Optical Coherence Tomography Results Research Articles

Presence of subfoveal hyperreflective dots as an anatomic and functional prognostic biomarker in macular holes

ObjectiveTo evaluate the presence of subfoveal hyperreflective dots (SfHD) using optical coherence tomography (OCT) in macular holes (MH) and establish whether there is a relationship with postoperative anatomical and functional outcomes. MethodsAn observational cross-sectional study was conducted at the Dr. Elías Santana Hospital. Sixty-eight eyes of 67 patients with a tomographic diagnosis of full-thickness MH who underwent pars plana vitrectomy (PPV) and internal limiting membrane (ILM) peeling were included. Preoperative and postoperative measurements were obtained using radial macular scans and HD raster scans with Optovue and Cirrus 5000 (Zeiss) OCT machines. The main outcome measures were anatomical closure by OCT and functional outcome through best-corrected visual acuity (BCVA). ResultsThe anatomical closure rate in our study was 63%. MHs that failed to achieve anatomical closure exhibited a higher number of hyperreflective dots and worse postoperative BCVA. A statistically significant association was found between exposed retinal pigment epithelium (RPE) in microns and the number of SfHD (p = 0.001). ConclusionSfHD is a common tomographic finding in MH, and the presence of a higher number of these points is associated with poorer anatomical and functional outcomes. This imaging finding is a potential prognostic biomarker in this pathology.

Presencia de puntos hiperreflectivos subfoveales como biomarcador pronóstico anatómico y funcional en agujero macular

ObjectiveTo evaluate the presence of subfoveal hyperreflective dots (SfHD) using optical coherence tomography (OCT) in macular holes (MH) and establish whether there is a relationship with postoperative anatomical and functional outcomes. MethodsAn observational cross-sectional study was conducted at the Dr. Elías Santana Hospital. Sixty-eight eyes of 67 patients with a tomographic diagnosis of full-thickness MH who underwent pars plana vitrectomy (PPV) and internal limiting membrane (ILM) peeling were included. Preoperative and postoperative measurements were obtained using radial macular scans and HD raster scans with Optovue and Cirrus 5000 (Zeiss) OCT machines. The main outcome measures were anatomical closure by OCT and functional outcome through best-corrected visual acuity (BCVA). ResultsThe anatomical closure rate in our study was 63%. MHs that failed to achieve anatomical closure exhibited a higher number of hyperreflective dots and worse postoperative BCVA. A statistically significant association was found between exposed retinal pigment epithelium (RPE) in microns and the number of SfHD (p=0.001). ConclusionSfHD is a common tomographic finding in MH, and the presence of a higher number of these points is associated with poorer anatomical and functional outcomes. This imaging finding is a potential prognostic biomarker in this pathology.

Potential ocular indicators to distinguish posterior cortical atrophy and typical Alzheimer’s disease: a cross-section study using optical coherence tomography angiography

BackgroundPosterior cortical atrophy (PCA) is a form of dementia that frequently displays significant visual dysfunction and relatively preserved cognitive and executive functions, thus hindering early diagnosis and treatment. This study aimed to investigate possible fundus markers in PCA patients and compare them with those of typical Alzheimer’s disease (AD) patients to seek potential diagnostic patterns.MethodsAge-matched PCA and AD patients and healthy controls (HC) completed optometry, intraocular pressure measurement, neuropsychologic assessments, optical coherence tomography (OCT), and optical coherence tomography angiography (OCTA) examination in one visit. Overall, six outcomes of thicknesses of various retinal layers and seven outcomes of the retinal microvascular network were calculated. After adjusting for age, sex, and years of education, the OCT and OCTA results were analyzed using analysis of covariance and generalized linear models. Correlation analyses were performed using Spearman correlation, and ROC curves were plotted.ResultsTwelve PCA patients, nineteen AD patients, and thirty HC, aged 45–80 years were included. Fifty HC, thirty AD, and twenty PCA eyes were available for foveal avascular zone (FAZ) area analysis; forty-nine HC, thirty-four AD, and eighteen PCA eyes were available for OCT and OCTA assessments. PCA patients had thinner retinal nerve fiber layer and ganglion cell layer + inner plexiform layer than HC in the 0–3 mm circle and 1–3 mm ring. Few structural differences were observed between the AD group and the other two groups. The flow area of the superficial capillary plexus and the intermediate capillary plexus was smaller in the PCA group than in the HC group in the 0–1 mm circle, 0–3 mm circle. MMSE performed better than any combination of optical parameters in identifying AD and PCA from HC (AUC = 1), while the combination of MoCA, retinal thickness and vascular density of ICP in the 1-3 mm ring, with flow area of ICP in the 0-1 mm circle showed the strongest ability to distinguish PCA from AD (AUC = 0.944).ConclusionsPCA patients exhibited similar impairment patterns to AD patients in the fundus structure and microvascular network. OCTA may aid in the non-invasive detection of AD and PCA, but still remains to be substantiated.

