Macular volume and fovea thickness as OCT-criteria for multiple sclerosis. Preliminary results

Background. The characteristic optical coherence tomography (OCT) changes in the optic nerve head in patients with multiple sclerosis are known and have been described many times, however, the state of the macular area is described in a small number of publications.The aim: to analyze the changes in the macular area of the retina in patients with multiple sclerosis, to identify the OCT signs pathognomonic for this disease and to trace their changes over time as the disease progresses.Material and methods. In addition to the standard ophthalmological examination, 28 patients (55 eyes) diagnosed with multiple sclerosis underwent OCT of the macular zone to determine the thickness of the fovea and the volume of the macula in the 6 mm zone. The follow-up period was 6–12 years. The endpoints were the primary treatment and the most recent inspection.Results. At the initial examination, the visual acuity was 0.96 ± 0.24 (95% CI: 0.9–1.03), fovea thickness – 253.0 μm (Q1–Q3: 233.0–264.0), macular volume – 5.471 mm3 (Q1–Q3: 5.281–5.625). In 37 cases (67.3 %), the macular volume was below normal. The initial fovea thickness was below normal in 9 cases (16.4 %). At the end of the study, visual acuity did not change statistically (p = 0.824) and amounted to 0.96 ± 0.25 (95% CI: 0.90–1.04). The fi nal thickness of the fovea was 247.5 μm (Q1–Q3: 233.0–260.0), changes are statistically significant (p = 0.02). Number of cases with a thickness below normal in the fi nal study was 11 (20 %), change of frequency of cases was not statistically signifi cant (p = 0.5). The fi nal macular volume was 5.393 mm3 (Q1–Q3: 5.197–5.565), the changes are statistically significant (p = 0.023). The final number of cases with a volume below the norm was 42 (76.4 %), the change in the frequency of cases is close to statistically signifi cant (p = 0.063). At all stages of the study, there was no case of an isolated decrease in the thickness of the fovea without a decrease in the volume of the macula.Conclusion. The decrease in the volume of the macula with time while maintaining the thickness of the fovea within the normal range can be attributed to the pathognomonic OCT signs of multiple sclerosis. This criterion can be used for a comprehensive assessment of the course and therapy of this disease.

Decreased retinal microvasculature densities in pterygium

AIM: To investigate the retinal vascular network alterations in eyes of patients with pterygium. METHODS: Totally 18 left eyes from 18 female pterygium patients and 18 left eyes from 18 female healthy control subjects were enrolled. Optical coherence tomography angiography (OCTA) images were generated of the superficial retinal layer and deeper retinal layer of the macular retina for each eye. The microvascular (MIR) and macrovascular (MAR) densities were calculated and MIR, MAR, and total microvascular (TMI) density was compared in the healthy control and pterygium groups. RESULTS: In pterygium group, in the superficial retinal layer, the vascular density in superficial MIR, superior right (SR), inferior right (IR), right (R), superficial central annuli (SC)1, SC2, and SC3 decreased significantly in the macular area (P<0.05). Furthermore, the vascular density in all those decreased regions except R, was significantly and negatively correlated with the disease course (r=-0.6038 to -0.7762, P=0.0008), and the area size of pterygium (r=-0.6043 to -0.9508, P<0.05). For the deeper retinal layer, the density of deep total microvessel (DTMI), deeper MIR, SR, IR, R, DC2, and DC3 decreased significantly in macular area of pterygium patients (P<0.05). Furthermore, the vascular density in all those decreased regions was significantly and negatively correlated with the disease course (r=-0.6901 to -0.7795, P=0.0015), and the area size of pterygium (r=-0.6043 to -0.9563, P<0.05). No statistically significant differences and correlation was found in other region density (|r|<0.47, P>0.05). CONCLUSION: OCTA findings suggest that pterygium patients present with decreased retinal MIR density, and the major vascular alterations occurr mainly on the bitamporal side. The vascular density of the superficial SC1, SC2, SC3 adjacent to the foveal and deep layer of DC2, DC2 regions, significantly decreased.

