Koloboma: description of the disease, causes and treatment

Koloboma - a defect in the membranes of the eye (retina, iris, optic nerve, eyelid, vascular membrane), manifested as the absence of their part.Most pathology is innate, but can be acquired. In the case of intrauterine disorders, the anomalous structure of the eye membranes is usually accompanied by other defects - a cleft of the hard palate, a hare lip. More details about the types of pathology, the causes of its appearance, the main symptoms and methods of treatment further.

Definition of disease

Koloboma is a pathology of a polyethological nature, for which isolated or combined splitting of the iris, vascular membrane, retina of the optic nerve or eyelid is characteristic.The main clinical manifestation of all forms of colobomas is a drop in visual acuity, pronounced pain, asthenopic complaints. There are no conservative methods for therapy of colobomas - at the moment the disease is treated only surgically.

The term Koloboma appeared in 1821. The word in Greek means "the missing part".

Cases of congenital colobomas in the population are diagnosed in the amount of 0.5-0.7 per 10000 newborns. The most common is the coloboma of the iris (: 000). Women and men are affected equally.

Leaders in the prevalence of colobomas - China, the United States and France.

Types and Classifications

Coloboma can affect the various structures of the eye, although the iris is most often affected. Other types of pathology depending on the site of localization:

• choroid(damage to the choroid);
• chorioretinal(combination of a defect in the retina and the vascular membrane);
• retinal damage;
• ciliary body defects;
• damage to the vitreous body;
• changes in eyelids.

The rarest forms of colobomas are defects in the optic nerve and lens.

Depending on the extent of the spread of the disease occurs:

• isolated(defect of a certain department);
• combined(defeat of several parts of the eye);
• complete(if all the shells of the eye are affected);
• one- or two-sided(depending on whether one eye is damaged or both).

Also, the colonies are typical and atypical. In the second case, the flaw can go beyond the description of pathology in terms of character, localization.

Causes

There are two reasons for the development of colobanks:

• Congenital- appears as a result of the effect on the rudiments of the eye of various intrauterine factors, leading to improper closure of the embryonic fissure.
• Acquired- develops due to injuries, necrosis of tissues, after operations.

  Coliboma of the iris of the eye

Acquired coloboma is a frequent postoperative defect.

Symptoms

The symptomatology of colobolics depends on which shells are affected and when their deformational changes began. With the acquired coloboma of the eye, the muscles together with the pupil do not contract, since it does not allow them to do the affected area of ​​the pupillary sphincter. With congenital anomalies, the pupil contracts, but does not take the required dimensions.

When the iris is damaged, a pronounced cosmetic defect is noted - a spot having the shape of a keyhole or a pear.The visual acuity in this case does not change much, but the patient begins to complain not blinding - it arises as a result of the inability of the eye to regulate the amount of rays arriving on the retina. The result is a violation of the function of light perception. When the vascular membrane is damaged, scotoma - darkened areas are formed. If the process affects both eyes, nystagmus appears.

Symptoms in the coloboma of the optic nerve depend on the extent of the lesion.With an isolated defect, vision can remain normal, but if splittings of other structures or microphthalmos join it, development of blindness is possible. The clinical picture resembles myopic-type astigmatism.

Congenital coloboma of the optic nerves is noted in the syndrome of Down, Edwards, Goldenhara.

The isolated defects of a retina in any way do not show itself - complaints appear only after development of secondary complications.Coliboma of the ciliary body disrupts the accommodation of the eye, and the patient begins to have difficulty with the examination of closely located objects.When the lens is damaged, refractive functions suffer.

Possible complications

Congenital splitting of vascular membranes is the main cause of blindness and visual impairment in childhood. The progress of the optic nerve colonies causes macular edema, rupture, retinal detachment. With defeat of the iris, pathology of light perception develops. Coloboma of the lens is often complicated by secondary conjunctivitis.

Diagnostics

Specific diagnosis of colobomas is determined by taking into account the type of lesion - it can include visual examination, ophthalmoscopy, visometry, biomicroscopy, ultrasound (B-mode), CT and MRI.So for the diagnosis of the colophony of the iris, a visual examination will suffice, and to distinguish a congenital defect from acquired is used by exposure to a light beam (congenital pathology is reduced along with lens). Ultrasound biomicroscopy shows that the congenital form is combined with ciliary hypoplasia. Visometry allows to assess the degree of visual acuity reduction.

MRI

To diagnose "coloboma of the iris it is enough to conduct a visual inspection.

Coloboma of the optic nerve is diagnosed with the help of ophthalmoscopy- it is possible to assess the degree of increase in the diameter of the nerve, determine the presence of light depressions of a rounded shape. Computer tomography reveals the deepest defects of the posterior pole of the eyeball, and MRI - hypoplasia of the optic nerve in the intracranial department.

Do you need histology in coloboma? If the doctor wants to confirm the presence or absence of concentrically oriented smooth muscle fibers, then yes.

With defects of the choroid, ophthalmoscopy is performed, revealing the formation of white(usually they are located in the lower parts of the fundus). Visometry is necessary for the detection of myopia, and biomicroscopy is the splitting of the lens.

Treatment

Surgical tactics are the only way to treat colobomas at the moment. Basic ways:

• peritomia;
• collagenoplasty;
• laserocoagulation;
• vitrectomy.

  Laser Coagulation Procedure

The method is selected taking into account the form of the disease, the affected area and the degree of defect.If the iris has suffered, besides it is not strong, surgical correction is not necessary - it is enough will limit the arrival of light with the use of dark contact lenses or special mesh points. When the vision is reduced, peritomy is made with the cross-linking of the edges of the iris, the collagenous plastic is able to stop the defect (a special collagenous structure prevents the spread of the defect).

Laser coagulation is indicated for lesion of the optic nerve with the formation of the subretinal neovascular membrane.If vision decreases to 0.3 diopters and is accompanied by macular detachment of the retina, an operative removal of the vitreous humor is also performed.

The only way to correct the defect of the eyelid is blepharoplasty.

Chorioretinal coloboma requires internal drainage through an intermediate membrane followed by laser photocoagulation of the retina around the marginal zone.For the treatment of pronounced lens colonies, it is necessary to remove and install the intraocular lens.

Conduction of blepharoplasty

Prevention

Preventive measures of colobomas do not exist, but it is possible to prevent the development and aggravation of pathological changes.In case of primary disturbances, the patient must visit the ophthalmologist twice a year and observe his prescriptions. Distortion of light perception requires timely correction by wearing sunglasses or darkened contact lenses.

Video

conclusions

Koloboma - defective changes in the retina, iris, optic nerve, eyelid or choroid of the eye.Pathology can be congenital and acquired, affecting one or two eyes. In the absence of treatment complications develop. The only way to treat colobolics today is a surgical operation.

Also read about heterochromia, a congenital pathology of the eye, characterized by a different color of the iris.