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.