cataract
Introduction
Introduction to cataract Cataract is a disease that occurs in the lens of the eye. Any opacity of the lens can be called a cataract, but when the lens is lightly turbid, it does not significantly affect vision without being discovered or ignored. Into the ranks of cataracts. According to the survey, cataract is the most common cause of blindness and visual disability, and about 25% of humans suffer from cataracts. Mild opacity of the lens does not affect the visual acuity, and has no clinical significance. When the lens opacity causes vision loss, the clinically significant cataract is identified. In the epidemiological investigation, the lens is turbid and the visual acuity is reduced by 0.7 or less. index. Cataract is the leading cause of blindness and visual impairment in the world. It is more common in elderly people over the age of 50. As the population grows and ages, the visual impairment caused by cataracts will increase. Cataract blindness can cause blindness, and cataract surgery can be performed before visual acuity has been significantly impaired, which can significantly reduce blind and low vision patients. basic knowledge The proportion of illness: 0.003%--0.004% Susceptible people: no specific people Mode of infection: non-infectious Complications: vitreous hemocytosis cystoid edema
Cause
Cause of cataract
Any cause such as aging, genetics, local dystrophies, immune and metabolic abnormalities, trauma, poisoning, radiation, etc., can cause lens metabolism disorders, resulting in lens protein denaturation and turbidity, leading to cataracts. The disease can be divided into congenital and acquired:
Congenital cataract (30%):
Also known as developmental cataract, mostly exist before and after birth, mostly static type, may be associated with hereditary diseases, endogenous and exogenous, endogenous and fetal developmental disorders, exogenous are maternal or Congenital cataract is divided into anterior cataract, posterior cataract, orbital cataract and total cataract.
Acquired cataract (50%):
Lens opacity caused by systemic diseases or local eye diseases, abnormal nutrient metabolism, poisoning, degeneration and trauma after birth, divided into 6 types: 1 senile cataract, the most common, also known as age-related cataract, more common in 40 years old The above, and increased with age, related to multiple factors, such as the elderly metabolism is slow to occur degenerative diseases, others are thought to be related to long-term exposure to sunlight, endocrine disorders, metabolic disorders and other factors, according to the location of the initial turbidity can be divided It is divided into two major categories: nuclear and cortical. 2 complicated cataract (concurrent with other eye diseases). 3 traumatic cataracts. 4 metabolic cataracts. 5 radioactive cataracts. 6 drugs and toxic cataracts.
Prevention
Cataract prevention
1. Pay attention to the spirit of the camera: When you are in trouble, you should be broad-minded, keep your mood comfortable, and you must make anger, cultivate interest in raising flowers, raising birds, raising goldfish to cultivate sentiment, talk to young people, and be distracted. The attention of the matter, stimulating a strong life enthusiasm, can play a role in preventing and delaying the progress of the disease.
2. Strengthen eye hygiene, usually do not rub your hands, do not use unclean handkerchiefs, wipe your eyes, wash your eyes, use appropriate eyes to relax, sedentary workers should be 1 to 2 hours apart for 10 to 15 minutes, raise your eyes If you look far, or do eye exercises, you must have enough sleep and recover from fatigue in time.
3. Active prevention and treatment of chronic diseases, including eye diseases and systemic diseases, especially diabetes is most likely to be complicated by cataracts. It is necessary to control blood sugar in a timely and effective manner to prevent further development of the disease.
4. Diet should be rich in protein, calcium, trace elements, eat more foods containing vitamins A, B, C, D, usually eat more fish, can maintain normal vision, slow the progress of the disease.
5. Smoking is prone to cataract has been confirmed by practice, smoking should be quit early.
Complication
Cataract complications Complications, vitreous hemocytosis-like edema
Multiple complications can occur after cataract surgery, and symptomatic treatment must be based on the cause of each complication.
(1) For the shallow anterior chamber caused by leakage of the incision, it is recommended to re-sewn the incision; if the degree is light, the eye can be restored by pressure bandaging, sometimes the shallow anterior chamber can be restored, if the choroidal detachment is accompanied by incision leakage, it should be re The incision is sutured to form the anterior chamber; if the choroidal detachment is large, the posterior scleral incision drainage can accelerate the recovery of intraocular pressure and choroidal detachment; if the detachment range is small, there is no obvious incision leakage, which can strengthen anti-inflammatory, After a few days of pressure dressing, the detachment of pluripotency gradually disappears. In the early stage of pupillary block, a strong mydriatic agent can be used. Local application of corticosteroids can reduce inflammation or systemic hypertonicity. However, the most fundamental measure is to re-communicate the traffic before and after the room. Iris incision can achieve this goal, and YAG laser is more convenient for peripheral iris incision.
(2) Because the damage of the corneal endothelium is irreversible, once sustained corneal edema occurs, the corneal optical recovery depends on partial penetrating keratoplasty; for patients with inconvenient corneal transplantation, the local can pass the hypertonic agent, with Soft contact lens or remove the epithelial cell layer of the lesion area and conceal the conjunctival flap to relieve symptoms. Avoid contact between the instrument and the artificial lens in contact with the corneal endothelium, use viscoelastic to protect the corneal endothelium, avoid long-term washing of the anterior chamber; postoperative Dealing with contact between the vitreous and other tissues and the corneal endothelium as soon as possible can reduce the occurrence of postoperative persistent corneal edema to a large extent.
