Primary and secondary open angle glaucoma

The primary open-angle glaucoma without a visible glaucomatous lesion is called ocular hypertension (a condition in which the intralusional pressure is above 21 mm Hg). This condition should also be attributed to glaucoma. The development of glaucomatous lesions can occur with intraocular pressure above 21 mm Hg. St, and at lower its values. Nevertheless, the likelihood that this will happen increases with increasing pressure.

[1], [2], [3]

Causes of the open-angle glaucoma

The pathogenesis of open-angle glaucoma is associated with a disruption of the normal function of the drainage system of the eye, through which the outflow of fluid from it is carried out, in the drainage zone of the limbus, dystrophic and degenerative changes are always found. In the initial stage of the disease, these changes are minimal: the trabecular plates thicken, the intubecular gaps narrow, and especially the helmet canal. Subsequently, the trabecula almost completely degenerates, the cracks in it disappear, the canal helm and part of the collector canals overgrow. In the late stages of glaucoma, degenerative changes in the eye are secondary and are associated with an effect on the tissue of increased intraocular pressure. With open-angle glaucoma, the trabeculae move toward the outer wall of the helmet canal, narrowing its lumen. This condition is called the functional block of the venous sinus of the sclera. The blockade of the sinus arises more easily in the eyes with anatomical predisposition, i.e., in the forward position of the venous sinus of the sclera, the weak development of the scleral spur and the relatively posterior location of the ciliary muscle. All changes in the drainage system of the eye to a certain extent depend on nervous, endocrine and vascular disorders. Therefore, the primary glaucoma is combined with such diseases as atherosclerosis, hypertension, diabetes, and lesions of the podbugorkovoy region. The degree and nature of dystrophic changes in the drainage apparatus for glaucoma are determined by genetic factors. As a consequence, open-angle glaucoma is often family-related.

[4], [5], [6], [7]

Risk factors

The risk factors for primary open-angle glaucoma include elderly age, heredity, race (representatives of the Negroid race are 2 to 3 times more likely to suffer), diabetes mellitus, glucocorticoid exchange disorders, arterial hypotension, myopic refraction, early hyperopia, pigment dispersion syndrome.

[8], [9], [10], [11]

Symptoms of the open-angle glaucoma

Most often, open-angle glaucoma begins and progresses imperceptibly for a patient who does not experience any unpleasant sensations and consults the doctor only when gross visual impairments appear (developed or advanced stages), in these stages it becomes very difficult to stabilize the process, if at all perhaps.

With the open-angle form of glaucoma, it can be confused with cataract, leave the patient without treatment and allow the development of incurable blindness.

With cataracts, intraocular pressure is normal, and when examining transmitted light, the pink glow of the pupil is weakened and black strokes and spots of more intense opacities can be distinguished against it.

With glaucoma, intraocular pressure rises, the field of vision begins to progressively narrow from the nose, the glow of the pupil in transmitted light is bright pink (if there is no concomitant cataract), and the optic nerve becomes grayish, the vessels bend over its edge (glaucomatous excavation). The same changes are characteristic for open-angle glaucoma with normal intraocular pressure. In addition, this type of glaucoma is characterized by hemorrhages on the optic nerve disk, pericapillary atrophy, superficial excavation of the optic nerve disk, sometimes with a pale neuroretinal ring, gliose-like changes in the retina, and some changes in the conjunctival vessels. All these symptoms are determined by the ophthalmologist and indicate additional factors involved in the mechanism of glaucomatous lesions in this type of glaucoma. With glaucoma of normal pressure of the cerebrospinal fluid in the retrobulbar part of the optic nerve, acute hemodynamic disturbances (hemodynamic crises, lowering of arterial pressure at night, vascular spasms) and chronic disturbances of blood microcirculation in the optic nerve disk (venous discirculation, microthrombosis) are observed.

Treatment of the open-angle glaucoma

The slightest suspicion of glaucoma requires detailed examination in specialized offices or even in a hospital.

Patients with glaucoma should be on dispensary supervision with an ophthalmologist (visit the doctor 2-3 times a year, and if necessary, a bowl), which controls the field of vision, visual acuity, level of intraocular pressure, the state of the optic nerve. This allows us to judge the dynamics of the pathological process, change the medication regimen in time, and in the absence of normalization of intraocular pressure under the influence of drops, we recommend recommending a surgical treatment - traditional or laser. Only such a package of measures is able to help preserve visual functions for many years. Any antiglaucomal operation aims to only reduce intraocular pressure, i.e., in its essence is a symptomatic method of treatment. It does not involve the improvement of visual functions or the elimination of glaucoma.

Prevention

The basis for the prevention of blindness from glaucoma is the early detection of the disease. To this end, all people over forty years of age need to be instrumental in measuring intraocular pressure every 2-3 years. In those cases where there are patients with established glaucoma, their relatives should do this from the age of thirty-five, while it is desirable to assess the field of vision with a perimeter and examine the optic nerve disk.

[12], [13], [14], [15], [16]

Forecast

The prognosis for glaucoma with normal pressure is similar to that for glaucoma with increased blood pressure. In the absence of adequate, lowering intraocular pressure therapy, blindness may occur. However, the peculiarity of glaucoma with normal pressure is that, despite pronounced disorders of visual functions, cases of complete blindness are rare. This is due to the fact that with age, the role of vascular risk factors that cause this type of glaucoma (low blood pressure and violations of vascular regulation) is weakening.

[17], [18]