The spectrum of ultraviolet light associated ocular surface pathology. Setting the scene for novel methods in their assessment and management.

Abstract

The "ophthalmohelioses" represent a conglomeration of ocular surface and adnexa disease strongly influenced by increased ultraviolet light B exposure. Despite overlapping pathogenesis pathways, the severity of these differs across the different spectrums. Ocular surface squamous neoplasia (OSSN), pterygium and conjunctival melanocytic lesions represent the three most impacting subtypes of such "ophthalmohelioses" affecting the ocular surface. OSSN represents a broad class of squamous dysplastic lesions ranging from benign papillomas till invasive squamous cell carcinomas. Melanocytic tumours such as primary acquired melanosis have a great propensity to become malignant, especially if cells are atypical. Finally, pterygium is a benign growth commonly treated with surgical excision, but patients often face an endless remitting-relapsing cycle of pterygium recurrence and repeat surgery. If untreated, patients sight limitation secondary to visual axis invasion.

The early detection of OSSN, pterygium and melanocytic lesions is non-existent and often disease requires to be excised and subsequently microscopically analysed before a formal conclusion is made. For pterygium, the identification of Fuchs' Flecks at the head of pterygium may serve as satellite cells ahead of the main pterygium body. Handedness may serve a role in the eye in which pterygium is worse or develops. From a therapeutic point of view, these three "ophthalmohelioses" tend to recur consistently despite optimized treatments. This therapeutic dilemma presents themes of concern, including vision disruption, secondary to repeat surgeries given the relapsing-remitting characteristic of all three disease entities. Topical eye drops such as interferon alfa-2b combined with retinoic acid serve as a potential solution which offer superior tumour-free follow-up and rapid tumour resolution of OSSN or primary acquired melanosis lesions. The viral influence of human papilloma virus upon OSSN may be mitigated with the application of topical cidofovir. Additionally, specialized pterygium surgery may be an effective alternative to otherwise other subtypes of pterygium excision, others often being anatomically more destructive. At essence, a focus of novel therapeutic options that target pathways within "ophthalmoheliosis" pathogenesis is being presented within this thesis which may hopefully improve and expand ophthalmologist's arsenal against disease spectrums very relevant to the Australian populace.