Ocular fluid refers to the fluid present in the eye. It is a composite term used for both Aqueous humour and Vitreous humour. The test is performed to test the levels of pathogenic organisms. The sample collection is done either from the vitreous humour or the aqueous humour or both. The test results tell us about any infection if there is any present in the eye. The reasons for the infection also could thereby be detected by the test. The sensitivity to pathogenic substances like pollens, dust particles can also be tested. The test is performed both before the presence of infection is detected and after the treatment is administered.