25 November 2020
New imaging technique to diagnose eye lesions
Published online 25 September 2011
Conjunctival and corneal intraepithelial neoplasia (CCIN) causes freely moving lesions in the sclera, the white of the eye, with characteristic clusters of blood vessels. It is often accompanied by a grey, opaque, thickened epithelium in the cornea. CCIN is treated by surgery, and more recently by topical application of interferon alpha-2b or 5-fluorouracil.
Mohamed Abou Shousha, an ophthalmologist at the Bascom Palmer Eye Institute, University of Miami School of Medicine, and at the University of Alexandria, Egypt, led a team of researchers who used a prototype ultra-high-resolution (UHR) optical coherence tomography (OCT) device to diagnose CCIN and to follow up after surgery and topical treatment.
The team, whose findings appear in Ophthalmology, studied the eyes of 13 patients who had undergone one of the two types of treatment. They found that the non-invasive UHR OCT was a good option for monitoring patients during topical treatment to make sure it was not terminated too early. Morphological changes of thickened epithelium, sometimes too subtle to be seen clinically, could be seen using this technology.
At present, a post-treatment biopsy is the only way to confirm that treatment has been successful. Doctors perform small incisions to collect samples after treatment to make sure that the lesions have disappeared. This may cause scarring in the conjunctiva. Moreover, it can often lead to false-negative results by missing the smallest lesions. The study suggests that UHR OCT could be a more reliable alternative, as it offers a highly magnified view of the entire ocular surface, making it easier to see all lesions. It also does not have the dangers of excisional biopsies.
The researchers stress that a larger sample of patients is needed before UHR OCT can be specified for diagnosis of CCIN. The procedure also has some limitations, especially with very thick hyperreflective lesions, as it can cast a shadow, obscuring the doctor's view.