What is a retinal detachment?
The retina is a thin layer of light-sensitive tissue on the back wall of the eye. The optical system of the eye focuses light on the retina much like light is focused on the film in a camera. The retina translates that focused image into neural impulses and sends them to the brain via the optic nerve.
A retinal detachment occurs when the retina peels away from its underlying layer of support tissue. Initial detachment may be localized, but without rapid treatment the entire retina may detach. This is considered a medical emergency that almost always leads to blindness unless it is treated.
There are different types of retinal detachments.
Rhegmatogenous retinal detachment - This type of detachment occurs due to a hole, tear, or break in the retina that allows fluid to pass from the vitreous space into a space in the retina, causing a detachment.
Exudative, serous, or secondary retinal detachment - These detachments occur due to inflammation, injury, or vascular abnormalities that results in fluid accumulating underneath the retina without the presence of a hole, tear, or break.
Tractional retinal detachment - A tractional retinal detachment occurs when fibrovascular tissue, caused by an injury, inflammation, or neovascularization, pulls the retina from its normal position.
What are the symptoms of retinal detachments?
Flashes of light (photopsia) in the extreme peripheral (outside of center) part of vision that last longer than a few moments
A sudden, dramatic increase in the number of floaters
A ring of floaters or hairs just to the temporal side of the central vision
A slight feeling of heaviness in the eye
A dense shadow that starts in the peripheral vision and slowly progresses towards the central vision
The impression that a veil or curtain was drawn over the field of vision
Straight lines (scale, edge of the wall, road, etc.) that suddenly appear curved
Central visual loss
Please note that although these are symptoms of a retinal detachment, these symptoms do not always indicate a retinal detachment.
What causes retinal detachments?
A substantial number of retinal detachments result from trauma, including blunt blows to the orbit, penetrating trauma, and concussions to the head.
Other conditions make patients more prone to retinal detachments, including:
Nearsightedness (Myopia) above 5 diopters
Previous eye surgeries, like cataract surgery
Previous retinal detachment in the other eye
Family history of spontaneous retinal detachments
Weak areas in your eye that can be detected by our optometrists
Occasionally, posterior vitreous detachment, injury or trauma to the eye or head may cause a small tear in the retina. The tear allows vitreous fluid to seep through it under the retina, and peel it away like a bubble in wallpaper.
Who develops retinal detachments?
The risk of retinal detachment in otherwise normal eyes is around 5 in 100,000 per year. Detachment is more frequent in the middle-aged or elderly population, with rates of around 20 in 100,000 per year. The lifetime risk in normal eyes is about 1 in 300.
Severely myopic patients have a lifetime risk increases to 1 in 20. The estimated risk of retinal detachment after cataract surgery is 5 to 16 per 1000 cataract operations.
Tractional retinal detachments can also occur in patients with proliferative diabetic retinopathy or those with proliferative retinopathy of sickle cell disease. In proliferative retinopathy, abnormal blood vessels (neovascularization) grow within the retina and extend into the vitreous. In advanced disease, the vessels can pull the retina away from the back wall of the eye causing a traction retinal detachment.
Although retinal detachment usually occurs in one eye, there is a 15% chance of developing it in the other eye, and this risk
increases to 25-30% in patients who have had cataracts extracted from both eyes
How are retinal detachments diagnosed?
Our optometrists can diagnose retinal detachment during our comprehensive eye examinations where we look at the inside of your eyes with a dilated eye examination and/or special retinal photography.
What is the treatment for a retinal detachment?
There are several methods of treating a detached retina which all depend on the type, location, and size of the retinal detachment.
In this treatment, silicon oil is a sterile, colorless liquid injected into the eye and mechanically holds the retina in place until it reattaches. The oil is not intended to remain in the eye permanently, but is usually removed within a year.
Cryopexy and Laser Photocoagulation
Cryotherapy (freezing) and laser photocoagulation are treatments used to create a scar/adhesion around the retinal hole to prevent fluid from entering the hole and accumulating behind the retina and exacerbating the retinal detachment. Cryopexy and photocoagulation are generally interchangeable. However, cryopexy is generally used in instances where there is a lot of fluid behind the hole; laser retinopexy will not take.
These treatments cause little to no discomfort and can be performed in an ophthalmologist's office.
Scleral buckle surgery
Scleral buckle surgery is an established treatment in which the eye surgeon sews one or more flexible silicone bands to the outside of the eyeball. The bands push the wall of the eye inward against the retinal hole, closing the hole and allowing the retina to re-attach. The bands do not usually have to be removed. The most common side effect of a scleral operation is myopic shift. That is, the operated eye will be more short sighted after the operation.
This is another method of repairing a retinal detachment in which a gas bubble is injected into the eye after which laser or freezing treatment is applied to the retinal hole. The patient's head is then positioned so that the bubble rests against the retinal hole, keeping it in place. Patients may have to keep their heads tilted in a specific orientation for several days to keep the gas bubble in contact with the retinal hole. The surface tension of the air/water interface seals the hole in the retina, and allows the retina to be pulled back into place. This procedure is usually combined with cryopexy or laser photocoagulation. and is generally performed in the ophthalmologist's office under local anesthesia.
Vitrectomy is an increasingly used treatment for retinal detachment in countries with modern healthcare systems. It involves the removal of the vitreous gel located in the middle of the eye and is usually combined with filling the eye with a gas bubble. Advantages of this operation is that there is no myopic shift after the operation. A disadvantage is that a vitrectomy always leads to more rapid progression of a cataract in the operated eye. In many places, vitrectomy is the most commonly performed operation for the treatment of retinal detachment.
After treatment, patients gradually regain their vision over a period of a few weeks, although the visual acuity may not be as
good as it was prior to the detachment, particularly if the macula (the area of best vision) was involved in the detachment. However, if left untreated, total blindness could occur in a matter of days.
There will be a little discomfort. Medication will be prescribed. Certain activities may be temporarily restricted, such as flying in airplanes. Please follow all directions from your ophthalmologist and optometrist to ensure that you have the best outcome possible.
What is the prognosis for retinal detachments?
Vision may take many months to improve after surgery. In some cases, it may not recover to the vision that was present before the retinal detachment. The more severe the detachment, the less vision may return. For this reason, it is very important to see an eyecare professional at the first sign of any trouble!