What Is Glaucoma?

Glaucoma is a group of diseases characterized by atrophy and depression of the optic nipples, visual field defects, and decreased vision. Pathologically elevated intraocular pressure and insufficient blood supply to the optic nerve are the primary risk factors for the disease. Sex is also related to the occurrence and development of glaucoma. Obstruction of any part of the aqueous humor circulation pathway can lead to pathological changes caused by increased intraocular pressure, but some patients present with normal intraocular pressure glaucoma. Glaucoma is one of the three major blindness disorders that cause blindness in humans, with a prevalence of 1% in the general population and 2% after the age of 45. Clinically, glaucoma is classified into three categories: primary, secondary, and congenital according to the etiology, angle of the room, and tonometry.

Basic Information

English name

glaucoma

Visiting department

Ophthalmology

Common causes

Various factors cause increased intraocular pressure due to aqueous circulatory disorders

Common symptoms

Eye swelling, eye pain, photophobia, tearing, headache, sharp vision loss, etc.

Causes of glaucoma

Pathologically elevated intraocular pressure is a major risk factor for glaucoma. Increased intraocular pressure causes optic nerve damage through two mechanisms of mechanical compression and optic nerve ischemia. The longer the increase in intraocular pressure, the more severe the visual impairment. The cause of the increased intraocular pressure in glaucoma is the disruption of the dynamic balance of the aqueous humor circulation. A few due to excessive secretion of aqueous humor, but most still have obstacles to the outflow of aqueous humor, such as narrowing or even closing of the anterior chamber angle, trabecular sclerosis and so on.

Elevated intraocular pressure is not the only risk factor for the onset of glaucoma. Some patients with normal intraocular pressure have undergone typical glaucoma pathological changes, and some patients with glaucoma have controlled intraocular pressure, but the optic nerve damage is still developing, indicating that there are other factors. Related to the onset of glaucoma, such as local anatomy of the eyeball, age, ethnicity, family history, myopia, cardiovascular disease, diabetes, and abnormal blood rheology.

Clinical manifestations of glaucoma

Primary glaucoma is classified into closed-angle glaucoma and open-angle glaucoma based on the state of the anterior chamber angle when the intraocular pressure is elevated, and closed-angle glaucoma is divided into acute angle-closure glaucoma and chronic angle-closure type according to the acute onset of the disease. glaucoma.

Acute angle-closure glaucoma

The occurrence of acute angle-closure glaucoma is caused by the sudden narrowing or closing of the angle of the eye in the eye, and the aqueous humor cannot be discharged in time, causing the aqueous humor to be full and the intraocular pressure to rise sharply. It is more common in middle-aged and elderly people, accounting for 90% of people over the age of 40. The incidence of females is high. The ratio of males to females is 1: 4. The onset is fierce and the symptoms are sharp. There may be transient or repeated small episodes before the onset of acute onset. Fog vision, rainbow vision, with pain in the forehead or sore nose. At the time of the onset, the anterior chamber was narrow or completely closed, showing sudden onset of severe eye swelling, eye pain, photophobia, tears, headache, sharp vision loss, hard eyes such as stones, conjunctival congestion, and systemic symptoms such as nausea and vomiting. After an acute attack, it can enter the chronic period of continuous damage to the optic nerve, until the optic nerve is severely damaged, and the vision is reduced to the absolute period of no light perception and irreparable.

2. Chronic angle-closure glaucoma

Age of onset is over 30 years. This type of attack usually has obvious causes, such as emotional excitement, visual fatigue, excessive use of eyes and brain, long-term insomnia, habitual constipation, women during menstruation, or local or systemic improper medication can be induced, manifested as the eye Dryness, fatigue and discomfort, soreness, blurred vision or decreased vision, rainbow vision, dizziness, insomnia, increased blood pressure, can be relieved after rest. Some patients can go blind without any symptoms. The intraocular pressure may be normal or fluctuating, or not too high during the examination, 20-30mmhg, and the fundus can be normal early. This type is most likely to be misdiagnosed. Such recurrent attacks, once the adhesion of the anterior chamber angle is closed, violent glaucoma can be formed.

There are four early symptoms: often feel eye fatigue and discomfort. The eyes are often sore and will ease after resting. blurred vision, myopia or presbyopia suddenly deepened. The eyes often feel dry.

3. Primary open-angle glaucoma

It usually occurs in people over 40 years of age. 25% of patients have a family history. The vast majority of patients have no obvious symptoms, often the disease progresses to advanced stages, and is only noticed when the visual function is severely impaired. The corner is always open.

Glaucoma examination

1. Basic inspection items

(1) IOP The normal IOP range is 10 to 21 mm Hg. If the IOP exceeds 21 mm Hg, or if the difference in intraocular pressure is greater than 5 mm Hg, or if the IOP difference is greater than 8 mm Hg in 24 hours, It is a pathological increase in intraocular pressure. There are many methods for measuring intraocular pressure, and it is generally accepted that Goldmann's applanation accuracy is relatively best.

