Birth defects of the lens

The lens is a transparent body in the form of a biconvex lens. The imaginary line connecting the anterior and posterior poles of the lens is called the axis of the lens. The normal lens does not have blood vessels. In the eyeball, it is suspended by special structures, numerous fibers of which attach to the anterior and posterior capsules of the lens in the region of the equator. The capsule of the lens is a membrane that surrounds it. The lens is continuously growing. It is surrounded by moisture and uses it as a source of nutrients and as a "shell" for waste of its vital activity. In children, the lens contains 65% water and soluble proteins.

Congenital aphakia - absence of the lens - is extremely rare. Congenital aphakia is divided into primary and secondary. With primary aphakia, even the lens is not laid in the process of intrauterine development of the child. With secondary aphakia, the developing lens undergoes spontaneous resorption. Both types of aphakia are usually combined with other eye anomalies.

Lenticonus and Lentiglobus. Lenticonus - conical deformation of the anterior or posterior surface of the lens. The posterior lenticonus is more common than the anterior one. This pathology is usually one-sided. With a lentiglobus, a spherical deformation of the lens surface is observed. The posterior lentiglobus occurs more often than the anterior, and is more often combined with the opacity of the posterior pole of the lens. Deformation of the anterior or posterior surface of the lens, as a rule, leads to a decrease in visual acuity and may be the cause of amblyopia development.

The columboma of the is an anomaly of its shape. Primary coloboma is a wedge-shaped lens defect, which occurs as an isolated anomaly. Coloboma of the lens can be combined with a vascular coloboma. In the areas adjacent to the coloboma, a clouding or thickening of the capsule of the lens is possible.

Microspherofakia is an anomaly in which the crystalline lens diameter is reduced and the lens has a spherical shape. The spherical shape of the lens leads to an increase in the refractive force, and as a result, the patient has high-degree myopia. The spherical lens can block the pupil and cause the development of glaucoma. Microspherophagia is more often observed in the syndrome of Weil-Markezani. Patients with this syndrome have a small growth, short, "chopped off" fingers and wide brushes with reduced mobility of the joints.

Aniridia is a partial or almost complete absence of the iris. This is a rare syndrome that can be combined with diffuse opacification of the superficial layers of the cornea, glaucoma, underdevelopment of the yellow body( see above) and the optic nerve, as well as with involuntary movements of the eyeballs. An aniridia is almost always bilateral, two-thirds of all cases are familial, and one-third is the first occurrence of an anomaly of development. At a birth at children with an aniridia the combination with a clouding of a lens is possible or probable. Lens clouding develops in 50-85% of patients with aniridia during the first 20 years of life.