ABSTRACT
Toxoplasma chorioretinitis (TC) can exhibit atypical features in immunocompromised patients including bilaterality, extensive spread, multifocal presentation, large areas of retinal necrosis without adjacent retinal scarring, and diffuse necrotizing retinitis resembling the viral retinitis that may cause confusion in the differential diagnosis. The aim of this study was to present the clinical features of four eyes of three immunocompromised patients with active toxoplasma chorioretinitis. Two of the patients were female and one, male. Two patients had hematological malignancies and the remaining patient was under adalimumab treatment for ankylosing spondylitis. Visual complaints began 10 days to four months prior to TC diagnosis. All four eyes had mild-to-moderate anterior chamber cells together with severe vitritis on slit-lamp examination while there were solitary chorioretinitis lesions on fundoscopy. Despite all patients were negative for anti-toxoplasma immunoglobulin M, all were positive for immunoglobulin G. All three patients were successfully treated with a combined treatment of systemic and intravitreal anti-toxoplasmic drugs. Clinicians should be cautious for the possible toxoplasma chorioretinitis besides the other infectious entities when a new uveitis episode is detected in an immunosuppressed patient in order to avoid misdiagnosis and thereby wrong treatment.
ABSTRACT
BACKGROUND: To compare distinctive features of hyperreflective particles observed on spectral-domain optical coherence tomography (OCT) sections in eyes with acute toxoplasma chorioretinitis (TC) and non-infectious uveitis (NIU). METHODS: Medical records and the spectral-domain OCT images of the patients with TC and NIU were retrospectively reviewed. The TC and NIU groups were compared in terms of age, sex, mean OCT image quality, mean central macular thickness (CMT), presence of intraretinal fluid (IRF), presence of subretinal fluid (SRF), number of hyperreflective particles in the posterior vitreous area and mean particle measurement in the posterior vitreous area. RESULTS: Non-infectious uveitis group included nine patients (60 %) with Behcet's uveitis, five patients (33.3 %) with idiopathic posterior uveitis or panuveitis, and the remaining patient (6.7 %) with HLA-B27 associated uveitis. Comparison of the mean age, sex distribution, mean OCT image quality, mean CMT, presence of IRF, presence of SRF and the mean number of hyperreflective particles in the posterior vitreous area between the two groups showed no statistically significant differences (p = 0.085, p = 0.051, p = 0.748, p = 0.431, p = 0.109, p = 0.080 and p = 0.152, respectively). However, the mean length of the hyperreflective particles in the posterior vitreous area was 27.22 ± 8.60 µm in the TC group, and 21.91 ± 3.58 µm in the NIU group, with a significant difference between the two groups (p = 0.036). CONCLUSION: This pilot study aimed to assess the hyperreflective particles in the posterior vitreous area using spectral-domain OCT images and image processing software. Despite its limitations, such as the small sample size, limited understanding of the nature of hyperreflective particles, and the absence of differentiation between acute and chronic uveitis, our study points out the potential role of the measurement of the hyperreflective particle length located in the posterior vitreous in differentiating the acute infectious versus non-infectious uveitis as the hyperreflective particles tend to be larger in infectious cases.
