Evaluation of conjunctival autograft reperfusion in pterygium surgery using anterior segment optical coherence tomography angiography (OCT-A)

Purpose: to sequentially study the healing response of conjunctival autografts (CAGs) using optical coherence tomography angiography (OCTA) in patients undergoing pterygium surgery Methods: seventeen eyes of seventeen patients who underwent pterygium excision with CAG were included. OCTA was performed at 1 week, 2 weeks, and 4 weeks post-operatively. The vessels were assessed at two different depths: 1. From conjunctival epithelium to a depth of 200 µm 2. From a depth of 200 µm to a depth of 1000 µm. Results: All CAGs demonstrated swelling during the first week. Intragraft hemorrhage was observed in 15 eyes (88.2%). CAG vessels showed variable dilation and tortuosity at this time. Under-perfusion of the scleral bed was noted in areas that showed a gap between CAG and the edges of the conjunctiva. During the second week after surgery, fine vessels formed connections between CAG and conjunctiva. Early evidence of vascular remodeling of marginal corneal arcades (MCAs) was visible at this time point. In the fourth post-operative week, CAG vessels were more complex and homogenous. Reconstruction of MCAs occurred in 15 patients (88.2%). Vessels of the conjunctival bed were dragged toward the autograft. Conclusion: OCTA of the anterior segment can be used reliably to assess healing response following pterygium excision with CAG. Episcleral vessels play a major role in the re-vascularization of CAG. The use of mitomycin C with conjunctival autografting does not significantly interfere with the natural reperfusion of the graft. Failure of MCA reconstruction might contribute to the recurrence of pterygium.