No Evidence for a Pathogenic Role of Human Papillomavirus Infection in Ocular Surface Squamous Neoplasia in Germany

Purpose: The etiology of ocular surface squamous neoplasia is unknown. Possible etiologic factors are physical and/or viral damage by human papillomavirus (HPV), especially in Sub-saharian populations. This study focused on the presence of human papillomavirus in ocular surface squamous neoplasia in comparison to pterygia and normal conjunctiva. Methods: Thirty-one consecutive samples of ocular surface squamous neoplasia from a single institution (24 conjunctival intraepithelial neoplasias of various grades and 7 invasive conjunctival squamous cell carcinomas) were analyzed for evidence of HPV infection by immunohistochemistry and multiplex polymerase chain reaction (PCR). The results were compared to 11 samples of pterygia and 5 of normal conjunctiva. Results: Twenty-one (68%) of 31 ocular surface squamous neoplasia showed solar elastosis, while all cases analyzed were negative for HPV. Six (19%) of 31 ocular surface squamous neoplasia specimens demonstrated overexpression of p53 with a lack of p21 upregulation indicating a functional tumor suppressor gene p53 (TP53) mutation. Carcinomas presented a dysbalance between proliferation and apoptosis possibly contributing to tissue transformation and tumor growth. Conclusions: In our study, exposition to ultraviolet (UV) appears to be an important risk factor for the development of ocular surface squamous neoplasia, while HPV infection was not detected. TP53 mutations were also rare but may play a role in the progression from conjunctival intraepithelial neoplasia to invasive carcinoma in a subset of cases.