YAMOUT OPTICAL CENTER

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Glaucoma
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Primary Open-Angle Glaucoma (POAG)

POAG is the most common form of glaucoma. POAG has no symptoms until its late stages, which is why the disease can remain undetected without regular eye examinations. In POAG, pressure in the eye increases, even though there is no visible abnormality of the trabecular meshwork. Though the direct cause is yet unknown, it is believed that a defect occurs in the ability of the cells within the trabecular meshwork to carry out their normal function. Some believe that poor cellular regeneration or an enzyme deficiency within the meshwork may be the cause of this malfunction. The continued high pressure within the eye acts by either decreasing the blood supply to the optic nerve fibers, or interfering with the movement of the nutrients along the nerve fibers themselves.

Treatment of Open-Angle Glaucoma

Treatment for glaucoma is targeted at reducing the production of aqueous fluid, or by inducing the outflow of fluid through the trabecular meshwork drainage system. The objective of treatment is to lower the IOP to the normal range between 10 and 20mmHg. Eye drops are the most common form of treatment; certain oral medications may be used as well.

· Laser Trabeculoplasty

When medications become intolerable or ineffective, laser surgery may be considered. The way that laser surgery works is by modifying the drainage mechanism of the eye. In many cases, glaucoma medications will still be required after surgery. Complications may include inflammation and irritation of the eye immediately following the procedure. Overall, the procedure is usually effective and the risks are relatively low.

· Filtering Bleb

When medication and/or laser surgery are not effective in lowering pressure inside the eye, then more invasive surgery is required. A small hole is made in the wall of the eye and the fluid then drains through the opening and passes under the conjunctiva into a bleb. In more severe cases of glaucoma, a plastic or silicone shunt may be inserted to redirect the fluid drainage from the eye.

· Cryoablation

When other types of surgical intervention fail, or due to the severity of the glaucoma condition, cryoablation may be considered. The procedure works by reducing the total amount of fluid produced inside the eye by destroying the ciliary body (the tissue which produces the aqueous fluid inside the eye) by freezing the tissue. This procedure is usually reserved for cases of end-stage glaucoma.



Normal Tension Glaucoma (NTG)

NTG is also known as low-tension glaucoma. The optic nerves of different patients have different levels of pressure tolerance. Patients with NTG demonstrate progressive optic nerve damage and visual field loss, even though intraocular pressures remain normal. It is believed that these patients may have pre-existing conditions which predispose them to optic nerve damage. One theory is that this damage is caused by poor blood flow to the optic nerve. Diseases such as diabetes, hypertension and cardiovascular malfunction are suspected factors.

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