Cataracts are caused by the clouding of the lens in the eye from transparent to opaque, preventing light from entering the eye and thus affecting vision. The initial clouding has little effect on vision, but gradually worsens, significantly affecting vision or even blindness. Many people who have cataracts think that they are presbyopia. In fact, cataracts are the leading cause of blindness in China.
Age-related cataracts, also known as age-related cataracts, are mostly seen above the age of 40 and increase with age. The cause is related to slow metabolic degeneration in the elderly, and some people think it is related to long-term exposure to sunlight, endocrine disorders, metabolic disorders and other factors.
A. The difference between cataract and pterygium Some elderly cataract patients often ask President Zhou if cataract is a white obscuration growing on the surface of the eye? Dr. Zhou says that this is actually a confusion between cataract and pterygium. A cataract is a clouding of the lens in the eye, while a pterygium is a degenerative tissue that grows on the cornea (commonly referred to as the black eye), so cataracts are usually invisible to the naked eye and can only be diagnosed through an instrumental examination at a hospital.
Cataracts are most common in the elderly, so age-related cataracts are usually characterized by progressive loss of vision and may include hyperopia and monocular diplopia. If the clouding occurs in the periphery of the lens in the early stage, it does not affect the vision in the early stage, and only when the clouding develops in the central part does it cause vision loss; if the clouding of the lens is mainly nuclear, there will be an increase in myopia and a decrease in presbyopia, which is often regarded by the elderly as “rejuvenation”. “If the clouding occurs in the central posterior capsule, such patients often feel that vision is poor in the sun, but in the indoor vision is better.
It is understood that no less than dozens of drugs are commonly used clinically, with eye drops or oral Chinese and Western medicines, but none of them have a definite therapeutic effect. The only way to restore vision is to remove the cataract through surgery and implant an artificial lens at the same time, which is commonly used clinically at present is ultrasonic emulsion extraction.
B. How to choose the timing of surgery At present, due to the continuous development of surgical technology, cataract does not need to wait until it is fully mature before surgery. On the contrary, proper advancement of surgery can effectively prevent the occurrence of glaucoma caused by mature cataract in some patients and also avoid delaying the treatment of some patients with fundus disease. Each patient has different vision requirements, for example, a rural lady and a university professor have different vision requirements, so when the vision loss caused by cataract has affected your daily life and work, you can consider surgery.
The incision of the currently used ultrasonic emulsion extraction is only about 1.8-3.0mm. Only a folding IOL can be implanted into the eye through such a small incision, and nowadays, a blade-free surgery (femtosecond laser-assisted cataract surgery) is more precise and safe with faster recovery. There are also many types of folding IOLs to choose from, such as aspheric, astigmatism correction and multifocal IOLs that take into account both distance and near vision, etc. The post-operative effect is better and is the “icing on the cake”, which can correct pre-cataract surgery myopia, hyperopia and astigmatism.
C. Will cataract recur after surgery Many patients often ask the question after surgery: Will cataract recur in the future? Since the surgery is to remove the cloudy material inside the lens and retain part of the capsule, which can support the IOL, the capsule of a small number of patients will be cloudy after surgery and affect the vision again, which is usually called “recurrence” or posterior cataract; with the progress of surgical technology and improvement of IOL, the incidence of posterior cataract is very low. Even if they do occur, they can be restored with a simple laser treatment.
Cataract surgery only relieves the portion of vision loss caused by the cataract. If the eye only has cataract, the vision may be restored well after surgery; however, if the eye has other eye diseases such as corneal leukoma, optic nerve atrophy, retinitis pigmentosa, retinal detachment, macular degeneration, etc. in addition to cataract, the vision may not be restored to normal after cataract surgery. Therefore, there is no need to worry about cataract, as timely adoption of appropriate surgical methods can restore vision and correct the preoperative refractive error.