1.What is cataract
The lens of the human eye is like the lens of a camera. If the lens becomes cloudy, you will not be able to see clear images. If the lens becomes cloudy, we cannot see clearly. We call it a cataract when its transparency decreases due to various causes of lens clouding. Initially, cataracts have little effect on vision, but as the clouding of the lens increases, vision gradually decreases and can eventually lead to blindness. The most effective treatment for cataract is surgery, and most patients can successfully recover their vision through surgery.
2.What are the causes of cataract?
The causes of cataracts are many, except for traumatic cataracts, congenital cataracts, metabolic cataracts, drug and toxic cataracts, which have more obvious causes. The common causes of senile cataracts are quite complex, and the pathogenesis has not been fully revealed so far, and is related to age, gender, race, geographical environment, diabetes, family genetic factors, drugs, nutrition, radiation exposure, smoking, severe diarrhea, hypertension, and renal disease.
Among them, increasing age is the most important risk factor for senile cataract. It has been confirmed that the incidence of cataract is relatively higher in highland areas and areas with more sunlight radiation because of long-term exposure to ultraviolet radiation, which can affect the redox process of the lens and cause degeneration and clouding of lens proteins, resulting in cataract. In addition, the occurrence of senile cataracts can be affected by the use of certain drugs, the nutritional status of the body and the general condition of the body.
Therefore, to prevent the occurrence and slow down the development of senile cataract, the easiest way is to reduce the exposure of ultraviolet rays to the eyes, pay attention to a reasonable diet, maintain good and balanced nutrition, and pay attention to the treatment of systemic diseases, such as diabetes, hypertension and kidney disease, which are all risk factors for senile cataract.
3.The best time for cataract surgery
With the increasing maturity of cataract surgery, there is no longer any technical difficulty in performing cataract surgery at any time. Cataract surgery can be performed when the damage to vision caused by cataract affects the patient’s normal life. Visual acuity does not fully represent the quality of a patient’s vision. Some patients can still have vision of 0.8 or more through the gap in the cataract, while their lives will still be affected due to the darkened visual field. Therefore, visual acuity is only one of the indicators for choosing the timing of surgery, and the decision of when to operate depends mainly on the patient’s needs.
Doctors do not recommend patients to wait for cataract to mature before surgery, because when cataract develops to the middle or late stage (such as swelling stage and over-ripe stage), if left untreated, many serious complications will arise, such as glaucoma and uveitis, which may lead to irreversible damage to vision. Therefore, cataract must be treated surgically when it develops to a certain degree.
4.What are the common surgical methods for cataract?
At present, cataract intracapsular extraction and cataract extracapsular extraction with large incisions have become history, and cataract extracapsular extraction with small incisions and cataract ultrasonic emulsification have become widely used surgical methods in clinical practice.
Cataract ultrasound emulsification surgery can be performed through an incision of about 2-3 mm, using an ultrasound emulsifier to crush and aspirate the lens nucleus and cortex. Its significant advantages are small surgical incision, fast healing, no need for sutures, small corneal astigmatism, and satisfactory vision can be obtained at early stage.
5.Is there an age limit for cataract surgery?
With the improvement of living standard, more and more elderly people need to have cataract surgery. There is no uniform age limit for cataract surgery. Some elderly people are in good health, with stable blood pressure and heart condition. Moreover, cataract surgery is currently very short, and most of them use dotted eye drops anesthesia (surface anesthesia), which causes very little pain, so most elderly patients can afford the surgery.
The ability to withstand cataract surgery does not depend on age, but on the patient’s physical condition.
6.What tests should be done before cataract surgery?
In order to ensure the safety of the surgery and the post-operative effect, adequate examination is needed before cataract surgery, including: eye examination and general examination.
The eye examination generally includes: visual acuity, intraocular pressure, corneal curvature, A-ultrasound and corneal endothelial count, among which the corneal curvature and A-ultrasound are for calculating the IOL to be implanted during surgery.
The whole body examination generally includes: blood and urine routine, liver and kidney function, infection disease screening, blood sugar and other laboratory tests, as well as blood pressure, electrocardiogram and other tests, the purpose of which is to understand the patient’s whole body condition and whether he/she can withstand cataract surgery.
7.What should patients do before cataract surgery
The preparation work before cataract surgery is very important. In addition to cooperating with the doctor for a series of eye and body examinations, the patient should also make physical and mental adjustments. Patients with systemic diseases should adjust their blood pressure, blood sugar, cardiovascular and cerebrovascular indexes to the best condition (blood pressure ≤160/90mmHg, fasting blood sugar ≤8mmol/l) under the guidance of internal medicine doctors. Pre-operative antimicrobial eye drops are routinely ordered. Cataract surgery patients can eat normally before surgery, but do not eat too much.
8. What is an IOL?
An IOL is a special lens made of synthetic materials to replace the lens itself. The shape and function of IOLs are similar to the lens of the human eye, and they are light in weight, have good optical properties, and are non-antigenic, inflammatory, carcinogenic, and biodegradable. After cataract surgery, the cloudy lens is removed and an IOL is implanted in the eye to replace the original lens so that external objects can be focused and imaged on the retina and the surrounding objects can be seen clearly.
Folding IOLs can fold the optical part of the IOL so that the IOL can be implanted through an incision half as small as that of a conventional IOL, resulting in faster recovery and less corneal astigmatism.
There are also many types of folding IOLs according to material, function and shape, and the price varies greatly. The doctor will work with the patient to choose the right IOL according to the patient’s needs and eye condition.