Anterior Segment Imaging in Ocular Surface Squamous Neoplasia

Abstract

Recent advances in anterior segment imaging have transformed the way ocular surface squamous neoplasia (OSSN) is diagnosed and monitored. Ultrasound biomicroscopy (UBM) has been reported to be useful primarily in the assessment of intraocular invasion and metastasis. In vivo confocal microscopy (IVCM) shows enlarged and irregular nuclei with hyperreflective cells in OSSN lesions and this has been found to correlate with histopathology findings. Anterior segment optical coherence tomography (AS-OCT) demonstrates thickened hyperreflective epithelium with an abrupt transition between abnormal and normal epithelium in OSSN lesions and this has also been shown to mimic histopathology findings. Although there are limitations to each of these imaging modalities, they can be useful adjunctive tools in the diagnosis of OSSN and could greatly assist the clinician in the management of OSSN patients. Nevertheless, anterior segment imaging has not replaced histopathology's role as the gold standard in confirming diagnosis.

Extending far and wide: the role of biopsy and staging in the management of ocular surface squamous neoplasia

“…In addition, we found that while AS‐OCT is a reliable tool for the broad clinical diagnosis of OSSN, it was unable to consistently differentiate between invasive and non‐invasive tumours. These findings emphasize that neither AS‐OCT imaging nor clinical appearance alone can be used to reliably identify invasion, which is consistent with the AJCC's current heightened emphasis on biopsy with histopathologic analysis for OSSN staging (particularly for stages Tis, T1 and T2, for which depth of histopathologic invasion is explicitly defined).…”

Corneal Microlayer Optical Tomography Review

“…Corneas with scarring and Salzmann's nodular degeneration have a normalthickness epithelium overlying a dense, hyper-reflective lesion overlying Bowman's layer on UHR-OCT [16]. Epithelial hypo-reflective cysts without basement membrane thickening are seen in Meesman's dystrophy [60]. Eyes with secondary corneal amyloidosis show deposits of amyloid above Bowman's layer, and destruction of Bowman's layer as the disease progresses [61].…”

“…UHR-OCT can detect early secondary corneal amyloidosis as a dense spot in Bowman's layer [61]. Corneas with Thiel-Behnke Dystrophy have extensive deposits of hyper-reflective material in a saw-tooth pattern on the surface of Bowman's layer [60]. UHR-OCT images may become adjunct to clinical evaluation and provide an optical biopsy image in other conditions.…”

“…UHR-OCT images may become adjunct to clinical evaluation and provide an optical biopsy image in other conditions. Eyes with spheroidal degeneration show cystic structures in Bowman's layer and superficial stroma, and Salzmann's nodular degeneration has hyper-reflective material which replaces anterior stroma and Bowman's layer with thin epithelium [60] (Figure 2). Limbal stem cell deficiency exhibits a hyper-reflective material which replaces Bowman's layer as well as the anterior stroma, with irregular overlying epithelium (Figure 3).…”

“…Eyes with granular dystrophy show hyper-reflective material in the anterior stroma and clear intervening spaces. Macular dystrophy corneas show hyper-reflective stroma with areas of discrete, small hyper-reflective deposits in the subepithelial space, stroma, and Descemet's membrane [60]. Corneal Microlayer Optical Tomography Review DOI: http://dx.doi.org/10.5772/intechopen.84750…”