Application of Angio Optical Coherence Tomography and Flash Electroretinogram in the Study of Retinal Morphology and Function in High Myopia

Purpose: Using optical coherence tomography (OCTA) and flash electroretinography (F-ERG), we investigated changes to the retinal micromorphology and the overall function of the retina in eyes with different degrees of high myopia. Design: Case-control study. Participants: A total of 64 cases of 118 eyes with axial high myopia with diopters ranging from -−6.0 D to −15.0D were included in the study. The individuals were 18-40 years old.Methods: Subjects were divided into three groups according to the axial length (AL) of the eye and the spherical equivalent (SE)of the lens: the high myopia group (AL: ≤26 mm and SE: −6.0D to −9.0D) with 32 eyes, the ultra-high myopia group (AL: 26-28 mm and SE: -9.25D to -12.0D) with 43 eyes, and the extremely high myopia group (AL: ≥28 mm and SE: −12.25D to −15.0D) with 43 eyes. We used the OCTA measurements macular foveal retinal thickness (MRT), foveal avascular zone (FAZ), and superficial macular and deep retinal microvascular density, and the F-ERG measurements retinal dark-adaptation a-wave and b-wave, oscillation potential (OP) wave, light adaptation a-wave and b-wave, and 30-Hz flicker light amplitudes, which represent the functional state of the retina.Results: The differences in retinal thickness in the macular area between the three groups were only statistically significant within 1 mm of the fovea (P = 0.006). MRT was positively correlated with AL (r = 0.278, P = 0.002) and negatively correlated with SE (R = −0.200, P = 0.031). The difference in the FAZ area between the three groups was also statistically significant (P = 0.036), and FAZ was negatively correlated with AL (r = −0.377, p < 0.001) and positively correlated with SE (r = 0.192, P < 0.5). Both the superficial and deep blood flow density of the macular fovea were positively correlated with AL (p < 0.001). The superficial parafoveal blood flow density was negatively correlated with AL (r = −0.280, P = 0.002) but positively correlated with SE (R = 0.254, P = 0.006). The overall blood flow density of the deep retina, the parafoveal blood flow density, and the blood flow density around the fovea were negatively correlated with AL (p < 0.001) and positively correlated with myopic SE (p < 0.001). The dark-adaptation b-wave, maximum comprehensive response a-wave and b-wave, OP wave, bright-adaptation a-wave and b-wave, and 30-Hz flicker amplitudes of the retina were negatively correlated with AL and positively correlated with SE. The amplitudes of light adaptation a-wave and b-wave were[1] negatively correlated with the foveal avascular density (p < 0.001), and the average amplitude of the OP wave was positively correlated with the superficial retinal avascular density (p < 0.001).Conclusions: Before obvious pathological changes or central vision damage, the morphology and function of the macular area show subtle changes in patients with high myopia. As the degree of myopia increases and the axis of the eye increases, the activity of the cone cells in high myopia eyes decreases and the microvascular circulation in the inner retina and function of inner layer cells, such as non-proa cells, are affected. The changes of retinal dark adaptation are more sensitive than those of bright adaptation, which indicates that retinal rod cell damage may be earlier than cone cell damage in high myopia. Therefore, we believe that the combined use of OCTA and F-ERG can help in the early diagnosis and monitoring of patients at a high risk of myopia and to guide their clinical treatment.Because the p-value is clearly provided, the term “significantly” is not necessary (removed to reduce wordiness).

Automatic segmentation of the borders of the pathological focus in the macular area of the retina to calculate the area of the pathological focus

Optical coherence tomography (OCT) is a modern, non-contact method of diagnostic examination that enables the visualization of various tissues of the human eye in a cross-sectional view at the microscopic level with the required morphological information. The software pre-installed in such devices contains many different tools for analyzing scans and has almost all the functionality necessary for the doctor to make a correct diagnosis. However, as time passes, more and more advanced methods of analyzing the images appear, which actualizes new tasks of developing additional software that can supplement and expand the functionality of the diagnostic equipment. This paper proposes an algorithm for automatic segmentation of the borders of a pathological focus in the macular area of the retina to calculate the area of the pathological focus, which together with other algorithms for analysis of morphometric parameters of the human eye, which are still under development, will be used for more accurate diagnosis of the stage of age-related macular degeneration.

