ABSTRACT

Tear secretion involves several processes that are regulated by neural, endocrine, and immune mechanisms. The lacrimal glands are adequately innervated with sensory and autonomic nerve fibres and secrete fluid, electrolytes, and proteins in response to neurotransmitters released from these nerves. This study evaluated the effect of nasal anaesthetic on tear production using sixty (60) healthy individuals with normal ocular surface and Schirmer I tear-test scores >10 mm. Schirmer I values of each subject was obtained on each visit to rule out subjects with scores <10mm and to also establish a normal baseline. Next, the left nasal mucosa of the subject was anaesthetised with aerosolized 10% lidocaine. After a 10-min period to allow the anaesthetic to take effect and reflex tearing to subside, the Schirmer I test was repeated. On a separate day, a saline nasal spray acting as negative control was applied to the left nasal mucosa and Schirmer I test repeated. Results showed that mean tear production decreased significantly (p<0.001) by approximately 19% in OD and OS after nasal anaesthesia compared to baseline.

It is therefore concluded that nasal anaesthetic has significant effect on tear production. Consequent to that, nasal mucosal damage, disease or denervation can predispose a patient to dry eye disease.