Post-fever Retinitis With a Positive Weil-Felix Test: A Study From a Tertiary Center in South India.

Background Post-fever retinitis (PFR) is reported two to six weeks after fever and affects one or both eyes. Rickettsial fever is one of the most common causes of PFR. This study aimed to report the clinical features and treatment outcomes of PFR cases with a positive Weil-Felix test. Methodology In this study, we collected demographic data, fever details, eye symptoms, ocular examination findings, optical coherence tomography (OCT) and fundus fluorescein angiography findings, laboratory findings, and length of follow-up of consecutive PFR cases with a positive Weil-Felix test. All cases were treated with oral doxycycline and prednisolone. Final best-corrected visual acuity (BCVA) and ocular examination findings were recorded. Visual field examination and follow-up OCT results were noted if available. Results A total of nine patients (eight males) with a mean age of 39.1 years with fever before ocular symptoms and positive Weil-Felix test were included.Six patients had bilateral disease. The mean initial and final BCVA in the affected eyes was 1.16 and 0.35 logMAR units, respectively (p < 0001). All 15 eyes had typical white retinitis patches and retinal hemorrhages which resolved after treatment. OCT showed hyperreflectivity and inner retinal disorganization over retinitis patches. White subretinal lines were noted in three patients and retinal nerve fiber bundle defect with corresponding visual field defect was seen in one eye. Conclusions In this study, PFR due to rickettsia infections has been reported from our region for the first time. Hence, eye specialists in the region should be aware of this entity.

Prognostic Value of Optical Flow Ratio among Patients with Coronary Artery Disease after Percutaneous Coronary Treatment: A Hospital-Based Retrospective Cohort Investigation

Objective: The goal of this study was to examine the prognostic performance of optical flow ratio (OFR) among patients with coronary artery disease (CAD) after percutaneous coronary intervention (PCI). Methods: We recruited patients with CAD undergoing optical coherence tomography (OCT)-directed PCI between January 2019 and June 2021 for our single-center, hospital-based, retrospective cohort investigation. We assessed the link between post-PCI OFR and major adverse cardiovascular events (MACE) via multivariate Cox regression analysis. Results: Receiver operating characteristic analysis revealed that the best post-PCI OFR threshold for MACE was 0.91, and introduction of OFR into the baseline profile and OCT results markedly enhanced MACE identification after PCI. On the basis of survival curves, patients with OFR ≤0.91 (P &lt; 0.001) and thin-cap fibroatheroma (TCFA) (P = 0.007) exhibited higher MACE incidence, and myocardial infarction (MI) incidence was considerably greater among patients with OFR ≤0.91 (P &lt; 0.001), compared with OFR &gt;0.91. Multivariate Cox regression analysis suggested that OFR ≤0.91 (hazard ratio [HR]: 3.60; 95% confidence interval [CI]: 1.24–10.44; P = 0.019), and TCFA (HR: 3.63; 95% CI: 1.42–9.20; P = 0.007) were independent risk factors for MACE, and OFR ≤0.91 was independently associated with MI (HR: 14.64; 95% CI: 3.27–65.54; P &lt; 0.001). Conclusion: OFR after PCI is an independent MACE bio-indicator among patients with CAD. Adding OFR to post-PCI OCT results may potentially enhance MACE prediction.

