Changes in Ocular Subfoveal Choroidal Thickness After Carotid Endarterectomy Using Enhanced Depth Imaging Optical Coherence Tomography: A Pilot Study.

The influence of both severe chronic carotid stenosis and carotid endarterectomy (CEA) on ocular tissue has been poorly evaluated. The goal of this study was to measure subfoveal choroidal thickness (SFCT), before and after CEA, in patients with severe carotid stenosis. Consecutive patients (n = 36) with severe carotid stenosis were prospectively included. Patients (n = 19) were followed up at 1 and 3 months after CEA. The SFCT was measured bilaterally using enhanced depth imaging optical coherence tomography (EDI-OCT). Preoperatively, the median SFCT of the ipsilateral eye did not differ significantly from the contralateral eye (223 vs 236 µm; P = .75). In the ipsilateral eye, the mean SFCT was significantly higher at 1 month postsurgery and the effect was maintained at 3 months (226.3 ± 17.1 at 3 months vs 210.8 ± 16.5 µm at baseline; P < .001). For the contralateral eye, the increase in SFCT reached statistical significance at 3 months (220.1 ± 11.3 at 3 months vs 214.8 ± 11.5 µm at baseline; P = .04). The mean SFCT significantly increased bilaterally after CEA, with a more noticeable effect in the ipsilateral eye. Further studies are required to determine whether EDI-OCT could be useful as a potential marker of ophthalmologic outcomes.

Three simple approaches to visualize the transparent vitreous cortex during vitreoretinal surgery.

BACKGROUND: Initial historical considerations to perform a pars plana vitrectomy were made for opaque vitreous cortex due to dense asteroid hyalosis or vitreous hemorrhages. However, current indications for vitreoretinal surgery include mainly vitrectomies in the presence of a clear vitreous, for example retinal detachments, epiretinal membranes or macular holes, thus visualization of the transparent vitreous gel facilitates proper vitreous removal. MATERIALS AND METHODS: The transparent structure of the vitreous cortex as well as the thin epiretinal membrane may become visible during surgery by mild vitreous hemorrhages or intravitreous application of 0.05 ml crystalline triamcinolone acetonide. Eyes with a significant breakdown of the blood-retinal barrier accumulate intravenously applied vital dyes, for example fluorescein, in the vitreous cavity. RESULTS: Mild accidental intraoperative bleedings or intended injection of 0.05 ml autologous blood may help to stain transparent vitreous structures and visualize the remaining vitreous. Intravitreous triamcinolone crystals attach to the surface of the vitreous cortex, bursa premacularis or retina itself allowing better visualization of a controlled vitreous removal. A preoperative diagnostic fluorescein angiography in eyes with active uveitis or diabetic retinopathy may lead to a moderate accumulation of the dye in the vitreous cavity and greenish staining of the vitreous cortex at the vitreoretinal interface. DISCUSSION: A safe and complete removal of clear vitreous or transparent membranes may be achieved by the intraoperative application of autologous blood or triamcinolone. The preoperative systemic application of fluorescein greatly enhances the visualization of previously clear structures.