Retinal detachment
Encyclopedia
Retinal detachment is a disorder of the eye
Human eye
The human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...

 in which the retina
Retina
The vertebrate retina is a light-sensitive tissue lining the inner surface of the eye. The optics of the eye create an image of the visual world on the retina, which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical...

 peels away from its underlying layer of support tissue. Initial detachment may be localized, but without rapid treatment the entire retina may detach, leading to vision loss
Vision loss
Vision loss or visual loss is the absence of vision where it existed before, which can happen either acutely or chronically .-Ranges of vision loss:...

 and blindness
Blindness
Blindness is the condition of lacking visual perception due to physiological or neurological factors.Various scales have been developed to describe the extent of vision loss and define blindness...

. It is a medical emergency
Medical emergency
A medical emergency is an injury or illness that is acute and poses an immediate risk to a person's life or long term health. These emergencies may require assistance from another person, who should ideally be suitably qualified to do so, although some of these emergencies can be dealt with by the...

.

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
Optic nerve
The optic nerve, also called cranial nerve 2, transmits visual information from the retina to the brain. Derived from the embryonic retinal ganglion cell, a diverticulum located in the diencephalon, the optic nerve doesn't regenerate after transection.-Anatomy:The optic nerve is the second of...

. Occasionally, posterior vitreous detachment
Posterior vitreous detachment
A posterior vitreous detachment is a condition of the eye in which the vitreous humour separates from the retina.Broadly speaking, the condition is common for older adults and over 75% of those over the age of 65 develop it. Although less common among people in their 40s or 50s, the condition is...

, 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.

Types

  • Rhegmatogenous retinal detachment – A rhegmatogenous retinal detachment occurs due to a break in the retina that allows fluid to pass from the vitreous space into the subretinal space between the sensory retina and the retinal pigment epithelium. Retinal breaks are divided into three types - holes, tears and dialyses. Holes form due to retinal atrophy especially within an area of lattice degeneration. Tears are due to vitreoretinal traction. Dialyses which are very peripheral and circumferential may be either tractional or atrophic, the atrophic form most often occurring as idiopathic dialysis of the young.
  • Exudative, serous, or secondary retinal detachment – An exudative retinal detachment occurs due to inflammation, injury or vascular abnormalities that results in fluid accumulating underneath the retina without the presence of a hole, tear, or break. In evaluation of retinal detachment it is critical to exclude exudative detachment as surgery will make the situation worse, not better. Although rare, exudative retinal detachment can be caused by the growth of a tumor on the layers of tissue beneath the retina, namely the choroid. This cancer is called a choroidal melanoma.
  • Tractional retinal detachment – A tractional retinal detachment occurs when fibrous or fibrovascular tissue, caused by an injury, inflammation or neovascularization, pulls the sensory retina from the retinal pigment epithelium.


A minority of retinal detachments result from trauma, including blunt blows to the orbit, penetrating trauma, and concussions to the head. A retrospective Indian study of more than 500 cases of rhegmatogenous detachments found that 11% were due to trauma, and that gradual onset was the norm, with over 50% presenting more than one month after the inciting injury.

Frequency

The incidence of retinal detachment in otherwise normal eyes is around 5 new cases in 100,000 persons per year. Detachment is more frequent in middle-aged or elderly populations, with rates of around 20 in 100,000 per year. The lifetime risk in normal individuals is about 1 in 300.
  • Retinal detachment is more common in people with severe myopia
    Myopia
    Myopia , "shortsightedness" ) is a refractive defect of the eye in which collimated light produces image focus in front of the retina under conditions of accommodation. In simpler terms, myopia is a condition of the eye where the light that comes in does not directly focus on the retina but in...

     (above 5–6 diopters), in whom the retina is more thinly stretched. In such patients, lifetime risk rises to 1 in 20. About two-thirds of cases of retinal detachment occur in myopics. Myopic retinal detachment patients tend to be younger than non-myopic ones.

  • Retinal detachment is more frequent after surgery for cataracts. The estimated long-term prevalence of retinal detachment after cataract surgery is in the range of 5 to 16 per 1000 cataract operations, but is much higher in patients who are highly myopic, with a prevalence of up to 7% being reported in one study. One study found that the probability of experiencing retinal detachment within 10 years of cataract surgery may be about 5 times higher than in the absence of treatment.

  • Tractional retinal detachments can also occur in patients with proliferative diabetic retinopathy
    Diabetic retinopathy
    Diabetic retinopathy is retinopathy caused by complications of diabetes mellitus, which can eventually lead to blindness....

      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, leading to tractional retinal detachment.


Although retinal detachment usually occurs in just one eye, there is a 15% chance of it developing in the other eye, and this risk increases to 25–30% in patients who have had cataracts extracted from both eyes.