Results of a survey of ophthalmologists on the special aspects in performing and interpreting optical coherence tomography examination of the macula

BACKGROUND: Optical coherence tomography (OCT) is the main method for in vivo examination of the morphology of ocular posterior segment structures, used in modern ophthalmological practice.&#x0D; AIM: Study of special aspects in performing and interpreting the results of OCT of the macula by ophthalmologists working in the healthcare system of the Russian Federation.&#x0D; MATERIALS AND METHODS: In the anonymous survey, conducted using an original online questionnaire of 12 questions 59 respondents took part. They confirmed being ophthalmologists with experience in performing OCT and gave their consent to took part in the survey.&#x0D; RESULTS: The majority of respondents (79.6%) reported that they face the need to perform OCT without obtaining the patients clinical data. 66.1% of respondents always evaluate the correct placement of segmentation boundaries. Only 56% of the respondents always or often perform frontal (en face) scans during OCT examination of the macula. At the same time, 16.9% of specialists indicated that they did not know what segmentation boundaries are, and 8.5% noted that they did not understand the term en face scan. The principle of layer-by-layer analysis is used by 94.9% of respondents when describing images. Significant discrepancies were also revealed in the interpretation by the respondents of some parameters on specific examples of OCT scans. 71.2% of respondents have experience in using templates when describing OCT images, and 13.6% use them constantly. The proportion of specialists who consider it expedient to develop and introduce into clinical practice a standard protocol (template) for describing macular OCT images was 84.7%.&#x0D; CONCLUSIONS: Insufficient awareness of some ophthalmologists about particular principles of interpreting the results of an OCT imaging and about certain practical aspects of its application was revealed. This indicates the need in improving the quality of informational support and training of specialists. A request was received from ophthalmologists about the need to develop a standard protocol (template) for describing OCT images of the macular area with the aim of subsequent implementation into the clinical practice of the healthcare system of the Russian Federation.

Use of Adjunctive Corticosteroid With Antivascular Endothelial Growth Factor Agents in the Treatment of Choroidal Neovascular Membrane Associated With Presumed Ocular Histoplasmosis

Purpose: To evaluate the impact of combination treatment of antivascular endothelial growth factor (anti-VEGF) intravitreal injections and corticosteroids in patients with choroidal neovascularization (CNV) secondary to presumed ocular histoplasmosis syndrome (POHS). Methods: A retrospective multicenter study was conducted in a cohort from Illinois and Missouri. Patients were identified over an 8-year period, and data were evaluated over a 1-year study window commencing with treatment initiation. Group 1 included patients treated with intravitreal injections of anti-VEGF, and group 2 included those who received intravitreal injections of anti-VEGF and adjuvant corticosteroids. Optical coherence tomography (OCT) measurements and increases in Early Treatment Diabetic Retinopathy Study (ETDRS) letter score were compared between each group. Results: Using the method of last visit carried forward, the visual acuity (VA) in group 2 was 6.42 ETDRS letters better than the VA in group 1 at the final assessment. Patients in group 2 had a mean ETDRS letter gain of 21.50 ( P = .06) from the initial baseline vision. The average amount of decrease in OCT central subfield thickness compared with baseline was lower in group 1 (80.9 ± 129.8 µm) vs group 2 (102.8 ± 90.40 µm) at the 1-year follow-up visit ( P = .25). Conclusions: Approved treatment of CNV secondary to POHS is limited. Adjuvant corticosteroid treatment in patients with CNV secondary to POHS may provide better long-term vision and OCT outcomes than anti-VEGF alone and may offer an additional therapy option for these patients.

Multimodal OCT Control for Early Histological Signs of Vulvar Lichen Sclerosus Recurrence after Systemic PDT: Pilot Study.

Photodynamic therapy (PDT) is a modern treatment for severe or treatment-resistant vulvar lichen sclerosus (VLS). The chronic and recurrent nature of VLS requires control of recurrences at an early stage. In this paper, a non-invasive multimodal optical coherence tomography (OCT) method was used to control for early histological signs of VLS recurrence after systemic PDT using Photodithazine®. To interpret the OCT data, a histological examination was performed before PDT and 3 months after PDT. Two groups of patients were identified: with early histological signs of VLS recurrence (Group I, n = 5) and without histological signs of VLS recurrence (Group II, n = 6). We use structural OCT, OCT angiography, and OCT lymphangiography throughout 6 months after PDT to visually assess the skin components and to quantitatively assess the dermis by calculating the depth-resolved attenuation coefficient and the density of blood and lymphatic vessels. The OCT data assessment showed a statistically significant difference between the patient groups 3 months after PDT. In Group II, all the studied OCT parameters reached maximum values by the 3rd month after PDT, which indicated recovery of the skin structure. At the same time, in Group I, the values of OCT parameters did not approach the values those in Group II even after 6 months. The obtained results of multimodal OCT can be used for non-invasive control of early histological recurrence of VLS after systemic PDT and for adjusting treatment tactics in advance, without waiting for new clinical manifestations of the disease.

