LECTURE No. 19. Tumors of the choroid and anomalies of the vascular tract

1. Cysts of the iris

In the iris, single thin-walled or multiple blisters of various shapes and sizes are determined, which grow and can cause secondary glaucoma. If the cysts have a yellowish tint, they are called pearl cysts. They can occur in the iris due to the germination of the corneal epithelium into it after perforated wounds or surgical interventions.

2. Cysts of the ciliary body

Determined by cycloscopy and gonioscopy. At the extreme periphery, at the dentate line, yellow-gray bubbles are visible, protruding into the vitreous body. Ciliary body cysts should be differentiated from retinal detachment, which is characterized by the presence of light gray or pink blisters, retinal swelling, and changes in the course and color of blood vessels. Cysts often cause secondary glaucoma.

Treatment is carried out, as a rule, in the event of secondary glaucoma and consists in diathermocoagulation of the ciliary body, sometimes in excision of the cyst. Iris cysts are treated with diathermo or photocoagulation and excision.

3. Angioma of the choroid

Angiomas are more often localized in the paracentral parts of the fundus, have a round shape, a yellowish-cherry color, and their borders are unclear. According to the location of the angiomas, a defect in the field of view is observed. If angioma of the vascular tract does not grow, it cannot be treated. When angioma grows, it should be differentiated from melanoblastoma. Diagnosis is aided by radioisotope studies and angiography. It should be taken into account that melanoblastoma occurs mainly in adults and elderly people.

4. Pigment tumors

These benign melanomas in children can be localized in different parts of the vascular tract. Benign melanomas ("birthmarks") of the iris are of different sizes, slightly rise above its surface and have a dark color of varying intensity. They usually don't grow.

Melanomas of the ciliary body are almost never detected in vivo and do not cause noticeable changes in the functions of the eye.

Choroidal melanomas are often discovered incidentally during ophthalmoscopy. They look like spots of varying sizes and localization, dark with a gray tint, round in shape, with fairly clear boundaries. The retina under these spots is not changed or, due to the pronounced thickness of the melanoma, is somewhat protruded into the vitreous body. The state of eye function depends on the severity and location of melanomas.

Children with melanomas of the vascular tract are subject to dispensary observation. At the slightest increase in the size of melanoma, radioisotope diagnostics and other additional studies are indicated.

Melanoblastoma of the vascular tract in children is almost never registered. It is more common in people over thirty years of age.

Treatment. Surgical intervention, diathermo, photo or laser coagulation.

5. Neurofibromatosis

If, during examination using lateral illumination and biomicroscopy, the unevenness of the anterior chamber is determined, multiple nodules of a brownish-yellowish round shape with clear boundaries are found in the iris, slightly rising above the surrounding unchanged tissue of the iris, you should find out whether the patient has changes on the skin (pigment spots café-au-lait color, tumors along the skin nerves), which is characteristic of neurofibromatosis, or Recklinghausen's disease.

It must be remembered that in such a patient, an increase in intraocular pressure is possible. Sometimes, in the absence of common clear manifestations of neurofibromatosis, the detection of changes in the organ of vision is of great diagnostic value.

6. Anomalies of the vascular tract

Congenital coloboma of the iris (coloboma iridis congenitum) is the result of non-closure of the slit of the eye cup. The downward direction of the coloboma, the preservation of the sphincter of the pupil and its reaction to light, and sometimes the symmetry of the lesion of both eyes are characteristic. Sometimes it is combined with coloboma of the choroid itself and other malformations. With ophthalmoscopy, the coloboma of the choroid itself appears as a varied shape and size of a white sector with clear edges, over which the retinal vessels pass without change. Choroid coloboma, depending on its location, can cause a decrease in visual functions.

Polycoria (polycoria) multiple pupils. Corectopia (corectopia) displacement of the pupil. Both of these anomalies may be accompanied by a decrease in vision.

Aniridia (aniridia congenita) absence of the iris. In transmitted light, a bright red reflex is recorded. Visual functions are sharply reduced. May be associated with glaucoma. In such cases, surgical treatment of glaucoma is indicated.

Heterochromia is the difference in the color of the irises in the right and left eyes.

Albinism (albinismus) is the absence or deficiency of pigment in the choroid, retinal pigment epithelium, skin, and hair. Often such individuals have pronounced nystagmus and poor vision due to excessive light in the eyes. Wearing smoky glasses is shown.

The residual pupillary membrane (membrana pupillarus perseverans) is the remnants of a film that closes the pupil, which dissolves by the end of uterine life. It has the appearance of thin threads starting from the small arterial circle of the iris or from its surface and attached to the anterior lens capsule. Sometimes, crossing the pupil, the membrane goes to the small arterial circle on the opposite side. Occasionally, the remnants of the pupillary membrane are an accumulation on the anterior capsule of the lens of small pigment clumps, shaped like asterisks.

Author: Shilnikov L.V.

