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Μελέτη μέτρησης πάχους χοριοειδούς οφθαλμών με κερατόκωνο με SD-OCT (EDI) και προσπάθεια ανάδειξής του ως κλινικού δείκτη πρόγνωσης και εξέλιξης στον κερατόκωνο (Master thesis)

Νασίκας, Βασίλειος

Purpose: Keratoconus is a bilateral ectatic disorder characterized by progressive thinning and steepening of the cornea. The pathogenesis of keratoconus has been partly attributed to atopy and inflammation, whose effects on collagen structure have been implicated in disease progression. Choroidal collagen type and vascular response to inflammatory mediators may be indirect indicators of such pathophysiologic mechanisms [1], [2], [3], [4], [5], [6]. In this study, we aim to determine choroidal thickness in keratoconus patients and compare the results with a control group. Methods: This is a cross-sectional, comparative study. We have been gathering data from 95 eyes, of which 51 are keratoconic and 44 are control cases, age- and refraction-matched. We use Pentacam® HR (Oculus, Inc.) topography for keratoconus confirmation and Spectralis® (Heidelberg Engineering) SD-OCT to measure choroidal thickness on a 12 mm B-scan image obtained with the enhanced depth imaging (EDI) mode without pupil dilation. EDI measurements are taken at nine points: one subfoveal, three nasal and five temporal to the fovea, at 500 μm intervals. Results: Mean age of the participants was 32.5 years. There was a statistically significant correlation between age and thinnest corneal pachymetry, mean choroidal pachymetry and thinnest choroidal pachymetry, (P<0.05). Nonetheless, age was not found to affect keratoconus index (KI), (P>0.05). Mean choroidal thickness was 322,6 and 346,4 microns in keratoconus patients and healthy subjects, respectively. There was not a statistically significant difference between keratoconus patients and healthy subjects in terms of choroidal thickness, (P>0.05). Moreover, keratoconus stage (TKC) does not affect mean choroidal thickness in keratoconus patients, (P>0.05). Finally, there was a statistically significant positive linear correlation between thinnest choroidal thickness and the choroidal thickness measured 1500 microns nasally from the umbo. Conclusion: Choroidal thickness may be a clinical biomarker for disease progression in keratoconus. Further research is needed to determine whether there is actual correlation between choroidal thickness and keratoconus.