12/08/2020
EYE DISEASES
Glaucoma
Glaucoma is one of the leading causes of blindness worldwide. It is an eye disease in which the pressure of the fluid inside the eye is too high, resulting in permanent damage to the optic nerve ( the pathway through which information is passed from the eye to the brain ).
In glaucoma, the eye pressure is elevated. This is because too much fluid is produced inside the eye or the channel in the eye through which the fluid normally drains out is blocked.
Glaucoma causes irreversible damage to sight by its pressure effect on the delicate nerve fibres as well as the fine blood vessels that nourish them at the back of the eye.
Glaucoma worsens gradually in the vast majority of cases. Patients are usually not aware of the damage until vision is significantly impaired or the visual field is greatly constricted.
Types Of Glaucoma
Chronic Open Angle Glaucoma
This is the commonest form of glaucoma in most countries. It affects people who are middle-aged and older. Relatives of people with this form of glaucoma have higher risk of developing this disease due to its hereditary tendency. People who are short-sighted are also at risk.
This disease progresses slowly and often goes unnoticed for many years. This is because the disease doesn't affect the straight-ahead vision and reading vision until the end stage. However, a gradual loss of night vision and peripheral vision.
The condition respond well to glaucoma eye drop but in a few cases, surgery is required to provide an additional drainage channel for the eye fluid in order to relieve the eye pressure.
Acute or Angle-Closure Glaucoma
This is the most common type of glaucoma in Chinese. It affects the middle-aged and elderly, especially women. There is a sudden, severe increase of pressure in the eye, resulting in permanent blindness if the eye pressure is not brought down promptly. Unlike chronic glaucoma, this form of glaucoma is associated with very dramatic symptoms such as severe pain in the eye, loss of vision, redness, seeing haloes around lights, headache and vomiting.
Congenital Glaucoma
This type of glaucoma occurs at birth. It is rare. Enlargement of the baby's eyes, tearing and sensitivity to light are warning features to parents that their baby needs full ophthalmological examination.
Secondary Glaucoma
This is glaucoma caused by pre-existing conditions in the eye. For instance, inflammation if the eye, tumours eye surgery, injuries or mature cataracts can all cause fluid to retain in the eye, causing high pressure to build up.
Treatment
The earlier the condition is diagnosed, the greater are the chances of success in preventing further visual loss. Although the damaged nerve fibres and their lost function can't be recovered, as long as the glaucoma is controlled, further damage can be avoided. The type of treatment depends on the form of glaucoma one has. It comprises medications ( eye drops and tablets ), laser and surgery.
Following successful treatments, having normal eye pressures means the glaucoma is controlled, and further visual deterioration should be halted. It doesn't imply the condition has been cured. The patient has to be followed up on a regular basis to ensure that optimum eye pressure is maintained to prevent progressive damage to the eye.
青光眼 "鬼鬼祟祟的视力小偷"
什么是青光眼
青光眼是可导致眼睛视觉神经受损和失明的一组疾病。它是由眼压( I O P )增加所致，眼睛的排出系统畸形或功能障碍都可能会导致眼压上升。
青光眼经常被指为[鬼鬼祟祟的视力小偷],因为病情会抹悄无声息，毫无明显症状之下加重。
谁有可能患上青光眼?
虽然任何人都可能患上青光眼，但是一些八的风险会比他人来得高。
-凡年过四十者
-家族中有青光眼历史者
-患有其它眼疾，可能间接造成青光眼或眼压升 高者
-在糖尿病病患者之中相当普遍
它有何病状和徵兆?
闭角型( 紧急 )
-视力突然衰减
-眼睛剧痛和发红
-头痛
-噁心和呕吐
-感到光线刺眼和对光敏感
先天性
-流眼泪
-对光敏感
-眼角膜增大
-丧失周边视野
患青光眼者会发现，虽然他可以清楚看到前方的事坝，但是却会遗漏旁边或眼角馀光的物体。
治疗
如今已有各种疗法可降低眼压，降低眼压是唯一已知有效的青光眼疗法。
传统治疗青光眼的手术是在小梁网上开一新切囗。这新切囗帮助液体流出眼外，以降低眼
及早发现和治疗可以减缓，或甚至抑止青光眼病情加重!
