Evaluation of inner retinal layers with optic coherence tomography in vigabatrin-exposed patients.

Abstract

In order to reveal the underlying retinal pathology leading to dysfunction in vigabatrin-exposed patients, we aimed to evaluate the inner retinal layers encompassing ganglion cell complex (GCC) layer and inner plexiform layer with new generation optic coherence tomography (OCT). Fourteen patients with epilepsy and exposure to vigabatrin and 12 clinically normal individuals, constituting the control group, were included. Retinal images were obtained using spectral-domain OCT (Optovue RTVue Fourier domain). Nasal and superior quadrants of retinal nerve fiber layer (RNFL) were found to be significantly lower in the patient group compared to the controls (p<0.01). No significant difference was shown in the thickness of GCC layer (p>0.05). Foveal thickness was significantly higher in the patient group (p: 0.006), but no significant difference was found in perifoveal and parafoveal regions between groups (p>0.05). The thickness of RNFL was found to be lower in vigabatrin-exposed patients without any reduction in GCC layer in the macular region. However, foveal thickness was found to be significantly higher compared to perifoveal and parafoveal macular regions in vigabatrin-exposed patients. In conclusion, OCT revealed reduced thickness of RNFL without any reduction in ganglion cell layer in our study. The objective quantitative assessment of OCT is a practical noninvasive method and it can have role in future monitoring of these patients.