Eyeworld

EW CORNEA 42 May 2014 O cular surface squamous neoplasia (OSSN) remains a serious condition that is likely to appear among an ophthalmologist's patients but can be difficult to diagnose. Recent trends have moved treatment beyond surgery. Frederick W. Fraunfelder MD, chairman of the Department of Ophthalmology, University of Missouri, and director of the Mason Eye Institute, Columbia, Mo., said recognizing OSSN depends on pat- tern recognition. Dysplasia of the ocular surface has a distinctive ap- pearance whether it is epithelial in origin, lymphomatous or from pigmented cells, he said. Clinically, epithelial cell lesions appear stuck onto the surface of the eye and have an irregular blood vessel pattern. "Some clinicians describe this pat- tern as cherries on a cherry tree," Dr. Fraunfelder said. In addition, growth is a key fea- ture of premalignant or malignant lesions, and elevation of a lesion can sometimes indicate malignant trans- formation. Vincent de Luise, MD, assistant clinical professor of ophthalmology, Yale University School of Medicine, New Haven, Conn., said that al- though OSSN is uncommon and has variable presentation, such patients present to ophthalmologists "more than rarely." "It is better to be overly con- cerned about a suspicious lesion and excise it in total than to presume it is benign and follow it," Dr. de Luise said. He noted that an elevated, gelat- inous, pinkish, polypoid, fimbriated, papillomatous lesion, especially if the lesion stains with lissamine green or rose-bengal dye, is highly suspicious for OSSN. However, even sessile or flat leukoplakic lesions that appear clinically "benign" and that stain minimally or not all may also be dysplastic and cancerous. Watch for risk factors Correlative risk factors that have been identified in the etiology of OSSN include advanced age, HPV infection, HIV immunosuppression, genetic predisposition, smoking, cumulative UV exposure over time, proximity to the equator, and dermatological conditions such as actinic dermatitis and xeroderma pigmentosum, Dr. de Luise said. A preponderance of cases appears in elderly males. Ruling out invasion of OSSN is important, Dr. Fraunfelder said. High frequency ultrasound of the anterior segment allows ophthalmologists to check for that possibility. "Optical coherence tomography (OCT) has shown some promise in identifying and following OSSN as these lesions can show a hyperreflec- tive epithelial layer and a thickened epithelial layer," Dr. Fraunfelder said. Carol L. Karp, MD, professor of ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, said high-reso- lution OCT allows her to identify neoplastic tissue on the conjunctiva, "just like OCTs of the retina that can pick up very subtle abnormalities." Dr. Karp and her group have published numerous articles using a custom built device that gives 2-3 microns of resolution. The device is not yet available. However, a com- mercially available version of the custom OCT device will be "the wave of the future." Dr. de Luise noted that exci- sional biopsy with histopathological correlation remains the gold stan- dard for the diagnosis of OSSN. Treatment shift Shahzad I. Mian, MD, associate professor of ophthalmology and visual sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, Mich., said that after a diagnosis, use of excisional biopsy with clear margins or an incisional biopsy then cryotherapy helps treat margins if they are diffi- cult to identify. Adjuvant or primary treatment with topical interferon alpha-2b or mitomycin-C (MMC) is also effective. Subconjunctival injec- tions of interferon may be beneficial in patients where compliance is dif- ficult because of frequency of drops or irritation from the drops. Dr. Karp said that her favorite way to treat OSSN is with topical in- terferon because it is so kind to the ocular surface. Her second favorite medication to treat OSSN—after in- terferon—is 5-fluorouracil because it is less painful than MMC, very inex- pensive, compounded, and does not need refrigeration. Recent research co-authored by Dr. Karp examined the recurrence rates between surgical excision and interferon-only treatments and found no statistical difference be- tween the 5% and 3% recurrence rates. 1 "So they are both very good strategies," Dr. Karp said. Dr. de Luise noted that other reported series have found much higher recurrence rates when wide surgical excision—with or without cryotherapy—was the sole treat- ment. Recurrence rates reached 50% in cases of incomplete tumor exci- sion and up to 33% in cases with clear margins. Markers for recurrence include tarsal location of the initially pre- senting lesion, ocular irritation as a presenting symptom, and the pres- ence of dysplastic cells at the mar- gins of the primary resected lesion, Dr. de Luise said. by Rich Daly EyeWorld Contributing Writer Changes in the diagnosis, management of ocular surface squamous neoplasia O cular surface squamous neoplasia (OSSN) is an umbrella term for a group of conditions including squamous papilloma, conjunctival-corneal intraepithelial neoplasia (CIN), carcinoma in situ (CIS), or invasive squamous cell carcinoma (SCC). Invasive SCC, when dysplastic cells have migrated past the epithelial basement membrane into the stroma, carries the worst prognosis. If there is intraocular or intraorbital spread, enucle- ation or exenteration may be required. It is crucial that the ophthalmologist be able to identify these lesions and recognize when something looks more suspicious than a routine pterygium. One should also be comfortable in knowing when to observe a lesion, perform a biopsy, or refer the patient for tertiary management. New technology such as high-resolution anterior segment optical coherence tomography (OCT) may have a role in the management of OSSN, and there is increasing evidence for treat- ment options other than excisional biopsy with or without cryotherapy. Many cornea specialists advocate adjunctive or primary topical medical treatment using mitomycin- C, interferon alpha-2B, or 5-fluorouracil. In this month's "Cornea editor's corner of the world," Vincent de Luise, MD, Frederick Fraunfelder, MD, Carol Karp, MD, and Shahzad Mian, MD, share their expertise and discuss their experience in the diagnosis and management of ocular surface squamous neoplasia. Clara C. Chan, MD, cornea editor A patient presenting with ocular surface squamous neoplasia Source: Frederick W. Fraunfelder, MD Cornea editor's corner of the world

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