Relationship between Full-Thickness Macular Hole Onset and Posterior Vitreous Detachment: A Temporal Onset Theory

PurposeTo evaluate the relationship between full-thickness macular hole (FTMH) onset and perifoveal posterior vitreous detachment using optical coherence tomography (OCT) data.DesignRetrospective study.ParticipantsA total of 742 patients with FTMH or impending macular hole (MH) in at least one eye, as determined by ophthalmoscopy and OCT.MethodsMHs were staged using OCT results. Patients with the posterior vitreous membrane clearly detected in the OCT images and vitreoretinal adhesion size ≤ 1500 μm—eyes with MH stages 1–3—were included in the study. The contralateral eyes were also included in the analyses if they showed the focal type of vitreomacular adhesion (VMA) (i.e., vitreoretinal adhesion ≤ 1500 μm). The distance between the posterior vitreous membrane and the surface of the retina was defined as the posterior vitreous separation height (PVSH). Using the OCT images, PVSHs of each eye in four directions (nasal, temporal, superior, and inferior) at 1 mm from the center of the MH or fovea were calculated.Main Outcome MeasuresThe main outcome measures were PVSHs according to the MH stage and VMA, the relationship of the foveal inner tear with PVSH, and the likelihood of a foveal inner tear based on the direction.ResultsThe PVSH trends in each of the four directions were as follows: VMA < MH stage 1 = MH stage 2 < MH stage 3. Initial MH stage 2 (onset of FTMH) was defined as the presence of a gap in only one of the four directions from the center of the MH. With increased PVSH, the likelihood of a gap increased (P = 0.002), and a temporal gap was more likely to occur than a nasal gap (P = 0.002).ConclusionsAt FTMH onset, a foveal inner tear likely appears on the temporal side or the side showing a high PVSH value.

Multimodal imaging of laser-induced choroidal neovascularization in pigmented rabbits

This study aimed to demonstrate longitudinal multimodal imaging of laser photocoagulation-induced choroidal neovascularization (CNV) in pigmented rabbits. Six Dutch Belted pigmented rabbits were treated with 12 laser lesions in each eye at a power of 300 mW with an aerial diameter spot size of 500 μm and pulse duration of 100 ms. CNV progression was monitored over a period of 4 months using different imaging techniques including color fundus photography, fluorescein angiography (FA), photoacoustic microscopy (PAM), and optical coherence tomography (OCT). All treated eyes developed CNV with a success rate of 100%. The margin and morphology of CNV were detected and rendered in three dimensions using PAM and OCT. The CNV was further distinguished from the surrounding melanin and choroidal vessels using FDA-approved indocyanine green dye-enhanced PAM imaging. By obtaining PAM at 700 nm, the location and density of CNV were identified, and the induced PA signal increased up to 59 times. Immunohistochemistry with smooth muscle alpha-actin (αSMA) antibody confirmed the development of CNV. Laser photocoagulation demonstrates a great method to create CNV in pigmented rabbits. The CNV was stable for up to 4 months, and the CNV area was measured from FA images similar to PAM and OCT results. In addition, this study demonstrates that contrast agent-enhanced PAM imaging allows for precise visualization and evaluation of the formation of new blood vessels in a clinically-relevant animal model of CNV. This laser-induced CNV model can provide a unique technique for longitudinal studies of CNV pathogenesis that can be imaged with multimodal imaging.

Finite-Element Modelling Based on Optical Coherence Tomography and Corresponding X-ray MicroCT Data for Three Human Middle Ears.

