Reproducibility of Anterior Segment Optical Coherence Tomography (AS-OCT) for Imaging Conjunctivochalasis

Conjunctivochalasis refers to loose redundant, non-edematous inferior conjunctiva that is situated between the globe and lower eyelid, and usually it occurs bilaterally. It has been reported to cause ocular discomfort, tear instability, alteration of tear spreading and subsequently dry eye, which is a common condition that affects vision and quality of life in patients. This condition has also been reported to be associated with aging and ocular surface inflammation. The assessment of conjunctivochalasis was traditionally based on silt lamp examination and this may be cumbersome and highly subjective. Only recently, researchers have advocated the use of imaging and more objective documentation by anterior segment optical coherence tomography (AS-OCT), using Fourier-Domain RTVue-100 OCT. The AS-OCT is an imaging method that documents the tear meniscus and prolapse of conjunctiva into the tear meniscus in a safe, rapid and non-invasive way. Image analysis on the area of prolapsed conjunctiva can then be used to ascertain the severity of conjunctivochalasis. We propose the use of HD-Cirrus AS-OCT for the imaging of conjunctivochalasis, since this technique provides more magnified and colored digital images, which helps to delineate different tissues and serves as a better education tool for patients. This current study aims to investigative the inter and intra examiner reproducibility of imaging conjunctivochalasis using HD-Cirrus AS-OCT, using patients from the dry eye clinic from the Singapore National Eye Centre. These patients will be asked to come to the centre for imaging and have three scans of the same eye performed in one session by two trained investigators consecutively. The resulting limits of repeatability will be very useful for us to follow up patients who undergo surgical or diathermy treatment for conjunctivochalasis, and for sample size calculation in the planning of interventional studies.