John Lean, MD and Peter Leaver, MD

‘Five of them were foolish, and five were wise. Those who were fools, when they took their lamps, took no oil in them, but the wise took oil in their vessels with their lamps.’

—The Parable of the Wise and Foolish Virgins

   Matthew 25:1-13

‍

Until the 1960s, the retinal disease that we now know as proliferative vitreoretinopathy (PVR) was called massive vitreous retraction (MVR) and as the name implies, was felt to be the result of massive retraction of the vitreous caused by membranes forming within it and on the surface off the detached posterior hyaloid.1

In the absence of a way to safely remove the vitreous, the disease was regarded as untreatable. The crucial insight that eventually led the way to treatment was the realization by Drs. Taylor Smith, Paul Cibis, and others that in addition to contraction of the vitreous, contractile membranes formed on the surface of the retina and successful treatment would require separation of these membranes from the retina. A very lucky circumstance arose at that point.

In unrelated work, Dr. William Stone was exploring the allogenic effects of silicone oil, among a number of agents, on animal tissue and had found it to be very well tolerated. Cibis realized that if this viscoelastic material was injected between the membranes and the retinal surface, it would achieve the needed separation. Cibis also noted that because of its relatively high interfacial tension, the oil would not easily pass through any retinal breaks.

He confirmed through animal studies that silicone oil was non-toxic, then began to use it in otherwise-hopeless surgical cases. Employing a syringe that looked like it was built for a car mechanic (Figure 1) and visualizing the end of the needle with the indirect ophthalmoscope, this extremely gifted surgeon reattached a proportion of retinas otherwise regarded as inoperable.

The “tour de force” that this involved should not be underestimated. First, retro­hyaloid fluid was drained via the pars plana with a needle, and then replaced with injected silicone oil. Next, the oil needle was advanced under the sheet of retinal membranes, and oil injection was continued while subretinal fluid was drained via an external sclerotomy.

All of this was accomplished by manually pushing viscous silicone through a narrow-gauge needle and visualizing the procedure through the inverted image produced by the indirect ophthalmoscope.2

Tragically——Cibis died very young in 1965 at age 53. No surgeon replaced him in the United States, perhaps partially because of the implacable opposition of Dr. Charles Schepens to silicone oil. In the United Kingdom, the mantle was taken up by the late Dr. John Scott in Cambridge and Drs. Peter Leaver and Rod Gray at Moorfields Eye Hospital in London, England.

Scott was a supremely talented surgeon who was able to manipulate instruments inside the eye with ease, building on Cibis’ work and expanding it to treat giant breaks.3 Once, when asked how he was able to overcome the difficulty of the indirect ophthalmoscope’s inverted image during surgery, Scott  apparently dismissed the issue by simply advising the questioner to think about moving the instrument as one would the tiller of a boat—push to the right and the boat moves to the left. That easy? No way!

Meanwhile, Peter Leaver and Rod Gray, also highly talented surgeons and prodigious publishers of their work, reviewed the Moorfields experience in a paper in the British Journal of Ophthalmology4 and “summarized” it in the biblical quotation above.

In the United States, treatment of this condition had moved toward vitrectomy. As vitrectomy developed—and particularly when bimanual surgery debuted and it became possible to directly dissect these membranes from the retinal surface—this approach became a much more attractive and less technically challenging option.

John Scott continued with oil injection, but by the late 1970s, Moorfields increasingly adopted US treatment techniques. Sometimes the results were spectacular, but often initial success was followed by failure as membranes re-proliferated—not just on the retinal surface and detached posterior hyaloid but also on the exposed residual vitreous base. In this situation, the previous technique of oil injection was no longer available.

So, in early 1980s, the group at Moorfields began to experiment with combining vitrectomy with silicone oil injection both for PVR5and giant breaks.6 It was hoped that in PVR, prolonged tamponade with silicone would close retinal breaks more effectively. In eyes that still failed, the investigators hoped that silicone oil would limit fluid recruitment through the break, thereby reducing the extent of recurrent detachment so it could be “walled off” with laser.

In giant breaks, the ability to exchange fluid slowly allowed the possibility of controlled unfolding of the mobile flap without the need for the physical gymnastics of prone fluid ­gas exchange. (Remember, this was before the advent of perfluorocarbon liquids.) Another potential advantage of an initial vitrectomy was to permit later removal of the silicone, which might reduce its complications.

At the time, these complications were thought to be intrinsic to the silicone oil, although later as purer silicones became available, it became clear that the culprit was likely impurities in the silicone rather than the silicone itself. In the United States, perhaps because of the continued fierce opposition of Dr. Charles Schepens and perhaps due to the legal risk of using a device not approved by the Food and Drug Administration (FDA), silicone oil use remained under the radar.  

