Coherence Tomography In Patients Research Articles

Analysis of Optic Disc Morphology and the Peripapillary Retinal and Choroidal Thickness by the Swept Source Optical Coherence Tomography in Patients with Moyamoya Disease

Introduction: Moyamoya Disease (MMD) is a chronic cerebrovascular occlusive disorder. Ocular involvement in patients with MMD has increasingly been recognized and reported in recent years. This study aimed to investigate the changes of optic disc morphology and the peripapillary retinal and choroidal thickness in patients with MMD. Methods: This cross-sectional study included 56 patients diagnosed with idiopathic MMD and 56 healthy controls matched by age and gender. All participants underwent swept-source optical coherence tomography to capture the optic disc morphology as well as the peripapillary retinal and choroidal thickness. Optic disc parameters, including cup area, rim area, cup volume, rim volume, C/D area ratio (CDR), linear CDR, and vertical CDR were measured and compared between the two groups. Additionally, the thickness of the peripapillary whole retina, retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), and choroid were evaluated and analyzed across 12 clock-hour segments around the peripapillary region. Results: The rim area in MMD patients was significant less than controls while the CDR in MMD patients was significantly larger than that in the control group. There was no statistically significant difference between the two groups regarding disc area, cup area, cup volume, rim volume, vertical and horizontal diameter of disc. The retinal thickness at the 7 o'clock position was significantly thinner in the MMD group compared to the control group and the temporal RNFL thickness, particularly at the 7 o'clock and 9 o'clock positions, was significantly reduced in the MMD group (p<0.05). The GCL layer at the 7 o'clock position was thinner in the MMD group than in the control group (p<0.05). The MMD group showed a notably reduced average choroidal thickness, particularly in the inferior-temporal region (p<0.05). There was a correlation between peripapillary choroidal and GCL layer thickness in the MMD group, but no significant correlations were found with rim area, CDR, or RNFL. Conclusions: In patients with MMD, there is an increase in the CDR accompanied by a decrease in the rim area. Additionally, there is thinning of the temporal RNFL, GCL, and choroidal thickness, notably in the inferotemporal quadrant of the optic disc.

Characteristics of optical coherence tomography in patients with iron deficiency anemia : a systematic review and meta-analysis.

The primary objective of this systematic review and meta-analysis was to assess the association between iron deficiency anemia (IDA) and retinal changes via optical coherence tomography (OCT). The search was conducted in MEDLINE, Scopus, Embase, Web of Science, and Google Scholar until February 1, 2024. Two independent researchers included the articles based on the inclusion and exclusion criteria. Data regarding the study design, patient characteristics, number of patients with and without IDA, mean and SD of the retinal nerve fiber layer (RNFL), C/D ratio, foveal avascular zone (FAZ) area and perimeter, foveal density and superficial and deep capillary plexus (SCP and DCP) vascular density (VD) were collected. STATA version 17.0 was used to compute pooled measures of the standardized mean difference. I2 and chi-square tests were used to assess heterogeneity between studies. We found 1378 nonduplicate studies, 35 of which were potentially relevant. 19 articles met the inclusion criteria and were included in the review. The meta-analysis confirmed that there was a statistically significant association between IDA and RNFL thickness reduction (SMD = -0.76, 95% CI: -1.09 to -0.44 ; p-value = 0.001, I2 = 86.88%), FAZ area (SMD =-0.35, 95% CI: -0.67 to -0.02; p value = 0.04, I2 = 59.76%) and SCP VD (SMD = -1.12, 95% CI: -1.85 to -0.39; p-value = 0.001, I2 = 83.15%). The associations between IDA and the C/D ratio (SMD = 0.07, 95% CI: -0.13 to 0.28; p value = 0.49, I2 = 0.0%) and DCP VD (SMD = -0.30, 95% CI: -0.89 to 0.29; ,p-value = 0.32 ,I2 = 77.20%) were not significant. There was no considerable publication bias. The results of this meta-analysis demonstrated that, compared with healthy controls, individuals with IDA presented a thinner RNFL, a smaller FAZ, and lower SCP and DCP vascular densities. However, further studies are needed to reach more conclusive results.

