Background: Chlamydia Trachomatis is the most common cause of trachoma and subsequently give rise to neonatal chlamydial conjunctivitis (NCC), adult ophthalmic inclusion infection, sexually transmitted diseases (STD) and pneumonia. The goal of this study was to access the incidence of chlamydia trachomatis in the normal (ophthalmic infection free) population.

Methods: In a cross sectional study 250 patients referring to Farabi Eye university Hospital Tehran, Iran for non infectious ophthalmic disease in different age categories were selected and accessed for chlamydial IgM and IgG by ELISA method.

Results: 250 patients (50% men and 50% women) with the mean age of 40 (ranging from one to 83 years old) were tested. IgG was detected in 11 (five females and six males) patients (4.4%) All of them had more than 31 years old. IgM was detected in 18 (13 females and 5 males) patients (7.2%). No test revealed simultaneous high IgG and IgM titre in the same patient.

Conclusions: There was a low grade of chlamydial infection in our study population. So it is recommended to use serological methods for screening of ophthalmic infections in centers where no other test methods are available and in case of positive results confirmatory antigen tests to be used.