Editing Glaucoma (section)

==Diagnosis==
[[File:Glaukompapille2.jpg|thumb|Optic nerve in advanced glaucoma disease]]
[[File:Optic disc topography, case 1, R, glaucoma.png|thumb|Glaucoma (right eye) with significant optic disc involvement. 80-year-old man. Optic disc topography.]]
Screening for glaucoma is an integral part of a standard eye examination performed by optometrists and ophthalmologists.<ref name="mayo22">{{cite web |title=Glaucoma diagnosis |url=https://www.mayoclinic.org/diseases-conditions/glaucoma/diagnosis-treatment/drc-20372846 |publisher=Mayo Clinic |access-date=22 September 2023 |date=30 September 2022}}</ref> The workup for glaucoma involves taking a thorough case history, with the emphasis on assessment of risk factors. 

The baseline glaucoma evaluation tests include intraocular pressure measurement by using tonometry, [[anterior chamber angle]] assessment by [[optical coherence tomography]], inspecting the drainage angle ([[gonioscopy]]), and [[retinal nerve fiber layer]] assessment with a [[fundus (eye)|fundus]] examination, measuring corneal thickness ([[pachymetry]]), and [[visual field]] [[Perimetry|testing]].<ref name=mayo22/>

=== Types ===
{{More citations needed section|date=August 2015}}
Glaucoma has been classified into specific types:<ref name="Paton">{{cite journal |vauthors=Paton D, Craig JA |year=1976 |title=Glaucomas. Diagnosis and management |journal=Clinical Symposia |volume=28 |issue=2 |pages=1–47 |pmid=1053095}}</ref>

===Primary glaucoma and its variants===
Primary glaucoma (H40.1-H40.2) includes primary open-angle glaucoma (chronic open-angle, chronic simple, glaucoma simplex) which can be high-tension or low-tension, and primary angle closure glaucoma (primary closed-angle, narrow-angle, pupil-block, acute congestive), which can manifest as acute, chronic, intermittent, or superimposed on chronic open-angle closure glaucoma (also called "combined mechanism" glaucoma).

Other variants of primary glaucoma include:
*[[Pigment dispersion syndrome|Pigmentary glaucoma]]
*[[Exfoliation glaucoma]], also known as pseudoexfoliative glaucoma or glaucoma capsulare
*[[Primary juvenile glaucoma]]

'''Primary angle closure glaucoma''' is caused by contact between the iris and trabecular meshwork, which in turn obstructs outflow of the aqueous humor from the eye. This contact between iris and trabecular meshwork (TM) may gradually damage the function of the meshwork until it fails to keep pace with aqueous production, and the pressure rises. In over half of all cases, prolonged contact between iris and TM causes the formation of synechiae (effectively "scars").

These cause permanent obstruction of aqueous outflow. In some cases, pressure may rapidly build up in the eye, causing pain and redness (symptomatic, or so-called "acute"-angle closure). In this situation, the vision may become blurred, and halos may be seen around bright lights. Accompanying symptoms may include a headache and vomiting.

Diagnosis is made from physical signs and symptoms - pupils mid-dilated and unresponsive to light, cornea edematous (cloudy), reduced vision, redness, and pain. However, the majority of cases are asymptomatic. Prior to the very severe loss of vision, these cases can only be identified by examination, generally by an eye-care professional.

===Developmental glaucoma===
Developmental glaucoma (Q15.0)
*[[Primary congenital glaucoma]]
*Infantile glaucoma
*Glaucoma associated with hereditary or familial diseases

===Secondary glaucoma===
[[Secondary glaucoma]] (H40.3-H40.6) encompasses numerous subtypes: inflammatory glaucoma (all types of uveitis, Fuchs heterochromic iridocyclitis); phacogenic glaucoma (angle-closure with mature [[cataract]], phacoanaphylactic glaucoma from [[lens capsule]] rupture, [[phacolytic glaucoma]], [[lens subluxation]]); glaucoma secondary to intraocular hemorrhage ([[hyphema]], [[Hemolysis|hemolytic]]/erythroclastic glaucoma); traumatic glaucoma (angle recession glaucoma); postsurgical glaucoma (aphakic pupillary block, ciliary block); neovascular glaucoma; drug-induced glaucoma (corticosteroid-induced, alpha-chymotrypsin); and glaucoma of miscellaneous origin (associated with [[Eye neoplasm|intraocular tumors]], [[Retinal detachment|retinal detachments]], severe chemical burns, [[essential iris atrophy]], or toxic glaucoma).

'''Neovascular glaucoma''', an uncommon type of glaucoma, is difficult or nearly impossible to treat, and is often caused by proliferative [[diabetic retinopathy]] (PDR) or [[central retinal vein occlusion]] (CRVO). It may also be triggered by other conditions that result in [[ischemia]] of the [[retina]] or [[ciliary body]]. Individuals with poor blood flow to the eye are highly at risk for this condition.

Neovascular glaucoma results when new, abnormal vessels begin developing in the angle of the eye that begin blocking the drainage. People with such condition begin to rapidly lose their eyesight. Sometimes, the disease appears very rapidly, especially after cataract surgery procedures.

'''Toxic glaucoma''' is open-angle glaucoma with an unexplained significant rise of intraocular pressure following unknown pathogenesis. Intraocular pressure can sometimes reach {{convert|80|mmHg|abbr=on}}. It characteristically manifests as ciliary body inflammation and massive trabecular edema that sometimes extends to Schlemm's canal. This condition is differentiated from malignant glaucoma by the presence of a deep and clear anterior chamber and a lack of aqueous misdirection. Also, the corneal appearance is not as hazy. A reduction in visual acuity can occur followed neuroretinal breakdown.

===Absolute glaucoma===
Absolute glaucoma (H44.5) is the end stage of all types of glaucoma. The eye has no vision, absence of [[pupillary light reflex]] and [[pupillary response]], and has a stony appearance. Severe pain is present in the eye. The treatment of absolute glaucoma is a destructive procedure like cyclocryoapplication, cyclophotocoagulation, or injection of 99% alcohol.