A standard test to determine fluid pressure in the eye. One type of tonometry is the Non-Contact Tonometer (NCT) or "air puff" test, which measures the resistance of the eye to a puff of air. Another type, the Goldman Tonometry test, is the world standard test for intraocular pressure. If this pressure is too high, then the person may have Glaucoma.
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When traditional treatment for glaucoma fails and eye drops, pills, or laser surgery (trabeculoplasty) does not lower intraocular pressure to a safe level, your eye doctor may recommend a trabeculectomy to prevent blindness.
A trabeculectomy differs from a trabeculoplasty in that a new drain is created in the eye by removing a tiny piece of the wall of the eye, which may include the trabecular meshwork (the natural drain). This creates a new drain, bypassing the trabecular meshwork to reduce eye pressure. Fluid can now drain easily through the new opening into a tiny blister-like reservoir (bleb) underneath the conjunctiva (the clear covering of the surface of the eye). The fluid is then absorbed by the body and the result is normal to near-normal eye pressures.
Trabeculoplasty is a procedure used in glaucoma patients to open the trabeculum of the eye, relieving the pressure and restoring normal fluid outflow. In glaucoma, optic fluid cannot be released normally due to blockage in the trabeculum. Having a laser trabeculoplasty can relieve the pressure and improve drainage of the optic fluid, thus reducing the amount of pressure and damage to the optic nerve.
A type of lens requiring three different prescriptions, allowing vision at three separate distances.