Retinal Detachment

What is the retina ?

The retina is a light-sensitive extension of the brain that lines the inner surface of the eyeball. It detects light and converts the image of the external world into electrical impulses that are sent from the eye to the brain for interpretation along the optic nerve. It is only 10 cells thick with the outermost layer, the retinal receptors being responsible for light detection. The retina can be likened to the film of a camera. If the retina is not functioning properly vision can be hampered or even lost.

What is a retinal detachment ?

A retinal detachment can be of two main types 1) exudative or 2) rhegmatogenous.

Exudative retinal detachments occur due to the collection of fluid between the retina and the outer coats of the eye. This fluid may have many origins including inflammation and tumors.

When the retina is detached from the coats of the eye, it fails to function properly leading to blurred vision in the area of the detachment.

Rhegmatogenous retinal detachments (rhegma-Greek for break) are due to holes that occur in the retina allowing fluid from the vitreous cavity to lift the retina from the outer coats of the eye. These breaks or holes in the retina can be from trauma, high myopia or near-sightedness, or some rare familial eye diseases.

Who is at risk for retinal detachment ?

The following people are at increased risk of retinal detachment

• moderate to high myopes
• recent serve ocular blunt or penetrating trauma
• recent ocular surgery including cataract surgery
• those with history or retinal detachment
• those with family history of retinal detachment
• patients with severe diabetic retinopathy

What are the symptoms of retinal detachment ?

When the vitreous jelly within the eye changes shape, usually due to aging, there may symptoms that the patient can experience. They are

• flashes of light that occur even in the dark
• onset of floaters or black spots before the eyes

These symptoms only signify that there is traction on the retina or that there has been a change in the shape or configuration of the vitreous. This traction can lead to a tear in the retina followed by retinal detachment but in the vast majority of patients this does not occur. Evaluation by an ophthalmologist with a dilated fundus exam to assess the peripheral retina for signs of traction or holes in the retina will reassure the patient of the benign nature of these changes.

However, if traction persists and a hole does develop in the retina, the retina may detach leading to new symptoms such as

• a dark curtain coming across the field of vision
• loss of central or reading vision

How serious is a retinal detachment ?

Retinal detachment is one of the most serious causes of loss or sight and even possibly the loss of the eye itself. The detachment of the macular region of the retina can mean longterm loss or reading vision to varying degrees.

If the retinal detachment is large and is not repaired the nutrition of the eye itself is threatened and the eye can shrink in size, a condition known as phthisis.

How is a retinal detachment treated ?

Retinal detachments are repaired by ophthalmologists who have recieved special training in diseases of the the eye. The can use varied methods of repairing retinal detachments, each method dependent on location and size of the retinal detachment and the accompanying holes. Holes may repaired without surgical intervention if a retinal detachment has not yet developed by

• laser retinopexy
• cryoretinopexy

Once a rhegmatogenous retinal detachment has occurred then methods for repair include

• retinal pneumopexy
• vitreous surgery to release traction
• encircling materials (bands, tires etc.)
• intraoperative endolaser
• use of intraocular gases and silicone oil

Treatment of retinal detachments try to attain 2 main goals 1) save the globe by anatomically reattaching the retina and 2) restore as much useful vision as possible.

Complications from the surgery include redetachment, infection, chronic fluid collection in the retina, fibrosis of the retina and vitreous known as PVR or proliferative vitreoretinopathy.