Sir,

We report a case of cat scratch disease with manifestation of multifocal chorioretinal lesions and we document the imaging findings through spectral domain optical coherence tomography (SD-OCT) during the course of the disease from early presentation until the resolving of symptoms.

Case report

A 37-year-old woman presented at our emergency Eye Department complaining of blurred vision in her right eye for a period of 1 week. Visual acuity was 6/60 in the affected eye and 6/9 in the left eye. There was a history of contact with cats and dogs. Patient reported also cough and fatigue during the past week. Slit-lamp examination revealed mild inflammatory reaction in the anterior chamber and central vitreous haze. Biomicroscopy revealed two white focal chorioretinal elevated lesions superiorly temporarily to the fovea (Figure 1) and in the inferonasal peripapillary area (Figure 2). OCT revealed hyper-reflective inner retina layers in the lesions casting a shadow on the posterior retinal layers and choroid (Figure 3, purple arrows) and the presence of intraretinal and subretinal fluid causing neurosensory detachment (Figure 3). FFA demonstrated late hyperfluoresence from the focal lesions (Figure 1). Interestingly, exudation around the fovea appeared 12 days after the initial presentation (Figure 3, yellow arrows).

Figure 1
figure 1

(a) Colour fundus photograph taken at presentation and indicating one of the retinal lesions. (b, c) Fluorescein angiography images where late hyper-fluorescence was observed from the focal lesion. No signs of optic nerve head involvement or vasculitis were observed. A full colour version of this figure is available at the Eye journal online.

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Figure 2
figure 2

The second focal lesion of the retina. Colour fundus photograph (a) and OCT image (b). A full colour version of this figure is available at the Eye journal online.

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Figure 3
figure 3

OCT and infrared fundus images corresponding to each day of the follow-up during the course of disease. Column a comprises OCT (3D OCT-1000, Topcon Corporation, Tokyo, Japan) images from the fovea where intraretinal and subretinal fluid diminished after 12 days while exudates (yellow arrows) were visible in the OCT after that time point. Column b presents images from the foveal focal area where hyper-reflectivity of the inflamed lesion casts a shadow in the OCT (purple arrows). Column c presents infrared images of the fovea where the sites of lesion and exudates are evident.

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Treatment with trimethoprim-sulfamethoxazole 160/800 mg twice/day was prescribed. The serology tests were negative for toxoplasmosis and strongly positive for Bartonella henselae (IgM: 80 and IgG: 512).

Four weeks after the initiation of the treatment VA was 6/9 in the affected eye with no signs of active inflammation while the exudates had resolved and the focal lesions appeared to have pigment in their margins.

Comment

In our case, cat scratch disease was initially strongly suspected and presented without the involvement of optic nerve head but with an initial presence of multiple exudates, a finding more common than previously believed.1, 2, 3, 4, 5 Serology tests confirmed the diagnosis and following treatment VA had progressively increased, with intraretinal and subretinal fluid accumulation resolving dramatically within days and hyper-reflectivity on OCT at primary lesions was diminished. OCT showed noticeable correlation with clinical findings and may have a significant role in the diagnosis and follow-up of patients with cat scratch disease.