[Thickness of the retinal photoreceptor layers and the choroid, and bioelectrical activity of the macula in retinitis pigmentosa]. / Tolshchina fotoretseptornykh sloev setchatki, khorioidei i bioélektricheskaia aktivnost' makuliarnoi oblasti pri pigmentnom retinite.

PURPOSE: To assess the changes in photoreceptor retinal layers and the choroid in comparison with bioelectrical activity of the macula in patients with retinitis pigmentosa (RP). MATERIAL AND METHODS: The study included 10 patients (20 phakic eyes) with RP. Mean age was 27±18.5 years; mean best corrected visual acuity was 0.38±0.22. In addition to standard ophthalmological examination and fundus photography, each patient underwent an electrophysiological study on an electroretinograph MBN (Russia) recording general electroretinogram (ERG), maximal ERG (cone-rod response), 30 Hz flicker ERG and macular ERG (mERG). Choroidal thickness (CT) measurement and segmentation of the retina with following calculation of the thickness of different retinal layers was performed on SD-OCT RS-3000 Advance 'Nidek', Japan), it included obtainment of the 6-mm-diameter map in accordance with the Early Treatment Diabetic Retinopathy Study (ETDRS). RESULTS: The study revealed a decrease in thickness of the choroid, retina, and the photoreceptor layers: 1) the layer with photoreceptor outer segment (OS) and retinal pigment epithelium (RPE) and 2) the layer with photoreceptor inner segment (IS) and outer nuclear layer. Decreased thickness of these layers is associated with the reduction of bioelectric activity of the macula as seen with mERG. CONCLUSION: Decreased thickness of the retina, choroid and photoreceptor layers in all segments of the macula according to EDTRS standards is associated with reduced bioelectric activity of the macula recorded with mERG.

[Ocular blood flow and retinal electrogenesis in retinitis pigmentosa].

AIM: to investigate correlations between changes in ocular hemodynamics revealed by color Doppler flow mapping (CDFM) and pulsed-wave (PW) Doppler imaging, one the one hand, and electrical activity of the retina, on the other, in patients with early, moderate, and severe retinitis pigmentosa (RP). MATERIAL AND METHODS: A total of 20 patients (40 eyes) aged from 16 to 40 years (28.4 ± 8.2 years on average) with retinitis pigmentosa were enrolled. The control group consisted of 20 healthy volunteers of the same age range. All participants underwent full-field electroretinography (ERG), flicker ERG, and macular ERG as well as blood flow assessment in the ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (SPCA) by means of CDFM and PW-Doppler. RESULTS: Ocular blood flow in CRA and SPCA appeared disturbed in patients with early RP. In cases of moderate and severe RP, the peak systolic velocity of CRA and SPCA blood flow was significantly decreased. Systolic and end diastolic blood flow velocities in CRA and SPCA has been shown to be directly related to full-field ERG a-wave and b-wave amplitudes, correspondingly, but negatively correlated with their implicit times. CONCLUSION: The revealed decrease in CRA and SPCA blood flow indices proves retinal and choroidal circulation deficit in patients with advanced RP. As shown, moderate blood flow changes are already present in early RP and progress as retinal photoreceptors and bipolar cells become suppressed, which may be useful for RP diagnosis and monitoring.

[Macular and multifocal electroretinography in the diagnosis of Stargardt's dystrophy].

Retinal bioelectrical activity was studied in Stargardt's dystrophy from the data of multifocal and macular electroretinography (M-ERG) and retinal morphometry was carried out. The group of 11 patients (22 eyes) with the central form of Stargardt's dystrophy showed reductions in the retinal density of a bioelectric response of a P1 component, the amplitude of N1 and P1 components in the area of 0 to 16 degrees, as well as decreases in the amplitude of M-ERG a- and b-waves and in the retinal thickness in the macular region. The mixed Stargardt's dystrophy group was characterized by reductions in the retinal density of an electrical response of a P1 component, in the amplitude of N1 and P1 components in the entire posterior pole in the area of 0 to 32 degrees, as well as decreases in the a- and b-waves of M-ERG, photopic, scotopic, and mixed ERG; the lowered retinal thickness was found in the foveal and parafoveal regions. A statistically significant relationship was established between the morphometric indices of the volume of the central retina, the amplitude of M-ERG b-wave, and the moderate retinal density of P1 component bioelectrical activity in the central regions.

[Contrast sensitivity in amblyopia, abiotrophy and optic nerve atrophy in children]. / Kontrastnaia chuvstvitel'nost' pri ambliopii, abiotrofii i atrofii zritel'nogo nerva u detei.

The threshold spatial contrast sensitivity was assessed in children with amblyopia, tapetoretinal abiotrophy, and partial atrophy of the optic nerve of different origin. The measurements were carried out at spatial frequencies of 0.5-22 cycle/grad. Tests with white, red, green, and blue arrays against a black background realized in the Zebra software for IBM computers with VGA or SVGA displays were carried out. Classification of curves representing the contrast sensitivity for the above conditions is proposed. Characteristics of the groups with the above diseases are described, based on the height, shape, and mutual position of the curves.

[Critical frequency of flashes fusion in differential diagnosis of vision disorders in children]. / Kriticheskaia chastota sliianiia mel'kanii v differentsial'noi diagnostike patologii zritel'nogo analizatora u detei.

Critical frequency of fusion of flashes (CFFF) was measured in children by CFFF-D device recommended for clinical trials by the Ministry of Health and Medical Industry of the Russian Federation (Protocol No. 4 of June 13, 1996). A total of 213 children with central and peripheral retinal abiotrophy, partial atrophy of the optic nerve, refraction and dysbinocular amblyopia, and healthy children were examined. The most expressed changes of CFFF were observed in children with optic nerve atrophy. The CFFF-D device provides reliable results for the diagnosis.