Optical coherence tomography (OCT) is an emerging imaging modality which is non-invasive, can be employed in vivo, and can record both anatomy and vibrations. The purpose here is to explore the application of finite-element (FE) modelling to OCT data. We recorded vibrations for three human cadaver middle ears using OCT. We also have X-ray microCT images from the same ears. Three FE models were built based on geometries obtained from the microCT images. The material properties and boundary conditions of the models were obtained from previously reported studies. Tympanic-membrane (TM) vibration patterns were computed for the three models and compared with the patterns measured using OCT. Frequency responses were also computed for all three models for several locations in the middle ear and compared with the OCT displacements and with the literature. The three models were compared with each other in terms of geometry and function. Parameter sensitivity analyses were done and the results were compared among the models and with the literature. The simulated TM displacement patterns are qualitatively similar to the OCT results. The simulated displacements are closer to the OCT results for 500Hz and 1kHz but the differences are greater at 2kHz. This study provides an initial look at the combined use of OCT measurements and FE modelling based on subject-specific anatomy. The geometries and parameters of the existing FE models could be modified for individual patients in the future to help identify abnormalities in the middle ear.

Optical Coherence Tomography Can Reduce Colposcopic Referral Rates in Patients With High-Risk Human Papillomavirus.

This study aimed to evaluate the feasibility of combined human papillomavirus (HPV) and optical coherence tomography (OCT) cervical cancer screening strategies. The OCT and cytology results were compared with the pathological results to calculate the sensitivity, specificity, positive predictive value, negative predictive value, and immediate cervical intraepithelial neoplasia grade 3 or worse (CIN3+) risk. The authors compared the efficiency of colposcopy by using different triage strategies. They discussed differentiation in OCT screening in different age groups. Eight hundred thirteen participants with high-risk HPV-positive and cervical cytology results underwent OCT before colposcopy between March 1 and October 1, 2021. The HPV16/18 genotyping with OCT triage has a specificity of CIN3+ lesions (61.1%; 95% CI = 57.6%-64.6%), intraepithelial neoplasia grade 2 or worse (CIN2+) (66.0%; 95% CI = 62.4%-69.6%). The HPV16/18 genotyping with cytology triage has a specificity of CIN3+ (44.0%; 95% CI = 40.4%-47.6%), CIN2+ (47.0%; 95% CI = 43.2%-50.8%). The OCT triage has a higher positive predictive value compared with the cytology, with a significant difference in CIN2+ lesions (45.0%; 95% CI = 38.8%-51.3% vs 29.2%; 95% CI = 24.7%-33.7%). The combination of OCT and high-risk HPV triage (both genotyping and nongenotyping) had a similar immediate CIN3+ risk stratification and reduced the number of colposcopies compared with the cytological triage strategy.

Optical coherence tomography-assisted interventional treatment of a woven coronary artery: a case report

sBackgroundA woven coronary artery is a rare feature on coronary angiography. Distinguishing woven-like change and recanalization of an occluded artery is difficult.Case presentationA 59-year-old man was admitted to the hospital for chest tightness. Coronary angiography showed a woven coronary artery at the middle segment of the left anterior descending branch (LAD). The middle segment of the right coronary artery (RCA) exhibited 99% occlusion. A 3.5 × 26-mm drug-eluting stent was implanted in the middle segment of the RCA. One week later, we examined the LAD using optical coherence tomography (OCT). Considering the patient’s medical history and the results of OCT, a 2.7 × 38-mm drug-eluting stent was inserted into the LAD. Re-examination by OCT indicated that the stent was well attached to the wall, with no dissection at the edge of the stent. Antiplatelet therapy and statin-based plaque stabilization were continued. No obvious abnormality was found during follow-up one year later.ConclusionsOCT can help distinguish woven-like change and recanalization of an occluded coronary artery. The evaluation and formulation of treatment strategies for a woven coronary artery are important.

