Systemic Autonomic Function in Subjects With Primary Angle-Closure Glaucoma

Abstract

Abstract: : Purpose: Autonomic dysfunction is thought to be a contributory factor in primary angle closure glaucoma, with autonomic neuropathy possibly involved in precipitating pupil block in anatomically predisposed eyes. This study aims to compare systemic autonomic function between subjects who have suffered a previous episode of acute angle closure (AAC), those with asymptomatic chronic angle closure glaucoma (CACG), and age and sex-matched controls. Methods: Exclusion criteria were the use of salbutamol or ipratropium bromide, oral or topical beta-blockers, topical pilocarpine, and those on systemic anticholinergic or antidepressant medications. Tests for systemic parasympathetic function included the heart-rate response to standing (30:15 ratio), heart-rate variation during deep breathing, and the ratio of the heart rate at phases IV and II of the Valsalva maneuver (Valsalva ratio). For assessment of the sympathetic nervous system, blood pressure was recorded supine and then after 2 and 5 minutes of standing. A modified sweat test, the sympathetic skin response was recorded on the palm and sole. Results: A total of 30 subjects were examined, 8 AAC, 8 CACG and 14 control subjects. The mean ages were similar, and all except one subject were Chinese. There was no difference in the sex ratio between the groups. There was no significant difference (p>0.05) found between groups for the 30:15 ratio, heart rate variation during deep respiration and the Valsalva ratio. No significant orthostatic hypotension was detected in any subject. The occurrence of abnormal sympathetic skin response was slightly higher in the control group. Conclusion: Our data suggests that in subjects with acute and chronic primary angle closure glaucoma, the autonomic nervous system is normal.

Keywords: intraocular pressure • innervation: neural regulation • clinical (human) or epidemiologic studies: ris