Keratoendotheliitis Fugax Hereditaria

Keratoendotheliitis fugax hereditaria is a rare inflammatory genetic condition characterized by recurrent episodes of debilitating unilateral corneal and conjunctival hyperemia, corneal edema, visual impairment, corneal opacification, and photophobia that last for 2 to 5 days. Lacrimation, pain, colored halos, diplopia, a mild anterior chamber reaction, guttata-like changes (pseudoguttata), and a "gritty" feeling may also occur. The inheritance pattern of keratoendotheliitis fugax hereditariais is autosomal dominant. The pathology generally begins temporally before quickly progressing to surround the entirety of the cornea. In the acute phase, the pain or discomfort is often severe enough to disrupt sleep. Although both the hyperemia and opacification generally resolve entirely within 2 to 4 days, localized opacity in the cornea may persist for weeks to months after the acute phase. Initial reports indicated that regardless of the duration of the corneal haze or the number of episodic incidents a person experiences, the opacification always completely remits, and vision returns to normal. However, additional cases have shown individuals with permanent stromal opacification after numerous incidents. These opacities, though evident on examination, may or may not affect visual acuity between episodes. The disease was first described in 1964 and named in Valle's pedigree-based case report of Finnish individuals. However, later reports hint that small differences in findings may indicate that the patients studied by Valle may have a closely related but slightly different pathology. The frequency of these symptomatic inflammatory attacks varies by age demographic. Patients who are 15 to 20 years old experience the most frequent symptoms, occurring 1 to 8 times a year. Attacks decrease in frequency and severity as the patient ages, though patients generally still experience moderate-to-severe events throughout their forties. However, by their mid-fifties, it appears patients are substantially less affected, with incidents causing comparatively mild symptoms and occurring less frequently.