LECTURE No. 21. Pathologies of the fundus (part II)

1. Retinoblastoma

Retinoblastoma is a malignant neoplasm that develops in the retina of the eye. It belongs to congenital tumors. It is detected in children aged two to four years. Retinoblastoma can be either unilateral or bilateral. The disease is detected more often in the first year of life. In approximately 30% of cases, the process is bilateral, often of a family-hereditary nature.

Etiology, pathogenesis and pathological anatomy. The etiology has not been reliably established. A possible cause is considered to be a mutation of the chromosomes of germ cells due to internal and external factors. Retinoblastoma consists of neuroglia, that is, it is a glioma in its structure. Glia develops from the ectoderm and has great energy to reproduce and form new elements. Glial tissue permeates all layers of the retina and optic nerve.

There are differentiated and undifferentiated forms of the tumor. The specific structures of differentiated retinoblastoma are true rosettes, which consist of a cylindrical form of embryonic-type neuroepithelial cells, sometimes there are abortive forms of the outer segment of photoreceptors. In undifferentiated forms, small cells with a large nucleus and a narrow rim of the cytoplasm are found, located diffusely or forming pseudorosettes around the vessels, surrounded by a zone of necrosis and calcifications. Mitoses are often noted in the tumor, dissemination to the vitreous body and the anterior chamber of the eyeball develops.

Forms and stages of retinoblastoma.

There are five stages of tumor development:

1) latent;

2) primary;

3) developed;

4) far gone;

5) terminal.

The latent stage of retinoblastoma is characterized by such early indirect signs as unilateral pupil dilation, slowing or lack of its reaction to light. More pronounced is not a direct, but a friendly pupillary reflex. The depth of the anterior chamber may be reduced. These signs can be combined with slight changes in the fundus.

The initial stage is characterized by the fact that ophthalmoscopy reveals a yellowish-white lesion with unclear contours in the fundus, often covered with retinal vessels. Small satellite lesions are observed around the lesion. Tumor growth leads to amaurosis (blindness). The tumor can spread into the vitreous body in the form of grayish-white, sometimes yellowish or greenish masses with blurred boundaries, on the surface of which hemorrhages are visible. Retinoblastoma is detected in lateral lighting and with the naked eye by the yellow glow of the pupil area. It is the last symptom that usually forces parents to show the child to an ophthalmologist. The process can spread across the retina (exophytic growth) and towards the vitreous body (endophytic growth). The appearance of retinal detachment makes diagnosis difficult.

The advanced stage (glaucoma stage) is characterized by tumor growth and an increase in the volume of the contents of the eye, which often leads to an increase in intraocular pressure. In this case, pain in the eye, congestive injection, corneal edema, a decrease in depth and clouding of the moisture of the anterior chamber (pseudohypopion) are possible due to the fact that individual particles of the tumor come off and disperse inside the eye. The pupil is dilated and does not react to light. In some cases, implantation nodules resembling tuberculous ones are found in the iris.

Advanced stage (germination stage). This stage of retinoblastoma is characterized by tumor growth beyond the eyeball, more often through the sclera, along the vessels, through the sheaths of the optic nerve, etc. Posterior growth of the tumor is manifested by exophthalmos with limited eye mobility, the spread of the process into the cranial cavity causes an expansion of the optic nerve canal, which is detected on radiograph.

In the terminal stage (stage of metastases), enlarged cervical, submandibular lymph nodes are determined, further gross changes are observed from the side of the eye, up to the collapse of the membrane and the sharpest exophthalmos (the eye is dislocated). Tumor-like formations in the bones of the skull are revealed, and tuberosities of the liver, spleen, kidneys and other organs are enlarged. The process is accompanied by pain, the onset of cachexia, changes in the blood picture.

Clinical picture. Retinoblastoma can be unilateral or bilateral. Bilateral tumors are often combined with microcephaly, cleft palate and other embryonic developmental defects. The onset of the disease usually goes unnoticed. The first clinical symptom may be decreased visual acuity. Sometimes an early clinical sign of a unilateral lesion may be strabismus. Then there will be a change in eye color (yellowish reflex), observed in the depths of the eyeball and visible through the pupil (the so-called amaurotic cat's eye). This phenomenon occurs due to the presence of gliomatous nodes on the retina and forces the child’s parents to consult a doctor. The tumor is characterized by slow growth.

In the clinic of retinoblastoma, with an objective examination of the fundus, four stages are distinguished.

At the first stage, retinal whitish-pink lesions with smooth or uneven relief, newly formed vessels and gray areas of calcifications are visible. Their dimensions do not exceed one quadrant of the fundus, the surrounding tissues are not changed.

In the second stage, intraocular dissemination occurs. Whitish inclusions of various sizes are already observed in the vitreous body, precipitate-like deposits are noted in the angle of the anterior chamber of the eyeball and on the posterior surface of the cornea. Secondary glaucoma, buphthalmos (hydrophthalmos) appear. When a tumor grows into the retina, the accumulation of exudate under it leads to retinal detachment. Vision is reduced to complete blindness.

