The Role of Anterior Segment Optical Coherence Tomography in the Evaluation of the Pterygium

Abstract

Background: To evaluate the ability of anterior segment optical coherence tomography (AS-OCT) to visualize the anatomic features of the pterygium and its invasion of the corneal layers. Methods: Seventy-five eyes of 54 patients diagnosed with pterygium were included. All subjects underwent complete ophthalmologic examinations, including AS-OCT. The limbus-apex distance, vertical height at the limbus, invasion of the Bowman's and stromal layers, and other morphologic structures of the pterygium tissue were analyzed. Results: The mean age of the patients was 49.67 & PLUSMN; 16.49 (20-85) years. The mean apex-limbus distance was 2548.37 & PLUSMN; 1026.32 (933-4597) & mu;m, and the mean vertical height at the limbus was 4843.89 & PLUSMN; 1374.10 (1740-7784) & mu;m. A space was observed beneath the pterygium tissue in 44 (58.67%) eyes. The mean width and height of this space were 1756.33 & PLUSMN; 560.22 (1009-3095) & mu;m and 231.70 & PLUSMN; 85.88 (109-465) & mu;m, respectively. Invasion of the Bowman's layer was apparent in 74 (98.67%) eyes, and invasion of the stromal layer was detected in 33 (44%) eyes. A hyperreflective layer was observed beneath the epithelial layer at the edge of the pterygium apex in 31 (41.33%) eyes. In 24 (92.31%) of the 26 advanced pterygium cases and 20 (40.82%) of the 49 early pterygium cases, a subpterygium space was found beneath the lesion (p = 0.0001). Conclusion: AS-OCT enables measurement of the actual size and thickness of pterygia, assessment of invasion of the Bowman's and stromal layers of the cornea, and evaluation of the pterygium structure. Over half of the eyes exhibited space beneath the pterygium.