retinal detachment

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Retinal Detachment

Definition

Retinal detachment is movement of the transparent sensory part of the retina away from the outer pigmented layer of the retina. In other words, the moving away of the retina from the outer wall of the eyeball.

Description

There are three layers of the eyeball. The outer, tough, white sclera. Lining the sclera is the choroid, a

Retinal detachment refers to the movement of the retina away from the inner wall of the eyeball, resulting in a sudden defect in vision. Persons suffering from diabetes have a high incidence of developing retinal disease.

(Illustration by Electronic Illustrators Group.)

thin membrane that supplies nutrients to part of the retina. The innermost layer is the retina.

The retina is the light-sensitive membrane that receives images and transmits them to the brain. It is made up of several layers. One layer contains the photoreceptors. The photoreceptors, the rods and cones, send the visual message to the brain. Between the photoreceptor layer (also called the sensory layer) and the choroid is the pigmented epithelium.

The vitreous is a clear gel-like substance that fills up most of the inner space of the eyeball. It lies behind the lens and is in contact with the retina.

A retinal detachment occurs between the two outermost layers of the retina—the photoreceptor layer and the outermost pigmented epithelium. Because the choroid supplies the photoreceptors with nutrients, a detachment can basically starve the photoreceptors. If a detachment is not repaired within 24-72 hours, permanent damage may occur.

Causes and symptoms

Several conditions may cause retinal detachment:

Scarring or shrinkage of the vitreous can pull the retina inward.
Small tears in the retina allow liquid to seep behind the retina and push it forward.
Injury to the eye can simply knock the retina loose.
Bleeding behind the retina, most often due to diabetic retinopathy or injury, can push it forward.
Retinal detachment may be spontaneous. This occurs more often in the elderly or in very nearsighted (myopic) eyes.
Cataract surgery causes retinal detachment 2% of the time.
Tumors can cause the retina to detach.

Retinal detachment will cause a sudden defect in vision. It may look as if a curtain or shadow has just descended before the eye. If most of the retina is detached, there may be only a small hole of vision remaining. If just a part of the retina is involved, there will be a blind spot that may not even be noticed. It is often associated with floaters—little dark spots that float across the eye and can be mistaken for flies in the room. There may also be flashes of light. Anyone experiencing a sudden onset of flashes and/or floaters should contact their eye doctor immediately, as this may signal a detachment.

Diagnosis

If the eye is clear—that is, if there is no clouding of the liquids inside the eye—the detachment can be seen by looking into the eye with a hand-held instrument called an ophthalmoscope. To evaluate the blood vessels in the retina, a fluorescent dye (fluorescein) may be injected into a vein and photographed with ultraviolet light as it passes through the retina. Further studies may include computed tomography scan (CT scan), magnetic resonance imaging (MRI), or ultrasound study. Other lenses may be used to examine the back of the eyes. One example is binocular indirect ophthalmoscopy. The doctor dilates the patient's eyes with eyedrops and then examines the back of the eyes with a handheld lens.

Treatment

Reattaching the retina to the inner surface of the eye requires making a scar that will hold it in place and then bringing the retina close to the scarred area. The scar can be made from the outside, through the sclera, using either a laser or a freezing cold probe (cryopexy). Bringing the retina close to the scar can be done in two ways. A tiny belt tightened around the eyeball will bring the sclera in until it reaches the retina. This procedure is called scleral buckling and may be done under general anesthesia. Using this procedure permits the repair of retinal detachments without entering the eyeball. Sometimes, the eye must be entered to pump in air or gas, forcing the retina outward against the sclera and its scar. This is called pneumatic retinopexy and can generally be done under local anesthesia.

If all else fails, and especially if there is disease in the vitreous, the vitreous may have to be removed in a procedure called vitrectomy. This can be done through tiny holes in the eye, through which equally tiny instruments are placed to suck out the vitreous and replace it with saline, a salt solution. The procedure must maintain pressure inside the eye so that the eye does not collapse.

Prognosis

Retinal reattachment has an 80-90% success rate.

Prevention

In diseases such as diabetes, with a high incidence of retinal disease, routine eye examinations can detect early changes. Early treatment can prevent both progressing to detachment and blindness from other events like hemorrhage. The most common problem is weakness of blood vessels that causes them to break down and bleed. When enough vessels have been damaged, new vessels grow to replace them. These new vessels may grow into the vitreous, producing blind spots and scarring. The scarring can in turn pull the retina loose. Other diseases can cause the tiny holes and tears in the retina through which fluid can leak. Preventive treatment uses a laser to cauterize the blood vessels, so that they do not bleed and the holes, so they do not leak.

