Glossary

TED - Thyroid Eye Disease  Commonly occurs in association with an overactive thyroid gland. The abnormal auto-immune response attacks the muscles and soft fatty tissues around the eyes and is characterised by episodes of inflammation and engorgement of these tissues and then a healing response. However, the tissues can become red, swollen and even scarred causing dry eyes, lid swelling and retraction, bulging of the eyeballs, double vision and pain on eye movement.

Tomography - Imaging technique used to provide detailed information about structures inside and around the eye. It is useful for imaging the anatomic layers within the retina and retinal thickness can be measured using the OCT (Optical Coherence Tomographer). It is helpful in detecting disorders and disease of the retina and optic nerve including: AMD, diabetic retinopathy, macular holes, macular swelling and glaucoma.

Tonometry - Measures the fluid pressure inside the eye (intra-ocular pressure) by measuring the force required to flatten a known area of the cornea. It is an important test in the evaluation of glaucoma and internal eye inflammation. Most Tonometers are calibrated to measure pressure in mmHg (millimetres of mercury) and can either touch the cornea with the aid of anaesthetic (contact Tonometer) or use a fast puff of air that bounces of the cornea (non-contact Tonometer).

Topical - Administration of a drug applied directly to the eye to be treated (eye drops).

Topography - Maps the surface curvature of the cornea. This piece of diagnostic equipment produces detailed information on the power and shape of the cornea and uses computerised imaging to show a 3-D map which aids in the planning of refractive surgery but also in the diagnosis and monitoring of various visual conditions.

Toric Lens - A type of lens used to correct astigmatism, whose surface is a combination of a sphere and a cylinder. Can either be a spectacle lens, contact lens or intra-ocular lens (IOL).

Trabecular Meshwork - A meshwork of drainage channels located around the base of the cornea, near the Ciliary body that is responsible for the drainage of aqueous humour from the eye.