Effect of acupuncture on intraocular pressure and tear production in healthy horses

Abstract

Acupuncture is an ancient Chinese form of therapy that involves needle stimulation of specific points on the body for therapeutic and homeostatic effects. In ophthalmology, acupuncture helps as a conventional or adjuvant therapy for numerous eye disorders, including myopia, strabismus, dry eye, and cataracts. This study aimed to evaluate the effect of acupuncture on tear production (TP) and intraocular pressure (IOP) in horses. Ten healthy horses, females and males with ages varying between eight months and nine years, were used. Schirmer’s I test and applanation tonometry were used to evaluate the basal TP and IOP of both eyes. The measurements were taken immediately before (T10) the insertion of the needles and 5 (T5), 15 (T15), 30 (T30) and 60 (T60) minutes and 24 (T24) hours after a 20-minute acupuncture session. Mean values of both eyes were analyzed over time. TP increased in 50% of the animals at T5, T15 and T24, in 30% at T30, and in 40% at T60, with an increase of up to 8.5 mm/min at T15 and T60. In addition, there was a significant difference between T24 and T30, with a 14.1% increase in TP at T24. Meanwhile, IOP decreased in 50% of the animals at T5 and T30, in 20% at T15, in 60% at T60, and in 70% at T24. Thus, we suggest that acupuncture is a technique that can benefit horses with diseases that alter these parameters, either alone or as an adjunct in conventional therapeutic protocols.