Introduction: To describe a case of unilateral exudative retinal detachment and severe uveitis with a large subretinal deposit in a 6-year-old girl presenting with left thigh lymphadenitis. Case Presentation: A metagenome next-generation sequencing (mNGS) of the vitreous body was performed, revealing Bartonella henselae. The patient showed the resolution of retinal detachment and uveitis, as well as improvement of left thigh lymphadenitis, in response to systemic and ocular antibiotics and corticosteroids. Conclusion: Bartonella henselae neuroretinitis may manifest as exudative retinal detachment with extensive subretinal lesions and uveitis. The treatment involving systemic and ocular antibiotics and corticosteroids proved to be effective.

Bartonella henselae is a Gram-negative bacillus, mainly parasitizing on cats. When a child is scratched by a cat, they may present with the disease symptoms including regional lymphadenopathy, malaise, fever, and splenomegaly, which is known as cat-scratch disease (CSD). Ocular manifestations occur in 5–10% of patients with CSD. Neuroretinitis is the most common, and, in addition, Parinaud oculoglandular syndrome, endophthalmitis, retinochoroiditis, vascular occlusions, multiple mass-like lesions resembling ocular metastases, serous macular detachments, and retinal vasoproliferative lesions may also occur. We report a case of unilateral exudative retinal detachment and uveitis with a large subretinal deposit on the macula in a 6-year-old female with CSD, along with lymphadenitis on her left thigh. To the best of our knowledge, this case of exudative retinal detachment and uveitis with a large subretinal deposit under the retina affecting the macular area above the optic disc has not been previously reported.