Assesment of the impact of transcatheter aortic valve implantation on retinal thickness as measured by optical coherence tomography in patients with severe aortic stenosis

Background:Severe aortic stenosis (AD) is an anatomical obstruction of the left ventricular outflow tract that prevents the passage of blood to the aorta in systole. This may lead to retinal ischemia by decreasing cardiac output due to the prevention of blood flow from the heart. Transcatheter aortic valve implantation (TAVI) relieves the mechanical obstruction and provides normal blood flow from the heart to the whole body. The purpose of this study is to investigate the influence of TAVI on the ganglion cell complex (GCC) thickness and retinal and retinal nerve fiber layer (RNFL) as measured by spectral domain optical coherence tomography (OCT) in patients with severe degenerative AS. Materials and Methods: This study was conducted using a prospective design andincluded 50 elderly patients (age 78.5 ± 6.9 years) with severe AS who were performed TAVI between December 2017 and June 2018. GCC, retinal and RNFL thicknesses were measured with spectral-domain OCT by ophthalmology department of our hospital just before TAVI and at 1 day and 1 month post TAVI and analysed. Results: In the left eye, the average retinal thickness (p= 0.04) was significantly increased 1 day after TAVI compared to pre-TAVI value. In addition, GCC thickness was detected to be significantly thinner at 1-day post-TAVI than pre-TAVI value in the inner inferior quadrant and outer temporal quadrant of the left eye respectively (p= 0.04,p= 0.05).There was no statistically significant change in retinal and GCC thickness in the right eye. There could not be determined any significant changes in RNFL thicknesses of both eyes after TAVI procedure. Conclusions: Here, we have revealed a significant influence of TAVI on the average retinal thickness of the left eye. However, it could not be observed the same impact on the GCC and RNFL thicknesses. Therefore, larger case series with longstanding follow-up should be conducted before interpreting our current findings.