A small sample of tissue (biopsy) is taken from the eyes and usually also the mouth. These biopsies are evaluated under a fluorescence microscope and tested for antibodies associated with MMP. Whilst biopsies from skin and mouth MMP lesions are less than 10% likely to give false negative results, unfortunately biopsies from the eye can give a false negative result in 30-50% of cases. So a positive result from the eye confirms the diagnosis, but a negative result from the eye does not necessarily mean that the diagnosis is not MMP. In a proportion of patients with negative biopsy results, treatment with immunosuppressive therapy (which suppresses an overactive immune system) in a similar manner to patients with positive biopsy results, may be necessary.
A blood test may also be used to detect the antibodies in the circulation, but they are detectable in less than 30% of ocular MMP patients.
If it is likely that you will require immunosuppressive medication (which suppresses an overactive immune system), Ms Saw will request that you have baseline pre-treatment blood tests (including a full blood count, electrolytes & renal function, liver function tests) to establish if there are any pre-treatment abnormalities which require investigation or treatment, or which may alter her decision regarding which immunosuppressive medication would be best for your situation. These blood tests are usually done at the time that the biopsies are taken.
Once a diagnosis of OCP is made, you may be referred to a Dermatologist, an Oral Medicine specialist and/or an Ear, Nose & Throat (ENT) specialist, depending on your symptoms. Multi-disciplinary care is essential for successful management of OCP/ MMP.