Advances in technology improve posterior segment surgery
Over the past decade, developments such as wide-field viewing and perfluorocarbon liquids have changed posterior segment procedures.
Vitreoretinal surgery has come a long way in recent years, and it continues to evolve with the development of wide-field illumination systems, perfluorocarbon liquids and biodegradable drug implants.
Glenn J. Jaffe, MD, said he barely remembers the last time he used a Stryker frame bed to repair a giant retinal tear because of the substantial advances in technology in the past 10 years.
“Posterior segment surgery is different, there is no question about it. The advances have made a big difference and have made it much easier,” Dr. Jaffe said in an interview with Ocular Surgery News. “Some of the things we used to do, the people coming out [of training] now have not even [been] seen before because we do not do them anymore.”
Wide-field viewing
According to Jay S. Duker, MD, one of the biggest innovations is wide-field viewing for vitrectomy surgery.
“The wide-field viewing has enabled us to treat diseases of the retinal periphery easier than we could previously, such as proliferative vitreoretinopathy and giant retinal tear,” Dr. Duker said in an interview with OSN.
Wide-field viewing has reduced operating room time and enabled surgeons to do complex cases that previously would have been impossible, such as proliferative vitreoretinopathy cases that involve extensive vitreous-based dissections, he said.
“We used to use contact lens systems, frequently held by an assistant with irrigation to keep the cornea moist. If the case was a long case, the cornea could get swollen or you could get an epithelial defect,” Dr. Jaffe said. “They only provide a limited view of one particular area of the retina, and with the wide-field systems, it allows you to get a view of a much larger field of the retina, so if you’re working in one area you can see the effect on another area.”
For example, with older viewing systems, the surgeon could be working on one part of the membrane while unknowingly exerting traction in another part of the retina, which could cause damage, Dr. Jaffe explained.
“You wouldn’t have been able to see that happening because you had a much smaller field of view,” he said. “Wide-field viewing also makes it significantly easier to address some of the peripheral pathology in patients with retinal diseases.”
Improved tools
Another significant innovation is the advent of high-speed cutters with cut rates greater than 1,000 per minute, Dr. Duker said.
“They have enabled us to use the cutter as a delaminating instrument, thereby reducing the need for scissors, simplifying the surgery and protecting the retina,” Dr. Duker said.
The development of brighter illumination systems has also been an important change, according to Dr. Jaffe.
“Because the lighting has become better and better, it’s allowing new technologies like the 25-gauge system to progress. It also gives us the advantage of being able to add a light function to instruments to make them multifunctional,” he said. “Some of this wasn’t possible even a couple of years ago because the lights weren’t bright enough. With the more bright light sources, we are able to deliver the light through a smaller fiber, and it just makes the instruments work better. To me, that is a significant advance.”
Perfluorocarbon liquids
Liquid perfluorocarbon has helped increase the success rate for giant retinal tear surgery from 60% or 70% to over 90%, according to Dr. Duker.
“It used to be that giant retinal tears were frequently referred from community retina specialists to academic centers or to people who were considered at the top of their field because they were considered more difficult than what the typical retina specialist would attempt,” Dr. Jaffe said. “Since the advent of perfluorocarbon, it has made it much easier for general retina specialists to do these things on their own. At an academic center, we probably see fewer giant retinal tears because people are more comfortable handling them because of the usefulness of that surgical tool.”
The vitreous fluid in the eye is the density of water and does not have enough weight to push a detached retina back down, Dr. Jaffe said.
He recalled using a Stryker frame rotating bed to turn patients upside down under anesthesia so that a gas bubble would be injected that would push up against the retina to hold it flat.
“You had to lie under the patient to do the manipulations,” he said.
Another way to repair a giant retinal tear was to inject silicone oil and unfold the retina under the heavy silicone oil, which was challenging, he said.
“The perfluorocarbon is a liquid that is heavier than water, so it sinks and you can use it as a surgical tool, so when you put it in the eye it will help to unroll the retina in a gentle and controlled way, and because it’s heavier than water it will sit on the retina and doesn’t allow it to come back up,” Dr. Jaffe explained. “I also find it extremely useful for complicated retinal detachments.”
Dyes and drugs
The use of indocyanine green dye has also been an advance in vitreoretinal surgery, Dr. Duker said. The dye stains the internal limiting membrane of the retina, which makes membrane peeling in macular hole surgery safer and simpler. It also contributes to a higher surgery success rate.
