Unilateral retinal nerve fiber myelination with contralateral amblyopia.

Comment. Intraocular invasion of conjunctival squamous cell carcinoma is rare. The Bowman membrane is a thick acellular layer composed largely of collagenous tissue. Due to its structure, it often acts as an impenetrable barrier to the intraocular spread of conjunctival melanoma.Moreaggressivehistologicvariants that have a greater potential for invasion include spindle cell and mucoepidermoid carcinomas. It is of note that although the lesion in our patient did not fall within this subtype, it still demonstrated invasive behavior. Although squamous cell carcinoma generally exhibits slow growth and has a low likelihood of metastasis, this case highlights the need for accurate diagnosis and early intervention. This patient received successful treatment of invasive squamous cell carcinoma of the conjunctiva with proton beam therapy. Recently, the therapeutic options available to the clinician for the treatment of superficial conjunctival and corneal squamous cell carcinoma have expanded. Promising reports in the literature describe the use of photodynamic therapy and topical mitomycin C for the treatment of more extensive and recurrent lesions. However, previous to this article, the options that were suggested for the treatment of intraocularly invasive squamous cell carcinoma were limited to enucleation. This article suggests proton beam therapy as a potential alternative to enucleation. On review of the literature, some authors describe visually limiting complications with the use of external beam radiation for the treatment of conjunctival malignancy. Compared with other forms of irradiation, proton beam therapy can be delivered precisely to the superficial tissues and anterior chamber structures without significant deeper tissue penetration, thus minimizing unnecessary irradiation of the lens, ciliary body, and retina. Such a treatment approach is particularly suited to elderly patients who may be limited in surgical options by other medical comorbidities. Proton beam therapy was extremely well tolerated by our patient, who experienced no adverse effects from the radiation. Adverse effects may include dry eye, intraocular inflammation, conjunctival scarring, or glaucoma. Our knowledge of the efficacy of proton beam therapy is limited by the fact that we have only treated 1 patient and that we have relatively shortterm follow-up data. The regression of tumor and lack of recurrence in this patient does, however, suggest that proton beam therapy should be considered as a possible alternative to enucleation for the treatment of invasiveconjunctival squamouscell carcinoma.