Retinal detachment is an ocular medical emergency that can lead to permanent vision loss if not treated promptly. This condition occurs when the retina, a thin layer of nerve tissue at the back of the eye, detaches from its normal position. The retina plays a crucial role in vision, as it is responsible for receiving light and sending images to the brain.
What is the retina?
The retina is a membrane made up of light-sensitive cells called photoreceptors. These cells capture light entering the eye and transform it into electrical signals sent to the brain via the optic nerve. The brain then interprets these signals to create the images we see. For the retina to function properly, it must remain attached to the back wall of the eye, where it receives oxygen and nutrients from the underlying blood vessels.
How does retinal detachment occur?
Retinal detachment occurs when this layer of tissue separates from the underlying layer, depriving retinal cells of their oxygen and nutrient supply. If not treated promptly, this lack of circulation can lead to retinal cell death, resulting in permanent vision loss.
There are three main types of retinal detachment:
- Rhegmatogenous detachment: This is the most common type. It occurs when a tear or hole forms in the retina, allowing fluid from inside the eye to seep under the retina and separate it from the back wall.
- Tractional detachment: This type is usually associated with diseases such as diabetic retinopathy, where scar tissue forms on the surface of the retina, exerting traction that can detach it from the eye wall.
- Exudative detachment: Here, there are no holes or tears in the retina, but fluid accumulates under the retina due to inflammatory or vascular disease, causing the retina to detach.
What are the symptoms of retinal detachment?
Retinal detachment is generally not painful, but the visual symptoms are often alarming and should be taken very seriously. Here are some warning signs:
- Sudden appearance of floating bodies: These small spots or “flying flies” in the field of vision can be a warning sign.
- Flashes of light: Seeing flashes of light in one or both eyes, especially in a peripheral field of vision, may indicate that the retina is detaching.
- Blurred or reduced vision: Vision may suddenly become blurred or darkened.
- Shadow or curtain over vision: Some people describe a “curtain” or shadow that descends over part of their field of vision, indicating that the retina is detaching.
Who is at risk of retinal detachment?
Several factors can increase the risk of retinal detachment:
- Age: People over 50 are at greater risk, as the retina becomes more fragile with age.
- Family history: A family history of retinal detachment increases the risk.
- Severe myopia: People with severe myopia have an increased risk of retinal tear or detachment.
- Ocular trauma: A blow or injury to the eye can cause detachment.
Treatment and prognosis
Treatment of retinal detachment depends on the severity and type of detachment. In most cases, surgery is required. Options include:
- Laser photocoagulation: A laser is used to create scars around a retinal tear, preventing fluid from passing under the retina.
- Cryopexy: A cold probe is applied to the outer surface of the eye to freeze and seal the retinal tear.
- Vitrectomy: A more complex procedure in which the vitreous (the gelatinous substance in the eye) is removed and replaced by a gas or oil bubble to reposition the retina against the eye wall.
Prognosis depends on the speed of treatment. The sooner the detachment is treated, the better the chances of restoring normal or near-normal vision. However, an extensive or untreated detachment can lead to permanent blindness.
Retinal detachment is a serious ocular emergency requiring immediate medical attention. Knowing the symptoms and risk factors is crucial to preserving vision. If you or someone you know has any warning signs of this condition, it's essential to see an ophthalmologist without delay to assess the situation and, if necessary, receive appropriate treatment.
