Retinal detachment is a condition whereby the retina pulls away from its usual position. When it detaches, vision becomes blurry. It is a sight-threatening condition that must be attended to urgently. If not treated within two or three days, retinal detachment can cause permanent loss of vision.
The retina refers to a layer of tissue that lines the back of the eye. It senses light and transmits messages to the brain through the optic nerve. There is a vitreous (a clear gel) located in the middle of the eye and attached to the retina. Sometimes, small pieces of the vitreous may cast shadows on the retina causing dots or specks called floaters. Due to age, the vitreous may pull away from the retina hard enough to cause a retinal tear. Fluid may pass through the tear forcing the retina to shift from its back position, hence a retinal detachment.
- Rhegmatogenous retinal detachment
A tear in the retina causes the fluid to gather below it. This action detaches it from its underlying blood supply.
- Tractional retinal detachment
Conditions such as diabetes may cause retinal detachment. Scar tissue that grows on the surface of the retina may displace the retina from its normal position.
- Exudative retinal detachment
An eye with unusual inflammation or excessive leakage from abnormal blood vessels may cause the detachment. In this uncommon type of detachment, liquid seeps out of the blood vessels and collects underneath the retina.
Causes and Risk Factors
Retinal detachment affects people of all ages. It is, however, widespread in people aged 40 and above. Retinal detachment is also more common in men than women. It is prevalent in whites compared to African-Americans.
Retinal detachment mostly affects people who:
- Have experienced trauma
- Have had an eye injury
- Have had cataract surgery
- Have experienced a retinal detachment before
- Have high myopia (nearsightedness)
- Have other conditions such as hyperopia (farsightedness)
- Have a family history of retinal detachment
Signs & Symptoms
The symptoms of retinal detachment include:
- Floaters which suddenly increase in number
- A decrease in vision
- Flashes (lightning streaks) which suddenly appear
- Shadows that appear in the periphery of the eye
- A gray curtain moving in a person’s field of vision.
The eye care professional will conduct a thorough examination of the peripheral retina. He or she will use dilating eye drops which widen the pupils of the eyes. He/she may also photograph the retina to determine the level of detachment. An optical coherence tomography (OCT) scan may be done to establish if the fluid has separated the middle of the retina (the macula).
Treatment is directed towards reattaching the retina to the back wall of the eye. It is also aimed at closing the tears responsible for the retinal detachment.
Pneumatic retinopexy is used to treat retinal detachment. The eye doctor will inject a gas bubble into the eye. The patient is required to maintain a particular posture to place the bubble over the tear. The tear may be sealed with a freezing treatment during the procedure. It can also be sealed using laser after the retina is reattached.
There are three types of surgeries:
- Scleral buckle involves placing a silicone band outside the wall of the eye. This action pushes the eye wall closer to the retina to close the tear. Freezing treatment follows which permanently seals the tear. The fluid that accumulates underneath the retina is removed during surgery.
- Vitrectomy removes the vitreous gel and drains the fluid from under the eye. Gas is injected into the eye to replace the vitreous and help the retina to reattach. The surgeon then uses a laser or cryopexy (freezing treatment) to seal the holes.
- Laser surgery and cryopexy are used when the detachments are small. The laser is used to prevent the detachment from spreading.
Retinal detachment treatment is successful in nine out of ten cases. Sometimes more than a single procedure is needed to correct the detachment. The final vision outcome may remain unknown for some months. Chances of success are higher if surgery is done before the macula (center of the retina) detaches.
Individuals with a family history of retinal detachment or nearsightedness should have regular dilated eye examinations. Wearing protective eyewear during sports or similar events may prevent injury and by extension, retinal detachment.