ASSOCIATION OF DRY EYE SEVERITY WITH HEADACHE OF UNKNOWN ETIOLOGY AND COMPARATIVE TREATMENT OUTCOMES

Abstract

Background: Dry eye disease (DED) and primary headache disorders frequently overlap through shared trigeminovascular pathways, yet remain clinically siloed. DED-driven headache often masquerades as tension-type headache or migraine, while primary headache can provoke ocular symptoms mistaken for DED — leading to misdirected treatment and persistent disability.

Objective: To assess the correlation between dry eye severity and headache burden, and to compare the clinical efficacy of Systane Ultra versus Vismed (0.18% sodium hyaluronate) in patients with comorbid dry eye disease and headache of unknown etiology.

Methods: This randomized comparative clinical trial enrolled 104 patients (52 male, 52 female) aged 18–45 years with diagnosed DED and associated headache. Participants were randomly allocated to receive either Systane Ultra or Vismed four times daily for four weeks. Dry eye severity was evaluated using the Ocular Surface Disease Index (OSDI), tear film break-up time (TBUT), and Schirmer's I test. Headache severity and disability were quantified using the Headache Impact Test-6 (HIT-6). Baseline and follow-up assessments were analyzed using SPSS version 27; paired t-tests evaluated within-group changes, independent t-tests compared between-group improvements, and Spearman's correlation examined the dry eye–headache relationship. Statistical significance was set at p < 0.05.

Results: A moderate to strong positive correlation was demonstrated between dry eye severity and headache disability (rₛ = 0.648, p = 0.001), indicating that escalating tear film dysfunction corresponds to greater headache-related functional impairment. Both treatment groups achieved significant symptomatic improvement post-intervention (p < 0.001 for both). However, Systane Ultra produced superior mean improvement (5.2 ± 1.1) compared to Vismed (3.6 ± 1.4), with a statistically significant between-group difference (t = 2.45, p = 0.016).

Conclusion: The significant DED–headache correlation supports trigeminovascular pathophysiology. Persistent headache despite lubrication signals primary headache mechanisms rather than intensified ocular treatment. Routine tear film assessment in headache clinics and integrated ophthalmic-neurological evaluation are essential to distinguish these entities and prevent diagnostic delay.