Cogan syndrome masquerading as corneal ectasia

Area of Science:

• Ophthalmology
• Rheumatology
• Audiology

Background:

• Cogan syndrome is a rare autoimmune disorder characterized by non-syphilitic interstitial keratitis and vestibuloauditory dysfunction.
• It often presents with ocular and auditory symptoms, but the initial presentation can be varied, sometimes mimicking other corneal conditions.

Observation:

• A 43-year-old woman with presumed keratoconus and keratoconjunctivitis sicca developed eye pain, blurry vision, and monocular diplopia.
• She later reported tinnitus, vertigo, and sensorineural hearing loss.
• Scheimpflug tomography revealed bilateral asymmetric corneal ectasia-like changes, while anterior segment optical coherence tomography (OCT) showed focal stromal inflammation and epithelial hypertrophy, not thinning.

Findings:

• The patient was diagnosed with Cogan syndrome based on the combination of interstitial keratitis and sensorineural hearing loss.
• Treatment with topical steroids and systemic immunosuppression led to near resolution of corneal abnormalities and diplopia.

Implications:

• Cogan syndrome should be considered in patients with corneal stromal disease accompanied by auditory or vestibular symptoms.
• Anterior segment OCT is valuable in differentiating inflammatory corneal conditions from ectatic diseases, aiding in the diagnosis of subtle Cogan syndrome cases.