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Purpose: This study was performed to assess the prevalence of the vascularized foveal zone, including macular-foveal capillaries (MFC) and congenital retinal macrovessels (CRM), and to analyze the structural characteristics of the macular area in patients with MFC., Material and Methods: The first phase of the study evaluated the prevalence of MFC and CRM. Optical coherence tomography angiography (OCT-A) was performed, and OCT-A images of the foveal avascular zone were analyzed. In the second phase, two groups were formed: the MFC group (12 eyes, 9 patients, mean age 43.8±10.7 years) and the control group (18 eyes, 17 patients, mean age 43.0±11.8 years). A comparative analysis was performed assessing central retinal thickness (CRT), thickness of retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), and foveal pit depth., Results: MFCs were detected in 45 eyes from a total sample of 1031 eyes of 536 patients. The presence of CRM was recorded in three eyes of three patients. RNFL thickness was significantly higher in the MFC group in the inferior parafoveal sector (26.50 [26.00; 29.50] and 24.50 [21.75; 26.50] μm; p =0.022) and in the foveal zone (15.50 [14.00; 16.00] and 12.00 [11.00; 14.00] μm; p =0.017). Additionally, patients with MFC had a higher thickness of GCL and IPL in the fovea, inferior, nasal, and temporal parafoveal sectors. The depth of the foveal pit was significantly lower in the MFC group compared to the control group (83.0 [77.4; 101.6] and 128.0 [107.5; 147.05] μm; p =0.001)., Conclusion: The prevalence of MFC was 4.36% (calculated per number of eyes), while the prevalence of CRM - 0.29%. The macular area in patients with MFC had increased thickness of the inner retinal layers and decreased depth of the foveal pit, suggesting potential disruption in the natural process of ganglion cell migration and apoptosis during embryogenesis.

This review is devoted to the English- and Russian-language terminology of quantitative metrics that are used in the evaluation of images obtained by optical coherence tomography angiography (OCT-A). The paper presents an analysis of the use of terms characterizing intraretinal blood flow (vascular density, perfusion density, skeletonized density, etc.), area and shape of the foveal avascular zone, and choriocapillaris blood flow. The factors causing the heterogeneity of OCT-A terminology are described, including the lack of a unified international nomenclature for OCT-A, features of their Russian translation, inconsistency of the parameters in optical coherence tomography systems of different manufacturers. The article also considers ways to standardize the terminology.

Background and Objective: There is an emerging role for optical coherence tomography angiography (OCTA) in detecting microvasculature changes in diabetic retinopathy (DR). This study aimed to investigate visual functions and OCTA parameters of retinal and choriocapillaris (CC) flow in patients with type 1 diabetes mellitus (T1DM) without apparent DR., Patients and Methods: Patients and age-matched healthy volunteers were enrolled. All participants underwent low-luminance visual acuity assessment, OCT, and OCTA. Assessed OCTA parameters included foveal avascular zone area, acircularity index, vessel density (VD), skeletonized density, and CC flow deficits., Results: Low-luminance deficit (LLD) was significantly higher in patients with diabetes mellitus and correlated with skeletonized density and VD in the superficial vascular plexus (SVP). In the T1DM group, vessel density and skeletonized density were reduced in the SVP and deep capillary plexus. Flow deficits density and the mean size of the flow deficits were increased in patients with T1DM., Conclusion: Functional and microvasculature changes were observed at the preclinical stage of DR. Correlation of LLD and OCTA parameters can be a sign of early neurovascular impairment. [ Ophthalmic Surg Lasers Imaging Retina . 2021;52:S30-S34.] .

The article reviews the concept of swept source optical coherence tomography (SS-OCT) and presents a brief history of the technology, its implementation in modern commercial tomography, the advantages and disadvantages of the method.

The article reviews the evolution of visual acuity assessment and gives comparison of the visual acuity charts (Snellen vs. ETDRS) widely used in research and clinical practice.

Insufficient and controversial knowledge about the macular drusen (MD), a lack of scientifically proven management methods for drusen and their strong correlation with AMD active progression makes MD an important area of research., Aim: The purpose of the study – to assess clinical feature of MD using modern digital imaging technologies., Material and Methods: Patients with both hard and soft drusen were studied using fluorescein angiography, swept-source optical coherence tomography (OCT), OCT-angiography, autofluorescence (both short-wavelength and near infra-red), scanning laser ophthalmoscopy in Multicolor mode. The retina, choroid and vitreoretinal interface were assessed on 50 patients with AMD and drusen using different imaging modalities. An additional group of the study was presented by 5 patients with geographic atrophy (GA) formed as a result of soft drusen fading, where retrospective assessment of the OCT scans was performed with special attention to the signs of soft drusen regression associated with atrophy of the overlying RPE., Results: Two types of hard drusen were defined as the reticular pseudodrusen and the cuticular drusen. The qualitative and comparative analysis of data for each type of MD was performed. Vitreoretinal interface evaluation demonstrated the correlation between vitreomacular adhesion and mixed reticular and cuticular drusen. The choroidal thickness assessment in 9 different macular sectors in drusenoid eyes does not reveal a significant difference with control group. All of the analysed drusen-faded-eyes initially had been presented with OCT patterns of “nascent” GA., Conclusion: The modern retinal imaging techniques enable new approach to the diagnostic differentiation and description of various macular drusen types. The value of these methods for AMD prognosis is yet to be further investigated.

Aim: To evaluate the ganglion cell complex (GCC) changes in projection to the state of the retinal nerve fiber layer (RNFL) in patients with multiple sclerosis (MS)., Material and Methods: A total of 216 participants (370 eyes) were studied. Patients were divided into three groups: 1-st - 87 MS patients (121 eyes) with a history of optic neuritis (ON); 2-nd - 95 MS patients (186 eyes) without a history of ON; 3-rd - disease-free control 34 volunteers (63 eyes). Thirty-two MS patients (61 eyes) from the cross-sectional cohort were included for longitudinal analysis, follow-up period was 30 (9.5-36) months. Sixteen patients (21 eyes) had a history of optic neuritis. The study included anamnesis, refracted visual acuity and optical coherence tomography (OCT) performed with the use of RTVue-100 ОСТ system., Results and Conclusion: RNFL and GCC thickness was significantly decreased both in MS+ON and MS-ON groups compared to controls. No difference in the annual change of RNFL thickness and GCC parameters between patients with ON and patients who did not have any visual impairment in the anamnesis was found. Changes of GCC were detected only in patients with secondary progressive MS. The study of GCC and RNFL thickness can be used to describe and characterize the level of axonal damage in MS.