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bioRxiv · 10.1101/478719

Early detection of retinal alteration by visible and near-infrared optical coherence tomography (vnOCT) in a dexamethasone-induced ocular hypertension mouse model

Song, W.·Fu, S.·Song, S.·Zhang, S.·Zhang, L.·Ness, S.·Desai, M.·Yi, J.
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Abstract

PurposeTo apply a novel visible and near-infrared optical coherence tomography (vnOCT) in the dexa-methasone-induced ocular hypertension mouse model, and test the capability of four optical markers, peri-papillary retinal nerve fiber layer (RNFL) thickness, total retinal blood flow, VN ratio and hemoglobin oxygen saturation (sO2), in detecting retinal ganglion cell (RGC) damage in association with ocular hyper-tension.\n\nMethodsTwelve mice (C57BL/6J) were separated into a control (n=6) and a dexamethasone group (n=6) receiving twice daily saline or dexamethasone eye drops, respectively, for 7 weeks. Intraocular pressure (IOP) measurements were taken at baseline and weekly. Optical measurements by vnOCT were longitudinally taken at baseline, 4 weeks and 7 weeks. Following week 7, ex vivo RGC counting was performed by immunostaining.\n\nResultsThe dexamethasone group showed a measurable rise in IOP by week 2. Despite the IOP differences between the dexamethasone and control groups, there was not a statistical difference in RNFL thickness or total blood flow over 7 weeks. The dexamethasone group did show an increase in retinal arteriovenous sO2 difference (A-V sO2) that was significant at week 4 and 7. The RNFL VN ratio showed a significant decrease at week 4 and 7 in dexamethasone group associated with a decreased RGC count.\n\nConclusionsRNFL VN ratio and A-V sO2 are capable of detecting early retinal alterations in the dexamethasone-induced ocular hypertension mouse model. Data analysis suggests VN ratio and A-V sO2 are corralated with RGC loss secondary to ocular hypertension, while being independent of IOP.

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Song, W., Fu, S., Song, S., Zhang, S., Zhang, L., Ness, S., Desai, M., Yi, J.. 2018-11-29. Early detection of retinal alteration by visible and near-infrared optical coherence tomography (vnOCT) in a dexamethasone-induced ocular hypertension mouse model. https://doi.org/10.1101/478719

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