Macular edema
Encyclopedia
Macular edema
occurs when fluid and protein
deposits collect on or under the macula
of the eye
(a yellow central area of the retina
) and causes it to thicken and swell. The swelling may distort a person's central vision
, as the macula is near the center of the retina
at the back of the eyeball. This area holds tightly packed cones
that provide sharp, clear central vision to enable a person to see detail, form, and color that is directly in the direction of gaze.
Macular edema sometimes appear for a few days or weeks after cataract surgery
, but most such cases can be successfully treated with NSAID or cortisone
eye drops
.
Until recently there were no good treatments for macular edema caused by central retinal vein occlusion
(CRVO). Laser photocoagulation
has been used for macular edema caused by branch retinal vein occlusion (BRVO).
formation,
including Irvine-Gass syndrome and others.
Diabetic macular edema is classified into focal and diffuse types. Each can be treated by types of laser photocoagulation
.
and BRVO.
Edema
Edema or oedema ; both words from the Greek , oídēma "swelling"), formerly known as dropsy or hydropsy, is an abnormal accumulation of fluid beneath the skin or in one or more cavities of the body that produces swelling...
occurs when fluid and protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
deposits collect on or under 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...
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...
(a yellow central area of 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...
) and causes it to thicken and swell. The swelling may distort a person's central vision
Visual perception
Visual perception is the ability to interpret information and surroundings from the effects of visible light reaching the eye. The resulting perception is also known as eyesight, sight, or vision...
, as the macula is near the center of 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...
at the back of the eyeball. This area holds tightly packed cones
Cone cell
Cone cells, or cones, are photoreceptor cells in the retina of the eye that are responsible for color vision; they function best in relatively bright light, as opposed to rod cells that work better in dim light. If the retina is exposed to an intense visual stimulus, a negative afterimage will be...
that provide sharp, clear central vision to enable a person to see detail, form, and color that is directly in the direction of gaze.
Macular edema sometimes appear for a few days or weeks after 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...
, but most such cases can be successfully treated with NSAID or cortisone
Cortisone
Cortisone is a steroid hormone. It is one of the main hormones released by the adrenal gland in response to stress. In chemical structure, it is a corticosteroid closely related to corticosterone. It is used to treat a variety of ailments and can be administered intravenously, orally,...
eye drops
Eye Drops
Eye Drops was a television program on TechTV that showcased short computer animation movies and clips made using off the shelf 3D animation software. The show claimed to showcase all different types of animation, but only a very small number of shorts featured non-CG animation...
.
Until recently there were no good treatments for macular edema caused by central retinal vein occlusion
Central retinal vein occlusion
The central retinal vein is the venous equivalent of the central retinal artery, and like that blood vessel can suffer from occlusion , similar to that seen in ocular ischemic syndrome...
(CRVO). 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...
has been used for macular edema caused by branch retinal vein occlusion (BRVO).
Classification
Cystoid macular edema (CME) is any type of macular edema that involves cystCyst
A cyst is a closed sac, having a distinct membrane and division on the nearby tissue. It may contain air, fluids, or semi-solid material. A collection of pus is called an abscess, not a cyst. Once formed, a cyst could go away on its own or may have to be removed through surgery.- Locations :* Acne...
formation,
including Irvine-Gass syndrome and others.
Diabetic macular edema is classified into focal and diffuse types. Each can be treated by types of 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...
.
Approved treatments
In 2010 the US FDA approved the use of Lucentis injections for macular edema.Clinical trials
In 2005, steroids were investigated for macular edema due to retinal blood vessel blockage such as CRVOCentral retinal vein occlusion
The central retinal vein is the venous equivalent of the central retinal artery, and like that blood vessel can suffer from occlusion , similar to that seen in ocular ischemic syndrome...
and BRVO.
See also
- Diabetic retinopathyDiabetic retinopathyDiabetic retinopathy is retinopathy caused by complications of diabetes mellitus, which can eventually lead to blindness....
- Intermediate uveitisIntermediate uveitisIntermediate uveitis refers to inflammation localized to the vitreous and peripheral retina. Primary sites of inflammation include the vitreous of which other such entities as pars planitis, posterior cyclitis, and hyalitis are encompassed...
- Fuchs spotFuchs spotThe Fuchs spot or sometimes Forster-Fuchs' retinal spot is a degeneration of the macula in case of high myopia. It is named after the two persons who first described it: Ernst Fuchs who described a pigmented lesion in 1901 and Forster who described subretinal neovascularisation in 1862...
- macular telangiectasiaMacular TelangiectasiaIdiopathic Juxtafoveal Macular Telangiectasia is a blinding condition of the retina about which little is known.It is a form of pathologically dilated blood vessels at the region of highest visual acuity, the yellow spot in the human eye...