Analysis of Retinal Capillary Using Optical Coherence Tomographic Angiography of Unilateral Normal Tension Glaucoma

Purpose: The purpose of this study was to analyze retinal capillary parameters using optical coherence tomography angiography (OCTA) of the affected eye and the fellow eye of unilateral normal tension glaucoma (NTG) patients and compare the findings with eyes from a normal control group.Methods: A retrospective cross-sectional study was carried out on patients diagnosed with unilateral NTG (24 affected eyes and 24 fellow eyes each) and normal individuals (29 eyes, the control group). OCTA was used to measure the vascular density (VD) and perfusion density (PD) of the macular area and the peripapillary area.Results: In the superficial capillary plexus, the fellow eye group of unilateral NTG patients showed a decrease in VD of the inner-inferior and PD of the inner-inferior and outer-average peripapillary area, compared with the normal control group (p = 0.008, p < 0.001, and p = 0.001). In the affected NTG eye group, the VD (p = 0.014, p = 0.011, p < 0.001, p < 0.001, and p < 0.001) and PD (p = 0.017, p = 0.023, p < 0.001, p = 0.001, and p < 0.001) of the total, inner-average, inner-inferior, and outer-inferior peripapillary area, and the outer-inferior macular area decreased compared to the fellow eye and normal control group, as well as the VD of the outer-average peripapillary area (p = 0.010). The PD of the outer-average peripapillary area (p = 0.003); the VD (p = 0.041, p = 0.008, p = 0.006) and the PD (p = 0.013, p < 0.001, p = 0.001) of the total, inner-inferior, and outer-average macular area; and the PD of the outer-temporal macular area (p = 0.003) were lower than the normal control group. There was no difference in the VD or PD obtained from the deep capillary plexus of the macular area among the groups.Conclusions: It is useful to observe retinal capillary parameters using OCTA for patients with unilateral NTG.

The features of diagnosis and treatmentof unilateral concomitant strabismus with visual fixation defect in preschool children

BACKGROUND:Particular difficulties in treatment of children with monolateral strabismus are associated with the presence of severe amblyopia in the squinting eye in combination with a visual fixation defect (acentral or intermittent). AIM:To assess the anatomical and functional status of children with visual fixation defects, to find out the causes of failures in treatment of this group of patients, to determine the tactics of their management. MATERIALS AND METHODS:The study included 92 children of preschool age (from 3 to 7 years) with monolateral concomitant strabismus. The follow-up period for the children ranged from 12 to 72 months. The average age of the examined children was 4.6 1.1 years. Three variants of visual fixation were identified in the squinting eye: central visual fixation (CVF) 68 eyes; intermittent visual fixation (IVF ) 7 eyes; and acentral visual fixation (AVF) 17 eyes. All patients underwent a comprehensive examination: visometry; strabometry; autorefractometry; determination of the critical frequency of light flashes; assessment of visual fixation; optical coherence tomography of the retina. All children underwent passive and active pleoptics. RESULTS:The visual acuity of children with CVF significantly increased due to pleoptics. At the same time in cases of IVF and even more in those of AVF, visual acuity remained significantly lower than that of the fixating eye, pleoptics were ineffective in this group of patients. In patients with CVF, the critical frequency of light flashes of the squinting eye increased in statistically significant figures, while in IVF and AVF, the difference between squinting and fixing eye remained. According to OCT data, changes in the macular area were detected in 18 (75%) eyes in patients with IVF and AVF, which allows us to distinguish organic pathology from amblyopia. CONCLUSIONS:In children with monolateral strabismus, it is necessary to determine visual fixation of the squinting eye. At IVF and AVF, it is mandatory to conduct optical coherence tomography of the macular area to exclude organic pathology. In patients with monolateral concomitant strabismus with IVF and AVF, surgery on oculomotor muscles is indicated.

Comparison of Retinal Vascular Arcade Trajectory Between Eyes with an Idiopathic Macular Hole and the Healthy Fellow Eye

Purpose: We aimed to present a method to evaluate the retinal arcade vascular trajectory by measuring the distance between the retinal veins in eyes with idiopathic macular hole (IMH) and compare this measurement with healthy fellow eyes.Methods: In this Cross-sectional study18 patients with unilateral IMH were enrolled. We used standard fundus photographs, which were obtained from each eye with a digital fundus camera using a 55-degree lens. The calculation of the retinal arcade vascular trajectories was done by drawing and measuring 5 vertical lines within the macular area. Results: The mean age of the patients was 65±9 years. The between-groups differences of each vertical line were not statistically significant, except for the differences between the most temporal line, which was greater in the diseased group (9388 vs. 8322 mm; P=0.034). The ratio between the 5th (most temporal) and the third (fovea-center) vertical lines was greater than 1 (V-shape) in 72% of eyes with a macular hole, whereas it was less than one (U-shape) in 78% of control eyes (P=0.003). Conclusions: We demonstrated that in eyes with an IMH the vascular arcade has more tendency to diverge on its path temporal to the fovea.

