Ophthalmic manifestation of bilateral ocular toxocariasis: a case-series

To explore the clinical features of bilateral ocular toxocariasis (OT).

In this case-series, the ocular characteristics and treatments of the patients diagnosed with bilateral OT from 2015 to 2024 were reviewed and analyzed. The influences of clinical manifestations on prognosis were evaluated.

Ten patients aged 21 ± 15 years were included. In all the patients, the onset of the two eyes was asynchronous. The first-affected eyes (FAEs) had worse visual acuity than the second-affected eyes (SAEs) (paired t test, P = 0.024). Peripheral granulomas were observed in 16 eyes (FAE/SAE: 9/7), followed by posterior granulomas in 3 eyes (all FAEs). The peripheral granulomas in FAEs were longer than those in paired SAEs (6.38 ± 1.69 mm versus 5.29 ± 1.77 mm, P = 0.045). Cyclitic membrane, vitreous strand, epiretinal membrane, tractional retinal detachment and ciliary body detachment were observed in 10 (FAE/SAE: 5/5), 6 (FAE/SAE: 3/3), 12 (FAE/SAE: 7/5), 5 (FAE/SAE: 2/3) and 1(FAE) eye at baseline, respectively. The incidences of these lesions didn't vary greatly from baseline to the latest visits except for an increased incidence of tractional retinal detachment (25% to 60%, P = 0.016). Cataract, posterior synechia, band keratopathy and ocular hypertension occurred in 14 (FAE/SAE: 8/6), 9 (FAE/SAE: 6/3), 5 (FAE/SAE: 3/2) and 7 eyes (FAE/SAE: 4/3), respectively. Peripheral granulomas might be correlated with poor visual recovery in this series (Stepwise linear regression, P = 0.003).

Bilateral OT cases tended to have an asynchronous onset and asymmetric severity between the two eyes. Such feature could help to maintain the diagnosis of OT and prompt further test of anti-T. canis antibody for confirmation despite bilateral involvement.