En-face Optical Coherence Tomography as a Novel Tool for Exploring the Ocular Surface: A Pilot Comparative Study to Conventional B-Scans and in Vivo Confocal Microscopy

Abstract

PurposeTo explore the potential of spectral-domain optical coherence tomography (SD-OCT) using the en-face technology for the imaging of ocular surface diseases and to correlate the findings with in vivo confocal microscopy (IVCM) images. Patients and methods113 eyes of 75 subjects with various ocular surface diseases were investigated with the RTVue® anterior-segment en face OCT. En face OCT images were compared to B-scan OCT and IVCM images. ResultsPatients with corneal dystrophies, corneal deposits, keratitis, pterygium, conjunctivochalasis, or ocular surface squamous neoplasia and patients who underwent lamellar corneal surgeries were included. En-face OCT images showed ocular surface tissue changes that were not discernible using conventional B-scan OCT. Nevertheless, there was a good correlation with IVCM analysis. Compared with IVCM, the major advantages of en-face OCT included easy operation and rapid image acquisition, with minimal operator experience required. In addition, the non-contact method avoided patient discomfort and external pressure on the globe, which was especially useful in patients with corneal dystrophies, ulcers, or corneal abscesses. Although the resolution of en-face OCT was lower than that of IVCM, it allowed useful overall visualization of corneal lesions due to the larger areas analyzed. ConclusionEn-face SD-OCT is a novel, valuable tool to assess a wide variety of ocular surface diseases. It can provide additional information and new insight into different ocular surface conditions with no corneal contact.