The retina rests at the back of the eye, where it receives light from the lens and converts it into signals which it sends directly to the brain. Its function depends on its tight adhesion to the back of the eye, which gives the retina its shape and allows it to process light appropriately. When the retina becomes detached from the back of the eye, its function is greatly impaired, leading to problems that include permanent blindness.
What Are the Symptoms of a Detached Retina?
Although external injury can damage the retina, most detachments occur without warning symptoms and without pain. Shortly before detachment, though, patients often experience unexplained flashes of light, loss of peripheral vision, and the appearance of new specks or threads in their field of vision. These specks, commonly known as floaters, are normal for everyone, but people about to suffer detached retinas can notice a huge increase in their volume.
How Are Detached Retinas Diagnosed?
Ophthalmologists routinely inspect the retina as part of routine eye exams. When your doctor dilates your pupils with special eye drops, it’s largely to widen your pupils enough to get a clear view of the entire retina. This is also the best way to detect the early warning signs, which can make a big difference in the success of any needed treatment.
Some detachments happen abruptly, but others are preceded by retinal tears. These are exactly what they sound like, and present the same symptoms as detached retinas. If left untreated, retinal tears allow the fluid that fills the eye to seep in between the retina and the tissue to which it normally adheres, gradually pulling the retina away and causing a complete detachment. Fortunately, retinal tears can usually be corrected with a quick surgery.
How Are Damaged Retinas Treated?
Several treatments are available for retinal tears, each appropriate to different severity of the tear. Each might seem drastic, but some can be performed right in an ophthalmologist’s office.
Freezing or laser therapy are often used to repair small tears. Each causes the ends of the torn tissue to re-adhere to each other, after which they normally heal completely.
Retinopexy introduces a small gas bubble into the eye, where it floats upward. When patients take care to keep their heads facing downward, the bubble rises to the retina and gently presses the torn tissue back into place, where it heals. Retinopexy is also used to treat entirely detached retinas.
A scleral buckle is a thin silicone band sewn around the sclera or white of the eye. This increases pressure on the retina, which keeps the affected tissue in place until it heals naturally. The band itself is invisible and permanent. Scleral buckles are commonly used to treat severe tears and complete detachments.
Vitrectomy is the most invasive treatment for torn or detached retinas. The entire vitreous humor—the viscous liquid that fills the eye—is removed and replaced with saline solution, usually at a slightly higher volume. Like some other approaches, this increases the pressure on the retina, bringing it or its torn bits into shape and keeping it there while the retina heals and re-establishes its adhesion to its backing tissue.
How Can Detached Retinas be Prevented?
Regular eye exams can detect even small tears in the retina, which can go a long way toward preventing a complete detachment.
Patients with complicating factors like diabetes and high blood pressure should be especially sure to get regular eye exams and to insist on thorough retinal examinations. Patients suffering from those underlying conditions should, of course, do everything possible to bring them under control and should share the details of any medication regimen with their ophthalmologist. Because those conditions also increase the risk of retinal detachment due to injury, affected patients should always wear eye protection when engaging in activities such as racquetball or woodworking.
Extreme nearsightedness is commonly associated with retinal detachment and should encourage the same vigilance as other risk factors.