Retinal Detachment – Understanding This Surgical Emergency

The retina is an important layer in the back of the eye, whose function is to absorb and process light that enters the eye, very much like the film which captures images in a camera.

The retina contains millions of photoreceptors called rods and cones. The rods are found mainly in the outer parts of the retina, and are important for night vision and seeing movement. The cones are found mainly in the central part of the retina (around a region called the macula), and they are responsible mainly for colour vision and fine vision.

What is Retinal Detachment?

Retinal detachment occurs when there is a hole or tear in the retina. When this happens, the aqueous humor, which is the fluid within the eyeball, can pass through this tear, and underneath the retinal layer. This causes the retina to get detached from the underlying wall of the eye. Vision in the detached part of the retina is severely affect, and is typically seen as a “veil” or “dark curtain” that comes across the visual field.

What are the Symptoms?

Retinal detachment is considered a medical emergency, and if you should experience any of the following symptoms, you should immediately consult your doctor:

• Sudden dramatic increase in the number of floaters

• Flashes of light

• Sudden decrease in vision

• A “veil” or “dark curtain” that obscures part or all of your vision

• Slight feeling of heaviness or pressure in the eye

What are the Risk Factors?

• Having severe short sightedness. Myopia is associated with over 60% of cases of retinal detachment.

• Having retinal detachment in one eye, increases the risk of retinal detachment in the other eye.

• Retinal detachment occurs slightly more frequently after cataract surgery.

• Having proliferative diabetic retinopathy or proliferative retinopathy of sickle cell disease.

• Injury to the eyeball can potentially increase the risk of retinal detachment.

How is it Diagnosed?

Your eye doctor/ophthalmologist will make the diagnosis of retinal detachment based on your symptoms and physical examination. Some of the following tests are done as part of the eye examination:

• Visual acuity

• Visual field testing

• Examination of the retina to look for tears in the retina, or detached areas. This is done using a magnifying instrument with a powerful light source.

How is it Treated?

A retinal detachment is considered a surgical emergency, and should be dealt with by an ophthalmologist immediately to repair it, or stop it from getting worse.

The most common methods of repairing a detached retina include:

1. Scleral buckling surgery

In this form of surgery, a band of plastic, known as a scleral buckle, is placed around the eyeball to indent it. This relieves traction on the retina, thus preventing retinal tears from getting worse. This is often combined with pneumatic retinopexy, in which a gas bubble is injected into the eye, to help press gently against the retinal tear, and help keep the formerly detached retina in place. The ophthalmologist then uses a laser or freezing probe to seal off the tear in the retina.

2. Vitrectomy

In this procedure, tiny instruments are inserted into the vitreous cavity (back part of the eye), to remove the vitreous gel and reposition the detached retina from the inside of the eyeball. Vitrectomy gives ophthalmologists better access to the retina to repair large tears, and it is often also combined with laser treatments and gas injections to help repair the damaged retina.