Technique Revolutionizes Retinal Surgery

The retina at the back of the eyeball acts like the film in a camera, carrying images to the brain. If it becomes detached from its supports, part or all vision is lost.

It's estimated that about one in 10,000 people experience retinal detachment every year. Patients complain of seeing flashes of light or stars followed by the sensation of a curtain moving across the eye. Vision loss depends on the location of the detachment.

Patients with a high degree of short-sightedness are more susceptible to detachment. It also occurs in about one per cent of cases following cataract surgery.

Retinal detachments are closely related to aging. As years pass, the normal jelly-like vitreous chamber at the back of the eye becomes less homogeneous.

Fibrous bands form, tugging on the retina. This can cause a small hole and fluid seeps behind the retina. The pressure from both the bands and the fluid causes the detachment.

Retinal detachment should be repaired as soon as possible. But the degree of emergency depends largely on the status of the macula, that part of the retina responsible for central vision and our ability to read.

The retina receives its blood supply from the underlying choroid. The longer the retina is detached, the longer the sensitive photo receptors are without an adequate blood supply and the greater the damage.

Repairing Retinal Tearing

Repairing retinal detachment has always taxed the ingenuity of ophthalmologists. For many years surgeons have used what's called a "buckling procedure."

During this operation, a band is placed around the eyeball to bring the detached retina close to its former point of attachment. Doctors then use a laser beam to weld the retina to the choroid. But this operation has limitations in repairing difficult detachments.

This is where perfluorocarbons open a new dimension to retinal surgery, and for patients whose buckling operations have failed.

Dr. Stanley Chan, a New York ophthalmologist, pioneered the work on PCLs, which were originally developed as blood substitutes. The liquid is injected into the back vitreous chamber of the eye and removed at the conclusion of the operation.

PCLs are heavier than water so when patients lie on their backs the liquid drops to the bottom of the eye. This creates a "steamroller effect," which flattens the detached retina.

Prior to the use of PCLs, surgeons injected air into the eye in an attempt to push back the detached retina.

But when air is injected into the vitreous chamber it's hard for surgeons using optical instruments to see. The last thing eye surgeons want is cloudy vision while trying to repair detachments -- particularly when they're working at the extreme periphery of the eyeball where most detachments occur. In contrast, PCLs provide excellent visualization.

PCLs also have a very high boiling point. This enables surgeons to cauterize the retina while PCLs are still in the eye.

There are a few dos and don'ts after retinal-detachment surgery. Infection is a major worry so it's important to stay away from swimming pools for several weeks. And it's unwise to engage in strenuous physical activity where the eye could be injured.

Some retinal-detachment operations require the injection of air or gas into the eye. While the gas is still present, flying is hazardous as it causes a severe increase in intraocular pressure.