How to do conjunctival and buccal biopsies to investigate cicatrising conjunctivitis: improving the diagnosis of ocular mucous membrane pemphigoid

A 79-year-old female presented with a 3-year history of trichiasis and red eyes (figure 1A). Multiple operations for entropion and trichiasis had been carried out previously, and a conjunctival biopsy investigating mucous membrane pemphigoid (MMP), had been negative. Her right eye was blind due to retinal detachment and glaucoma. Acuity was light perception in the right eye (OD) and 6/12 in the left eye (OS). There was active inflammation and bilateral inferior symblepharon, left upper lid entropion and trichiasis. There were no systemic features of MMP.  Figure 1 (A) The patient's cicatrised inflamed left eye. (B) Taking a biopsy from the eye (not the same patient). If the speculum does not fit, manually open the lids. (C) Taking a buccal biopsy. (D) Michel's transport medium. (E) Direct immunofluorescence showing linear IgG, IgA along the basement membrane zone. Conjunctival and buccal mucosa biopsies were undertaken. Serum was tested for indirect inmunofluorescence. Conjunctival and serum immunofluorescence were negative, but buccal mucosa showed linear IgG and IgA staining along the basement membrane zone (BMZ), consistent with MMP. Oral prednisolone 1 mg/kg/day on a tapering course over 6 weeks, and mycophenolate 1 g twice daily were commenced. Nine months later, left upper lid entropion surgery was performed with excellent results. 1. What investigations are needed to identify the cause of cicatrising conjunctivitis? 2. Describe how to do conjunctival and buccal biopsies? 3. How would you manage the patient if you suspect ocular MMP, but all immunopathology …