How is a conjunctival biopsy done? What is the actual procedure? What is the post-biopsy care? Can one see immediately after, or does the eye have to be covered?

J.M.

The conjunctiva is the outermost layer of the white part of the eye. There are many eye conditions that may require a conjunctival biopsy, a procedure in which a piece of the tissue is surgically removed and sent to the lab for analysis. For example, doctors may want to make sure a lesion on the conjunctiva is not malignant cancer, with squamous cell carcinoma and malignant melanoma being the two most common. Another reason for a conjunctival biopsy is to look for immune cells within the conjunctiva that are signs of disease affecting the whole body, such as sarcoid, ocular pemphigoid, Stevens-Johnson syndrome or amyloidosis.

The biopsy procedure itself usually does not take long and is often performed in a doctor's office, rather than in an operating room. First, local anesthetic eyedrops are applied, and sometimes a tiny injection of anesthetic is given beneath the suspicious lesion. Then, the doctor uses a forceps to grasp the conjunctiva, and a small piece of tissue is removed with surgical scissors. Afterward, an antibiotic ointment is applied, and sometimes the eye is patched for a few hours. If the eye is not patched, a person's vision should be just the same as before the procedure. To guard against infection, the patient may also be prescribed antibiotic eyedrops to use for a few days after this procedure.

One variation to the standard biopsy procedure is when a serious conjunctival tumor is strongly suspected. In these cases, the procedure is often done in a real operating room, and the entire lesion is carefully removed along with some surrounding tissue to make sure no cancerous cells are left behind. Otherwise, post-operative care is similar.