Ophthalmology

The Ophthalmology is the branch of medicine responsible for the treatment of diseases of the eye and its annexes. It is a medical-surgical specialty.

Summary Ocular Anatomy and Physiology 1 1.1 The Eye 1.1.1 An anterior segment 1.1.2 A posterior segment 1.1.3 The adnexa 2 The eye examination 2.1 Visual Acuity 2.2 Scope visual 2.3 Review of the anterior segment 2.4 Measurement of IOP 2.5 Review of the posterior segment 2.6 The supplementary examinations in ophthalmology 2.7 Measuring Instruments 3 Ophthalmic Pathology 3.1 Pathologies of the anterior segment 3.2 Retinal diseases 3.3 Diseases of the eyelid 3.4 The glaucomas 3.5 Refractive 3.6 Disorders of binocular vision and strabismus 3.7 Disorders of color vision 4 Surgery 5 Economics 5.1 The products of Ophthalmology 6 History of ophthalmology 6.1 History 6.2 Ophthalmologists famous 7 Notes and references 8 See also 8.1 Article Related 8.2 External Links

/ / Ocular Anatomy and Physiology

The eye

As in most mammals , birds , reptiles and fish , the human eye consists of an eyeball , consisting of three envelopes: the sclero-cornea, uvea, and retina (inwards).

An anterior segment

• the cornea , anterior part of the eyeball, is a transparent lens whose role is to capture and focus light onto the retina. It consists, from front to rear of the epithelium, Bowman's membrane, stroma, Descemet's membrane and finally to the endothelium. Its average diameter is 12 mm.
• the uvea , consisting of the iris , the pupil muscle bounding box "virtual" in the center of the iris , and allowing modification of the incoming light from the choroid and ciliary body ;
• the crystalline , biological lens used for the accommodation ("focus" on the object to be displayed to obtain a point object is a focal point image on the retina) is connected to the ciliary body via the zonule of Zinn; This is the lens which in turn opaque, causes cataracts.
• the aqueous humor , liquid located between the posterior surface of the cornea and lens before backwards. It is secreted by the ciliary body.

A posterior segment

• the retina , the membrane of nerve cells comprising photoreceptors called cones or sticks , for the transformation of the light wave into electrical impulses , to image processing by the nervous system;
• the choroid membrane of the retina and nourishing true "vascular sponge" that lines the inner surface of
• the sclera.
• the vitreous body , a kind of gel that fills the cavity behind the lens and in front of the retina.

The adnexa

Fourfold:

1. The orbital bone cavity, covered by a fibro-elastic membrane (the periorbita). Protective role
2. The muscles oculomotor, the role of travel. 6 in number in the human :
   1. 4 rectus muscles: superior rectus, inferior rectus, right internal (or medial) and right external (or lateral);
   2. 2 oblique muscles: obliquus (or superior oblique) and oblique (or inferior oblique)
3. The lid , membrane allowing more or less insulated from electromagnetic radiation , the spread of tear film and protect the cornea.
4. The lacrimal gland : located at the top and outside, it secretes 40% of our tears, the rest being secreted by accessory glands.

The ophthalmologic examination

A complete eye examination includes examination of the patient, and a physical examination.

Visual Acuity

Visual acuity is the term for measuring the angle of minimum resolution. Normal visual acuity was 10/10 in each eye.

Scales are used to test for measurements of subjective visual acuity. For example:

• Monoyer scale : distance vision test that uses the letters of the Latin alphabet (vision 3 and 5 m ).
• Armaignac scale and scale Landolt : for the illiterate (vision 5 m), with geometric shapes.
• Pigassou scale : with drawings, for children (vision 2.5 m).
• Parinaud scale : testing for near vision, which uses French texts of decreasing size, read about thirty centimeters eyes.
• Rossano scale-Weiss test for near vision that uses images.
• Ishihara test : test of color vision, and not visual acuity, which uses drawings (figures, patterns) made with splashes of color. This test can detect dyschromatopties (default color vision).

The measurement of visual acuity occurs in practice with a study of vision from near and far, and with no correction.

Visual field

It can be found on the finger and will be evaluated better by using instrumental methods by perimetry or perimetry.

Review of the anterior segment

It is made using a slit lamp biomicroscope or is a painless and noninvasive for studying the anterior segment and adnexa. It also includes an examination of the iridocorneal angle (gonioscopy)

Measurement of IOP

Systematic review, it can detect or monitor glaucoma (acute or chronic). The average intraocular pressure (that is to say, the pressure prevailing in the eye) must be between 9 and 21 mmHg , but this value must be balanced by that of the central corneal thickness (CCT) and resistance cornea (hysteresis).

Review of the posterior segment

It is the examination of the fundus , which is performed after administration of eye drops which dilate the pupil (or without expansion). Were visualized and directly or indirectly (depending on material used) the retina and its components: papillary (birthplace of the optic nerve ), macula (area of the retina responsible for clear vision), veins , arteries , peripheral retina, and vitreous.

