Diagnostics and treatment of ocular toxoplasmosis : Results of a survey

Abstract

Ocular toxoplasmosis (OT) is the most common infectious cause of posterior uveitis. This survey aimed to evaluate the current diagnostic and therapeutic approach to OT in Germany. Adetailed questionnaire with specific patient examples was sent in July 2021 to the members of the Uveitis Section of the German Ophthalmological Society (DOG) and the Retinological Society (RG). The questionnaire was answered by 53 (29RG and 24DOG) ophthalmologists. Of the respondents 16 (30%) work in private practice, 18 (34%) in aclinical facility and 19 (36%) in university hospital, 9 (17%) colleagues see < 50, 28 (53%) 50-200 and 16 (30%) more than 200 uveitis patients per year. The clinical results are still the gold standard (87%) for the diagnosis of OT and in cases of first manifestation 60% are supported by serological antibody investigations, while 10out of 53 (19%) ophthalmologists rely on the clinical presentation only. An IgM test is requested by 25 (47%) respondents, 6 expected an increase in IgG titer (11%) and 1 the detection of specific IgA antibodies (2%). The majority (n = 28, 53%) of ophthalmologists would aim at confirming the diagnosis by an anterior chamber puncture, from which 20(38%) prefer PCR, 3(6%) determination of Goldmann-Witmer coefficients (GW) and 5(9%) acombination of both methods. Clindamycin was most frequently used for treatment (n = 21, 40%), followed by pyrimethamine/sulfadiazine (n = 17, 32%) and trimethoprime + sulfamethoxazole (TMP/SMX) (n = 10, 19%); the latter was also used (n = 40, 75%) for secondary prophylaxis. The results show that apart from the clinical results as the gold standard for the diagnosis, there is no uniform approach to diagnosis and treatment of OT. The high request rate for serum IgM antibodies indicates awidespread uncertainty about the importance of serological findings. This should be viewed critically, given the continued high seroprevalence in Germany.