Symptoms

A retinal detachment is commonly preceded by a posterior vitreous detachment
Posterior vitreous detachment
A posterior vitreous detachment is a condition of the eye in which the vitreous humour separates from the retina.Broadly speaking, the condition is common for older adults and over 75% of those over the age of 65 develop it. Although less common among people in their 40s or 50s, the condition is...

 which gives rise to these symptoms:
  • flashes of light (photopsia
    Photopsia
    Photopsia is the presence of perceived flashes of light. It is most commonly associated with posterior vitreous detachment, migraine with aura, migraine aura without headache, retinal break or detachment, occipital lobe infarction and sensory deprivation...

    ) – very brief in the extreme peripheral (outside of center) part of vision
  • 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


Although most posterior vitreous detachments do not progress to retinal detachments, those that do produce the following symptoms:
  • 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 (positive Amsler grid
    Amsler grid
    The Amsler grid, used since 1945, is a grid of horizontal and vertical lines used to monitor a person's central visual field. The grid was developed by Marc Amsler, a Swiss ophthalmologist. It is a diagnostic tool that aids in the detection of visual disturbances caused by changes in the retina,...

     test)
  • central visual loss


(None of this is to be confused with the broken retina which is generally the tearing of muscle and nerve behind the eye)

Treatment of Rhegmatogenous Retinal Detachment

There are several methods of treating a detached retina, each of which depends on finding and closing the breaks that have formed in the retina. All three of the procedures follow the same three general principles:
  1. Find all retinal breaks
  2. Seal all retinal breaks
  3. Relieve present (and future) vitreoretinal traction


Cryopexy and Laser Photocoagulation : Cryotherapy
Cryosurgery
Cryosurgery is the application of extreme cold to destroy abnormal or diseased tissue. The term comes from the Greek words cryo and surgery meaning "hand work" or "handiwork"....

 (freezing) or laser photocoagulation
Laser photocoagulation
Laser coagulation or laser photocoagulation surgery is used to treat a number of eye diseases and has become widely used in recent decades...

 are occasionally used alone to wall off a small area of retinal detachment so that the detachment does not spread.

Scleral buckle surgery : Scleral buckle
Scleral buckle
A scleral buckle is one of several ophthalmologic procedures that can be used to repair a retinal detachment. Retinal detachments are usually caused by retinal tears, and a scleral buckle can be used to close the retinal break....

 surgery is an established treatment in which the eye surgeon sews one or more silicone bands (bands, tyres) to the sclera (the white outer coat of the eyeball). The bands push the wall of the eye inward against the retinal hole, closing the break or reducing fluid flow through it and reducing the effect of vitreous traction thereby allowing the retina to re-attach. Cryotherapy
Cryosurgery
Cryosurgery is the application of extreme cold to destroy abnormal or diseased tissue. The term comes from the Greek words cryo and surgery meaning "hand work" or "handiwork"....

 (freezing) is applied around retinal breaks prior to placing the buckle. Often subretinal fluid is drained as part of the buckling procedure. The buckle remains in situ. 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. Radial scleral buckle is indicated to U-shaped tears or Fishmouth tears and posterior breaks. Circumferential scleral buckle indicated to multiple breaks, anterior breaks and wide breaks. Encircling buckles indicated to breaks more than 2 quadrant of retinal area, lattice degeration located on more than 2 quadrant of retinal area, undetectable breaks, and proliferative vitreous retinopathy.

Pneumatic retinopexy : This operation is generally performed in the doctor's office under local anesthesia. It is another method of repairing a retinal detachment in which a gas bubble (SF6 or C3F8 gas) 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. Patients may have to keep their heads tilted for several days to keep the gas bubble in contact with the retinal hole. The surface tension
Surface tension
Surface tension is a property of the surface of a liquid that allows it to resist an external force. It is revealed, for example, in floating of some objects on the surface of water, even though they are denser than water, and in the ability of some insects to run on the water surface...

 of the air/water interface seals the hole in the retina, and allows the retinal pigment epithelium to pump the subretinal space dry and suck the retina back into place. This strict positioning requirement makes the treatment of the retinal holes and detachments that occurs in the lower part of the eyeball impractical. This procedure is usually combined with cryopexy or laser photocoagulation.

