Optical Coherence Tomography Findings In Acute And Chronic Retinal Artery Occlusion.

Purpose:To report spectral domain optical coherence tomography (SD-OCT) findings in acute and chronic retinal artery occlusions (RAO), and to compare these findings with other causes of inner retinal atrophy. Methods:Two cases of central retinal artery occlusion (CRAO) with perfused cilio-retinal artery and one case of cilio-retinal artery occlusion were observed in the acute phase and then followed for four months with SD-OCT. Other 4 cases of chronic central and branch RAO were also evaluated. SD-OCT images of different causes of inner retinal atrophy (advanced glaucoma and ischemic optic neuropathy) are reported and compared. Results:In the acute phase of RAO, SD-OCT discloses thickening and increased reflectivity of the inner retinal layers with shadowing effect on outer structures, and sharp demarcation between perfused and non-perfused retina. In the chronic phase, SD-OCT reveals severe and complete inner retinal atrophy and homogeneous intra-retinal structure, while outer nuclear layer and IS-OS/RPE hyper-reflective lines remain intact. On the contrary, in advanced glaucoma and optic neuropathy the inner retinal structure although reduced remains clearly detectable. Conclusions:SD-OCT in acute-CRAO demonstrates swelling of the inner retinal layers and sharp demarcation of the affected. In the chronic phases the homogeneous inner atrophy with absence of identifiable retinal layers represents a distinctive marker of RAO compared with other causes of inner retinal atrophy.