Assessment Of Conjunctival Autograft Reperfusion After Ptrygium Surgery By Optical Coherence Tomography Angiography (Octa)

To investigate and characterize revasularization of conjunctival autografts following pterygium surgery using optical coherence tomography angiography (OCTA)

 Farabi Eye Hospital, Tehran, Iran

Twenty-one eyes of 21 patients diagnosed with pterygium, based on cosmetic and visual indications, underwent pterygium excision with conjunctival autograft (CAG) without using Mitomycin-C. Over a 12-week follow-up period, changes in vascular density (VD), vascular density index (VDI), and vascular length density (VLD) were assessed at two distinct depths: superficial (<200 microns) and deep (>200 microns) using optical coherence tomography angiography (OCTA) during visits at 1, 4, and 12 weeks. Additionally, the revascularization rate and pattern were evaluated.

During the first week, the conjunctival graft was edematous and no sign of neovascularization was observed. In 4th week edema decreased and early signs of vascular formation appeared. Vessels originated from the episcleral bed of CAG and the surrounding episcleral vascular plexus. Smaller vessels connected these vessels in deep layers. In the 12th week, the deep vasculature was more condensed compared to the superficial layers. The deep layer vessels demonstrated a greater density of interconnectivity compared to the superficial layers, as evidenced by the presence of more small vessels connecting the deep layer vessels. VD and VDI significantly increased during the follow-up period (P<0.05). 

OCTA imaging emerges as a reliable tool for the qualitative and quantitative assessment of conjunctival graft vascularization, improving the monitoring of the healing process in the postoperative period. The evaluation of conjunctival graft revascularization patterns, in addition to vascular density (VD) and vascular density index (VDI), appear to be promising biomarkers that can predict the treatment's outcome and potential future recurrence.