(2) Angle of the room The angle of the angle of the opening or closing of the angle can be directly observed through the angle of the microscope to distinguish between angle-type and closed-angle glaucoma.

(3) Visual field Visual field inspection is one of the most important tests for diagnosis and follow-up of glaucoma treatment effects, including central field vision and peripheral field inspection.

(4) Optic disc Observe the size of the "cup-disc ratio C / D", the presence of notches along the disc, the hemorrhage of the optic disc, and the defect of the retinal nerve fiber layer through the method of fundus mirror, slit lamp front mirror or fundus photography. Wait.

2. Application of ultrasound biological microscope

This technology can dynamically and statically record the anatomic structure and physiological functions of the anterior segment of living human eyes in a natural state without interference, and can make quantitative measurements, especially the morphology of the ciliary body, the surrounding iris, the morphology of the posterior chamber, and the physiology and pathology. The changes are recorded in real time, which provides extremely valuable data for the diagnosis and treatment of primary angle-closure glaucoma, especially primary chronic angle-closure glaucoma.

3. Confocal laser scanning ophthalmoscope

The machine uses low-energy radiation scanning technology, real-time image recording and computer image analysis technology. Through confocal laser fundus scanning, it can pass through slightly opaque refractive interstitials to obtain high-resolution, high-contrast retinal tomographic images. Accurately recording and quantitatively analyzing the distribution of optic nerve fibers and stereoscopic images of the optic disc, and can simultaneously check the blood flow state of the optic disc area and complete local visual field and electrophysiological examinations, which are of great value for the early diagnosis, stage of disease and prognostic analysis of glaucoma.

4. Quantitative static visual field, graphic visual evoked potential

When glaucoma has a typical visual field defect, the loss of optic nerve fibers may have reached 50%. The computerized automatic perimeter provides a basis for the earliest diagnosis of glaucoma by detecting changes in visual threshold. Graphic visual electrophysiology PVEP and PE-RG examinations have certain sensitivity and specificity in glaucoma. Can significantly improve the early detection rate of glaucoma.

Glaucoma diagnosis

Acute angle-closure glaucoma

According to the typical history, symptoms, and eye signs, diagnosis is not difficult, and angle angle examination shows that angle closure is an important diagnostic basis. Care should be taken to distinguish it from acute iridocyclitis.

2. Chronic angle-closure glaucoma

Eye swelling headache, visual fatigue, rainbow vision and fog vision are often the symptoms, especially in the evening or in the dark, when the mood fluctuates. Examination of moderate intraocular pressure, shallow peripheral anterior chamber, moderately narrow angle of the chamber, typical glaucomatous optic disc depression at the fundus, and varying degrees of glaucoma visual field defect.

3. Primary open-angle glaucoma

In the early stage, there are many unconscious symptoms. If the ophthalmological examination reveals that there are more than two of the three items: increased intraocular pressure, optic disc damage, and visual field defect, gonioscopy shows that the angle is open, and the diagnosis can be made initially.

Glaucoma Treatment

Treatment principle

Glaucoma is one of the main causes of blindness in our country, and the visual function damage caused by glaucoma is irreversible and the consequences are extremely serious. In general, glaucoma cannot be prevented, but with early detection and reasonable treatment, most patients can maintain useful visual function throughout their lives. Therefore, blindness prevention for glaucoma must emphasize early detection, early diagnosis, and early treatment. The main purpose of treatment is to reduce intraocular pressure, reduce ocular tissue damage, and protect visual function.

2. Treatment measures

(1) Acute angle-closing glaucoma. Acute onset of topical frequent miotics should be used in combination with -adrenergic blocker eyedrops and oral carbonic anhydrase inhibitors to reduce intraocular pressure rapidly. After the intraocular pressure is reduced and the inflammatory response is controlled, further laser resection or other anti-glaucoma surgery is considered.

(2) Chronic angle-closure glaucoma can be treated locally with a miotic agent or -adrenergic blocker in the early stage. If the drug does not control intraocular pressure or has obvious optic nerve damage, filtering surgery is needed.

(3) Primary open-angle glaucoma can be tried with medication first, and 1 to 2 eye drops can be used to control intraocular pressure at a safe level, and regularly reviewed. Drug treatment is not ideal with laser treatment or filtering surgery. The most commonly used filtering surgery is trabeculectomy.

(4) Congenital glaucoma. Infants and young children are mainly treated by surgery, and can be treated by angulation and trabeculotomy. Adolescent type can be the same as open-angle glaucoma. When drug treatment cannot be controlled, trabecula can be used. Incision or trabeculectomy.

(5) Secondary glaucoma While treating the primary disease, IOP treatment should be performed. If the IOP control is not satisfactory, corresponding anti-glaucoma surgery can be done for the secondary cause.