Neovascular glaucoma

Description:

Neovascular glaucoma — rather often found pathology connected with neovascularization of an iris of the eye (an iris rubeosis). The expressed chronic ischemia of a retina is considered usually pathogenetic factor. The arising hypoxemic zones of a retina produce vazoproliferativny factors in the course of revascularization of these areas. Except the progressing retina neovascularization (a proliferative retinopathy), hypoxia factors extend also to a front segment of an eye, causing a rubeosis of an iris and formation of a fibrovaskulyarny membrane in coal of an anterior chamber. The last factor complicates outflow of watery moisture in the presence of an open corner and later leads to secondary closed-angle glaucoma, resistant to different types of treatment. Timely laser photocoagulation of ischemic zones of a retina can become prevention of neovascular glaucoma.

Symptoms of Neovascular glaucoma:

Depending on neovascularization degree of manifestation neovascular glaucoma is divided into 3 stages:
• Iris rubeosis.
• Secondary open angle glaucoma.
• Secondary sinekhialny closed-angle glaucoma.

Iris rubeosis.
• On pupillary edge reveal small capillaries, usually in the form of bunches or red small knots which not always notice at insufficiently attentive survey (without use of big increase).
• New vessels are located radially on an iris surface in the direction of a corner, sometimes connecting expanded blood vessels in a collateral. In this stage intraocular pressure is not changed yet, and neogenic vessels can spontaneously regress or as a result of treatment.
Neovascularization of a corner of an anterior chamber without involvement in process of area of a pupil can develop at occlusion of the central vein of a retina therefore in such eyes with high risk of complications the gonioskopiya has to be executed with extra care.

Secondary open angle glaucoma.
Neogenic vessels on an iris have usually cross direction, directing to its root. Sometimes neovascular fabric spreads to a surface of a ciliary body and a scleral spur, getting into a corner of an anterior chamber. Here vessels branch and create a fibrovaskulyarny membrane which blocks a trabecular zone and causes a secondary open angle glaucoma.

Secondary closed-angle glaucoma.
Develops when closing a corner of an anterior chamber as a result of reduction of fibrovaskulyarny fabric, a tension and shift
iris root to a trabecula. The corner is closed on a circle like a fastener of "lightning".
Clinical features.
• Considerable deterioration in visual acuity.
• Congestive injection and pain.
• High intraocular pressure and hypostasis of a cornea.
• Weigh blood in moisture, transuding of proteins from neogenic vessels.
• The expressed iris rubeosis with change of a form of a pupil, sometimes with an ectropion because of reduction of a fibrovaskulyarny membrane.
• At a gonioskopiya reveal sinekhialny closing of a corner with impossibility of visualization of its structures behind the Schwalbe line.

Reasons of Neovascular glaucoma:

1. Disturbance of blood circulation at occlusion of the central vein of a retina meets in 36% of cases of all vascular pathology. Approximately neovascular glaucoma develops in 50% of cases at such patients. An extensive luminescence of contrast on the periphery of a retina at the level of capillaries at a fluorescent angiography — the most valuable evidence of possible risk of development of neovascular glaucoma though in some cases lack of ischemic zones at a research does not mean that they cannot appear. Glaucoma is usually revealed in 3 months after a disease (100-day glaucoma), on average of 4 weeks up to 2 years.
2. At a diabetes mellitus neovascular glaucoma develops in 32% of cases. Patients with the diabetes within 10 or more years which is followed by a proliferative retinopathy make group of extra risk. The risk of glaucoma decreases after carrying out pan-retinal photocoagulation of a retina and increases after extraction of a cataract, especially at damage of the back capsule. Regular survey is obligatory during the first 4 weeks after intervention which are a critical period of development of a rubeosis of an iris. The vitrectomy in a zone of a flat part of a ciliary body can accelerate an iris rubeosis if the carried-out laser therapy was there is traction amotio of a retina.
3. Other irichina: narrowing of sleepy and central arteries of a retina, intraocular tumors, old amotio of a retina and chronic intraocular inflammation.

Treatment of Neovascular glaucoma:

The pas elimination of pain as the forecast for sight, as a rule, adverse is directed.
1. Medicamentous: local and system hypotensive drugs with an exception of miotik. Appoint atropine and steroids for stopping of an inflammation and stabilization of process even with the increased intraocular pressure.
2. Retina amotio. Carry out argonlazerny coagulation. In eyes with opaque optical environments the effect is reached transscleral diodlazerny or cryocautery of a retina.
3. Surgical treatment is recommended at visual functions before the movement of a hand above. 2 options are possible: a trabekulektomiya using a mitomitsin With or drainage surgery.
At the favorable result of operation intraocular pressure is compensated, but disappearance a svetovospriyatiya and development of a subatrophy of gpazny apple therefore a main objective — stopping of a pain syndrome is possible.
4. Transscleral diodlazeriy cyclodestruction can be effective for the purpose of normalization of VGD and stabilization of process, especially in a combination with medicamentous therapy.
5. Retrobulbariy alcoholization is applied to stopping of a pain syndrome, however in some cases it can lead to a constant ptosis.
6. Enucleation is carried out in the absence of effect of other types of treatment.