Ocular Toxoplasmosis Features Differ Between Men and Women

Clinical features of ocular toxoplasmosis differ between men and women even though clinical outcomes are similar, according to the findings of a prospective observational study published in the British Journal of Ophthalmology.

Sex-related differences have been reported for various forms of infectious and noninfectious uveitis. However, these findings are primarily limited to prevalence estimates. The purpose of this study was therefore to determine how sex influences the clinical presentation and outcomes of infectious uveitis, specifically ocular toxoplasmosis.

Researchers evaluated comprehensive ophthalmic examination data of 1 eye from 139 women and 123 men who were diagnosed with active or inactive ocular toxoplasmosis in São Paulo, Brazil between 2015 and 2017. There were no sex differences in mean age of presentation or in rates of active vs inactive ocular toxoplasmosis.

Men were significantly more likely to present with primary active disease (24.4% vs 12.9% of women; P =.050), whereas women were more likely to present with recurrent active disease compared with men (36.0% vs 28.5%; P =.050). Additionally, there was a trend towards atypical presentation for men (5.7% vs 1.4%), although this difference was not significant.

Men and women also differed with respect to the number and location of retinal lesions in ocular toxoplasmosis. One lesion was more commonly observed for men (50.4% vs 35.3% of women; P =.038), whereas multiple lesions were more commonly observed in women than men (54.7% vs 39.8%; P =.038). Women were more likely to have lesions at the posterior pole compared with men (56.1% vs 39.8%; P =.009). There were no differences in clinical outcomes between men and women including number and type of complications, time to complications, occurrence and timing of reactivation, and visual acuity.

These findings complement emerging evidence of gender- and sex-based differences of disease. Possible explanations for these differences in presentation of ocular toxoplasmosis include differences in occupational and sociocultural behaviors, gender-based differences in attitudes towards seeking medical care, and sex-based differences in immune response. Although this study did not include information about pregnancy, the authors also suggest, “The finding of more multifocal and posterior pole lesions in women versus men could support a hypothesis that different presentations are linked to the immunological adaptations that occur during pregnancy.”

These results may be influenced by selection bias against patients with asymptomatic or mild disease who did not require medical attention. Additionally, these findings are based only on self-reported gender and do not include both gender and sex.