Unusual retinal manifestations of cat scratch disease.

We report on 2 patients with unusual retinal manifestations of cat scratch disease (CSD), caused by Bartonella henselae. Case 1. A 42-year-old farmer presented with a 5-day history of blurred vision in his right eye. Right visual acuity was 20/25. Fundus examination of the right eye revealed mild vitreous hemorrhage and diffuse retinal hemorrhages in the mid-peripheral retina. Fluorescein angiography showed multiple vasculitic occlusions in the same area. A blood sample taken on the day of examination revealed the presence of immunoglobulin (Ig)M and IgG to B. henselae. Oral azithromycin was given for 8 days. One month later, right visual acuity was 20/20, the vitreous and retinal hemorrhages resolved, and arteriolar attenuation and sclerosis was observed in the peripheral temporal retina. Case 2. A 66-year-old craftsman with systemic hypertension and hypercholesterolemia complained of sudden visual loss (light perception) in his left eye. Fundus evaluation and fluorescein angiography revealed central retinal artery occlusion (CRAO) in the affected eye. About 2 weeks earlier, he had been bitten and scratched on his right hand by a stray cat. Serologic testing detected the presence of IgM to B. henselae. Oral azithromycin was given for 6 days. One month later, left visual acuity was hand motion. Ophthalmologists should be aware that unusual ocular complications associated with CSD include vitreous hemorrhage with retinal vasculitis and isolated CRAO. Vitreous hemorrhage and retinal vasculitis may be the only clinical manifestation of CSD.