Learn everything you need to know in 15 minutes or less
Step 1 – Learn how the eye works
Step 2 – Learn about the different types of retinal detachments
Step 3 – Learn about the treatment options for retinal detachment
The eye can be thought of as similar to a camera, with two main parts, a lens and a film. In addition, there is a gel called the vitreous that is located in front of the retina and is very firmly adherent to it. The film layer is called the retina and lines the back wall of the eye. The cells responsible for converting light to an electrical signal and producing vision are located in the outer layer of the retina. This layer receives blood flow from the outer wall of the eye.
A retinal detachment is a separation of the outer layer of the retina from the back wall of the eye. There are two causes of retinal detachment: A full-thickness hole in the retina which allows fluid underneath the retina or a tractional cause which pulls the retina away from the wall of the eye. Keep reading to learn more.
The gel (vitreous) seperates from the back of the eye towards the front of the eye as a normal part of aging. As the gel separates, it is a tug of war between the retina and the vitreous. The vitreous may pull hard enough that it rips a hole in the retina. A hole in the retina allows the fluid portion of the vitreous to pass through the retinal hole and travel underneath the retina. This fluid separates the retina from its blood supply and causes the patient to see a dark area in the peripheral vision. If the fluid travels underneath the central vision then it causes blurriness of the central vision.
Young patients may experience a retinal detachment by a different mechanism. In these patients, small holes develop in the retina due to retinal thinning. These holes allow fluid to accumulate underneath the retina, and eventually separate the retina from the back wall of the eye.
Laser retinopexy is an in-office laser procedure which utilizes a laser to create a barricade (laser forms scar tissue) between the normal attached retina and the area of detachment. This is a good choice for patients who have a very small detachment and are not symptomatic from the area of peripheral vision lost from the retinal detachment.
Pneumatic retinopexy is an in-office laser procedure which consists of two main components: a gas bubble and either laser or cryotherapy (freezing). The gas bubble flattens the retina and prevents fluid from entering the retinal hole. This allows the retina specialist to close the retinal hole by lasering around the retinal tear (performed 2-3 days following the injection of gas) or cryotherapy (typically performed the same day as injection of gas).
Pars plana vitrectomy is an outpatient surgery which may be performed under twilight anesthesia (awake, relaxed, and without pain) or general anesthesia. 3 small ports (approximately 1/2mm in width) incisions are made into the white of the eye. The vitreous (gel) is removed. All retinal tears are relieved of any traction (pulling force) by the vitreous. The fluid between the retina and wall of the eye is removed and laser therapy is applied around the retinal tear. A gas bubble or silicone oil oil is then placed in the eye. The patient is asked to maintain a specific head position for 5-10 days.
Scleral Buckle is an outpatient surgical procedure which is typically performed under general anesthesia. A silicone band or sponge is used to indent the outer wall of the eye towards the retinal hole. The apposition of the outerwall of the eye against the retinal hole prevents fluid from entering the retinal hole, and thus causes the retinal to reattach. Cryotherapy (freezing therapy) is typically applied to the retinal tears at the time of scleral buckling surgery. Occasionally, scleral buckling surgery may be performed at the same time as a pars plane vitrectomy.
The Basics – Diabetic tractional retinal detachment – Abnormal new blood vessels grow from the retina surface into the vitreous. They proliferate within the back face of the vitreous. Over time, the abnormal blood vessels start to regress (go away) and transform into scar tissue. The scar tissue contracts, causing a pulling force on the retina. The pulling force may distort the area of central vision, cause edema (swelling) within or under the macula, or create a retinal tear.
Prognosis – The visual outcome following surgery is dependent on the characteristics of the tractional retinal detachment. For example, patients who have traction on their area of central vision may have a worse visual outcome than someone who has no involvement of their central vision.
Treatment – Retina specialists will typically begin treatment by treating all neovascularization (new blood vessel growth) with panretinal photocoagulation or intravitreal anti-vascular endothelial growth factors. Following resolution of neovascularization, the decision of whether or not to operate may be made.
The goals of tractional retinal detachment repair is release of all traction on the retina that is threatening the fovea (area responsible for central vision), treatment of retinal tears (if present), and application of laser (to decrease the risk of new blood vessel growth).
These goals are met by performing a pars plana vitrectomy, membrane peel (peeling of membranes), and endolaser (panretinal photocoagulation through an internal approach)
Proliferative Vitreoretinopathy (PVR) – Retinal detachments allow cells that are not normally exposed to the vitreous cavity to gain access and proliferate. The proliferation of these vessels may occur underneath, within, or on top the retina. The cells create thick plaques which overtime may exert enough force that it causes a retinal break, and re-detachment.
This condition most commonly occurs following retinal detachment repair, but may also occur prior to retinal detachment repair. There is nothing that the surgeon may do at the time of initial repair of retinal detachment to decrease the risk of this condition developing.
PVR represents a spectrum of disease, from the least severe, which may cause no visual symptoms, to the most severe which causes inoperable irreversible vision loss.
Prognosis – The visual prognosis for retinal detachment repair following the development of PVR is highly variable, and dependent on the characteristics of the detachment. Scar tissue may come back following surgery and lead to additional detachments, once again, requiring surgical intervention. Clinical trials have demonstrated that approximately 5-13% of patients maintain a vision of 20/40 or better following surgery.
Treatment – The treatment for PVR is surgical . The surgical goals include the removal of scar tissue causing tractional forces on the retina, addressing any intrinsic retinal shortening, and treatment of retinal tears utilizing laser. This is typically addressed using vitrectomy, with, or without a scleral buckle. In many cases, the surgeon will elect to fill the vitreous cavity with silicone oil to decrease the risk of re-detachment. The retina is allowed to heal over a period of 3-6 months, and the silicone oil is then removed. In some cases, a gas bubble is used as an alternative to silicone oil. The gas typically resolves over a period of 2-6 weeks.
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