Estudo das alterações funcionais e estruturais retinianas em pacientes com toxoplasmose ocular em fase cicatricial

Abstract

Introduction: ocular toxoplasmosis is the primary cause of posterior uveitis in Brazil and can result in significant losses of visual acuity. Structural retinal changes can be observed through spectral domain optical coherence tomography (SD-OCT), while functional losses can be assessed through standard automated perimetry. Objectives: to evaluate and describe the functional and retinal structural outcomes in patients with presumed cicatricial ocular toxoplasmosis using SD-OCT and standard automated perimetry. Methods: cross-sectional observational study conducted to assess functional and structural outcomes of presumed inactive ocular toxoplasmosis, involving participants from the Uveitis department of São Geraldo Hospital / HC-UFMG during the period from March 2021 to March 2023. Among the participants, thirty-seven patients had their epidemiological and clinical characteristics described and evaluated, whereas eighteen patients who completed the SD-OCT, the standard automated perimetry and met the inclusion criteria were considered for result evaluation. The statistical analysis compared the Mean Deviation (MD) measure, the global Retinal Nerve Fiber Layer (RNFL) and Ganglion Cell Layer (GCL) thickness between eyes with scars and without scars using non-parametric tests, adopting a statistical significance level of 5%. Results: There was a statistically significant reduction in eyes with scars compared to eyes without scars in MD in the 24-2 (p=0,014) and 10-2 (p=0,04) perimetry exams. The global RNFL and GCL thickness did not show statistically significant results. Among 27 patients with documented retinal zones, two-thirds had scars in zone 1; nevertheless, 51,4% of patients maintained best visual acuity between 20/20 and 20/40. The sample displays a prevalence range within the age of 25 to 45 years, with 68% being females. Conclusion: the reduction in MD was more pronounced in the group of eyes with scars, highlighting the functional impacts of this disease. The SD-OCT parameters exhibit greater variability due to the wide spectrum of clinical presentation of ocular toxoplasmosis.