Ocular surface tumors can be primarily one of three malignant or pre-cancerous neoplasia of the conjunctiva and cornea. These tumors are ocular surface squamous neoplasia (OSSN) (sometimes referred to colloquially as the “skin cancer of the eye), ocular surface melanocytic tumors, or lymphoid tumors of the conjunctiva. OSSN includes many subcategories such as squamous dysplasia, conjunctival intraepithelial neoplasia, and invasive squamous cell carcinoma. Ocular surface tumors are rare, but dangerous.
Risk factors for Ocular Neoplasia
These tumors are rare, so researchers aren’t certain who is most at risk. It appears that elderly Caucasian men, especially those who live closer to the equator, are most at risk. UV rays enhance the danger of developing these tumors, just as they do other disorders like macular degeneration, In young people, the risk increases if they have HIV or HPV. Other risk factors include smoking, petroleum product exposure, and genetic predisposition.
Diagnosis for Ocular Neoplasia
Ideally, diagnosis occurs with a biopsy examined under a microscope, because there are many differential diagnoses possible; that is, there are many conditions that can look like neoplasms.
Impression cytology, where a special kind of paper (cellulose acetate filter paper) is applied to the ocular surface to collect cells, is less invasive and relatively reliable. It is an initial screening that cannot differentiate between a group of abnormal cells and an invasive tumor.
The condition can be mild, moderate, or severe.
Treatment of Ocular Neoplasia
Routine observation for benign tumors, cryotherapy, chemotherapy, radiotherapy, nuclear therapy, and other treatments are possible. There are two types of biopsy that might be performed. First, excisional biopsy is the complete removal of a lesion. Incisional biopsy removes part of the lesion for study. Excision of corneal intraepithelial neoplasia without cryotherapy often leads to recurrence, so a combination treatment is preferred. Recurrent surgeries and multiple surgeries can lead to limbal stem cell deficiency and cicatricial changes. Therefore, in the case of recurrence, doctors might use an alternative treatment such as radiation.
Different surgical techniques for closing larger wounds include conjunctival autografting, limbal transplantation, oral mucosa transplantation, and amniotic membrane transplantation.
Amniotic Membrane after Surgery for Ocular Neoplasia
Amniotic membrane is used extensively in the treatment of eye disorders like restrictive strabismus, especially in treating wounds after surgery. In the case of ocular surface tumors, amniotic membrane is an alternative to a mucous membrane graft for wound closure. One researcher concluded, “The amniotic-membrane use to repair conjunctival defects larger than 10 mm is a safe and effective technique with minimal complications allowing surgeons to make large enough excisions.” Amniotic membrane might be particularly effective over other choices because it is antiangiogenic, anti-inflammatory, and antifibrotic, and promotes epithelization. Further, conjunctival grafts can result in donor-site morbidity including scarring or other dysfunctions. In one study, cryotherapy was performed on 10 patients and the ocular surface was grafted with cryopreserved amniotic membrane. The study concluded that amniotic membrane was safe and effective with mild complications.
Patients need proper diagnosis of any tumors on the ocular surface. There are several kinds of tumors that might be diagnosed, with different forms of treatment available. Amniotic membrane will help heal wounds after surgery.