Retinal anomalies: causes, symptoms, diagnosis, treatment

Anomalies in the development of the membranes of the eye are detected immediately after birth. The occurrence of anomalies is caused by mutation of genes, chromosomal abnormalities, exposure to exogenous and endogenous toxic factors during the intrauterine period of development. An important role in the occurrence of anomalies is caused by infectious diseases of the mother during pregnancy and environmental factors such as drugs, toxins, radiation, etc., which affect the fetus. The most severe changes are observed when exposure to harmful factors on the fetus in the first trimester of pregnancy. Among the most common infections are rubella, toxoplasmosis, syphilis, cytomegalovirus infection, herpes simplex and AIDS. To medicines and substances, which are the cause of the development of anomalies and congenital diseases of the retina, include thalidomide, cocaine, ethanol (fetal alcohol syndrome).

Retinal abnormalities include retinal coloboma, retinal dysplasia and hypoplasia, albinism, congenital hyperplasia of pigment epithelium, myelin nerve fibers, congenital vascular anomalies, phacomatosis.

Coloboma of the retina - the absence of retina in a restricted area. Usually it is associated with the coliboma of the iris and the choroid. Coloboma of the retina can be located in the center or on the periphery in the lower half of the eyeball. Its occurrence is associated with incomplete closure of the embryonic fissure. Ophthalmoscopically, the coloboma looks like a limited area of white oval or round shape with even edges, located close to or adjacent to the optic nerve disk. Where the retina and choroid are absent, the sclera is exposed. Coloboma can be combined with microphthalmus, skeletal anomalies and other defects.

Dysplasia (from Greek dis - violation, plasis - development) - an anomaly of retinal development during embryogenesis, expressed in violation of the normal ratio of cellular elements. This form refers to the non-retina of the retina - a rarely observed anomaly, the cause of which is the lack of invagination of the optical vesicle. Retinal dysplasia is a characteristic feature of trisomy 13 and Vocker-Warburg syndrome, combined with other malformations of the eye, cerebellum, and muscle tissue.

Albinism is a genetically determined disorder in the formation of the visual system associated with a change in the synthesis of melanin.

For patients with albinism, nystagmus, various refractive disorders in combination with astigmatism, decreased vision, poor ocular pigmentation, macular area dysplasia and violation of the optic nerve intersection are characteristic. Abnormalities of color vision and luminance sensitivity, as well as supernormal ERG and interhemispheric asymmetry of VEP, correspond to the described anomalies. Tyrosinase-negative albinism is due to the lack of synthesis of the enzyme tyrosinase and melanin pigment. Such patients have white hair and skin, they are not able to tan. The iris is light, easily translucent, the reflex from the fundus is bright pink and visible from a distance. Another form of this disease is tyrosinase-positive albinism, in which, on the contrary, the ability to synthesize melanin remains, but its normal accumulation is absent. The skin of these patients is slightly pigmented, but is capable of tanning, the hair is light or with a yellow tinge, visual disturbances are less pronounced.

Treatment of albinism does not currently exist. The optimal approach to assisting these patients is spectacle correction with the use of light filters to protect the eyes from the damaging effect of bright light.

Congenital hyperplasia of retinal pigment epithelium is manifested by focal hyperpigmentation. The grouped pigmented spots resemble a bearish trail. Foci of hyperpigmentation can be single and multiple. The retina around them is not changed. Foci of pigmentation rarely increase and are subjected to malignancy.

Myelin nerve fibers are referred to as developmental anomalies. In some manuals, they are described as anomalies in the development of the retina, in others - in the optic nerve.

Normally myelin coated optic nerve fibers usually end at the posterior margin of the trellis plate. Sometimes it extends beyond the disc of the optic nerve and passes to the nerve fibers of retinal neurons of the second order. Ophthalmoscopically myelinated nerve fibers look like white shiny radially arranged bands that run from the optic nerve disc to the periphery. These fibers may not be associated with the optic nerve disc. Usually, they do not cause any symptoms, but sometimes scotomas may appear in the field of vision.

Congenital vascular anomalies are manifested in the form of a clustered angioma, capillary hemangioma Gippel-Lindau, Coates disease, retinopathy of prematurity, cavernous hemangioma of the retina, milder aneurysms of Leber's retina, paraphoveal telangiectasias, capillary retinal hemangioma, etc.

Gasted-shaped angioma is a one-sided anomaly, characteristic ophthalmoscopic signs of which are a significant expansion and tortuosity of the arteries, veins and arteriovenous shunts. The combination of it with cerebral vascular pathology is called "Vaburn-Mason syndrome", in which central vision is reduced. As a rule, the disease does not progress. Treatment is not carried out.

Coates disease - congenital abnormalities of the vessels, including retinal telegalectasia, micro- and macro-aneurysms, which lead to exudation, and eventually to retinal detachment. Some authors refer to Coates's disease as a retinal vascular disease. The disease also has the name "external hemorrhagic retinitis." Coates disease is a one-sided disease, manifested in early childhood, more often (90%) in boys.

