Glaucoma is an eye disease in which the intraocular pressure rises intermittently or continuously. Continuous high intraocular pressure can cause damage to all parts of the eye and visual function, and if left untreated, the visual field can be completely lost to blindness. Glaucoma is one of the three major blindness-causing eye diseases, with a total population incidence of 1% and 2% after the age of 45.
I. Etiology
Glaucoma is a serious eye disease that can lead to blindness due to increased intraocular pressure, which causes depression of the optic disc (once called the optic papilla) and visual field defects. The normal IOP is 10-21 mmHg (Schitz IOP meter), and more than 24 mmHg is considered pathological. Increased IOP can lead to visual impairment, with large, deep depressions in the optic disc and glaucomatous changes typically seen in the visual field. The longer the IOP increase lasts, the more severe the damage to visual function. The cause of increased IOP in glaucoma is a disruption of the dynamic balance of the atrial fluid circulation. A few of them are due to excessive secretion of atrial aqueous, but most of them are due to impaired atrial aqueous outflow, such as narrowing or even closing of the anterior chamber angle and trabecular sclerosis.
Clinical manifestations
There are four main types of glaucoma: congenital glaucoma, primary glaucoma, secondary glaucoma, and mixed glaucoma. The clinical manifestations and characteristics of various types of glaucoma are different, so early detection and early treatment should be achieved.
1, congenital glaucoma
According to the age of onset, it can be infantile glaucoma and juvenile glaucoma, and all glaucoma under 30 years old belong to this category. The cause of congenital glaucoma is the abnormal development of the anterior chamber angle during embryonic development, resulting in the obstruction of atrial fluid drainage, causing an increase in intraocular pressure.
(1) Infantile glaucoma is the most common form of congenital glaucoma in children aged 0 to 3 years. It is usually bilateral, but not always simultaneous, and some children have monocular disease. The clinical manifestation is the protrusion of the eyeballs after birth, which resembles the eyes of a cow, hence the name “bull’s eye”. There may be photophobia, lacrimation, rubbing of the eyes, eyelid spasms, cloudy corneas, agitated crying, poor diet or vomiting, excessive sweating, and other systemic symptoms. The key to the prognosis of this type of glaucoma is timely and correct diagnosis, because the wall of the pediatric eye is developing, early detection and early treatment is beneficial to the prognosis of the child.
(2) Juvenile glaucoma is similar to open-angle glaucoma in that the clinical manifestations are between the ages of 3 and 30. In recent years, this type occurs in myopic patients, and there is a rising trend of incidence. 90% of patients do not show typical glaucoma symptoms.
2.Primary glaucoma
According to the morphology of the anterior chamber anterior angle and the urgency of the onset, it is divided into acute and chronic closed-angle glaucoma, open-angle glaucoma, etc.
(1) Acute closed-angle glaucoma Acute closed-angle glaucoma occurs when the atrial angle in the eye is suddenly narrowed or closed, and the atrial fluid cannot be discharged in time, causing the atrial fluid to fill up and the intraocular pressure to rise sharply. It occurs mostly in middle-aged and elderly people, accounting for 90% of those over 40 years of age, with a higher incidence in women and a male to female ratio of 1:4. The onset of the disease is fierce, the symptoms are mild and dramatic, and the anterior chamber is narrowed or completely closed at the onset, showing sudden onset of severe eye distention, headache, sharp loss of vision, hardness of the eye like a stone, conjunctival congestion, nausea, vomiting, constipation, and elevated blood pressure. No light perception, at this time is called “fulminant glaucoma”. However, some patients are more tolerant of pain and only show orbital and ocular discomfort, or even no symptoms in the eye, but the pain is transferred to the forehead, ear, maxillary sinus, teeth, etc. Acute angle-closure glaucoma is actually due to the repeated extension of chronic angle-closure glaucoma.
(2) The age of onset of chronic closed-angle glaucoma is 30 years or older. This type of attack generally has obvious triggers, such as emotional excitement, visual fatigue, eye and brain overuse, long-term insomnia, habitual constipation, women during menstruation, or improper local or systemic medication can trigger, manifested as eye dryness, fatigue, discomfort, distension, blurred vision or vision loss, rainbow vision, dizziness and pain, insomnia, increased blood pressure, which can be relieved after rest. Some patients can go blind without any symptoms. On examination, IOP can be normal or fluctuating, or not too high, 20-30 mmhg, and the fundus can be normal in the early stage, and this type is most easily misdiagnosed. With such repeated attacks, once the anterior chamber angle is closed by adhesions, fulminant glaucoma can be formed.
There are four types of early symptoms: frequent eye fatigue and discomfort. The eyes are often sore and swollen, which is relieved after rest. Blurred vision, myopia or presbyopia suddenly deepens. The eyes often feel dry.
(3) Primary open-angle glaucoma occurs mostly in people over 40 years old, 25% of patients have a family history, most patients have no obvious symptoms, some have no discomfort until blindness, and the anterior chamber angle is open during the attack.
3.Secondary glaucoma
Glaucoma caused by ocular and systemic diseases are all in this category, and the causes are quite complex and varied, only the most common types of secondary glaucoma are briefly described.
