The Effects of the Sympathetic Nervous System on Accommodation

The Effects of Phenylephrine on Pupil Diameter and Accommodation in Rhesus Monkeys

“…17 Gilmartin 18 concluded that the sympathetic system does not affect tonic accommodation, but provides a small, slow component of accommodation. The ␤-adrenergic antagonist timolol maleate is capable of increasing post-task regression to baseline refraction after a sustained reading task, 19 which, in agreement with previous studies, 8,14,20,21 suggests that the sympathetic contribution to accommodation may be evident after prolonged near work. This allows a build-up of sympathetic inhibitory activity over a background of parasympathetic activity, helping return the accommodative system to its baseline refraction.…”

The Effects of Phenylephrine on Pupil Diameter and Accommodation in Rhesus Monkeys

“…17 Gilmartin 18 concluded that the sympathetic system does not affect tonic accommodation, but provides a small, slow component of accommodation. The ␤-adrenergic antagonist timolol maleate is capable of increasing post-task regression to baseline refraction after a sustained reading task, 19 which, in agreement with previous studies, 8,14,20,21 suggests that the sympathetic contribution to accommodation may be evident after prolonged near work. This allows a build-up of sympathetic inhibitory activity over a background of parasympathetic activity, helping return the accommodative system to its baseline refraction.…”

Effect of β‐adrenoceptor antagonists on autonomic control of ciliary smooth muscle

“…Previous evidence supports the role of an inhibitory sympathetic input to the ciliary muscle which provides a mechanism for modulation of accommodative adaptation (Törnqvist, 1967; Hurwitz et al ., 1972a). The extended accommodative response times in the near‐to‐far direction exhibited in this study may however, be a manifestation of previous suggestions that the function of the inhibitory sympathetic component may be to stimulate accommodative decay following prolonged near work (Gilmartin and Hogan, 1985).…”

Autonomic drugs and the accommodative system in rhesus monkeys

“…Previous studies of adrenergic drugs have demonstrated that beta sympathetic stimulation by isoproteronol significantly decreased centrally stimulated accommodation by over 50% in vervet monkeys (Hurwitz, Davidowitz, Chin and Breinin, 1972a). It was also found that levarterenol, a non-selective sympathetic agonist with higher affinity for alpha rather than beta receptors, decreased accommodation, and the effect was blocked by propranolol, a beta-blocker (Hurwitz, Davidowitz, Pachter and Breinin, 1972).…”

The Effects of Phenylephrine on Pupil Diameter and Accommodation in Rhesus Monkeys

“…17 Gilmartin 18 concluded that the sympathetic system does not affect tonic accommodation, but provides a small, slow component of accommodation. The ␤-adrenergic antagonist timolol maleate is capable of increasing post-task regression to baseline refraction after a sustained reading task, 19 which, in agreement with previous studies, 8,14,20,21 suggests that the sympathetic contribution to accommodation may be evident after prolonged near work. This allows a build-up of sympathetic inhibitory activity over a background of parasympathetic activity, helping return the accommodative system to its baseline refraction.…”

Effect of β‐adrenoceptor antagonists on autonomic control of ciliary smooth muscle

“…Previous evidence supports the role of an inhibitory sympathetic input to the ciliary muscle which provides a mechanism for modulation of accommodative adaptation (Törnqvist, 1967; Hurwitz et al ., 1972a). The extended accommodative response times in the near‐to‐far direction exhibited in this study may however, be a manifestation of previous suggestions that the function of the inhibitory sympathetic component may be to stimulate accommodative decay following prolonged near work (Gilmartin and Hogan, 1985).…”

Autonomic drugs and the accommodative system in rhesus monkeys

“…Previous studies of adrenergic drugs have demonstrated that beta sympathetic stimulation by isoproteronol significantly decreased centrally stimulated accommodation by over 50% in vervet monkeys (Hurwitz, Davidowitz, Chin and Breinin, 1972a). It was also found that levarterenol, a non-selective sympathetic agonist with higher affinity for alpha rather than beta receptors, decreased accommodation, and the effect was blocked by propranolol, a beta-blocker (Hurwitz, Davidowitz, Pachter and Breinin, 1972).…”

The Effects of Phenylephrine on Pupil Diameter and Accommodation in Rhesus Monkeys

“…17 Gilmartin 18 concluded that the sympathetic system does not affect tonic accommodation, but provides a small, slow component of accommodation. The ␤-adrenergic antagonist timolol maleate is capable of increasing post-task regression to baseline refraction after a sustained reading task, 19 which, in agreement with previous studies, 8,14,20,21 suggests that the sympathetic contribution to accommodation may be evident after prolonged near work. This allows a build-up of sympathetic inhibitory activity over a background of parasympathetic activity, helping return the accommodative system to its baseline refraction.…”

Effect of β‐adrenoceptor antagonists on autonomic control of ciliary smooth muscle

“…Previous evidence supports the role of an inhibitory sympathetic input to the ciliary muscle which provides a mechanism for modulation of accommodative adaptation (Törnqvist, 1967; Hurwitz et al ., 1972a). The extended accommodative response times in the near‐to‐far direction exhibited in this study may however, be a manifestation of previous suggestions that the function of the inhibitory sympathetic component may be to stimulate accommodative decay following prolonged near work (Gilmartin and Hogan, 1985).…”

Autonomic drugs and the accommodative system in rhesus monkeys

“…Previous studies of adrenergic drugs have demonstrated that beta sympathetic stimulation by isoproteronol significantly decreased centrally stimulated accommodation by over 50% in vervet monkeys (Hurwitz, Davidowitz, Chin and Breinin, 1972a). It was also found that levarterenol, a non-selective sympathetic agonist with higher affinity for alpha rather than beta receptors, decreased accommodation, and the effect was blocked by propranolol, a beta-blocker (Hurwitz, Davidowitz, Pachter and Breinin, 1972).…”