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BETA‐ADRENERGIC RECEPTOR ANTAGONISM IN MYOPIA *
Author(s) -
Rosenfield Mark,
Gilmartin Bernard
Publication year - 1987
Publication title -
ophthalmic and physiological optics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.147
H-Index - 66
eISSN - 1475-1313
pISSN - 0275-5408
DOI - 10.1111/j.1475-1313.1987.tb00761.x
Subject(s) - timolol , ophthalmology , medicine , keratometer , refractive error , heterophoria , optometry , strabismus , eye disease , intraocular pressure , cornea
— A previous study has demonstrated that timolol maleate (0.5%), a non‐selective beta‐adrenergic antagonist, produces in emmetropes a significant reduction in accommodative convergence (AC) during the initial four minutes of a near‐vision task. The present study has examined the effect of timolol on AC for three refractive groups (each comprising N = 20): emmetropes, early‐onset myopes (EOMs), i.e. myopia onset prior to 15 years of age and late‐onset myopes (LOMs), i.e. myopia onset after 15 years. A double‐blind protocol was adopted between timolol and a saline control. AC was derived from accommodation stimuli of 3.3, 4.1 and 4.8 D with changes in heterophoria being assessed using a Maddox rod and tangent scale. The relationship between the ocular hypotensive effect of timolol and anterior corneal curvature was also investigated using a Goldmann applanation tonometer and a two‐position keratometer (Haag‐Streit). Timolol produced a significant reduction in AC in emmetropes but did not induce significant changes in AC in LOMs or EOMs. The timolol‐induced reduction in IOP did not result in any changes in anterior corneal curvature.