Q

quadrantanopia Visual field loss in a quarter of the visual field of the eye. The defect is usually bilateral, as it is caused by a lesion past the optic chiasma. It may be homonymous (binasal, bitemporal, upper or lower), crossed (one upper and the other lower), congruous (equal size of the defects), or incongruous (unequal size of the defects) (Fig. Q1). Syn. quadrantanopsia; quadrantic anopsia; quadrantic hemianopia.

See hemianopia.

quadrantanopia, superior A superior, homonymous quadrantanopia due to a lesion of the most anterior and inferior fibres of the

See loop, Meyer’s; radiations, optic.

quadrigemina, corpora See colliculi.

quantity of light See light, quantity of.

quantum See photon.

quantum theory See theory, quantum.

quartz See prism, Wollaston.

quinine amblyopia See amblyopia.

quinolones A class of broad-spectrum antibacterial drugs of which the main ophthalmic agents are ciprofloxacin and ofloxacin. They are used topically in 0.3% solution. They are effective against the majority of gram-negative pathogens, including Haemophilus, Neisseria gonorrhoeae, Chlamydia trachomatis, Pseudomonas aeruginosa (especially ciprofloxacin), staphylococci and streptococci. They are used in the treatment of conjunctivitis, blepharitis, keratoconjunctivitis and corneal ulcers.

See antibiotic.