The third stage is characterized by extraocular spread of the tumor. Accompanied by exophthalmos, tumor growth into the cranial cavity, most often along the optic nerve, gives symptoms of brain damage (headache, nausea, vomiting). Germination of retinoblastoma in the choroid leads to hematogenous dissemination and an unfavorable outcome. As a result of tumor necrosis, toxic uveitis may develop.

In the fourth stage, symptoms due to metastasis join the eye symptoms. Metastasis occurs to lymph nodes, bones, brain, liver and other organs.

Complications and diagnosis. A complication of retinoblastoma with a favorable outcome may be loss of vision in one or both eyes. A possible complication is the development of retinoblastoma into sarcoma (rhabdomyosarcoma), leukemia. The diagnostic criterion for retinoblastoma at the first stage of the disease is the detection of an amaurotic cat's eye. To objectively confirm the diagnosis, they resort to ophthalmoscopy, radiography, ultrasound examination of the eyeball and skull. Retinoblastoma should be differentiated from pseudoglioma, which occurs as a result of an inflammatory process, and it must also be distinguished from organized hemorrhage, proliferating retinitis, retinal detachment, Coates' disease, cysticercosis, tuberculosis, etc. Anamnesis (past infectious diseases) is important for making a diagnosis, the presence in some cases on the radiographs of the orbit of foci of calcification. Diaphanoscopy and echographic studies help in the diagnosis.

Treatment and prevention. At the first and second stages of the disease, organ-preserving cryoapplication is possible. At later stages, treatment consists in the timely surgical removal of the tumor (enucleation of the affected eye in a unilateral process or both eyes in a bilateral process). Enucleation of the eyeball is performed with resection of the optic nerve at a distance of 1015 cm from the posterior pole of the eyeball. In the future, radiation therapy is carried out in combination with chemotherapy or alone. Photocoagulation may also be performed. Cyclophosphamide, prospedin, methotrexatebeve are used as antitumor drugs.

Prevention of retinoblastoma consists in the timely genetic examination of those families whose relatives have been treated for retinoblastoma in the past.

2. Retinal anomalies

Patients do not complain. Ophthalmoscopy at the optic disc reveals white, shiny, with a silver tint smears, radially arranged, resembling white flames, somewhat passing to the optic disc. These are myelin fibers. When examining the functions of vision, no pathological changes were noted. There is an increase in the blind spot.

Author: Shilnikov L.V.

<< Back: 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))

>> Forward: Diagnosis, clinical picture and treatment of optic nerve pathologies (General diagnostic issues. Optic neuritis (neuritus nervi optici). Congestive papilla (disc) of the optic nerve (papillitis oedematosa s. oedema papillae n. optici). Optic nerve atrophy (atrophia nervi optici). Optic nerve glioma (glioma nervi optici) )

We recommend interesting articles Section Lecture notes, cheat sheets:

▪ Commercial activity. Lecture notes

▪ Advertising and promotional activities. Lecture notes

▪ Informatics and information technologies. 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 The perfect snack for heart health 09.06.2020 According to doctors from the UK, almonds can be considered an ideal daily snack that benefits the heart - it effectively protects against the development of many pathologies of the cardiovascular system. King's College London has determined that regular consumption of almonds improves the functioning of blood vessels (not to mention other health benefits). For this reason, they consider the product to be the perfect snack. The use of almonds helps to reduce the level of fat in the abdominal cavity and "bad" cholesterol in the vessels, which are the leading markers of heart disease. They conducted a study involving almost 7 thousand people (specialists monitored the nutritional habits of the subjects). It turned out that it was almond lovers who had the best indicators of heart health. People who prefer to snack on nuts during the day tend to consume less carbohydrate foods, trans fats, and salt in general. Another experiment showed that by replacing 20% ​​of junk food consumed daily with almonds, people can reduce their personal risk of heart disease by 32%. The antioxidants of this nut protect blood vessels from the harmful effects of free radicals, which can disrupt blood flow to the myocardium and provoke the development of coronary heart disease.

Other interesting news:

▪ Slow life saves from deadly mutations

▪ Predicting major solar flares

▪ The brain responds faster to an aggressive voice than to a calm one.

▪ Shave and heart

▪ MSP430FG6626 - microcontroller for portable measuring devices

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the Antenna website. Article selection

▪ article And who knows what he blinks. Popular expression

▪ Why did Elvis Presley's manager distribute I hate Elvis badges? Detailed answer

▪ article Working with a drying chamber. Standard instruction on labor protection

▪ article Designation of grounding systems for electrical installations with voltage up to 1 kV. Encyclopedia of radio electronics and electrical engineering

▪ article Flowers and doves. Focus Secret

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