Vitreoretinal Surgery
Perfluorocarbon Liquids in Vitreoretinal
Surgery
EDWARD
QUINLAN, MD, & JULIA A. HALLER, MD
The use of perfluorocarbon liquids as an intraoperative
tool is widely recognized as a significant advancement in the field of vitreoretinal
surgery. Stanley Chang, MD, Edward S. Harkness Professor and chairman of Ophthalmology
at Columbia University, has been honored for his pioneering work in this area. He
published the initial reports of the use of perfluorocarbon fluids in humans in
the late 1980s. Dr. Chang demonstrated that their use in complex retinal detachments
increased the success rate of retinal reattachment in these cases.
These
initial reports concerned retinal detachments associated with proliferative vitreoretinopathy,1
trauma,2
and giant retinal tears.3
The usefulness of perfluorocarbon liquids has led to an expansion in their indications
for use and reports have cited their benefit in patients with posteriorly dislocated
lenses, submacular hemorrhage, and suprachoroidal hemorrhage. This article will
review some of the uses of perfluorocarbon liquids in our practice.
WHY USE PERFLUOROCARBON
LIQUIDS?
Initially designed for use as a blood substitute
due to their high oxygen-carrying capacity, perfluorocarbon fluids have also
been investigated for use in liquid ventilation in preterm infants with respiratory
complications and in adults with acute respiratory distress syndrome. Perfluorocarbon
liquids possess a number of characteristics that make them quite useful in vitreoretinal
surgery. They have a high specific gravity (1.6-2.1) relative to saline, which results
in their excellent retinal tamponade effect. They have a high interfacial tension
that makes them cohesive enough to remain as a single large bubble. They are optically
clear fluids with refractive indices only slightly different than saline. This slight
difference in refractive index allows for easy visibility of the different fluid
interfaces. Their boiling point is greater than saline such that endophotocoagulation
can be performed without resulting in intraocular vaporization. And they also have
low viscosity (2cSt-3cSt at 25Þ C), allowing for easy injection and removal
with microsurgical instruments.
A number of commercial perfluorocarbon liquids are available for
use in vitreoretinal surgery. Perfluoro-n-octane (Perfluoron, Alcon, Fort Worth,
Texas) and perfluoroperhydrophenanthrene (Vitreon, Vitrophage, Lyons, Ill) are 2
perfluorocarbon liquids that have been tested in separate multicenter clinical trials
and have been shown to be safe and effective. In a study in which the 2 were compared
to each other, the efficacy in terms of retinal reattachment and final visual outcome
was similar; however, postoperative retention was found to be greater in the Vitreon
group compared with the Perfluoron group.4
Although Perfluoron is the perfluorocarbon liquid most commonly used in the United
States, Vitreon is also available and has been used with success.
FOR DIFFICULT REATTACHMENTS
At the Wilmer Eye Institute of Johns Hopkins
University, we encounter a number of complicated cases where we routinely use perfluorocarbon
fluids, most commonly with recurrent retinal detachments associated with proliferative
vitreoretinopathy. These cases require meticulous membrane dissection and occasionally
retinotomy or retinectomy in order to achieve retinal reattachment. The
ability of perfluorocarbon fluids to provide retinal tamponade and countertraction
significantly improves our ability to repair these complex retinal detachments.
In cases with proliferative vitreoretinopathy, we begin with removal of posterior
membranes and proceed anteriorly to relieve traction. Perfluorocarbon liquid is
then instilled over the optic nerve to flatten the retina. The perfluorocarbon liquid
will help to identify residual preretinal or subretinal membranes that appear as
persistent traction or elevation of the retina. After removal of all membranes,
if the retina does not flatten on the existing scleral buckle, a relaxing retinotomy
or retinectomy is performed. Additional perfluorocarbon liquid is instilled to flatten
the edge of the retina and to allow for placement of endophotocoagulation along
the retinotomy/retinectomy edge.
Subretinal hemorrhage that migrates into the subfoveal space generally
results in significantly poor vision. In retinal detachment cases with proliferative
vitreoretinopathy where retinectomy is being performed, we have found that an added
benefit to perfluorocarbon fluid tamponade of the posterior retina is protection
of the subfoveal space should there be significant hemorrhage that may arise from
severed retinal vessels or the choroid. In a recent case in which we were performing
an inferior retinectomy, an adhesion of the retina to the underlying choroid from
prior endophotocoagulation was disrupted, resulting in a focal site of choroidal
hemorrhage that pooled in the subretinal space. Fortunately, there was perfluorocarbon
liquid tamponading the macular region that did not allow the subretinal hemorrhage
to migrate into the subfoveal space. After a short period of intraocular pressure
elevation, the hemorrhaging subsided and the majority of the subretinal blood was
evacuated using a soft-tipped extrusion cannula. There remained a small crescent
of subretinal hemorrhage in the temporal macular region; however, no blood reached
the subfoveal space.
REMOVING TRAPPED SILICONE
OIL
|
A Badly Damaged Eye is Saved |
|
Dr. Haller, the coauthor of this article
and Robert Welch Professor of Ophthalmology at the Wilmer Eye Institute of Johns
Hopkins University, remembers a case in which the the use of perfluorocarbon liquid
was key to a successful outcome.
