Intraocular Inflammation Associated with Ocular Toxoplasmosis: Relationships Between Episodes of Active Disease

Abstract

Purpose : Host factors, including age, are associated with increased severity of toxoplasmic retinochoroiditis and shorter intervals to recurrence. We have previously shown that more severe inflammation of an episode also predicts shorter intervals to the next recurrence. We sought to determine if severity of an episode predicts other characteristics of recurrences as well.

Methods : We used a dataset of 210 patients with ocular toxoplasmosis from 7 international sites (North/South America, Europe). Longitudinal data for each episode were available for 46 patients with multiple documented recurrences. We compared the following factors at first visits of first-observed episodes to the same factors at first visits in all subsequent episodes: anterior chamber (AC) cell; vitreous haze; and intraocular pressure (IOP). We also compared duration of lesion activity between first-observed episodes and all subsequent episodes.

Results : Of 46 patients, there were 129 episodes (range 1-7 episodes/patient) including 558 visits with active disease. At first visits, AC cell was >1+ in 12 (27.3%) patients during first-observed episodes and in 11 (13.8%) episodes for all subsequent episodes. Median duration of lesion activity was 53 days (interquartile range [IQR] 27-91 days) for first-observed episodes and 45 days (IQR 32-68 days) for subsequent episodes. Those with >1+ AC cell at first-observed episodes more likely had >1+ cell at any subsequent episode (odds ratio [OR] 21.4 [95% CI 3.82-119.7], p=0.0002); agreement between episodes for individual patients was moderate (Kappa coefficient 0.478 [CI 95% 0.222-0.733]); however, >1+ AC cell was not related to elevated IOP (>21mmHg) subsequently (p=0.64). There were no relationships between first-observed episodes and all subsequent episodes for vitreous haze (p=0.18), elevated IOP (p=1.0), and duration of lesion activity (p=1.0).

Conclusions : Severe AC reactions during episodes of toxoplasmic retinochoroiditis predict not only shorter intervals to recurrences, but more intense inflammatory reactions in recurrent episodes. Despite a previously reported relationship between AC cell and elevated IOP at presentation, neither factor predicted elevated IOP at recurrences. Risk factors related to the characteristics of recurrent ocular toxoplasmosis have implications for management decisions, including the need for secondary prophylaxis against recurrence.

This is a 2021 ARVO Annual Meeting abstract.