To explore the methods of diagnosis and differential diagnosis of ocular toxocariasis (OT).

11 patients (11 eyes) who were diagnosed OT at Department of Ophthalmology Xi′an People′s Hospital (Xi′an Fourth Hospital) and had ever misdiagnosed by other hospital from November 2016 to February 2021 were collected. Among them, there were 7 males (7 eyes) and 4 females (4 eyes) with an average age was (21.4±13.8) years (ranged from 4 to 47 years). The patient′s medical history, clinical manifestations, diagnostic procedure, imaging results and intraocular fluid test results were recorded. Age and intraocular pressure were described by ±s. Occupation, place of residence, contact history of cats or dogs, main complaint, past medical history, visualacuity, eye manifestations, imaging examination results, intraocular fluid test results and differential diagnosis were described by the number of cases and percentage. The patients were followed up for 6 months to observe whether the clinical diagnosis was corrected.

All 11 cases were monocular. There were 6 cases (6 eyes) under 18 years, accounting for 54.55% (6 /11), and 5 cases (5 eyes) over 18 years, accounting for 45.45% (5/11). There were 11 cases (11 eyes) with vitreous opacity, accounting for 100.00% (11/11), 7 cases (7 eyes) with vitreous stratification, accounting for 63.64% (7/11), and 4 cases (4 eyes) with vitreous proliferation and traction retinal detachment, accounting for 36.36% (4/11). Ultrasound biomicroscopy (UBM) showed there were 4 cases (4 eyes) with anterior vitreous opacity, accounting for 36.36% (4/11), and 3 cases (3 eyes) with abnormal hyperecho, accounting for 27.27% (3 / 11), suggesting the formation of peripheral granuloma; 9 cases (9 eyes) with abnormal vitreous echo by B-mode ultrasound, accounting for 81.82% (9/11), including 5 cases (5 eyes) with specific strip and strip layered echo, accounting for 45.45% (5/11), 4 cases (4 eyes) with point and mass echo, accounting for 36.36% (4/11). There were 6 cases (6 eyes) with traction retinal detachment by B-mode ultrasound, accounting for 54.55% (6/11). Fundus fluorescein angiography showed there were 6 cases (6 eyes) with optic disc staining / fluorescein leakage and significant retinal vascular leakage, accounting for 54.55% (6/11), of which 3 cases (3 eyes) showed "fern like" leakage of retinal capillaries, accounting for 27.27% (3/11). Optical coherence tomography showed significant macular edema in 3 cases (3 eyes), accounting for 27.27% (3/11). During the first misdiagnosis, there were 4 cases (4 eyes) with non infective uveitis, 2 cases (2 eyes) with old retinal detachment, 2 cases (2 eyes) with persistent primitive vitreous hyperplasia, 1 case (1 eye) with retinoblastoma, 1 case (1 eye) with macular edema, 1 case (1 eye) of Coat′s disease with neovascular glaucoma, accounting for 36.36% (4/11), 18.18% (2/11), 18.18% (2/11), 9.09% (1/11), 9.09% (1/9), 9.09% (1/11), respectively. The immunoglobulin (Ig) g of Toxocara lumbricoides in intraocular fluid was much higher than that of 3 U, accounting for 63.64% (7/11). Of the OT types, there were typical 9 cases (9 eyes), accounting for 81.82% (9/11), including 2 cases (2 eyes) with posterior pole granuloma, accounting for 18.18% (2/11), 4 cases (4 eyes) with peripheral granuloma, accounting for 36.36% (4/11), and 3 cases (3 eyes) with endophthalmitis, accounting for 27.27% (3/11); there were atypical 2 cases (2 eyes), accounting for 18.18% (2/11). The patients were followed up for more than 6 months, and the clinical diagnosis was not corrected.

OT is mostly monocular, which can be found in children and adults. The clinical manifestations of OT are complex and diverse, including posterior pole and (or) peripheral granuloma, endophthalmitis, vitreoretinal proliferation and other typical manifestations. B-mode ultrasound and UBM can assist in the diagnosis, which can also only show panuveitis or intermediate uveitis, accompanied by atypical changes such as macular edema and "fern like" leakage of retinal capillaries. The detection of Toxocara antibody in intraocular fluid is of great significance in the auxiliary diagnosis of OT.