A Case of Bilateral Retinal Vasculitis in Atypical Cogan Syndrome

Cogan syndrome (CS) is a rare chronic inflammatory disease characterized by ocular and inner ear inflammation. Well-known ocular manifestations include non-syphilitic interstitial keratitis (IK); however, some cases are not associated with IK. Inner ear symptoms include sensorineural hearing loss, rotatory vertigo, and tinnitus, which can become irreversible without timely treatment. Therefore, early and appropriate diagnosis and therapeutic intervention are important. However, due to its rarity, few physicians have encountered CS and early diagnosis is difficult. In this report, we present the details of the diagnosis and treatment of an atypical CS. The patient was a 44-year-old Japanese woman who was admitted to the Department of Immunology and Allergy at Itami City Hospital (Itami City, Hyogo, Japan) due to a persistent fever of approximately 40°C for nine days. Multiple erythematous lesions appeared on both lower legs, and she experienced decreased vision in her left eye. Uveitis with retinal vasculitis was observed in both eyes and the optic nerve head showed remarkable swelling in the left eye. Hearing tests revealed impaired hearing in both ears. Based on these findings, we diagnosed atypical CS and initiated systemic and topical steroid therapy. Approximately two weeks later, visual acuity and hearing levels improved. Fluorescein angiography (FA) revealed a non-perfusion area in both eyes, and retinal photocoagulation was performed using a pattern-scanning laser. Eighteen months after the laser irradiation, retinal neovascularization (RNV) was observed in the area where the laser was applied to the left eye; therefore, an additional laser was applied. Combination therapy with steroids and immunosuppressive drugs was continued until the patient's last visit three years later and she did not experience any recurrence of uveitis or hearing loss. In this case, a pattern-scanning laser was used for retinal photocoagulation to prevent RNV; however, RNV occurred within the area of the laser spots. In such cases of retinal capillary occlusion due to vasculitis, it may be better to close the spacing or use a conventional laser system. In the presence of retinal vasculitis with systemic inflammation, CS should be suspected, and a hearing test should be performed, even in the absence of subjective symptoms. Early treatment and prevention of irreversible hearing loss should be necessary. Careful follow-up in collaboration with other departments is important for CS cases.