Wide-Field Swept-Source OCT Analysis of Interocular Symmetry of Choroidal Thickness in Subjects with Uncomplicated Pachychoroid

Background: We aimed to study the bilateral choroidal thickness (CT) symmetry and difference in uncomplicated pachychoroid subjects using wide-field swept-source optical coherence tomography (SS-OCT). Methods: All subjects underwent a wide-field 16-mm one-line scan using SS-OCT. Bilateral CT was measured at, and compared among, the following 12 points: three points at 900-µm intervals from the nasal optic disc margin (nasal peripapillary area), one point at the subfovea, six points at 900-µm intervals from the fovea to the nasal and temporal areas (macular area), and two peripheral points 5400 and 8100 µm from the fovea (peripheral area). Results: There were no statistically significant differences in CT between the right and left eyes in any area (all p > 0.05); they all showed significant positive correlations (all p < 0.01). However, the correlation coefficients (ρ) were smaller for the nasal peripapillary and peripheral areas compared to the macular area. Conclusions: The CTs in each region were bilaterally symmetrical in subjects with uncomplicated pachychoroid. However, interocular difference in CT increased from the center to the periphery, indicating that the anatomical variation of the nasal peripapillary and peripheral choroid was greater than that of the macula.

Posterior vitreous detachment and paravascular retinoschisis in highly myopic young patients detected by ultra-widefield OCT

The purpose of this study was to determine the relationship between a posterior vitreous detachment (PVD) and retinoschisis (RS) in 73 highly myopic (HM) young patients age 16.4 ± 6.9 years and 24 non-HM children age 8.4 ± 1.5 years. The presence of the paravascular retinal abnormalities was determined in the images obtained by a ultra-widefield OCT (UWF OCT) instrument with an image field of 23 × 20 mm. The results showed that a partial PVD was detected in 15 (21%) of the HM patients, and the number increased significantly with increasing age (P = 0.02). PVDs of any type were not found in the non-HM eyes. The number of microvascular folds also increased with age in the HM patients (P = 0.03). Medium-reflective columnar tissues were present between the detached vitreous and inner retinal surface in 4 (5%) eyes of the HM patients. Myopic RS was found in 3 (4%) HM patients in the paravascular area but not in the macular area. These results suggest that early partial PVD may play a role in pathological and proliferative vitreous changes of HM eyes. An intense vitreoretinal traction with bridging tissues may cause the various paravascular retinal abnormalities. In HM eyes, paravascular RS is already present at an early age which may progress to macular RS with aging.

Diagnostic difficulties of myopic staphyloma

Purpose. Comparative analysis efficiency of diagnostic of myopic staphylomas using optical coherence tomography (OCT) with scan protocols different lengths. Material and methods. A 52-year-old patient with high axial myopia with myopic staphyloma was examined. Profound ophthalmological examination was carried out using OCT of the posterior pole of the eye using scans protocols of various lengths, ultrasound ocular echography. The presence and localization of scleral staphyloma was assessed. Results. When examining the posterior pole of the eye using 12 mm linear OCT scanning, no signs of staphyloma were detected in both eyes. Radial OCT scans 10 mm in length, 3D OCT scans size 12×9 mm scan made it possible to suspect the presence of large macular myopic staphyloma. Examination of patient using 16.5 mm linear OCT scanning revealed distinct prolapse of the posterior pole of the eye, capturing the optic disk and the macular area in both eyes. Ultrasound B-scan confirmed the presence of staphyloma of the posterior pole of the eye in both eyes. Conclusions. 1. To identify the presence and localization of myopic staphyloma, the most informative method is 16.5 mm OCT scanning. 2. For the diagnosis of myopic staphilomas, it is possible to use 12 mm OCT scanning. Key words: optical coherence tomography, myopia, myopic staphyloma, scleral staphyloma.