Study of visual outcome and complications following conjunctival autograft transplant in management of primary pterygium

Abstract

Introduction: Pterygium is a common degenerative disease of the anterior segment of the eye characterized by a wedge-shaped fibrovascular dysplasia of the bulbar conjunctiva with a prevalence of 12%. Exact etiology is unknown; risk factors include, long term exposure of ultraviolet B rays, dust, wind, chemicals and air pollution. To minimize recurrence after the traditional bare sclera surgical technique, adjuvant therapies and modifications to the surgical technique are being adopted. Geographically, Vijayapura is located close to the equator with inherent risk of higher ultraviolet radiation exposures. Of late there is an upsurge in the number of patients with diagnosed with pterygium opting for surgical correction. Conjunctival autograft transplant is promising modification of bare sclera technique is associated with significant reduction in pterygium-induced astigmatism thereby improved visual acuity, decreased postoperative complications and decreased recurrence rates. Objective: To evaluate the visual outcome and complications following conjunctival autograft transplant in management of primary pterygium. Methods: The present study was conducted in the department of Ophthalmology, B.L.D.E. deemed to be university Shri B.M. Patil Medical College, Hospital and Research Centre, Vijayapura between October 2019 to April 2021. A total of 52 patients above 18 years with a diagnosis of primary pterygium were included in the study. Age, gender, occupation, side and severity of pterygium was recorded. Preoperative visual acuity and corresponding decimal pin whole equivalent was calculated for each patient. Upon surgery with conjunctival autograft under local anaesthesia, postoperatively, visual acuity, corresponding decimal pin hole equivalent and complications were evaluated at day 1, day 7 and day 30. Comparison of pre and postoperative data was done using appropriate statistical tests. Results: Mean age of patients was 54.38±10.70 years and 69.3% belonged to the age group of 50-70 years. Slight female predominance was noted with female to male ratio of 1.17:1. Most of the patients were farmers (48.5%) followed by housewives (23.1%). All patients had nasal pterygium prominently on the left side than right (61.5% vs 38.5%). 76.9% patients had grade 2 pterygia. Preoperatively, most patients had a visual acuity of 6/24 (25%), followed by 6/36 (19.2%) and 6/60 (17.3%). The mean decimal equivalent value was 0.35±0.21. Compared to preoperative visual acuity, significant improvement was seen at postoperative day 1 (p=0.000), postoperative day 7 (p=0.001) and at postoperative day 30 (p=0.001). Similarly significant increase in the decimal equivalent postoperatively (0.001) than preoperative values. Factors including age, gender, occupation, side and severity had significant association on the visual outcome based on visual acuity at all follow ups. Most common postoperative complication at day1 was subconjunctival haemorrhage (36%) is the common one followed by graft edema (36%) and graft retraction (13.5%). Resolution of complications was seen by day 30. Conclusion: Conjunctival autograft is a feasible and safe option in patients with primary pterygium with severe grading.