Optical Coherence Tomography Biomarkers in Predicting Treatment Outcomes of Diabetic Macular Edema after Ranibizumab Injections

Background and Objectives: The identification of possible biomarkers that can predict treatment response among DME eyes is important for the individualization of treatment plans. We investigated optical coherence tomography (OCT)-based biomarkers that may predict the one-year real-life outcomes among diabetic macular edema (DME) eyes following treatment by intravitreal ranibizumab (IVR) injections. Materials and Methods: A total of 65 eyes from 35 treatment-naïve patients with DME treated with ranibizumab injection were recruited. Best-corrected visual acuity (BCVA), central retinal thickness (CRT), intraocular pressure (IOP), and OCT scans were retrospectively recorded at baseline before treatment and at 3 months, 6 months, and 12 months after treatment. The OCT scans were evaluated for biomarkers of interest, which included central retinal thickness (CRT), amount and locations of hyperreflective foci (HRF), subretinal fluid (SRF), intraretinal cysts (IRC), large outer nuclear layer cyst (LONLC), ellipsoid zone disruption (EZD), disorganization of retinal inner layers (DRIL), hard exudates (HE), epiretinal membrane (ERM), and vitreomacular interface (VMI). Correlations between these OCT biomarkers and outcome measures (visual and structural) were statistically analyzed. Results: A total of 65 eyes from 35 patients with DME were enrolled. The mean age was 64.2 ± 10.9 years old. Significant improvement in terms of mean BCVA (p < 0.005) and mean CRT was seen at final follow-up compared to baseline. The biomarkers of DRIL, LONLC, and SRF were found to be predictive for at least 50 μm CRT reduction after treatment (with odds ratio of 8.69, 8.5, and 17.58, respectively). The biomarkers of IRC, LONLC, and SRF were predictive for significant improvement in terms of BCVA and CRT after treatment. Finally, the number of HRF was predictive for both BCVA improvement and a CRT reduction of less than 100 μm after treatment. No serious complications were reported during the study. Conclusion: Our study demonstrated the utility of OCT biomarkers as therapeutic predictors of ranibizumab treatment among DME eyes.

OCT outcomes as biomarkers for disease status, visual function, and prognosis in diabetic macular edema

PurposeTo evaluate disorganization of retinal inner layers (DRIL), as detected on spectral-domain optical coherence tomography (OCT) images, as a biomarker for diabetic macular edema (DME) activity, visual function, and prognosis in eyes with DME. DesignLongitudinal prospective. MethodsPost hoc correlation analyses were performed on data from a phase 2 clinical trial. Seventy-one eyes of 71 patients with treatment-naive DME received either suprachoroidally administered CLS-TA (proprietary formulation of a triamcinolone acetonide injectable suspension) combined with intravitreal aflibercept or intravitreal aflibercept with a sham suprachoroidal injection procedure. DRIL area, maximum horizontal extent of DRIL, ellipsoid zone (EZ) integrity, and the presence and location of subretinal (SRF) and intraretinal fluid (IRF) were evaluated at baseline and week 24 by certified reading centre graders. ResultsAt baseline, the area and maximum horizontal extent of DRIL were negatively correlated with best-corrected visual acuity (BCVA; r = –0.25, p = 0.05 and r = –0.32, p =0.01, respectively). Mean baseline BCVA progressively worsened with each ordinal drop in EZ integrity, improved with the presence of SRF, and was invariant to the presence of IRF. DRIL area and maximum extent were significantly decreased at week 24 (–3.0 mm2 [p < 0.001] and –775.8 mm [p < 0.001], respectively. At week 24, decreases in the area and maximum horizontal extent of DRIL were positively correlated with increases in BCVA (r = –0.40, p = 0.003 and r = –0.30, p = 0.04). Improvements in BCVA at week 24 were no different between patients showing improvement in EZ, SRF, or IRF and those showing no improvement or worsening from baseline. ConclusionsDRIL area and DRIL maximum horizontal extent were demonstrated to be novel biomarkers for macular edema status, visual function, and prognosis in eyes with treatment-naive DME.