However, at Duke University, Drs. Brooks McCuen and Robert Machemer were exploring the same approach.7 In Europe, Dr. Relya Zivojnovic was pushing the envelope even farther, employing large retinectomies8 to relieve traction in the vitreous base.

Perhaps most importantly, Zivojnovic was using his connection with instrument manufacturer Dutch Ophthalmic Research Center (DORC) to develop an oil pump that considerably facilitated silicone injection (Figure 2) and could be directly connected to the infusion line (Figure 3). And Dr. Fumitaka Ando9 had demonstrated the need for an inferior iridectomy in aphakic eyes to prevent angle closure.

By the mid-1980s, the main issue in PVR surgery had become whether tamponade with gas was a preferable to oil. There were strong protagonists—and even stronger opinions—on both sides. At that point, Drs. Walter Stern and John Lean sat down to write a protocol for a study to submit to the National Eye Institute (NEI). The main principles were that surgery would be standardized as far as possible (a video was made to demonstrate principles) and then once the retina was attached, the choice of tamponade would be made by opening an envelope.

Amazingly, a group of very experienced surgeons agreed to these conditions (perhaps because they were tired of smuggling silicone into the United States packed in socks in their luggage), and a proposal was presented to the NEI. Then came an unexpected roadblock. The Dow Chemical Company, which we needed to supply the silicone, had been severely burned by their silicone breast implant experience; the last thing the company wanted was to be associated with another use of silicone that might have complications.

Fortunately, thanks to persistent urging by Dr. Steven Ryan, Dow eventually relented. The study was approved, and in 1992, the first papers were published showing that silicone oil and C3F8 were similarly effective and both were preferable to SF6.10-11  

More papers followed. Chiron Vision Group produced highly purified Adatomed Silicone Oil OP5000, and in 1996, the FDA approved the use of silicone for bimanual retinal microsurgery, allowing it to finally enter the armamentarium of vitreoretinal surgeons in the United States and around the world.

References

1. Leaver P, Keeler R. Good News from Switzerland. A History of Retinal Reattachment Surgery. Royal Society of Medicine Press; 2013.

2. Cibis PA, Becker B, Okun E, Canaan S. The use of liquid silicone in retinal detachment surgery. Arch Opthhalmol. 1962;68:590-599. doi:10.1001/archopht.1962.00960030594005

3. Scott JD. Giant tear of the retina. Trans Ophthalmol Soc UK. 1975;95(1):1421-1424.

4. Grey R, Leaver PK. Silicone oil in the treatment of massive preretinal retraction. I. Results in 105 eyes. Br J Ophthalmol. 1979;63(5):355-360. doi:10.1136/bjo.63.5.355

5. Lean JS, Leaver PK, Cooling RJ, McLeod D. Management of complex retinal detachments by vitrectomy and fluid/silicone exchange. Trans Ophthalmol Soc UK. 1982;102(Pt 1):203-205.

6. Leaver PK, Cooling RJ, Ferretis EB, Lean JS, McLeod D. Vitrectomy and fluid/silicone-oil exchange for giant retinal tears: results at six months. Br J Ophthalmol. 1984;68(6):432-438. doi:10.1136/bjo.68.6.432

7. Sell CH, McCuen BW 2nd. Landers MB 3rd, Machemer R. Longterm results of successful vitrectomy with silicone oil for advanced proliferative vitreoretinopathy. Am J Ophthalmol. 1987;103(1):24-28. doi:10.1016/s0002-9394(14)74164-9

8. Zivojnovic R, Mertens DA, Peperkamp E. Liquid silicone in amotio surgery (II) Report on 280 cases-further development of the technique. Article in German. Klin Monbl Augenheilk. 1982;181:444-452.

9. Ando F. Intraocular hypertension resulting from pupillary block by silicone oil. Am J Ophthalmol. 1985;99(1):87-88. doi:10.1016/s0002-9394(14)75878-7

10. Vitrectomy with silicone oil perfluoropropane gas in eyes with severe proliferative vitreoretionpathy: results of a randomized clinical trial. Silicone Study Report 2. Arch Ophthalmol. 1992;110(6):780-792. doi:10.1001/archopht.1992.01080180052028

11. Vitrectomy with silicone oil or sulphur hexafluoride gas in eyes with severe proliferative vitreoretinopathy: results of a randomized clinical trial. Silicone Study Report 1. Arch Ophthalmol. 1992;110(6):770-779. doi:10.1001/archopht.1992.01080180042027

‍

Thumbnail image photo credit: The image shown was originally published on the Retina Image Bank® website. Manish Nagpal, MD, FRCS (UK), FASRS and co-author Gayathri Mohan. Buckled Silicone Oil Filled Eye. 2019; Image Number 31131. © the American Society of Retina Specialists.

‍

(Milestone essay published 2024)