Bartonella Neuroretinitis
A 55-year-old woman presented to the ophthalmology clinic with blurry vision and pain in the right eye that had persisted for several days. She had no associated fever or lymphadenopathy. An ocular examination revealed severe vision loss (she could only count fingers), a relative afferent pupillary defect, and reduced color vision in the right eye. A slit-lamp examination showed anterior-segment inflammation, a swollen optic nerve with hemorrhages in the nerve fiber layer, and serous macular detachment. A fundus examination revealed macular edema with stellate exudates, findings that are consistent with bartonella infection. This diagnosis was supported by the results of serologic evaluation: at week 1, the IgM antibody titer to Bartonella henselae was 80 mg per deciliter, and the IgG antibody titer was 256 mg per deciliter; on repeat testing at week 3, the IgG antibody titer had increased to 1024 mg per deciliter. Other possible infectious causes of neuroretinitis include toxoplasmosis and syphilis, although many cases are idiopathic. Bartonella henselae is the causative agent of cat scratch disease; in the current case, the patient had been exposed to cats but recalled no recent scratch. Treatment with topical glucocorticoid drops, oral doxycycline, and oral prednisone was initiated. The macular edema, nerve swelling, and relative afferent pupillary defect resolved, and the patient regained visual acuity of 20/80 in the right eye.
