Retinal detachment is a disorder of the eye in which the retina peels away from its underlying
layer of support tissue. Initial detachment may be localized or broad, but without rapid
treatment the entire retina may detach, leading to vision loss and blindness. It is a medical
emergency. Permanent damage may occur, if the detachment is not repaired within 24–72
hours. 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 or sensor in a camera. The retina translates
that focused image into neural impulses and sends them to the brain via the optic nerve.
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.
Potential causes or risk factors AIDS
Cataract surgery Diabetic retinopathy
Eclampsia Family history of retinal detachment
Homocysteinuria Malignant hypertension
Metastatic cancer, which spreads to the eye Retinoblastoma
Severe Myopia Smoking and Passive smoking
Stickler syndrome Von Hippel-Lindau disease
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 are very peripheral and circumferential, and
may be either tractional or atrophic. The atrophic form most often occurs 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 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. Signs and symptoms
A retinal detachment is commonly preceded by a posterior vitreous detachment which gives
rise to these symptoms: flashes of light – very brief in the extreme
peripheral 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 that suddenly appear curved central visual loss
In the event of an appearance of sudden flashes of light or floaters, an eye doctor needs
to be consulted immediately. A shower of floaters or any loss of vision, too, is a medical emergency.
Risk factors and prevention Risk factors for retinal detachment include
severe myopia, retinal tears, trauma, family history, as well as complications from 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. 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 or in high speed sports. 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, such as bungee jumping or
roller coaster rides. Intraocular pressure spikes occur during any
activity accompanied by the Valsalva maneuver, 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. Genetic factors promoting local inflammation
and photoreceptor degeneration may also be involved in the development of the disease.
Diagnosis Retinal detachment can be examined by fundus
photography or ophthalmoscopy. Fundus photography generally needs a considerably larger instrument
than the ophthalmoscope, but has the advantage of availing the image to be examined by a
specialist at another location and/or time, as well as providing photo documentation for
future reference. Modern fundus photographs generally recreate considerably larger areas
of the fundus than what can be seen at any one time with handheld ophthalmoscopes.
Treatment 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:
Find all retinal breaks Seal all retinal breaks
Relieve present vitreoretinal traction Cryopexy and laser photocoagulation
Cryotherapy or laser photocoagulation 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 surgery is an established treatment
in which the eye surgeon sews one or more silicone bands to the sclera. 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 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 for U-shaped tears or Fishmouth tears, and posterior breaks. Circumferential
scleral buckle is indicated for multiple breaks, anterior breaks and wide breaks. Encircling
buckles are indicated for breaks covering more than 2 quadrants of retinal area, lattice
degeneration 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 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 of the gas/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. Pneumatic retinopexy has
significantly lower success rates compared to scleral buckle surgery and vitrectomy.
Some initially successful cases will fail during the weeks and months after surgery.
In some of the failed cases, an area of the retina which was healthy and attached prior
to the initial pneumatic retinopexy repair procedure develops new tears and/or becomes
detached. Vitrectomy
Vitrectomy 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
or silicone 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, if filled
needs to be removed after a period of 2–8 months depending on surgeon's preference.
Silicone oil is more commonly used in cases associated with proliferative vitreo-retinopathy.
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 may not be as good as it was prior
to the detachment, particularly if the macula was involved in the area of the detachment.
Epidemiology
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. Asymptomatic retinal breaks are present in about 6% of eyes in both clinical
and autopsy studies. Retinal detachment is more common in people
with severe myopia, 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 or those with proliferative retinopathy of
sickle cell disease. In proliferative retinopathy, abnormal blood vessels 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 a retinal detachment and cataracts extracted from both eyes.
Prognosis Up until the early 20th century, the prognosis
for rhegmatogenous retinal detachment was very poor, and no effective treatments were
available. Currently, about 95 percent of cases of retinal detachment can be repaired
successfully. Treatment failures usually involve either the failure to recognize all sites
of detachment, the formation of new retinal breaks, or proliferative vitreoretinopathy.
Involvement of the macula portends a worse prognosis. In cases where the macula is not
involved, 90 percent of patients have 20/40 vision or better after reattachment surgery.
Some damage to vision may occur during reattachment surgery, and 10 percent of patients with normal
vision experience some vision loss after a successful reattachment surgery.
See also Cystathionine beta synthase deficiency
Lattice degeneration Retinoschisis
Retinal regeneration References
Additional references Goldman, Lee. Goldman's Cecil Medicine. Philadelphia:
Elsevier Saunders. p. 1362. ISBN 1437727883. Yanoff, Myron; Duker, Jay S.. Ophthalmology.
Edinburgh: Mosby. ISBN 978-0323057516. External links
Retinal Detachment Resource Guide from the National Eye Institute.
Overview of retinal detachment from eMedicine Guidelines from the American Academy of Family
Physicians Retinal detachment information from WebMD
Retinal detachment information from the Merck Manual