Anatomical Parameters of Eye and Associated Histological Features are Potential Risk Factors for Development of Pterygium

Background and Objectives: Pterygium occurs throughout the world but the exact pathogenesis is still not clear. The reports on the association between eye anatomical parameters and presence of pterygium is controversial, similarly how the histological features of the pterygium may differ due to these parameters is not known. Thus, the focus of this study was to explore this gap by assessing and comparing the anatomical parameters of eye in pterygium patients and in healthy controls. In addition, histological features of pterygium were assessed and correlated with the eye anatomical parameters of the patients. Methods: Forty-one pterygium patients of age range 25-70 years undergoing surgery were included in the study after taking written informed consent. Forty-two age and sex matched healthy controls were also recruited for assessing anatomical eye parameters. Relevant history with demographic details of every subject was obtained. All participants underwent a thorough ophthalmic examination. Assessment of orbital protrusion and interpalpebral distance was measured by millimeter scale. Tear film breakup time (TFBUT) and Schirmer test was used for tear film assessment. Presence of any meibomian gland dysfunction (MGD) was examined by slit lamp. Post-surgical tissue samples from patients were assessed for histological features with H& E, PAS & Verhoeff stains. Data were processed and analyzed by using SPSS version 21.0. Results: Eyeball protrusion and MGD was found higher in pterygium patients as compared to controls. Basement membrane fragmentation on histology significantly correlated with the eyeball protrusion (P<0.04) and TFBUT (P<0.020), inflammation significantly correlated with the MGD (P<0.05) while elastosis showed significant correlation with TFBUT (P<0.001). Conclusion: It can be concluded that eye anatomical parameters might be the risk factors in the development of pterygium. The correlation between certain histological features & eye anatomical parameters indicate that anatomical eye parameters can be taken as risk factor for recurrence in these patients.