Conjunctival Squamous Cell Carcinoma, from the CureRays guide library.

Conjunctival squamous cell carcinoma is a surface cancer of the clear membrane covering the white of the eye; it is treated with surgery plus topical chemotherapy eye drops, and radiation (often plaque brachytherapy) for higher-risk tumors, with excellent eye-preserving outcomes.

What it is.

Conjunctival squamous cell carcinoma is the most serious end of a spectrum called ocular surface squamous neoplasia (OSSN) — abnormal growth of the squamous cells covering the conjunctiva, the thin clear membrane over the white of the eye and the inner eyelids, and the adjacent cornea. It usually appears as a fleshy, gelatinous, or whitish growth near the edge of the cornea, often in areas exposed to sunlight, and may cause redness, irritation, or a foreign-body sensation. Risk factors include sun (ultraviolet) exposure, human papillomavirus (HPV) infection, a weakened immune system (including HIV), and the inherited condition xeroderma pigmentosum. Most of these cancers stay on the surface of the eye and grow slowly, so they are highly treatable with excellent results, but if neglected they can invade deeper into the eye or orbit and rarely spread to lymph nodes. Treatment aims to remove or destroy the tumor while preserving the eye and vision. The main approaches are surgical removal with a 'no-touch' technique and freezing of the edges (cryotherapy), and topical chemotherapy or immunotherapy eye drops that treat the whole ocular surface. Radiation — most often plaque brachytherapy, a small radioactive disc placed against the eye — is used for higher-risk, recurrent, or incompletely removed tumors. Outcomes are generally excellent with eye preservation.

How radiation treats it.

Radiation damages the DNA inside cancer cells so they can no longer divide and survive, while healthy cells repair themselves more effectively. In conjunctival squamous cell carcinoma, the most common form of radiation is plaque brachytherapy: a small disc holding a radioactive source is temporarily placed directly against the surface of the eye over the tumor bed, delivering a high, concentrated dose to the thin layer where the cancer lives while sparing the lens, retina, and optic nerve deeper inside. This is used for higher-risk, recurrent, or incompletely removed tumors and helps preserve the eye and vision. External-beam radiation may be used for more extensive disease. Radiation is given over a short period and, once the temporary plaque is removed, leaves no radioactivity in your body, so you remain safe to be around family and children. The overall goal is to control the cancer while keeping the eye.

The ways we can treat it.

Surgery. A no-touch excision removes the visible tumor with a margin, combined with cryotherapy to the wound edges; reconstruction of the ocular surface may be needed for larger tumors.

Plaque brachytherapy. A small disc holding a radioactive source is temporarily stitched to the eye over the tumor bed, delivering a concentrated dose to the surface while sparing deeper eye structures.

Topical (eye-drop) therapy. Chemotherapy or immunotherapy drops bathe the whole ocular surface, treating diffuse or hard-to-reach disease without cutting, often over several weeks.

Questions we hear often.

Will I lose my eye? Almost always no. Most conjunctival squamous cell carcinomas are caught as surface tumors and are cured while fully preserving the eye and vision, using surgery, eye drops, and — when needed — plaque radiation. Removing the eye is reserved for rare, neglected, or deeply invasive tumors.

Can it be treated with eye drops instead of surgery? Often, yes. Topical chemotherapy or immunotherapy drops can treat the entire ocular surface and are used either as the primary treatment or after surgery to lower the chance of recurrence. Your ophthalmic oncologist will recommend surgery, drops, radiation, or a combination based on your tumor.

Why did I get this, and can I prevent another? Sun (ultraviolet) exposure, HPV infection, and a weakened immune system raise the risk. Protecting your eyes from the sun with sunglasses and a hat, and addressing immune-related conditions, lowers the chance of recurrence and new tumors. Regular eye exams help catch any new lesion early.

This guide is informational only. It is not medical advice — please confirm anything here with your care team.