Glaucoma is a chronic eye disease causing high intraocular pressure, either periodic or constant, atrophy of the optic nerve (glaucomatose excavation). It also causes changes in the visual field. For instance, glaucomas can be primary, secondary and congenital.
It impairs the circulation of aqueous moisture and causes heightened intraocular tension. As a result of subsequent trophic changes in the eye tissues, high intraocular pressure develops. The impairment of vision happens as a result of the atrophy of the retina and optic nerve functional elements. The disease is typical of people older than 40 years of age. In the case of secondary glaucoma, changes in the intraocular liquid outflow tracts resulting in heightened intraocular tension.
In the case of congenital glaucoma, high intraocular pressure mainly arises from the impaired intraocular liquid outflow because of the mesoderm tissue blocking the angle of the forward chamber. There are two basic forms of primary glaucoma distinguished – open-angle and closed-angle. Disease development is usually latent and hidden for the patient.
Patients, as a rule, have no subjective sensations. However, in some instances, they may complain of a feeling of fullness in the eyes, headaches, misting of vision and iridisation. Visual changes in the eye are scarce. An examination may reveal the expansion of the forward ciliary arteries (the cobra symptom). Besides, biomicroscopy may show dystrophy of the retina and solution of the eye pigmentary edge continuity. Gonioscopy also exhibits that the angle is open.
In the case of closed-angle glaucoma, patients complain of pain in the eye and headaches, misting of vision, iridisation and stagnation in the forward eye segment. The disease begins with an acute or subacute attack.
The cornea is hydropic; the chamber is small; the pupil is mydriatic. The iris may also be hydropic. Besides, synechias and goniosynechias may form. Gonioscopy exhibits that the angle is completely closed.