Headache caused by ocular inflammatory conditions such as iritis, uveitis, scleritis or conjunctivitis and associated with other symptoms and clinical signs of the disorder.
A. Periorbital headache and eye pain fulfilling criterion C
B. Clinical, laboratory and/or imaging evidence of ocular inflammatory disease such as iritis, uveitis, cyclitis, scleritis, choroiditis, conjunctivitis or corneal inflammation
C. Evidence of causation demonstrated by at least two of the following:
1. headache has developed in temporal relation to the onset of the ocular disorder
2. either or both of the following:
a) headache has significantly worsened in parallel with worsening of the ocular disorder
b) headache has significantly improved or resolved in parallel with improvement in or resolution of the ocular disorder
3. either or both of the following:
a) headache significantly improves with topical application of local anaesthetic agent to the eye
b) headache is aggravated by pressure applied to the eye
4. in the case of a unilateral eye disorder, headache is localized ipsilateral to it
D. Not better accounted for by another ICHD-3 diagnosis.
Ocular inflammation takes many forms, and may be categorized variously by anatomical site (eg, iritis, cyclitis, choroiditis), by course (ie, acute, subacute, chronic), by presumed cause (eg, endogenous or exogenous infectious agents, lens-related, traumatic) or by type of inflammation (granulomatous, non-granulomatous).
Because of nociceptive field overlap and convergence (leading to complex pain referral), any ocular source of pain may lead to headache in any region. Nevertheless, if the eye disorder is unilateral, headache is likely to be localized ipsilateral to it.