Observational study of ocular surface squamous neoplasia: Risk factors, diagnosis, management and outcomes at a tertiary eye hospital in South Africa

Abstract

Background Ocular surface squamous neoplasia (OSSN) is the most common ocular surface tumour. Diagnosis and management have traditionally been by excision biopsy. Recently there has been success with the use of topical chemo or immunotherapy, which has resulted in a move from invasive diagnosis by histology to an array of non-invasive diagnostic tests. Methods This observational study aims to describe the characteristics of patients with OSSN at St John Eye Hospital in Johannesburg, South Africa. Non-invasive diagnostic tests (impression cytology, anterior segment-OCT, methylene blue staining) will be compared to the gold standard, histology. Treatment success, recurrence and adverse events will be documented between three treatment options that include: surgical excision, topical 5-Fluorouracil (5FU) chemotherapy, and topical 5FU with retinoic acid therapy. Discussion There is a trend to the use of less invasive diagnosis and management for OSSN. Minimally invasive diagnostic tests include cytology, anterior-segment OCT and methylene blue staining. The study will compare these to the gold standard histology, thereby providing evidence for their use in clinical practice. Interferon alpha 2b is commonly used as immunotherapy for OSSN. The cost of this medication is prohibitive to its adoption in a developing country. We therefore decided to use 5FU as the chemotherapeutic agent of choice in this study. The success, adverse events and recurrence rates with this agent may provide additional evidence for its use in the management of OSSN. Overall, if diagnosis and management can be implemented with good success in the outpatient environment, care can be improved for this condition in a developing country.

Ocular Surface Squamous Neoplasia: A 12-Month Prospective Evaluation of Incidence in Waikato, New Zealand

“…The remaining five histologically confirmed OSSN lesions were preoperatively suspected pterygia (n = 4, 22.2%) and pinguecula (n = 1, 5.6%). Diagnostic adjuncts can be useful, including vital dye staining, cytology, in vivo confocal microscopy, and anterior segment-optical coherence tomography (AS-OCT) [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ]. However, each modality comes with its own limitations, and caution must be used in interpreting these tests.…”

Synchronous eyelid oncocytoma and conjunctival intraepithelial neoplasia

“…If the surgical margins are found to be involved on histology, adjuvant topical chemotherapy can be given to minimize recurrence. [21][22][23] Medical alternatives in the form of topical applications like 5-Fluorouracil (5FU) and mitomycin C (MMC) have been extensively reported in the literature. 11 In 1994, Maskin was the first to report the use of topical interferon (IFNa2b) in a multi-focal limbal OSSN.…”

Ocular Surface Squamous Neoplasia: Changes in the Standard of Care 2003 to 2022

“…1 Incidence of OSSN is approximately 0.03 to 1.9 per 100,000 persons in the United States and Australia, with the lower estimate reflecting a histologic diagnosis of squamous cell carcinoma alone and the higher estimate including dysplasia, carcinoma in situ, and invasive squamous cell carcinoma. 2,3 In African populations, the incidence of OSSN has been estimated between 1.6 and 3.4 per 100,000, 3 with the higher estimates compared with the United States and Australia believed to be driven by HIV-associated immunosuppression. 4,5 The leading risk factors for OSSN are exposure to ultraviolet radiation, immunosuppression, and human papilloma virus infection, but the frequency of these risk factors likely vary by study population.…”