Additional tests in ophthalmology

• Angiography with fluorescein and indocyanine green
• Ultrasound eye
• Radiography of the orbit (in the case of traumatic disorders, or certain tumors)
• Scanner orbital and retro-orbital
• Electroretinogram
• Electro-oculogram
• VEP
• OCT (optical coherence tomography) technology developed by MIT in the 1990s and developed and disseminated clinical applications especially in the early 2000s, this test by computer to reconstruct the microscopic sections of the retina. Its two main indications are studying damage to the macula and the screening and monitoring of glaucoma by providing capital measurement residual optical fiber in an individual (capital decreases with age but decreases at high speed People with glaucoma)
• Specular microscopy : This test measures the share of corneal endothelial cells (cells, non-renewable, lining the posterior surface of the cornea or internal to which they provide transparency in setting the normal hydration of the cornea)
• ORA (hysteresis)
• Corneal topography: computerized analysis of the corneal surface, it performs real contours of the surface or the posterior surface of the cornea: its use is appropriate in certain diseases of the cornea in contact lens fitting and refractive surgery).
• Corneal pachymetry
• Biometrics
• GDX (laser polarimetry optical fibers)

Measuring Instruments

• refractor : simulator goggles for measuring subjective refraction.
• tonometer : measuring the pressure within the eye.
• pachymeter : measurement of corneal thickness.
• frontofocometer : measuring the power of corrective lenses.
• keratometer : a measure of the radius of curvature of the cornea.
• autorefractor : objective measurement of refraction.

Eye Diseases

Pathologies of the anterior segment

• Keratoconus
• Conjunctivitis
• Keratitis
• Anterior uveitis
• Cataract

Retinal diseases

• Macular Degeneration Age-related
• Retinal detachment
• Diabetic retinopathy
• Macular hole
• Occlusion of the central retinal artery
• Occlusion of central retinal vein
• Best disease
• Juvenile retinoschisis X-linked
• RP
• Macular hypoplasia due to a form of albinism
• Anterior ischemic optic neuropathy

Diseases of the eyelid

• Chalazion
• Stye

Glaucoma

• glaucoma

Refractive

Disorders of refraction are due to an abnormality of the optical system formed by the cornea , the lens and retina. In a normal eye, the focal point of the cornea-lens is located on the retina. In near vision, the ability to focus the lens (which bulges) can move the focus to the retina to maintain a focus on the retina the light rays that are no longer parallel but diverge.

• Myopia : the focal point is in front of the retina. Distant objects appear blurred.
• Hyperopia : The focal point is located behind the retina. Hyperopia is obliged to accommodate continuously to move the focal point, close objects appear fuzzy when the accommodation capacities are exceeded.
• Astigmatism : the light rays are focused in two distinct foci on the retina. This is usually caused by a defect in the cornea that causes failure of stigma.
• Presbyopia : decreased ability to focus the lens due to aging. Nearby objects appear blurred because the lens is no longer able to accommodate enough.

They can be corrected by wearing glasses or surgery.

Disorders of binocular vision and strabismus

Disorders of binocular vision are numerous. It is difficult to superimpose images of the right eye and left eye. This difficulty can cause, among other things, headaches, fatigue endurance with a bad visual visual limiting visual activities like reading, diplopia (double vision) and in some cases lead to strabismus.

Strabismus are disorders of binocular vision more advanced image fusion is no longer possible and the visual axes are deviated.

For more information on strabismus, read the " squint ".

Disorders of color vision

• daltonism

Surgery

• Eye surgery
• Refractive Surgery

Economy

Products of Ophthalmology

The market for ophthalmic equipment (surgical products, drugs for eye diseases, eye drops, contact lens solutions) amounted to 19 billion dollars in 2006 ^{History of ophthalmology}

History

Ophthalmology, due to the importance of the eye in human perception and the role of the eye in facial aesthetics, is a very old science. Several techniques have been developed in many parts of the world independently, China, Japan, Central America, Europe, Egypt and India since ancient times.

One of the oldest documents speaking of ophthalmology and obstetrics is the Papyrus Carlsberg. It dates to the oldest part of the ^second millennium BC. AD.

Famous Ophthalmologists

• Frdric Jules Sichel , (1802-1868)
• Charles Deval , (1806-1862)
• Desmarres Louis Auguste , (1810-1882)
• Franciscus Cornelis Donders , (1818-1889)
• Louis de Wecker (Wecker Ludwig) (1832-1906)
• Xavier Galezowski , (1832-1907)
• John Soelberg Wells , (1834-1879)
• Henri Parinaud (1844-1905), considered the father of the French Ophthalmology
• Jose Rizal , (1861-1896)
• Govindappa Venkataswamy , (1918-2006)

References

See also

Related articles

• Eye
• View
• Vision
• Lasik
• Orthoptics (rehabilitation of disorders of binocular vision)
• Optician

External Links

• French Society of Ophthalmology
• Historical sources of ophthalmology
• Syndicat National de France Ophthalmologists
• Handout National College of Ophthalmologists and handouts Universitaires de France CHU Pitie-Salpetriere