Viral involvement in the pathogenesis and clinical features of ophthalmic pterygium (Review)

Abstract

Pterygium is a potentially vision-threatening fibrovascular lesion originating from the conjunctiva that often extends on the corneal surface. Although it has been extensively studied, its pathogenesis has yet to be fully elucidated. Recent evidence on molecular genetic abnormalities in pterygium suggested neoplastic changes of limbal stem cells potentially associated with exposure to ultraviolet (UV) light. Human papillomavirus (HPV) is an oncogenic virus, associated with squamo-proliferative lesions of the anogenital region, skin and oropharynx. Several studies have shown HPV involvement in the pathogenesis of conjunctival neoplastic lesions, including papilloma and squamous cell carcinoma. The involvement of HPV as a co-factor in the pathogenesis of pterygium, although suggested by several studies using PCR and immunohistochemical techniques, remains controversial. Moreover, a marked variation in the prevalence of HPV in ophthalmic pterygium has been reported by different studies. Ethnic susceptibility and methodological differences in the detection of HPV may account for this variation. Surgical excision, often using sophisticated techniques, is the standard current method of therapy for pterygium. However, recurrences are frequent and recurrent lesions tend to be more aggressive. If indeed HPV is involved in pterygium pathogenesis or recurrence, anti-viral medications or vaccination may be new options in pterygium therapy.

Molecular Basis of Pterygium Development

“…[77][78][79] Previous investigations have analyzed the influence of viruses on pterygium pathogenesis. 11,80,81 From these reports, it was concluded that HPV is the virus most frequently found in pterygium, with prevalence rates ranging from very low up to 100%. According to these reviews, the lowest prevalence of HPV in pterygium samples has been identified in Turkish, Japanese, and Ecuadoran patients (0%, 4.8%, and 21%, respectively), [82][83][84] while the highest prevalence has been reported for Italian, Brazilian, and English patients (100%, 58.3%, and 50%, respectively).…”

Peroxiredoxin I and II in Human Eyes

“…A causative role for UV-B radiation is well documented by epidemiological and experimental data; other accepted risk factors include chronic inflammatory processes, alterations in cytokine expression, genetic factors and viruses (Cimpean et al 2013, Moran andHollows 1984;Lee et al 1994;Fox et al 2013;Siak et al 2011;Peng et al 2012;Chalkia et al 2013). Nonetheless, the underlying molecular mechanisms are poorly understood.…”

Identification of human papillomavirus in pterygium

“…We decided to apply IHC method to identify HPV in pterygia in order to avoid the false‐positive results, which are commonly associated with PCR technique (Chalkia et al. ). Moreover, most people develop immunity against HPV after a period of months or years of the infection and become HPV DNA negative (Onda et al.…”