Changes in Limbal Optical Coherence Tomography Angiography Outcomes in Patients With Overnight Contact Lens Wear

Objectives:To evaluate the perilimbal vasculature of patients who wear contact lenses (CLs) overnight with optical coherence tomography angiography (OCTA) and compare the results with healthy population.Methods:Forty-two patients were included in this observational study. The OCTA imaging was performed in the temporal quadrant of the perilimbal region using a swept-source optical coherence tomography system (Triton DRI-OCT; Topcon Corporation, Tokyo, Japan). The assessments were made in two depths: starting from the conjunctival epithelium to 200 m scleral depth and the scleral depth between 200 and 1,000 m. The vessel density, vessel length density, vessel diameter index, and fractal dimension were the main outcomes and compared between overnight CL users and healthy population.Results:Twenty-two patients who have been using CLs overnight for at least 3 months and 20 healthy individuals were included in the study. The vessel density at the superficial layer was significantly higher in the CL group compared with the control group (P<0.001). Vessel diameter index, vessel length density, and fractal dimension at the superficial layer did not differ between the groups (P>0.05 for all). There was no difference in the vessel density, vessel diameter index, vessel length density, and fractal dimension in the deep layer between the groups (P>0.05 for all).Conclusions:Patients who use CL overnight exhibit increased vessel density in the superficial layers of the perilimbal region, which may suggest new vessel formation in the conjunctiva. Anterior segment OCTA may be useful to evaluate the initial changes in limbal vasculature in CL users.