Vitrectomy : Vitrectomy
Vitrectomy
Vitrectomy is a surgery to remove some or all of the vitreous humor from the eye. Anterior vitrectomy entails removing small portions of the vitreous from the front structures of the eye—often because these are tangled in an intraocular lens or other structures...

 is an increasingly used treatment for retinal detachment. It involves the removal of the vitreous gel and is usually combined with filling the eye with either a gas bubble (SF6
Sulfur hexafluoride
Sulfur hexafluoride is an inorganic, colorless, odorless, and non-flammable greenhouse gas. has an octahedral geometry, consisting of six fluorine atoms attached to a central sulfur atom. It is a hypervalent molecule. Typical for a nonpolar gas, it is poorly soluble in water but soluble in...

 or C3F8 gas) or silicon oil. An advantage of using gas in this operation is that there is no myopic shift after the operation and gas is absorbed within a few weeks. Silicon oil (PDMS), if filled needs to be removed after a period of 2–8 months depending on surgeon's preference. Silicon oil is more commonly used in cases associated with proliferative vitreo-retinopathy (PVR). 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.

Results of Surgery

85 percent of cases will be successfully treated with one operation with the remaining 15 percent requiring 2 or more operations.
After treatment patients gradually regain their vision over a period of a few weeks, although the visual acuity
Visual acuity
Visual acuity is acuteness or clearness of vision, which is dependent on the sharpness of the retinal focus within the eye and the sensitivity of the interpretative faculty of the brain....

 may not be as good as it was prior to the detachment, particularly if the macula
Macula
The macula or macula lutea is an oval-shaped highly pigmented yellow spot near the center of the retina of the human eye. It has a diameter of around 5 mm and is often histologically defined as having two or more layers of ganglion cells...

 was involved in the area of the detachment. However, if left untreated, total blindness
Blindness
Blindness is the condition of lacking visual perception due to physiological or neurological factors.Various scales have been developed to describe the extent of vision loss and define blindness...

 could occur in a matter of days.

Risk factors and prevention

History of cataract surgery
Cataract surgery
Cataract surgery is the removal of the natural lens of the eye that has developed an opacification, which is referred to as a cataract. Metabolic changes of the crystalline lens fibers over time lead to the development of the cataract and loss of transparency, causing impairment or loss of vision...

 is an important risk factor for rhegmatogenous retinal detachment, which can manifest long after the operation has been completed. The risk is increased when there are complications during cataract surgery.

Retinal detachment can be mitigated in some cases when the warning signs are caught early. The most effective means of prevention and risk reduction is through education of the initial signs, and encouragement for people to seek ophthalmic medical attention if they suffer from symptoms suggestive of a posterior vitreous detachment
Posterior vitreous detachment
A posterior vitreous detachment is a condition of the eye in which the vitreous humour separates from the retina.Broadly speaking, the condition is common for older adults and over 75% of those over the age of 65 develop it. Although less common among people in their 40s or 50s, the condition is...

. Early examination allows detection of retinal tears which can be treated with laser or cryotherapy. This reduces the risk of retinal detachment in those who have tears from around 1:3 to 1:20. For this reason, the governing bodies in some sports require regular eye examination.

Trauma-related cases of retinal detachment can occur in high-impact sports (eg boxing
Boxing
Boxing, also called pugilism, is a combat sport in which two people fight each other using their fists. Boxing is supervised by a referee over a series of between one to three minute intervals called rounds...

, karate
Karate
is a martial art developed in the Ryukyu Islands in what is now Okinawa, Japan. It was developed from indigenous fighting methods called and Chinese kenpō. Karate is a striking art using punching, kicking, knee and elbow strikes, and open-handed techniques such as knife-hands. Grappling, locks,...

, kickboxing
Kickboxing
Kickboxing refers to a group of martial arts and stand-up combat sports based on kicking and punching, historically developed from karate, Muay Thai and western boxing....

, American football
American football
American football is a sport played between two teams of eleven with the objective of scoring points by advancing the ball into the opposing team's end zone. Known in the United States simply as football, it may also be referred to informally as gridiron football. The ball can be advanced by...

) or in high speed sports (eg automobile racing, sledding
Sledding
Sledding , sledging , sleding or tobogganing is a common activity in wintry areas, similar to sliding, but in a prone or seated position requiring a device or vehicle generically known in the US as a sled or in other countries as a sledge or toboggan...

). Although some doctors recommend avoiding activities that increase pressure in the eye, including diving and skydiving, there is little evidence to support this recommendation, especially in the general population. Nevertheless, ophthalmologists generally advise patients with high degrees of myopia to try to avoid exposure to activities that have the potential for trauma, increase pressure on or within the eye itself, or include rapid acceleration and deceleration.

Intraocular pressure spikes occur during any activity accompanied by the Valsalva maneuver
Valsalva maneuver
The Valsalva maneuver or Valsalva manoeuvre is performed by moderately forceful attempted exhalation against a closed airway, usually done by closing one's mouth and pinching one's nose shut...

, including weightlifting. An epidemiological study suggests that heavy manual lifting at work may be associated with increased risk of rhegmatogenous retinal detachment. In this study, obesity also appeared to increase the risk of retinal detachment.

External links

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