Deposits of solid exudate of bright yellow color are found in the subretinal space in the posterior pole of the eye. In the late stages of the disease develop cataracts, neovascular glaucoma, subatrophy of the eyeball. Moderately severe forms are represented only by telaegectasia.

Differentiate from tumor and other processes that can be masked by exfoliated retina and exudate, as well as from retinopathy of prematurity.

The aim of the treatment is obliteration of abnormal vessels to prevent exudation: laser photocoagulation and cryotherapy are performed.

With a common exudative detachment of the retina, surgical treatment is advisable.

Fakomatozy attributed to congenital malformations. They have characteristic systemic and ocular manifestations: the presence of hemangioma-like formations, a hamart or nodes. The phakomatosis includes the recombinase neurofibromatosis, tuberous sclerosis, Hippel-Lindau disease, characterized by an autosomal dominant type of inheritance, as well as a sporadic Sturge-Weber-Crabbe syndrome. The cause of the disease is a mutation of the tumor suppressor gene, which is identified with all the dominant types of the disease.

Neurofibromatosis Recklinghausen (NF-1) is characterized by the presence of a Schwann cell tumor, which often appears on the skin as a multiple fibroma (molluscum). The gene responsible for the development of type 1 neurofibromatosis is localized in the 17th chromosome of the 17qll.2 voxus. Diffuse neurofibromatous infiltration is the cause of deforming neuromatous elephantia. The diagnostic criterion is the presence on the skin of more than 6 spots of coffee color with milk (more than 1.5 cm).

Ophthalmic manifestations of type 1 neurofibromatosis are numerous and include plexiform neurofibroma of the eyelids and orbits, S-shaped ocular glen, congenital glaucoma (if the upper eyelid has neurofibromatous tissue), melanocytic hamartomas on the iris (Lish's nodules), hamartic infiltration of the choroid of the eyeball with corpuscle-like bodies, glioma of the optic nerve, astrocytic retina hamartoma, thickening and promising of the corneal nerves, conjunctival neurofibroma, pulsating exophthalmos, buf talm.

Hamartoma - a tumor that develops from embryonic tissue, the differentiation of which was delayed compared with the differentiation of the carrier. Cells that form hamartoma have a normal structure, but the density of cell populations and their ratio are abnormal. Melanocytic hamartomas (Lisha nodules) develop to skin manifestations, are observed on the iris in all adult patients and are a diagnostic criterion.

Plexiform neurofibroma is a tangle of intertwined, hypertrophied nerves that appear bulky due to the proliferation of Schwann cells and endonevral fibroblasts in the mucin intercellular substance.

Frequent complications of Type 1 neurofibromatosis are vascular disorders such as narrowing of the lumen of the vessels and their occlusion. Further, perivascular fibroglial proliferation develops. Characteristic features of retinal ischemia in type 1 neurofibromatosis are peripheral avascular zones, arteriovenous shunts, preretinal fibroglial membranes, optic disc atrophy.

Tumors leading to deformation of surrounding tissues and functional disorders are to be removed.

Type 2 neurofibromatosis is a rarely observed disease. A characteristic symptom is a bilateral schwannoma of the eighth pair (auditory nerve) of the cranial nerves. Ocular manifestations include combined retinal and pigment epithelial hamartomas, glioma, or meningioma of the optic nerve.

Hippel's disease - Lindau - a hereditary disease with gene localization in chromosome Sp25. Often, changes are found by chance when examining children about strabismus or regular check-ups. Retinal angiomas have the appearance of cherries with large convoluted feeding and draining vessels. These formations are called retinal hemangioblastomas because they are histologically similar to hemangioblastomas that develop in the cerebellum. In the retina, hemangioblastomas have endophytic or exophytic growth, the disk of the optic nerve and optic nerve can be involved in the process; often hemangioblastomas are combined with maculopathies. Other organs are involved in the pathological process. Along with retinal angiomatosis, kidney cystosis or renal carcinoma, pheochromocytoma, etc. Are detected.

Due to the violation of the permeability of the walls of the capillaries, sub- and intra-intestinal exudate containing lipids can accumulate in them. In the late stages of the disease, exudative retinal detachment develops. In the arteriovenous phase of PHAG, the accumulation of contrast medium in angiomas is noted, in the late phase, the increased permeability of fluorescein is determined, due to the inferiority of the vessels of the tumor.

Treatment: cryotherapy, laser coagulation, surgical removal of the tumor.

Tuberous sclerosis (Burne-ville disease) is a rarely observed disease with an autosomal dominant type of inheritance, caused by two genes localized in the 9th and 16th chromosomes. The classic triad of tuberous sclerosis is epilepsy, mental retardation and facial skin lesions (angiofibromas). On the fundus near the optic nerve disc, whiteish tumor-like formations resembling a mulberry berry are revealed. Astrocytomas formed on the optic nerve disk are called gigantic druses of the optic nerve. They can be mistaken for retinoblastoma.

Treatment is usually carried out in a neurological clinic. With the growth of neurological symptoms, patients die early.

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