Glaucoma has been called the “silent thief of sight” because loss of vision usually occurs without any apparent warning.
Acute glaucoma occurs when optic nerve damage results in a progressive loss of vision; the intra-ocular pressure is elevated abruptly and causes acute damage of the optic nerve. Glaucoma is one of primary causes of vision impairment worldwide.
The optic nerve consists of about 1 million small, individual thread-like nerve fibers that come from the retina. It carries visual information from the eye to the brain forming images. When someone has glaucoma, the little nerve fibers are wiped out slowly, a form of optic nerve atrophy. Obstruction from optic nerve atrophy cannot be reversed; the process progresses to the point that visual perception is dim and the vision field reduced. If the disease is left unattended, vision loss becomes permanent.
Possible risk factors for glaucoma include: high myopia, being over 60 years of age, having a family history of this condition, and high intraocular pressure (IOP). However, some people with normal eye pressure may also develop optic nerve atrophy, known as normal-tension glaucoma. Therefore, routine eye examinations can help detect and prevent any potential eye-blinding diseases.
Glaucoma is closely related to the drainage system of the eyes. Aqueous humor, made by the ciliary body near the lens, is the clear fluid that fills in the anterior chamber inside the eyes between the iris and the cornea. Aqueous humor flows around the anterior chamber and drains into the venous system through a tiny drainage duct (Canal of Schlemm). Proper functioning of the intraocular drainage system helps maintain normal eye pressure. Once the drainage canals become clogged, the buildup of intraocular fluid elevates intraocular pressure. Eventually, increased intraocular pressure pushes on the back of the eyes and damages the optic nerve, resulting in blind spots and blindness, i.e., optic nerve damage.
There are two basic forms of glaucoma: the open-angle type and the closed-angle type. The most common type is primary Open-Angle Glaucoma (POAG). POAG occurs when the drainage meshwork is becoming less efficient or compacted while the “angle” is still as wide open as it should be. The extra eye fluid increases and accumulates within the limited space of the eyeball. Increased IOP results in damage to the optic nerve. In most cases, symptoms are unnoticed until the deterioration of the optic nerve begins to affect peripheral visual field. If peripheral vision lose is not controlled, central vision loss occurs gradually.
Closed-angle glaucoma occurs when the drainage channel is clogged and the iris is pushed or pulled forward towards the cornea. When the angle is closed and the drainage system is completely blocked and IOP elevates quickly. This becomes an acute attack and needs treatment immediately; it is often accompanied with symptoms including severe headaches, nausea, vomiting, blurred vision, eye congestion and pain. Sadly, many such cases were frequently misdiagnosed as digestive diseases. Occasionally, closed-angle glaucoma may be overlooked because the symptoms may appear slowly and patients do not realize that they were being “attacked” until the damages to the optic nerve lead to vision lose.
Other types of glaucoma can be inherited, but rarely; secondary glaucoma is a type of glaucoma that results from other diseases, such as inflammation, injuries, or any other eye complications, including diabetic retinopathy and retinal vascular occlusion.
The damage from glaucoma is irreversible so early detection and treatment is important and can help preserve your vision. Trust Me Eye Center is a professional ophthalmic facility and provides essential equipments that can diagnose, treat and prevent further eye vision lose.
Trust Me Eye Center is equipped with following instruments that can detect glaucoma in its early stage:
(1) An automatic tonometer which can measure corneal thickness; this is an important factor in measuring intraocular pressure during glaucoma diagnosis. Historically, tonometic measurements were not considered to be an accurate way to measure IOP because the thin cornea of an IOP can be underestimated (and a thick cornea of an IOP being overestimated). However, the Trust Me Eye Center, with its automatic tonometer, can measure corneal thickness very accurately, affording very precise tracking of IOP.
(2)An anterior segment three-dimensional tomography instrument (Pantacam), which is used for the measurement and analysis of the anterior eye segment and which can also rebuild three-dimensional structures of the anterior chamber of the eye. It generates data concerning the structure of the anterior eye chamber: depth and angle of anterior chamber, thickness of lens.
(3) An automatic visual field machine which can measure the dynamic and static visual field changes and save the data to a computer for later analysis and investigation. It is an objective way to determine visual field changes.
(4) Trust Me Eye Center has also introduced the latest glaucoma scanning device called OCT — optical coherent tomography — that allow visualization of the optical nerve to 360 degrees and measure the thickness of the retinal nerve, enabling the detection of any retinal diseases before visual field changes occur.(圖四)
(5) A non-mydriatic fundus camera which allows the visualization of the optic nerve without resorting to eye-dilating procedures; it is very efficient in tracking glaucoma progression.
(6) A YAG Laser for the treatment of closed-angle glaucoma and the prevention of the onset of acute glaucoma.
(7) An express glaucoma shunt device which the Trust Me Eye Care Center uses as a device to filter out the aqueous humor in the anterior chambers, inserted in an endoscopic procedure. This surgery has been proven to have less post-surgical complications than traditional trabeculectomy.
Comments are closed.