Good control of diabetes can help prevent diabetic eye disease. Blood pressure control can prevent hypertension from damaging the retinal blood vessels. Eye protection can prevent direct injury to the eyes. Regular eye exams can also detect changes that the patient may not be aware of. This is important for patients with high myopia who may be more prone to detachment.

Resources

Organizations

American Academy of Ophthalmology. 655 Beach Street, P.O. Box 7424, San Francisco, CA 94120-7424. http://www.eyenet.org.

American Optometric Association. 243 North Lindbergh Blvd., St. Louis, MO 63141. (314) 991-4100. http://www.aoanet.org.

Key terms

Cauterize — To damage with heat or cold so that tissues shrink. It is an effective way to stop bleeding.

Diabetic retinopathy — Disease that damages the blood vessels in the back of the eye caused by diabetes.

Saline — A salt solution equivalent to that in the body-0.9% salt in water.

detachment

[de-tach´ment]

the condition of being separated or disconnected.

detachment of retina (retinal detachment) separation of the inner layers of the retina from the pigment epithelium, which remains attached to the choroid; it occurs most often as a result of degenerative changes in the peripheral retina and vitreous body, which produce holes or tears in the retina ranging from tiny breaks of less than 0.1 mm to extensive holes extending over the entire fundus. It is most common in persons over 40, and about two thirds of affected patients are myopic (nearsighted). Trauma to the eyeball, severe contusions, inflammatory lesions, and sometimes ocular surgery such as for a cataract can also lead to retinal detachment.

Symptoms. The onset of symptoms may be gradual or sudden, depending on the cause, size, number, and location of retinal holes. The patient usually sees flashes of light and then notices cloudy vision or loss of a portion of the visual field. Another common manifestation is the sensation of spots or moving particles in the field of vision. Treatment should be sought immediately when any of these occur. In severe retinal detachment there can be complete loss of vision.

Treatment. Retinal detachment is corrected surgically. Two outpatient modes of therapy currently in use are photocoagulation, using the light source of an argon laser; and cryosurgery, in which a freezing probe is used to penetrate the tissues of the eye and encircle the hole or tear in the retina. Scar tissue eventually forms and seals the opening.

Scleral buckling is another treatment, which places the retinal breaks in contact with the pigment epithelium and choroid. Adhesions form and bind the sensory retinal layers to these structures. In some cases, such as vitreous hemorrhage, the surgeon performs a combined vitrectomy and humoral retinal repair. The purpose of the surgery is to remove vitreous that is opaque because of accumulated blood, and to stabilize the retina in apposition to the choroid. Aqueous humor eventually fills the space.

Pneumatic retropexy, the most recently developed treatment, consists of injection of air or gas into the posterior vitreous cavity, followed by positioning of the patient so that the bubble rises, presses against the area of torn retina, and pushes it back into its normal position against the choroid. Laser photocoagulation and/or cryopexy is then done to create inflammation within the tissues, resulting in scarring and permanent reattachment of the area(s) of torn retina. This procedure is appropriate for only certain types and locations of retinal detachment.

Preoperative and postoperative care of the patient requires a thorough knowledge of the type of detachment afflicting the patient and the surgical procedure performed. Positioning of the patient and the level of physical activity allowed after surgery are determined by the surgeon. Before discharge from the hospital the patient will need instruction in follow-up care, especially the correct procedure for instilling eye drops.

Retinal detachment. From Frazier et al., 2000.

ret·i·nal de·tach·ment

, detachment of retina [MIM*312530, MIM*180050]

loss of apposition between the sensory retina and the retinal pigment epithelium.

Synonym(s): detached retina, separation of retina

Farlex Partner Medical Dictionary © Farlex 2012

retinal detachment

Ophthalmology Separation of the neurosensory–rods and cones–retina from the retinal pigment epithelium, accompanied by opening of the vestige of the cavity of the optic vesicle of the embryo; RD is a true ophthalmologic emergency that requires immediate therapy to prevent blindness; RD affects 18-30,000/yr–US Etiology

1. Retinal tear, which may be caused by vitreous traction, and results in vitreous fluid accumulation.

2. Exudative detachment, in which the neurosensory retina is lifted away from the retinal pigment epithelium by fluids that accumulate in response to local tumors–eg, melanoma, local inflammation, or malignant HTN, idiopathic, trauma, aging, tumors, inflammation; in premature infants, RD is caused by retinopathy of prematurity Clinical Progressive loss of visual field, often accompanied by scotomas; bleeding from small arterioles vessels may cloud vitreus; if macula is involved, central vision is affected Risk factors Myopia, family Hx of retinal detachment, Caucasian, ♂ Treatment A silicone oil may be used to treat complicated RTs uncorrectable with standard therapy. See Myopia.

