Clinical Spectrum and Geographic Distribution of Keratitis Fugax Hereditaria Caused by the Pathogenic Variant c.61G>C in NLRP3

Keratitis fugax hereditaria (KFH) is inherited periodic corneal inflammation characterized by painful attacks in the eye, with blurred vision and redness. Repeated attacks result in decreased vision in half of the patients. The disease is caused by a mutation in the gene named NLRP3. NLRP3 is a general inflammation mediator in the human body. The purpose of the study was to chart clinical findings in individuals with KFH and the geographic distribution of their ancestors. 

84 Finnish patients with genetically confirmed KFH were included. Clinical examination, corneal imaging, and a questionnaire regarding symptoms, quality of life, treatment, and comorbidities were performed. 

The oldest members in each family were born in Ostrobothnia in Western Finland or Southwestern Finland with historical ties to Sweden. One carrier was asymptomatic. Most patients experienced their first attack between age 6 and 20 years. Three-quarters had unilateral attacks 3 to 5 times per year, primarily triggered by cold wind or air, or stress. Almost half of the patients had corneal opacities and deformed cornea due to repeated attacks. Other than eye-specific symptoms were not systematically present. Large rigid contact (scleral) lenses helped to restore vision. 

Symptoms and signs of KFH are restricted to the eye and vary widely between individuals. We recommend contact lenses as the first-line treatment for reduced vision. Public genetic data suggest that KFH goes unrecognized in Sweden and populations with Scandinavian heritage. 

Original article:

Clinical Spectrum and Geographic Distribution of Keratitis Fugax Hereditaria Caused by the Pathogenic Variant c.61G>C in NLRP3. Immonen AT, Kawan S, Vesaluoma M, Heiskanen JM, Taipale C, Koskinen M, Majander A, Kivelä TT, Turunen JA. Am J Ophthalmol. 2021 Nov 3;236:309-318. doi: 10.1016/j.ajo.2021.10.025. Online ahead of print. PMID: 34740632