Abstract: Objective This study aimed to discuss the changes in macular retinal thickness and subfoveal choroidal thickness(SFCT)in patients with internal carotid artery occlusion(ICAO). Methods The data of 50 patients(100 eyes)diagnosed with ICAO were retrospectively analyzed. The patients included in the study had complete ICAO in one eye and ≤50% stenosis of the internal carotid artery in the contralateral eye. All eyes were scanned through the central fovea of the macula using spectral domain optical coherence tomography. The central macular thickness(CMT), average inner and outer retinal thickness within 1 mm from the fovea, and SFCT were then measured. Results The affected and contralateral eyes had a CMT of(244.56±18.25)μm and(248.02±23.12)μm, respectively, and this difference was not statistically significant(t=-1.673, P=0.101). The inner retinal thickness was(63.76±10.16)μm and(64.92±10.89)μm and the outer retinal thickness was(180.80±17.31)μm and(184.22±22.01)μm, for the affected and contralateral eyes, respectively. The differences between the two eyes in these aspects were also not statistically significant(t=-1.569,P=0.123;t=-1.839,P=0.072). In contrast, the SFCT of the affected eye was thinner at(240.36±27.03)μm compared to that of the contralateral eye at(248.06±30.33)μm, and this difference was statistically significant(t=-2.496,P=0.016). Conclusion The CMT and inner and outer retinal thickness were not significantly changed, whereas SFCT was significantly decreased in eyes with ICAO. These findings suggested that changes in choroidal morphology precede those in retinal morphology.

Key words: Internal carotid artery occlusion, Spectral domain optical coherence tomography, Retinal thickness, Choroidal thickness, Macula