The effect of pterygium on corneal thickness, corneal curvature, tear volume, and intraocular pressure in a Sudanese Population

Abstract

Background: Pterygium is a triangular fold of bulbar conjunctiva usually found in the nasal side of the interpalpebral fissure. It consists from apex and base. Its apex advancing progressively toward the cornea. The exact cause of pterygium is not well understood, but long-term exposure to sunlight, especially ultraviolet rays, wind, and chronic eye irritation from dry and dusty conditions seems to play an important causal role. It looks like scar, but it is not. The growth might spread slowly during a life or stop after a certain point. In extreme cases, pterygium can cover pupil and cause vision problems. Aim: The aim of this study is to reveal the effect of pterygium on corneal thickness, corneal curvature, tear volume, and intraocular pressure (IOP). Materials and Methods: A total of 100 patients have primary pterygium in one eye (unilateral) compared to their healthy (control) eye. The study was conducted in Makkah Eye Complex in Alkalakla branch between April 2016 and November 2017. The criteria of admission included individuals who have no history of systemic/chronic or other eye diseases. The patients whose pterygium enters the cornea within 2.0–3.0 mm and visual acuity at least 0.50 decimal (6/12) were selected. The data included age and gender, while the clinical procedures included testing vision and visual acuity (Snellen's type), autorefraction and autokeratometry, ultrasound pachymetry, applanation tonometry, and break-up time tear assessment. Frequency distribution tables and t-test were used to present the data. Results: The results showed that the pterygium was more apparent among male (53%) than female (47%). Significant decrease on visual acuity (77%) and tear volume (86%) of the pterygium eye (P Conclusions: Pterygium can cause significant change in ocular functions compared to HEs according to study parameters. Ocular dryness complications and vision impairment due to corneal astigmatism should be considered to make correct diagnoses for eye symptomatology.