Bioelectric Activity of the Macula and Light Sensitivity in Retinitis Pigmentosa with Foveal Atrophy and Cystoid Macular Oedema

The paper is aimed at studying the bioelectrical activity of macula, light sensitivity and macular structure in retinitis pigmentosa (RP) with cystoid macular oedema (CMO) and atrophic maculopathy. 29 patients (58 phakic eyes), aged 16 to 40 (the average age 28.4 ± 8.2 years) with retinitis pigmentosa (RP) were divided into two groups: patients with foveal atrophy (30 eyes) and CMO (28 eyes). The control group involved 29 healthy subjects of the same age. The total ERG, the 30 Hz flicker ERG and macular ERG (MERG) were determined. The amplitude and latency of a- and b-waves were assessed. Light sensitivity and perimetric indices were estimated with automatic computer perimetry. Spectral ocular coherent tomography (OCT) was performed. In atrophic maculopathy and CMO, the decrease of the amplitude of a- and b-waves of MERG and a prolonged implicit time of the a-wave were found. The increased implicit time of the b-wave was found only in patients with CMO and it correlates with intraretinal cystoid changes in the inner nuclear and outer plexiform layers of the retina. A significant positive correlation between the amplitude of the a-wave of maximal ERG and mean sensitivity (MS), and a significant negative correlation between the a-wave amplitude and mean deviation (MD) indices of automatic perimetry were found. Thus, the prolonged implicit time of the b-wave of MERG is a specific sign of CMO. Perimetric indices are additional diagnostic criteria and may be used together with electroretinography to diagnose RP and assess its progression // Russian Ophthalmological Journal, 2016; 1: 12-18

Electroretinography and OCT angiography of the retina and optic nerve in retinitis pigmentosa

OCT angiography, an innovative noninvasive technique, allows a comprehensive assessment of eye vessels, separately for the choroidal and the retinal vasculature. Purpose: to assess microcirculation changes in the macular and peripapillary areas of the retina in retinitis pigmentosa (RP) by OCT angiography in comparison with electrogenesis parameters of the macular area of the retina and the cone system. Material and methods. The results of microcirculation studies of the fovea and the optic disk were analyzed for 14 patients with RP aged 5 to 76 (mean age 26.9 ± 17.6 years). OCT angiography was performed with Optovue RX Avanti (Optovue, USA). Рarafoveal vessel density, blood flow index, blood flow area, the size of the foveal avascular zone (FAZ) in the superficial and deep capillary plexuses and the flow area in retinal peripapillary capillaries (RPC) were assessed. All patients were tested by electroretinography using the MBN electroretinograph (Russia), including the general electroretingram (ERG), the maximal ERG, 30 Hz flicker ERG, and the macular ERG (MERG). Results. Blood flow deficit in superficial and deep capillary plexuses and in peripapillary capillaries (decreased parafoveal vessel density, vascular index, flow area) was associated with the reduction of a- and b-wave amplitudes of MERG and the increase of the implicit time. The enlargement of FAZ found in the deep capillary plexus (DCP) (p < 0.0001).and the normal size of FAZ in superficial capillary plexus (SCP) may be due to the difference in their structures. Conclusion. The blood flow deficit, which is more pronounced in DCP than in SCP in the macula of RP patients, is associated with the reduction of a- and b-wave amplitudes of MERG and the increase of the implicit time Russian ophthalmological journal. 2017; 10 (3): 22-28. doi: 10.21516/2072-0076-2017-10-3-22-28 // (in Russian). For citations: Zolnikova I.V., Levina D.V., Okhotsimskaya T.D., et al. Electroretinography and OCT angiography of the retina and optic nerve in retinitis pigmentosa. Russian ophthalmological journal. 2017; 10 (3): 22-28. doi: 10.21516/2072-0076-2017-10-3-22-28 (in Russian)