A pilot study comparing optical coherence tomography, radiography, clinical photography, and polarisation microscopy for studies of hypomineralisation disturbances in enamel

AimTo investigate the use of optical coherence tomography (OCT) as a tool to assess general and localised hypomineralisation defects in the enamel. Design and MaterialsTen extracted permanent teeth (four teeth with localised hypomineralisation, four teeth with general hypomineralisation, and two healthy controls) were used in this study. In addition, four participants who underwent OCT served as living controls for the extracted teeth. MethodsThe OCT results were compared with clinical photographs, digital radiographs, and polarising microscopy images of tooth sections (considered the gold standard) to determine the method with the most accurate information regarding the extent of enamel disturbances: 1) visibility of enamel disturbance (visible yes/no); if yes, 2) extent of the disturbance in the enamel; and 3) determination of the plausible involvement of the underlying dentin. ResultsOCT was more accurate than digital radiography and visual assessment. OCT could provide information about the extent of localised hypomineralised disturbances in the enamel that was comparable to that with polarisation microscopy of the tooth sections. ConclusionWithin the limitations of this pilot study, it can be concluded that OCT is suitable for investigating and evaluating localised hypomineralisation disturbances; however, it is less useful in cases with generalised hypomineralisation of the enamel. In addition, OCT complements radiographic examination of enamel; however, more studies are necessary to elucidate the full extent of the use of OCT in case of hypomineralisation.

Third-Generation Sirolimus-Eluting Bioresorbable Tyrocore Scaffold Implantation in Patients with ST-Segment Elevation Myocardial Infarction: Baseline and 6-Month OCT and Clinical Outcomes-a FANTOM STEMI Pilot Study.

The aim of this study was to evaluate the safety and efficacy of the Fantom BRS 6months after implantation using the optical coherence tomography (OCT) imaging. Twenty STEMI patients treated with a sirolimus-eluting Fantom BRS were enrolled into a prospective, single-arm, serial observational study. The scaffold sizing, positioning and optimisation were guided by OCT imaging. The primary endpoint was device-orientated composite endpoints (DOCE), comprised of cardiac death, target-vessel-related myocardial infarction and target lesion failure. To evaluate the device performance at the scaffold level, we performed a quantitative coronary angiography (QCA) and OCT imaging at 6months. The primary endpoint did not occur in any patient within the 6-month follow-up. There were no major adverse cardiac events (MACEs) or DOCEs, no cases of scaffold thrombosis, target lesion revascularization and no deaths. In QCA, we observed a decrease in the minimum and mean lumen diameter in the in-scaffold region and in the proximal and distal peri-scaffold region. Similarly, the minimum lumen area and reference vessel diameter had decreased in both QCA and OCT. The OCT imaging showed improvement in the expansion index and malposition rate. A serial 6-month OCT imaging after implantation of a third-generation Tyrocore-based bioresorbable coronary scaffold indicated good coverage of the struts with excellent healing of the scaffold, low neointima growth and no signs of neoatherosclerosis.

MORPHOMETRIC FEATURES OF EYE STRUCTURES ACCORDING TO OCT AND CHANGES IN HEMODYNAMICS IN PATIENTS WITH ANTERIOR UVEITIS COMPLICATED BY OPTIC NEURITIS