“One of the things that probably decreased the need for some of the vitreoretinal surgical procedures are some of the pharmacologic advances,” Dr. Jaffe said. “An example of this type of technology is the drug Vitrase (hyaluronidase, Ista Pharmaceuticals), which is designed to make blood clear from the vitreous cavity more quickly. Theoretically you may be able to eliminate the need for vitrectomy by giving this drug to selected patients with this condition. I think the wave of the future is either going to be pharmacology that replaces vitreoretinal surgery in some cases or makes it work better.”
Drug release systems
The FDA-approved extended-release technology of the Vitrasert (ganciclovir intravitreal implant, Bausch & Lomb) allows surgeons to deliver medications in a sustained-release fashion to the posterior segment of the eye, Dr. Duker said.
Sewn to the wall of the eye, the FDA-approved device, containing ganciclovir, is indicated for treatment of cytomegalovirus retinitis, an opportunistic infection in AIDS patients, but the device itself can hold other medicines, he explained.
Dr. Jaffe agreed that the development of new pharmacology and sustained drug delivery systems will help treat different eye diseases.
“One in particular I was involved in was the [FDA-approved] Retisert (fluocinolone acetonide intravitreal implant, B&L), which is a nonbiodegradable implant,” he said. “There are others in development that are being tested now to be biodegradable so they disappear along with the drug. Those types of nonbiodegradable and biodegradable systems are just now starting to revolutionize treatment of diseases. … There are also drug delivery systems that are under development that will be put on the outside of the eye.”
An incremental advance
The surgeons said that some new technologies are more incremental advances, rather than wholesale changes.
“I think some people may talk about 25-gauge surgery as a great innovation,” Dr. Duker said. “I’m not going to list it because I don’t think it’s widely enough accepted that it’s going to change the way we operate totally. It’s fine that others may have that opinion that it’s an innovation, and it may prove to be, but I’m not prepared to say that it’s one of the greatest innovations in the last 10 years yet.”
Dr. Jaffe echoed the sentiment that 25-gauge technologies are an incremental advance.
“To me, going from the previous 19- to 20-gauge instruments to the smaller 25-gauge instrument is an improvement, not a revolutionary advance, but that’s just me,” he said. “Going from the very original vitrectomy probe to the smaller instruments was a major advance.”
Older techniques still valuable
Both Dr. Duker and Dr. Jaffe said there can still be some value in older techniques.
“There are certain times when I prefer using the old quartz contact lens system that is a non-wide-field viewing system,” Dr. Jaffe said. “I actually like that for certain macular procedures, where you need to get a magnified detailed view. I personally find that my view is better for some of those detailed procedures with some of the older contact viewing systems. The fellows coming out frequently don’t see those systems as much during their training because we use the wide-field so much.”
More cases of retinal detachment are being repaired with vitreoretinal surgical techniques, either with or without a scleral buckle, Dr. Jaffe said.
“There has been a little less emphasis on doing straight scleral buckling procedures, which I happen to think is still a very good procedure,” he said. “I think the fellows who come out now have a little less experience doing standard scleral buckling procedures because there has been more emphasis recently on either doing vitrectomy alone or combining it with the scleral buckle.”
Dr. Duker said, “In my training, I did 300 to 400 scleral buckles before I went out. Retina fellows now will do 300 to 500 surgeries, of which only 50 or 60 are buckles. I think we will continue to do fewer and fewer scleral buckles because the young vitreoretinal surgeons are much more comfortable doing vitrectomy and much less comfortable doing buckles.”
According to Dr. Jaffe, older procedures can be valuable if something goes wrong during surgery.
“One advantage of having seen those procedures is that if for some reason a piece of new equipment malfunctions, you have other tools from your past training that you can call on to get yourself out of a situation,” he said. “With the exception of that, because the advances have been significant enough, I would not go back and use those techniques.”
For Your Information:
- Jay S. Duker, MD, can be reached at New England Eye Center, 750 Washington St., Box 450, Boston, MA 02111; 617-636-4604; fax: 617-636-4866.
- Glenn J. Jaffe, MD, can be reached at Duke University Eye Center, Box 382, Durham, NC 27710; 919-684-4458; fax: 919-681-6474.
- Bausch & Lomb, maker of Vitrasert and Retisert, can be reached at 180 Via Verde, San Dimas, CA 91773; 909-971-5100; fax: 800-362-7006; Web site: www.bausch.com.
- Ista Pharmaceuticals, maker of Vitrase, can be reached at 15295 Alton Parkway, Irvine, CA 92618; 949-788-6000; fax: 949-788-6010; Web site: www.istavision.com.
- Daniele Cruz is an OSN Staff Writer who covers all aspects of ophthalmology.