EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
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114 EW CORNEA March 2013 Cornea editor's corner of the world A better view of ocular surface lesions by Vanessa Caceres EyeWorld Contributing Writer T he conventional approach to the diagnosis of possible malignant ocular surface lesions has been a biopsy. There was really no other way of obtaining an accurate diagnosis. Biopsies are very precise but have significant drawbacks. Conjunctival biopsy often requires a trip to the operating room, is relatively expensive, and delays treatment until the specimen is evaluated by a pathologist. Recently new technologies have been studied to make an immediate diagnosis in the clinic. Ultrasound has shown some potential, but high-resolution OCT is showing real promise as a technique that may some day eliminate the need for a biopsy. This technology will be especially valuable in the evaluation of pigmented lesions of the conjunctiva such as primary acquired melanosis versus melanoma. OCT may be a method for not only the diagnosis but also monitoring the response to therapy of ocular surface squamous neoplasia. OCT has the potential to give the clinician an immediate diagnosis and possibly eliminate the need for biopsy. Edward J. Holland, M.D., cornea editor Slit lamp photo of a conjunctival papilloma at the limbus Anterior segment surgeons find diagnostic and monitoring uses for OCT with lesions T he potential of ocular coherence tomography (OCT) to view the posterior segment of the eye is well-known. Many ophthalmologists also are discovering the technology's benefits for the anterior segment, such as viewing the tear film in dry eye patients, evaluating contact lens fittings, and taking refractive surgery-related images. Now, investigators are beginning to tout OCT's use to better view and diagnose ocular surface lesions. "OCT has not been used to image surface eye tumors until recently, so the images we are studying reveal patterns that have never been described before," said Frederick W. Fraunfelder, M.D., professor and director of cornea and refractive surgery, Oregon Health and Science University (OHSU) School of Medicine and the OHSU Casey Eye Institute, Portland, Ore. "We can get a very detailed look at surface eye tumor morphology and can determine if the tumor is invasive, how large it is, and where it is located," he said. More advantages The use of OCT to view ocular surface lesions can help clinicians zero in on an accurate diagnosis and then monitor the effects of treatment. "High-resolution OCT allows me to essentially perform an 'optical biopsy' on many ocular surface tumors and aids in the diagnosis of ocular surface squamous neoplasia [OSSN]," said Carol L. Karp, M.D., professor of ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine. Dr. Karp uses ultra-high-resolution (UHR) OCT regularly to view ocular lesions and is the senior author on a number of study papers on the topic. The technology also helps Dr. Karp differentiate OSSN from other kinds of lesions based on patterns of thickness shown via imaging. Based on the patient's OCT results, Dr. Karp will determine if a patient has OSSN or not and then decide if the patient needs an excisional biopsy or other intervention. After using treatments such as mitomycin-C, interferon, or 5-fluorouracil, Dr. Karp uses UHR OCT to monitor until the lesion is gone. "We do careful followup with the UHR OCT to make sure that there are no early recurrences that I cannot otherwise see with just the slit lamp," Dr. Karp said. Researchers are finding promising results when they compare OCT images of lesions to other traditional diagnostic methods. A study published online in January in Ophthalmology and led by Mohamed Abou Shousham M.D., and Dr. Karp's group at Bascom Palmer Eye Institute found close correlation with histopathologic specimens and UHR OCT images of various lesions. The noncomparative case series analyzed 54 eyes of 53 patients with biopsy-proven ocular surface lesions. The lesion types included primary acquired melanosis (eight lesions), amelanotic melanoma (five lesions), nevi (two lesions), OSSN (19 lesions), pterygia (11 lesions), conjunctival lymphoma lesions (six lesions), conjunctival amyloidosis lesions (six lesions), and one histiocytosis lesion. The outcome measures used were the patient's clinical course, photographs, UHR OCT images, and histopathology. RTvue OCT image of the same tumor as above. It shows that the lesion has not invaded into the eye. It has not broken through the epithelial basement membrane and is therefore not malignant. The image also shows the full depth and width of the lesion. Source (all): Frederick W. Fraunfelder, M.D.