Aim. Identify changes in the optic disc and vascular membrane by OCT, as well as features of hemodynamics and the possibility of communication between these parameters. Materials and methods. In 150 patients with idiopathic monolateral anterior uveitis, ophthalmic (visometry, refractometry, tonometry, perimetry, biomicroscopy, direct, reverse ophthalmoscopy), examination, rheophthalmography (ROG) and optical coherence tomography (OCT) of structures were performed. Patients received treatment according to the protocol, including, if necessary, antibacterial, antiviral, steroidal and nonsteroidal anti-inflammatory, immunosuppressive, desensitizing, vasodilating, immunomodulatory drugs. Statistical analysis was performed using Statistica 10.0 using Student's coefficient, pairwise correlation and Spearman's rank correlation Research results. The OCT results of the eyes of patients with optic neuritis on the background of anterior uveitis showed a significant increase in the thickness of the layer of peripapillary nerve fibers and vascular membrane by 34.3 and 38.9% relative to the data in anterior uveitis without complications. ROG revealed a significant increase in the tone of small and large vessels of the eye in neuritis on the background of anterior uveitis by 14.2 and 17.2% compared to those without neuritis. There was a direct significant strong relationship between the thickness of peripapillary fibers and the thickness of the vascular membrane with volumetric pulse blood filling, the volume of volumetric blood filling, tonic properties of large and small vessels (r = 0,699-0,909); average - between the diameter of the optic nerve at the entrance to the orbit and the parameters of the ROG (r = 0,647-0,797); weak - determined in the retrobulbar and middle department (r = 0.241-0.453). The development of neuritis in uveitis is accompanied by an increase in the thickness of the peripapillary fibers and vascular membrane, the diameter of the optic nerve at the entrance to the orbit, in the retrobulbar and middle department, as well as volumetric pulse blood filling, volumetric connection in all cases (Spearman r 0.421-0.754). Conclusions 1. The results of OCT of the eyes with optic neuritis on the background of anterior uveitis showed a significant increase in the thickness of the layer of peripapillary nerve fibers and vascular membrane relative to the data in persons with anterior uveitis without complications. 2. The horn of the tonic properties of the vessels revealed a significant increase in the tone of small and large vessels of the eye with optic neuritis on the background of anterior uveitis relative to those without neuritis. 3. The direct strong reliable correlation of indicators of thickness of peripheral fibers and a vascular cover with volume pulse blood filling, speed of volume blood filling, tonic properties of large and small vessels is revealed. Average connection - between the diameter of the optic nerve at the entrance to the orbit and the parameters of the ROG, weak connection with the diameter of the optic nerve in the retrobulbar and middle department. 4. The development of optic neuritis against the background of anterior uveitis is accompanied by an increase in the thickness of the peripheral fibers and choroid, the diameter of the optic nerve at the entrance to the orbit, in the retrobulbar and middle section. The tonic properties of large and small vessels, volumetric pulse blood filling, and the speed of volumetric blood filling, as indicated by the presence of a significant direct correlation. Key words: chronic anterior idiopathic uveitis, optic neuritis, OCT, eye hemodynamics.

The Usefulness of Optical Coherence Tomography in Disease Progression Monitoring in Younger Patients with Relapsing-Remitting Multiple Sclerosis: A Single-Centre Study.

The purpose of the study was to assess the usefulness of optical coherence tomography (OCT) in the detection of the neurodegenerative process in younger patients with multiple sclerosis (MS). The study group consisted of 61 patients with a relapsing remitting course of MS (mean age 36.4 ± 6.7 years) divided into two groups: short (≤5 years) and long (>10 years) disease duration. OCT, P300 evoked potential, Montreal Cognitive Assessment, and performance subtests (Picture Completion and Digit Symbol) of the Wechsler Adult Intelligence Scale were performed in all patients. Mean values of most parameters assessed in OCT (pRNFL Total, pRNFL Inferior, pRNFL Superior, pRNFL Temporalis, mRNFL, GCIPL, mRNFL+GCIPL) were significantly lower in MS patients in comparison to controls. And in patients with longer disease duration in comparison to those with shorter. Most OCT parameters negatively correlated with the EDSS score (p < 0.05). No significant correlation was found between OCT results and both P300 latency and the results of psychometric tests. OCT, as a simple, non-invasive, quick, and inexpensive method, could be useful for monitoring the progression of disease in MS patients.

Алгоритм сегментации ОКТ изображений макулы для анализа пациентов с возрастной макулярной дегенерацией

Age-related macular degeneration (AMD) is one of the main causes of loss of sight and hypovision in people over working age. Results of optical coherence tomography (OCT) are essential for diagnostics of the disease. Developing the recommendation system to analyze OCT images will reduce the time to process visual data and decrease the probability of errors while working as a doctor. The purpose of the study was to develop an algorithm of segmentation to analyze the results of macular OCT in patients with AMD. It allows to provide a correct prediction of an AMD stage based on the form of discovered pathologies. A program has been developed in the Python programming language using the Pytorch and TensorFlow libraries. Its quality was estimated using OCT macular images of 51 patients with early, intermediate, late AMD. A segmentation algorithm of OCT images was developed based on convolutional neural network. UNet network was selected as architecture of high-accuracy neural net. The neural net is trained on macular OCT images of 125 patients (197 eyes). The author algorithm displayed 98.1% of properly segmented areas on OCT images, which are the most essential for diagnostics and determination of an AMD stage. Weighted sensitivity and specificity of AMD stage classifier amounted to 83.8% and 84.9% respectively. The developed algorithm is promising as a recommendation system that implements the AMD classification based on data that promote taking decisions regarding the treatment strategy.