MMP is a rare disease and its occurrence in the eyes is, likewise, unusual. This also contributes to the difficulty of obtaining a swift and accurate diagnosis. It is thought to develop in 8 per 10 million people per year. Consequently, this disease is often not the first consideration when a doctor is trying to find a diagnosis.
To confirm a suspected diagnosis of MMP, a small piece of tissue called a biopsy, is taken from the affected mucous membrane and/or the skin under local anaesthetic and tests done to confirm the diagnosis. This test is called a direct immunofluorescence test (DIF). The blood is also tested for the presence of autoantibodies (serology testing). MMP often starts in the other mucous membranes (most commonly the mouth) or the skin and, if you have an MMP diagnosis, you may be referred to an ophthalmologist by a specialist in oral medicine or a dermatologist. This is to ensure the eyes are monitored for the effects of the disease. If the appearances in the eyes are typical of eye involvement by MMP there is no need for any further tests to confirm the diagnosis.
However, in about a quarter of cases, the eyes are the only or first affected site and the condition of OMMP is diagnosed by an ophthalmologist. The same tests are then done as described above but with the biopsies taken from the conjunctiva of both eyes using anaesthetic eye drops and usually one other site (commonly the mouth or skin). When these tests are positive, the MMP diagnosis is confirmed. Whereas these tests are usually positive for MMP affecting non-ocular sites (e.g., mouth, nose, skin) they are negative in about 50% of cases when the eyes are the only site affected by MMP; this may result in delays in diagnosis for ocular MMP (OMMP) patients.
However, when these tests are negative in OMMP the disease can still be diagnosed by ruling out the other causes of conjunctival scarring and inflammation. In this situation, an opinion by a specialist in OMMP can be very helpful and they will work together with your local ophthalmology service to confirm the diagnosis, provide shared care and optimise your treatment.
About 60% of MMP patients have some level of eye involvement in their condition. Some people have only the ocular version of MMP, but many people have other mucous membranes such as mouth, nose, larynx, oesophagus and the genital and anus areas affected. It can also cause blistering on the skin. The degree of scarring varies by the location. You are likely to be referred to a variety of medical specialists to monitor the extent of your disease.
The ophthalmologist will treat cases depending on the severity of disease and the rapidity with which it is progressing. About one in five patients with OMMP have mild disease and don’t need specific treatment. However, for most patients specialised treatments are needed to prevent or slow disease progression. Topical treatments (eye drops or eye ointments) haven’t been found to be effective in preventing progression of OMMP so the usual treatment is to prescribe drugs taken by mouth (called immunosuppressive drugs).
These drugs are designed to reduce the over activity of the immune system that is causing the disease, whilst maintaining it enough to perform its normal activity such as fighting infection. This is quite sppecialised treatment, very similar to that used for diseases like rheumatoid arthritis.
The immunosuppressive drugs most often used for OMMP are:
If your eye disease is particularly severe, a biological treatment such as Rituximab or Truxima might be used, or intravenous immunoglobulin (IViG) which replaces antibodies in your system. All of these drugs can have serious side effects and you will need to be monitored while you are on them. Since this disease is chronic – which means it might last for a very long time and may require you to take medication indefinitely – you are likely to need regular check-ups.
Where the disease has also caused entropian (the eyelids turning in) and the eyelashes are scratching the cornea, then you may be recommended to have the eyelashes removed with tweezers (epilated) which some patients can do at home, or have surgery either to reposition in-turned eyelids or remove the lashes completely. Treatments to control the other side effects of OMMP may also be prescribed such as lubricating gels, drops or ointments for dry eyes and treatment for blocked eyelid margin glands (blepharitis) that can be treated with hot compresses and lid margin cleaning, as well as keeping your eyelids clean.
You can self fund or use private medical insurance to fund your treatment.