Cornea hypostasis
Contents:
Description:
Hypostasis of a cornea is among the most characteristic complications of contact correction of sight and arises owing to disturbance of corneal metabolism because of insufficient supply of a cornea with oxygen when carrying contact lenses.
Cornea Hypostasis symptoms:
Clinical signs of hypostasis of a cornea are the structural changes of its layers revealed at biomicroscopic examination of a cornea: emergence of epithelial microcysts (more than 20), cornea striya (vertical lines in a cornea stroma), cornea endothelium folds, and also increase in thickness and disturbance of transparency of a cornea that leads to misting and decrease in sight, deterioration in portability of contact lenses.
The compensatory mechanism at chronic hypostasis of a cornea is its vascularization — education in a cornea of network of blood vessels. This complication a long time proceeds without subjective symptoms and comes to light at control biomicroscopic inspection of the patient. At vascularization of a cornea the structure of a stroma is broken, there is cornea epithelium hypostasis. At deep vascularization hemorrhages and a penetration of lipids in a cornea stroma are possible. Therefore at a long current vascularization of a cornea can lead to disturbance of transparency of a cornea and decrease in sight.
Cornea Hypostasis reasons:
The main reasons for developing of a hypoxia and edematization of a cornea are neadkvatny selection (abrupt landing of a lens), the disturbance of the mode of carrying (prolonged without removal for the night carrying lenses with low gas permeability) or an insufficient kislorodopronitsayemost of contact lenses, and also deterioration in gas permeability of lenses owing to the long term of carrying a lens, emergence of deposits or dehydrations (drying) of material of a lens.
The risk of development of vascularization of a cornea increases at purpose of contact lenses in the mode continuous (without removal for the night) carrying at patients with the damaged cornea (after injuries, operative measures on a cornea) or with cornea dystrophy.
Treatment of Hypostasis of a cornea:
Clinical recommendations:
Use of contact lenses with high gas permeability. Reduction of time of continuous carrying lenses. Instillations of the moistening drops for contact lenses. At persistent vascularization of a cornea transition to rigid gas-permeable lenses.
