Cotton wool spots as possible indicators of retinal vascular pathology in ocular lyme borreliosis.

Lyme borreliosis is an underdiagnosed infectious disease caused by a spirochete and transmitted by certain Ixodes ticks. In Lyme disease diagnostic problems are still discussed extensively as the laboratory workup is not standardized and a positive antibody result is not proof of active infection. It is therefore important to appreciate all clinical signs that can prompt us to the diagnostic investigation of Lyme borreliosis. We present a case of a woman with Lyme borreliosis and recurrent unilateral anterior uveitis in her right eye for 2 years, who developed cotton wool spots (CWS) in her left eye, followed by acute and recurrent anterior uveitis in this second eye. An extensive general examination, including blood coagulopathies and ultrasound of the carotid arteries, did not reveal any pathology. The CWS resolved within a few months. The recurrent anterior uveitis could be controlled by topical steroids. After treatment with 2 g of i.v. ceftriaxone for 3 weeks, she remained free of recurrences for 1 year of observation time. CWS can be the first clinical sign of ocular vascular pathology and/or uveitis. Further investigation will be necessary to confirm the relationship between CWS and ocular borreliosis. In patients with otherwise unexplained CWS, the possibility of an infection with borreliosis should be ruled out carefully.