The relationship between ocular toxoplasmosis and levels of specific toxoplasma antibodies

The relationship between ocular toxoplasmosis and levels of toxoplasma spec ific antibodies was examined in 195 patients, Using clinical information co llected by questionnaires, patients were divided into: 97 with ocular toxop lasmosis (group 1) and 98 with ocular lesions not due to toxoplasma (group 2). The geometric mean of dye test titres (+/-S.D. natural log titre) in gr oup 1 was 53.2 (+/-0.95) compared with 24.6 (+/-1.11) in group 2 (P < 0.001 ). Young females tended to have more active lesions compared with young mal es (P < 0.05). There was an age-dependent difference in dye test titres bet ween the groups (P < 0.001). Group 1 showed a decline in titre with age com pared with an increase in group 2. Ocular toxoplasmosis was diagnosed most frequently among 21-30 year olds. More group 1 patients had dye test titres greater than or equal to 65 iu/ml than group 2 (P < 0.05). Dye test titres greater than or equal to 65 iu/ml support a diagnosis of ocular toxoplasmo sis whereas lower titres suggest other causes for eye lesions.