Changes in tear film function in patients after pterygium excision surgery done under topical anaesthesia with and without conjunctival autograft – A protocol for a randomized interventional study

Abstract

Background: Pterygium is an extra-ocular disorder related to progressive subepithelial growth of degenerative conjunctival tissue over the cornea. There are multifactorial causes that lead to the growth of pterygium. The tear film becomes unstable due to the degenerative growth of the conjunctiva. The tear film is divided into three different layers. The lipid layer is secreted by the meibomian gland, which is the exterior layer exposed to the environment and prevents tears from drying out too rapidly. The lacrimal gland releases the middle layer, the aqueous layer, which provides oxygen to the corneal epithelial layer. The goblet cells secrete mucus, the innermost layer that makes the corneal epithelium hydrophilic. Due to uneven wettability brought on by the progression of pterygium, the tear film becomes unstable and may damage the ocular surface. It has been found that pterygium excision increases tear film stability. According to a study, the incidence of pterygium in central rural India is 12.9%. Incidence increases with age, gender, and occupation. Methods: The patients with pterygium will be divided into two groups for the pterygium excision surgery: Group 1 consists of patients in which conjunctival autograft will not be done after pterygium excision, and Group 2 consists of patients in which conjunctival autograft will be done after pterygium excision. Preoperatively and postoperatively, visual acuity was assessed in all the patients on day 1, 4 weeks, and 8 weeks on follow-up. Tear film evaluation was done through Tear film Break Up Time (T-BUT) and Schirmer’s Test in patients preoperatively and postoperatively on day 1, 4 weeks, and 8 weeks follow up. CTRI Registration: REF/2023/07/071130 (30/07/2023) Protocol version: v1 dated 7/08/2023