ret·i·nal de·tach·ment

, detachment of retina (ret'i-năl dĕ-tach'mĕnt, ret'i-nă)

Loss of apposition between the sensory retina and the retinal pigment epithelium.

retinal detachment

RETINAL DETACHMENT

Separation of the inner sensory layer of the retina from the outer pigment epithelium. It is usually caused by a hole or break in the inner sensory layer that permits fluid from the vitreous to leak under the retina and lift off its innermost layer. Causes include trauma and any disease that causes retinopathy, such as diabetes or sickle cell disease. Symptoms are blurred vision, flashes of light, vitreous floaters, and loss of visual acuity. The location of holes must be determined so that they can be repaired by laser therapy (i.e., photocoagulation). illustration;

Treatment

Scleral buckling techniques are used to treat retinal detachment in a large number of patients. Vitrectomy with laser and pneumatic retinopexy are occasionally employed as an alternative treatment.

illustration

retinal detachment

Separation of part or all of the retina from the underlying CHOROID by an accumulation of fluid. Retinal detachment usually follows the development of a hole or a tear (rhegmatogenous detachment) and is commonest in people with severe MYOPIA or who have had a crystalline lens removed for CATARACT. The condition is painless and presents with the perception of flashing lights and dark spots and the appearance of a black curtain covering part of the field of vision. Treatment involves the application of low temperature (cryopexy) to cause sterile inflammation, and the indenting of the white of the eye over the detachment by stitching on a silicone rubber sponge.

retinal detachment (RD)

Separation of the neurosensory retina from the pigment epithelium layer. There are three main types: rhegmatogenous retinal detachment, which is the most common type, exudative (serous or secondary) retinal detachment, and traction retinal detachment. See cryotherapy; macular hole; metamorphopsia; photocoagulation; lattice degeneration of the retina; retinal break; retinal dialysis; central serous retinopathy; retinopathy of prematurity; striae retinae; Ehlers-Danlos syndrome; Marfan's syndrome; Stickler's syndrome; ultrasonography; familial exudative vitreoretinopathy; vitreous detachment.
exudative retinal detachment d. A separation of the sensory retina from the retinal pigment epithelium due to fluid accumulating in the subretinal space in the absence of a retinal break or preretinal traction following damage to the blood-retina barrier of the choriocapillaris. Common causes are choroidal tumour, posterior uveitis, exudative age-related macular degeneration, uveal effusion syndrome, Coats' disease and central serous retinopathy. The patient notices a loss of vision in the area of the visual field corresponding to the detached area, reduced VA if the macula is involved, and floaters if there is an associated inflammation.The elevation is smooth and convex and the subretinal fluid shifts the area which is detached when the head moves (referred to as 'shifting fluid'). Treatment is aimed at the primary cause. Syn. serous retinal detachment; secondary retinal detachment.
rhegmatogenous retinal detachment d. A separation of the sensory retina from the retinal pigment epithelium due to fluid from the vitreous entering the subretinal space through a tear or break in the retina. The retinal breaks are most commonly the result of posterior vitreous detachment (PVD), which is found in a large percentage of patients older than 70 years, in aphakic eyes, and in degenerative myopic eyes. Retinal breaks may also occur as a result of trauma and occasionally ocular surgery. The patient notices floaters, flashes, photopsia and a loss of vision in one area of the visual field corresponding to the detached area. Management may involve scleral buckling (indenting the sclera over the retinal break) and usually draining the subretinal fluid, or pneumatic retinopexy (the retinal break is sealed and the retina reattached using an intravitreal gas bubble).
tractional retinal detachment d. A separation of the sensory retina from the retinal pigment epithelium due to contraction of vitreoretinal fibroproliferative membranes, which pull the retina away from the pigment epithelium. The main causes are proliferative diabetic retinopathy, retinopathy of prematurity, sickle-cell retinopathy and perforating ocular injury. Ophthalmoscopically the detachment typically appears concave. The condition is often asymptomatic. Treatment is aimed at releasing the vitreoretinal traction. See vitrectomy.

ret·i·nal de·tach·ment

, detachment of retina (ret'i-năl dĕ-tach'mĕnt, ret'i-nă) [MIM*312530, 180050, MIM*312530, MIM*180050]

Loss of apposition between the sensory retina and the retinal pigment epithelium.