(3) A small amount of anterior chamber blood is naturally absorbed within a few days. If the blood is filled with the anterior chamber with high intraocular pressure, the anterior chamber should be washed immediately. When the blood volume of the glass is small, it can be absorbed. When the blood is large, the posterior vitreous resection should be performed. The treatment of epithelial anterior chamber is not effective and the prognosis is poor. Once diagnosed, the deep sclera near the incision should be removed immediately, and the proliferative epithelial tissue behind the cornea in the affected area should be frozen, the affected iris removed, frozen or excised. The ciliary body should be treated with anterior vitreous to ensure that the vitreous does not adhere to the cornea. Post-operative uveitis is generally controlled by corticosteroids, prostaglandin inhibitors and mydriatic agents, but it is necessary to find the cause at the same time. Etiology treatment.
(4) Once cataract surgery is suspected of endophthalmitis, the aqueous humor and vitreous should be immediately taken for bacterial or fungal culture and drug susceptibility testing, and the affected vitreous should be removed with a vitrectomy and injected into the vitreous cavity, vein and subconjunctival Antibiotics, postoperative glaucoma treatment should be treated with local and systemic antihypertensive treatment at the same time. When the intraocular lens position is abnormal, the conservative treatment is usually performed. If necessary, the intraocular lens should be taken out or replaced with intraocular lens, YA G laser capsule. Membrane incision is the simplest and most effective method for treating posterior capsule opacity. If an intraocular lens has been implanted, the intraocular lens should be avoided when laser incision. In addition, a puncture knife can be used to enter the eye from the flat part of the ciliary body. Turbid and thickened posterior capsule incision, indomethacin, corticosteroids may be applied to retinal complications such as cystoid macular edema, and retinal detachment is treated surgically.
Symptom
Symptoms of cataracts Common symptoms are non-vitreous lesions... Vision is often foggy, blurring, dark spots, enlarged lens, shrinking, visible, white, reflective, diplopia, eye, squinting, eyeball adjustment, reduction... Congenital iris-free eye Burn feeling
Bilateral, but the incidence of both eyes can be sequential, vision declines, sometimes visible dark spots can be seen in the bright background, due to changes in refractive power of different parts of the crystal, multiple vision, single eye double vision, increased myopia Clinically, senile cataract is divided into three types: cortical, nuclear and subcapsular.
1, cortical cataract (cortical cataract): crystal cortical gray turbidity as the main feature, its development process can be divided into four phases: initial stage, immature stage, mature stage, over-mature period.
2, nuclear cataract (nuclear cataract): crystal opacity from the embryonic nucleus, gradually extended to the adult nucleus, early yellow, with the turbidity increased, the color gradually deepened as deep yellow, dark brown yellow, the density of the nucleus increased, The refractive index increased, the patient often complained that the reduction of myopia or the increase of myopia, the early peripheral cortex is still transparent, therefore, the dilated pupils in the dark place increased visual acuity, while in the strong light, the pupil reduces the visual acuity but decreases, so generally do not wait for the cortex Surgery is complete turbidity.
3, posterior subcapsular cataract (posterior subcapsular cataract): due to turbidity in the visual axis, early impact on vision.
Examine
Cataract examination
Before cataract surgery, you should know whether the vitreous, retina, optic papilla, macular area and choroid have lesions. There is a correct estimate of visual recovery after cataract surgery. You can use A and B ultrasound to understand the presence or absence of vitreous lesions and retinal detachment. Or intraocular mass, can also understand the axial length and dislocation of the crystal position, electroretinogram (ERG) is of great value in the evaluation of retinal function, monocular cataract patients to exclude macular degeneration, visual impairment caused by visual path disorders, surgery It can be used as an evoked potential (VEP) test. In addition, a visual interferometer can be used to check the macular function of immature cataract.
Diagnosis
Diagnosis of cataract
Differential diagnosis:
It is congenital and acquired. (1) Congenital cataracts existed before and after birth, and a small part gradually formed after birth, mostly hereditary diseases, endogenous and exogenous, endogenous and fetal developmental disorders, exogenous The maternal or fetal systemic lesions cause damage to the lens. Congenital cataracts are classified into anterior cataract, posterior cataract, orbital cataract and total cataract. The first two require no treatment. The latter two require surgery.
(2) Acquired cataract is a lens opacity caused by systemic diseases or local eye diseases, abnormal nutrition metabolism, poisoning, degeneration and trauma after birth. It is divided into 6 types: 1 senile cataract, the most common, more common in 40 More than one year old, and increased with age, the cause is related to the slow metabolism of the elderly, and some people think that it is related to long-term exposure to sunlight, endocrine disorders, metabolic disorders and other factors. According to the location of initial opacity, it can be divided into nuclear. There are two major categories of corticalness, visual acuity and the location and density of opacity. The posterior cortex and nuclear opacity affect vision early. The treatment is mainly surgery. After operation, contact lenses can be worn, and intraocular lens can be operated simultaneously. Implantation. 2 complicated cataract (concurrent with other eye diseases). 3 traumatic cataracts. 4 metabolic cataract (due to endocrine insufficiency, such as diabetic cataract). 5 radioactive cataracts (related to X-rays, beta rays, gamma rays, etc.). 6 Drugs and toxic cataracts, if not treated in time, the whitening in the lens will become more and more serious, and eventually completely blurred, the lens nucleus disintegrates, so that vision is completely lost.