<< Back: Choroiditis

>> Forward: Pathologies of the fundus (part I) (General diagnostic issues. Pigmentary dystrophy (degeneration) of the retina (retinitis pigmentosa). Macular degeneration of the retina (degeneratio maculae luteae). Macular degeneration in Tay Sachs disease. Retrolental fibroplasia. External exudative hemorrhagic retinitis, or Coats disease (retinitis exsudativa haemorrhagica externa Acute obstruction of the central retinal artery (embolia s. thrombosis arteriae centralis retinae). Thrombosis of the central retinal vein (thrombosis venae centralis retinae))

We recommend interesting articles Section Lecture notes, cheat sheets:

▪ Crisis management. Crib

▪ Quality control. Crib

▪ History of world religions. Crib

See other articles Section Lecture notes, cheat sheets.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

The existence of an entropy rule for quantum entanglement has been proven 09.05.2024

Quantum mechanics continues to amaze us with its mysterious phenomena and unexpected discoveries. Recently, Bartosz Regula from the RIKEN Center for Quantum Computing and Ludovico Lamy from the University of Amsterdam presented a new discovery that concerns quantum entanglement and its relation to entropy. Quantum entanglement plays an important role in modern quantum information science and technology. However, the complexity of its structure makes understanding and managing it challenging. Regulus and Lamy's discovery shows that quantum entanglement follows an entropy rule similar to that for classical systems. This discovery opens new perspectives in the field of quantum information science and technology, deepening our understanding of quantum entanglement and its connection to thermodynamics. The results of the study indicate the possibility of reversibility of entanglement transformations, which could greatly simplify their use in various quantum technologies. Opening a new rule ... >>

Mini air conditioner Sony Reon Pocket 5 09.05.2024

Summer is a time for relaxation and travel, but often the heat can turn this time into an unbearable torment. Meet a new product from Sony - the Reon Pocket 5 mini-air conditioner, which promises to make summer more comfortable for its users. Sony has introduced a unique device - the Reon Pocket 5 mini-conditioner, which provides body cooling on hot days. With it, users can enjoy coolness anytime, anywhere by simply wearing it around their neck. This mini air conditioner is equipped with automatic adjustment of operating modes, as well as temperature and humidity sensors. Thanks to innovative technologies, Reon Pocket 5 adjusts its operation depending on the user's activity and environmental conditions. Users can easily adjust the temperature using a dedicated mobile app connected via Bluetooth. Additionally, specially designed T-shirts and shorts are available for convenience, to which a mini air conditioner can be attached. The device can oh ... >>

Energy from space for Starship 08.05.2024

Producing solar energy in space is becoming more feasible with the advent of new technologies and the development of space programs. The head of the startup Virtus Solis shared his vision of using SpaceX's Starship to create orbital power plants capable of powering the Earth. Startup Virtus Solis has unveiled an ambitious project to create orbital power plants using SpaceX's Starship. This idea could significantly change the field of solar energy production, making it more accessible and cheaper. The core of the startup's plan is to reduce the cost of launching satellites into space using Starship. This technological breakthrough is expected to make solar energy production in space more competitive with traditional energy sources. Virtual Solis plans to build large photovoltaic panels in orbit, using Starship to deliver the necessary equipment. However, one of the key challenges ... >>

Random news from the Archive NexFET with double-sided cooling 31.01.2010 Texas Instruments announced the release of the industry's first family of standard-mount, high-power MOSFETs that dissipate heat through both the bottom and top of the package for high-current DC/DC applications. This design allows power system designers to efficiently remove heat from printed circuit boards in high voltage DC or AC applications. This makes it possible not only to increase the density of power supplies, but also to expand the range of supported current loads and increase the reliability of systems. The improved package technology reduces the thermal impedance towards the top of the package from 10 to 15°C per 1W to 1,2°C/W, resulting in an increase in heat dissipation capacity of up to 80%. Efficient two-way heat dissipation allows up to 50% more current through the transistor, giving designers the flexibility to use higher current processors without increasing the size of the final hardware. The industry-standard 5x6mm SON package simplifies design and reduces cost, saving 30mm2 of floor space compared to using two standard packages. The DualCool NexFET family includes five positions: CSD16325Q5C, CSD16322Q5C, CSD16321Q5C, CSD16407Q5C, CSD16408Q5C.

Other interesting news:

▪ Trusting on the Internet is easier

▪ DIY robot

▪ Adults and children perceive time differently.

▪ Virtual walking attachment

▪ Champagne for astronauts

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the website Electrotechnical materials. Article selection

▪ article Can't see the forest for the trees. Popular expression

▪ article When was the first sculpture created? Detailed answer

▪ Velokart article. Personal transport

▪ article Tunable square-wave generator. Encyclopedia of radio electronics and electrical engineering

▪ article Radiotelephones and all about them. Encyclopedia of radio electronics and electrical engineering

Leave your comment on this article:

All languages ​​of this page

Arabic	Hebrew	Polish
Bengali	Hindi	Portuguese
Chinese	Italian	Spanish
English	Japanese	Turkish
French	Korean	Ukrainian
German	Malay	Vietnamese

Home page | Library | Articles | Website map | Site Reviews

www.diagram.com.ua
2000-2024