Abstract
Purpose: :
Ocular Mucous Membrane Pemphigoid (OcMMP) is a rare, sight-threatening immune-mediated disease for which early diagnosis and appropriate treatment are essential. A study was performed to evaluate the incidence of new cases and their clinical signs, disease stage, treatment and duration of symptoms at the time of diagnosis.
Methods: :
Newly diagnosed cases of OcMMP were reported via the British Ophthalmological Surveillance Unit over a twelve month period. Reporting ophthalmologists were asked to complete a clinical data sheet detailing medical history, disease onset, extra-ocular manifestations, visual acuities, degree of cicatrisation and inflammation and corneal changes, treatments and biopsy results.
Results: :
Data were received for 48 cases from 22 hospitals in the UK. The minimum incidence of newly diagnosed cases of OcMMP in the UK was 0.7 per million, but there was significant geographical variation: the West Midlands had the highest incidence (1.8 per million), followed by London, the South West and Yorkshire (all at 1.1 per million), whilst there were no cases reported from the East Midlands or Wales. Patients were aged between 20 and 90 years, with a mean age of 67 years, and 45% were female. 19/48 (40%) cases had purely ocular disease. The duration of symptoms ranged from 1 week to 10 years, with a mean and median of 622 and 240 days respectively. Absence of preceding extraocular manifestations was significantly associated with diagnostic delay of more than one year (p=0.018). At the time of diagnosis 12/94 (13%) eyes had a visual acuity of 0.5 or less without any other attributable cause and 38/93 (41%) eyes had moderate or severe conjunctival inflammation. 16/93 (17%) and 12/93 (13%) could be classified as Mondino stages 3 or 4 respectively; 57/96 (59%) and 12/96 (13%) could be classified as Foster stages 3 or 4 respectively. 8/19 (42%) available direct immunoflourescence biopsy results were positive. Only 1/48 patients was on immunosuppressive therapy; for 27/48 (56%) immunosuppressive treatment was initiated or stepped up to more potent immunotherapy at the time of diagnosis.
Conclusions: :
The incidence of OcMMP is low but shows considerable geographical variation. Long delays in diagnosis of OcMMP are common, particularly in the absence of extraocular manifestations. At the time of diagnosis many patients already have moderate or severe disease. These findings highlight the importance of increasing awareness of this disease and prompt referral to centres with expertise in ocular surface immunosuppression.
Keywords: conjunctiva • autoimmune disease • clinical (human) or epidemiologic studies: prevalence/incidence