A prominent member of the Greek government was visiting her Aegean
island family home when she was struck by a beach umbrella that was driven through
her cheek and into her eye by a freak gust of wind. The popular politician was referred
to the Wilmer Eye Institute by the US ambassador to Greece and arrived with a recently
sutured 180Þ laceration, dislocated lens, and eye filled with blood.
"So much subretinal hemorrhage was present that there was initially
some thought that the central retinal artery had been revulsed," recalls Dr. Haller.
After a lensectomy and vitrectomy, a 360Þ retinotomy was
performed with the patient evacuation of thick mounds of clot. Retinal reattachment
was then achieved with Perfluoron followed by silicone oil.
"It was with pride that we watched her smoothly supervising the
100th modern Olympic Games in Athens with 2 attractive, functional eyes. The introduction
of perfluorocarbon liquids into the surgical armamentarium has been one of the the
signal advances of the last 20 years in the retinal field," asserts Dr. Haller. |
Perfluorocarbon fluids may also be useful
in the rare case where silicone oil migrates into the subretinal space. Some weeks
following a scleral buckling procedure combined with vitrectomy in which silicone
oil was used for postoperative tamponade, silicone oil migrated into the subretinal
space through a large open break posterior to the buckle. The break opened and expanded
due to contraction of epiretinal proliferation. When the silicone oil was removed
from the vitreous cavity at the beginning of the case, the retinal detachment became
more bullous and the silicone oil remained entrapped in the bullously detached retina.
Perfluorocarbon fluid was instilled over the optic nerve, pushing the subretinal
fluid and eventually the silicone oil globule through the open break. The epiretinal
proliferation was removed and the retina settled nicely into place, allowing laser
retinopexy to be applied around the break. The need for a large retinectomy to remove
the silicone oil from the subretinal space was avoided.
STABILIZING RETINA
Patients with proliferative diabetic retinopathy
and marked fibrovascular proliferation provide another setting in which perfluorocarbon
fluids may be highly useful. This is especially true when the fibrovascular proliferation
extends peripherally and involves areas of atrophic retina. Even with careful segmentation
and delamination techniques in these cases, retinal breaks may develop due to the
atrophic nature of the retina. In this setting, the retina may start to become bullously
elevated due to increasing fluid passing into the subretinal space. This makes further
membrane removal difficult.
Perfluorocarbon fluid instilled over the macular region will stabilize
the retina. It will also provide countertraction that assists with fibrovascular
proliferation removal. We find that it is imperative in these cases to relieve traction
on posterior breaks before infusing the Perfluoron and to infuse it only in limited
quantity and quite cautiously to avoid subretinal migration of the heavy liquid.
FOR LESS COMPLEX CASES
In addition to their utility in complex
vitreoretinal cases, perfluorocarbon fluids can also be quite useful in more standard
cases. In selected cases of primary vitrectomy for retinal detachment, the use of
perfluorocarbon liquids has virtually eliminated the need for a posterior drainage
retinotomy. After performing a meticulous vitrectomy, perfluorocarbon fluid is instilled
into the eye. This will displace the subretinal fluid anteriorly through peripheral
breaks. The perfluorocarbon fluid is instilled up to the posterior edge of the most
posterior peripheral retinal break. The retina anterior to the perfluorocarbon generally
remains elevated. A fluid/air exchange is performed, removing the aqueous layer
first and aspirating subretinal fluid through the peripheral breaks, resulting in
flattening of the anterior retina. Once all of the aqueous fluid has been removed,
the perfluorocarbon fluid is subsequently removed. Endophotocoagulation can then
be applied to create a chorioretinal adhesion around the retinal breaks.
CONCLUSION
Since their introduction in the 1980s, perfluorocarbon
liquids have revolutionized vitreoretinal surgery. They have improved surgical outcomes
in complex retinal detachments as well as routine cases and have resulted in shortened
operating times. Perfluorocarbon liquids remain an invaluable tool for the vitreoretinal
surgeon. RP
REFERENCES
1. Chang S, Ozmert E, Zimmerman NJ. Intraoperative
perfluorocarbon liquids in the management of proliferative vitreoretinopathy. American
Journal of Ophthalmology. 1988;106: 668-674.
2. Chang S, Reppucci V, Zimmerman NJ, Heinemann MH, Coleman DJ.
Perfluorocarbon liquids in the management of traumatic retinal detachments. Ophthalmology.
1989;96:785-91.
3. Chang, S, Lincoff H, Zimmerman NJ, Fuchs W. Giant retinal tears.
surgical techniques and results using perfluorocarbon liquids. Arch Ophthalmol.
1989;107:761-766.
4. Loewenstein A, Humayun MS, de Juan E Jr, Campochiaro PA, Haller
JA. Perfluoroperhydrophenanthrene versus perfluoro-n-octane in vitreoretinal surgery.Ophthalmology.
2000;107:107-1082.
Edward
Quinlan, MD, and Julia A. Haller, MD, are retina specialists at the Wilmer Eye Institute
of Johns Hopkins University. Dr. Quinlan may be reached via e-mail at
equinlan@jhmi.edu.
The authors have no financial interest in any of the products mentioned in the article.
Retinal Physician, Issue: November 2006