| open-angle glaucoma | <ophthalmology> A disorder which is characterised by increased pressure within the eyeball. This occurs secondary to the chronic blockage of normal fluid circulation within the eye. Increased pressure within the eye can cause damage to the optic nerve and eventual blindness. Glaucoma is the leading cause of blindness. Symptoms include decreased vision, halos around lights (worse at night) and mild chronic headaches. Treatment is generally with beta-blocker eyedrops. Synonym: chronic glaucoma, compensated glaucoma, simple glaucoma, glaucoma simplex. (22 Sep 2002) |
|---|---|
| open-hearted | Candid; frank; generous. O"pen-heartedly, O"pen-heartedness. Source: Websters Dictionary (01 Mar 1998) |
| open-label trial | A study in which both researchers and participants know what drug a person is taking and at what dose. (09 Oct 1997) |
| openbill | <zoology> A bird of the genus Anastomus, allied to the stork; so called because the two parts of the bill touch only at the base and tip. One species inhabits India, another Africa. Synonym: open-beak. Source: Websters Dictionary (01 Mar 1998) |
| opening | 1. The act or process of opening; a beginning; commencement; first appearance; as, the opening of a speech. "The opening of your glory was like that of light." (Dryden) 2. A place which is open; a breach; an aperture; a gap; cleft, or hole. "We saw him at the opening of his tent." (Shak) 3. Hence: A vacant place; an opportunity; as, an opening for business. 4. A thinly wooded space, without undergrowth, in the midst of a forest; as, oak openings. Source: Websters Dictionary (01 Mar 1998) |
| opening axis | An imaginary line around which the mandibular condyles may rotate during opening and closing movements. Compare: fulcrum line. (05 Mar 2000) |
| opening contraction | A contraction produced at the time of opening the circuit when using direct current to stimulate the muscle or a motor nerve. (05 Mar 2000) |
| opening movement | In dentistry, movement of the mandible executed during jaw separation. (05 Mar 2000) |
| opening of external acoustic meatus | The orifice of the external acoustic meatus in the tympanic portion of the temporal bone. Synonym: porus acusticus externus, external acoustic foramen, external acoustic pore, external auditory pore, external auditory foramen, orifice of external acoustic meatus. (05 Mar 2000) |
| opening of inferior vena cava | The orifice through which the inferior vena cava opens into the right atrium. Synonym: ostium venae cavae inferioris, orifice of inferior vena cava. (05 Mar 2000) |
| opening of internal acoustic meatus | The inner opening of the internal acoustic meatus on the posterior surface of the petrous part of the temporal bone. Synonym: porus acusticus internus, internal acoustic foramen, internal acoustic pore, auditory pore, internal auditory foramen, orifice of internal acoustic meatus. (05 Mar 2000) |
| opening of pulmonary trunk | The opening of the pulmonary trunk from the right ventricle, guarded by the pulmonary valve. Synonym: ostium trunci pulmonalis, pulmonary orifice. (05 Mar 2000) |
| opening of superior vena cava | The point of entry of the superior vena cava into the right atrium. Synonym: ostium venae cavae superioris, orifice of superior vena cava. (05 Mar 2000) |
| opening of the sphenoidal sinus | One of the pair of openings in the body of the sphenoid bone through which the sphenoid sinuses communicate with the sphenoethmoidal recess of the nasal cavity. Synonym: apertura sinus sphenoidalis, sphenoidal sinus aperture. (05 Mar 2000) |
| opening of uterus | The vaginal opening of the uterus. Synonym: ostium uteri, mouth of the womb, opening of uterus, orificium externum uteri, os uteri externum, ostium uteri externum. (05 Mar 2000) |