(1) refractive error (i.e. myopia, hyperopia) secondary glaucoma due to refractive system derangement, ciliary muscle dysfunction, imbalance of atrial fluid secretion, coupled with the iris root compression of the anterior chamber angle, atrial fluid drainage is blocked, so causing an increase in intraocular pressure, the clinical characteristics of such patients is the symptoms of self-conscious visual fatigue or no obvious discomfort, wearing glasses can not correct vision, easy to misdiagnosis.
(2) Intraocular inflammation of the cornea, conjunctiva, and uveitis secondary to glaucoma causes atrial aqueous clouding, ciliary muscle, iris, and corneal edema, shallowing of the atrial angle or pupil adhesion, and obstruction of the trabecular meshwork, which prevents normal drainage of atrial aqueous and causes IOP elevation.
(3) Cataract secondary glaucoma crystal clouding in the development process of edema expansion, or translocation resulting in anterior chamber relative narrowing, atrial aqueous discharge obstruction, causing IOP elevation, once the cataract surgery, soon optic nerve atrophy and blindness.
(4) Traumatic glaucoma atrial angle tear, iris root break, or anterior chamber blood accumulation, vitreous blood accumulation, retinal shock, so that atrial aqueous secretion, discharge pathway is blocked, secondary to glaucoma optic nerve atrophy.
4.Mixed glaucoma
More than two kinds of primary glaucoma exist at the same time, and the clinical symptoms are the same as each type of combined type.
III. Examination
1.Application of ultrasound biomicroscopy
This technology can record the anatomical structure and physiological function of the anterior segment of the living human eye in a natural state without interference, and can make quantitative measurements, especially for the morphology of the ciliary body, peripheral iris, posterior chamber morphology and physiopathological changes in real-time records, providing valuable information for the diagnosis and treatment of primary closed-angle glaucoma, especially primary chronic closed-angle glaucoma.
2.Confocal laser scanning detector lens
The machine adopts the low-energy radiation scanning technology, real-time image recording and computer image analysis technology, through the confocal laser fundus scan, it can obtain high-resolution, high-contrast retinal tomography images through the lightly clouded refractive interstitium, and can accurately record and quantitatively analyze the distribution of optic nerve fibers, stereoscopic images of the optic disc, and can simultaneously check the blood flow status of the optic disc region and complete local visual field and electrophysiological examination. It has important value for the early diagnosis, disease staging and prognosis analysis of glaucoma.
3.Quantitative static visual field and graphic visual evoked potentials
When a typical visual field defect occurs in glaucoma, the loss of optic nerve fibers may have reached 50%. Computerized automatic visual field meter provides the basis for the earliest diagnosis of glaucoma by detecting the change of visual threshold. Graphic visual electrophysiological PVEP and PE-RG examination, which have certain sensitivity and specificity in glaucoma, can significantly improve the early detection rate of glaucoma if the above two examinations are combined.
IV. Diagnosis
If chronic simple glaucoma can be diagnosed early, it is extremely important to protect the visual function, and the following points are helpful for early detection and diagnosis.
1. Family history
Family members with a history of glaucoma and who feel headache, eye swelling and visual fatigue, especially those who have presbyopia earlier, or elderly people who frequently change their presbyopic glasses, should go to the ophthalmology examination in time and have regular review.
2.Check the intraocular pressure
In the early stage of glaucoma, the IOP is often unstable, and the IOP may rise for only a few hours in a day, therefore, measuring the 24-hour IOP curve is helpful for diagnosis.
3.Fundus changes
Early on, the optic disc may not change significantly, but as the disease develops, the physiological depression of the optic disc gradually expands and deepens, and finally reaches the edge, forming a typical glaucomatous cup-shaped depression, and the damage to the retinal nerve fiber layer adjacent to the optic disc is the basis of the visual field defect, which appears before the optic disc or visual field changes, so it can be used as one of the early diagnostic indicators of open-angle glaucoma. .
4.Check the visual field
Visual field is an important test for the diagnosis of open-angle glaucoma, which will show visual field defects when pathological changes occur in the optic disc.
V. Differential diagnosis
The acute attack of acute closed-angle glaucoma is accompanied by severe headache, nausea, vomiting, etc. Sometimes the ocular symptoms are ignored and misdiagnosed as acute gastroenteritis or neurological disease, and the acute attack is easily confused with acute iridocyclitis or acute conjunctivitis, which needs to be differentiated.
VI. Complications
Acute closed-angle glaucoma is often combined with nausea, vomiting, fever, chills and constipation, etc. A few patients may have diarrhea. Chronic closed-angle glaucoma is often accompanied by visual blindness and iris vision.
VII. Treatment
1.Treatment principles
Glaucoma is one of the main causes of blindness in China, and the damage to visual function caused by glaucoma is irreversible and the consequences are extremely serious. Generally speaking, glaucoma cannot be prevented, but with early detection and reasonable treatment, most patients can maintain useful visual function throughout their lives. Therefore, the prevention of glaucoma must emphasize early detection, early diagnosis and early treatment.
2.Treatment measures
(1) Injection of vitamin B can be injected with vitamin B, which has certain curative effect.
(2) Laser therapy can be tried before taking other surgical procedures if the condition cannot be controlled by medication. New tests have shown that laser therapy is effective for wide-angle glaucoma. This is done by irradiating the iris with a laser to relieve eye pressure.
(3) Nutrient supplementation.
(4) Surgical treatment.
Glaucoma patients are advised to actively seek early and effective treatment to minimize damage to visual function.