopexy gets a bad name usually because the eye is not rescued promptly. In the Pneumatic Retinopexy Clinical Trial, the incidence of proliferative vitreoretinopathy was the same for scleral buckle and pneumatic retinopexy. —PT

There were many revisions of the paper sent between San Diego and Tahiti (via DHL). Once the presentation was accepted by the AAO, I requested Dr. Lincoff to referee the paper. He was well-known as one who did not embrace the procedure, and I felt if he was positive about the paper, more surgeons might accept the operation. Dr. Lincoff did not disappoint; he was fair, pointed out all the weak points of the study, but also admitted there was some validity to the operation. After 18 more months of follow-up we presented the PR Clinical Trial two-year data, again at the AAO which showed that the operation was lasting and that almost 90 percent of patients with detachment of the macula regained reading vision.^12,13

Pneumatic retinopexy has been controversial since the beginning and remains so today. Some surgeons were so concerned about the conclusions of the trial that they requested the raw data to personally review. Many published their poor initial experience with the procedure. Adverse events were quickly disseminated, several as single case reports.^14-21 Rarely were the publications prospective or randomized.²² 

One trial reported the aggregate results of many surgeons, each contributing a few of their early attempts with pneumatic retinopexy with understandably poor results.²³ Several papers concluded the operation was less successful in pseudophakic eyes, but also noted that failed cases ultimately did well.^24,25

Today, many surgeons remain reluctant to treat the simplest detachment with pneumatic retinopexy when the eye is pseudophakic. We agree that the single operation success rate is not as high in pseudophakic eyes but the procedure still works well in most cases and, if it does fail, no harm is done. Dr. Hilton and I subsequently published a paper addressing these adverse experiences and showed how most complications are avoidable.²⁶

Pneumatic retinopexy is performed less often today for many reasons. More preoperative time is required to prepare and educate the patient; vitrectomy instrumentation is reliable; fewer fellows are adequately trained with scleral buckling; surgeons are economically punished for performing pneumatic retinopexy; and doctors are not responsible for the total cost of the intervention (including inevitable cataract surgery following vitrectomy). 

In the very near future, I predict pneumatic retinopexy will become more popular. Surgeons will be compensated by their outcomes and resources they consume. Even if one assumes a 60-percent pneumatic success rate, pneumatic retinopexy is still more cost-effective than buckling or vitrectomy.

One cannot separate the surgeon from the surgery. Pneumatic retinopexy requires a trained eye to find the breaks, and an experienced surgeon to select the right operation and perform the pneumatic procedure correctly, which appears deceptively simple on the surface. It is especially important to perform a recue operation in a timely fashion. I continue to perform pneumatic retinopexy because it remains the best way to restore pre-detachment vision (See Figure 4).

Finally, for a trip down memory lane I suggest you visit youtube.com, where you will find a short video of Dr. Hilton performing and narrating pneumatic retinopexy, by searching “ George Hilton pneumatic retinopexy.”