The gold standard for OT diagnosis is identifying toxocara larvae in biopsy specimens. This is challenging, as it is difficult and risky to obtain a proper specimen for biopsy from the eye.
5,10 Currently, diagnosis relies on the typical clinical signs and symptoms, thus depends on the physician's knowledge.
11 Dana Woodhall et al. elucidated the diagnostic criteria of OT that OT is diagnosed by the identification of clinical signs consistent with disease on ophthalmologic examination, supported by testing for antibody to the toxocara parasite,
12 as well as Martínez-Pulgarín et al.
13 In 1986, Genchi assessed the serodiagnosis of ocular toxocariasis, demonstrating that specific immunoglobulin E (IgE) and G (IgG) toxocara antibodies could be used as laboratory evidence of the disease.
14 However, the interpretation of the required enzyme-linked immunosorbent assay (ELISA) results is not simple. Serum toxocara antibody tested positive in 2 to 18% of an apparently healthy population, suggesting possible past, self-cured infections.
15 On the other hand, even if serological toxocara antibody is negative, diagnosis of OT cannot be excluded.
16–19 Therefore, the detection of anti-toxocara IgG in the intraocular fluid (IF) has been suggested to confirm the diagnosis.
17 However, to date, a diagnostic cutoff value for IF anti-toxocara IgG has not been reported, and the diagnostic value of the Goldmann–Witmer coefficient (GWC) remains uncertain. For a more objective and precise diagnosis of OT, in this study, we detected the level of specific toxocara antibodies in serum and in IF, to further analyze their diagnostic value.