Differences in non-flow limiting non-culprit plaque characteristics after myocardial infarction in patients with versus without chronic kidney disease

Abstract Background Patients with chronic kidney disease (CKD) are at increased risk for recurrent cardiovascular events after myocardial infarction compared to patients with preserved renal function. This disparity may be related to differences in plaque morphology. Purpose To compare non-flow limiting non-culprit (NC) plaque characteristics as assessed by optical coherence tomography in patients with versus without chronic kidney disease presenting with myocardial infarction. Methods 438 patients presenting with myocardial infarction with additional non-flow limiting (defined as a fractional flow reserve >0.80) NC lesions were included in the prospective observational PECTUS-obs study after treatment of the infarct related artery. An independent core laboratory performed all quantitative and qualitative OCT analyses. For the present subgroup analysis, patients were grouped according to the presence or absence of CKD, which was defined as an estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m². Baseline characteristics were compared between groups on a patient-level and OCT characteristics were compared on a lesion-level while accounting for within-patient clustering. Results Out of 420 patients with at least one analyzable OCT, baseline renal function was known in 416. Among them, there were 55 patients with and 361 patients without CKD (mean eGFR 47.4 ± 9.2 vs 84.7 ± 15.0 ml/min/1.73 m², p<0.001). Patients with CKD were older (mean age 73 ± 9 vs 62 ± 10 years, p<0.001), more frequently were female (29.1% vs 17.2%, p=0.035) and predominantly presented with a non-ST-segment elevation myocardial infarction (72.2% vs 44.9%, p<0.001). Comorbid disease was more prevalent among patients with CKD, including a higher prevalence of hypertension (p=0.010), hypercholesterolemia (p=0.020), diabetes (p<0.001), history of myocardial infarction (p<0.001), carotid artery disease (p=0.019) and peripheral artery disease (p=0.002). Coronary lesions in patients with CKD on average had a larger maximal calcium arc (188 ± 114 vs 137 ± 87º, p=0.003) and length (11.9 ± 10.3 vs 8.4 ± 7.4 mm, p=0.021). Lipid plaques were less prevalent among lesions in patients with CKD (63.6% vs 78.0%, p=0.016) and less frequently had a lipid arc ≥90º (60.6% vs 76.1%, p=0.018). Although the mean minimal fibrous cap thickness was lower in patients with CKD (p=0.025), no difference was observed in the prevalence of thin-cap fibroatheromas (p=0.984) or high-risk plaques according to the PECTUS-obs criteria (p=0.665). Conclusion Non-flow limiting NC lesions in patients with CKD differ from those in patients without CKD in a cohort of patients presenting with myocardial infarction. Overall, plaques in patients with CKD show more extensive calcification, whereas lesions in patients without CKD more often consist of lipid plaques, but the prevalence of high-risk plaques was comparable.

New high-resolution prototype versus standard spectralis optical coherence tomography in patients with central serous chorioretinopathy

PurposeTo assess the accuracy of High-Resolution OCT in detecting biomarkers associated with central serous chorioretinopathy (CSC) compared to standard OCT.MethodsWe conducted a cross-sectional study involving CSC patients who underwent High-Resolution and standard OCT during the same visit. Using the SPECTRALIS High-Res OCT device (Heidelberg Engineering, Heidelberg, Germany), macular B-scans were obtained and compared with those acquired using a SPECTRALIS HRA + OCT device (Heidelberg Engineering, Heidelberg, Germany). Qualitative assessments were performed, and statistical analyses compared the performance of both OCT modalities.ResultsThirty-one patients diagnosed with CSC were included with a mean age of 56.3 years (± 10.2). Among them, 29% (n = 9) were classified as acute CSC (aCSC), while 71% (n = 22) had chronic CSC (cCSC). High-Resolution OCT outperformed standard OCT in detecting microstructural changes in the outer retinal layers, including a higher prevalence of disrupted interdigitation zone (IZ) (29% vs. 6%, p = 0.003) and retinal pigment epithelium (RPE) disruption (12% vs. 2%, p = 0.0024). Intergrader agreement was high (Cohen’s Kappa = 0.85).ConclusionHigh-Resolution OCT demonstrates promise in identifying critical biomarkers associated with CSC, particularly disruptions in the IZ and RPE. Further validation in larger cohorts is required to confirm their clinical relevance in patients with CSC.

TCT-757 Plaque Morphology According to Optical Coherence Tomography in Patients Undergoing Percutaneous Coronary Intervention for Saphenous Vein Graft Lesions in Acute Coronary Syndrome

TCT-757 Plaque Morphology According to Optical Coherence Tomography in Patients Undergoing Percutaneous Coronary Intervention for Saphenous Vein Graft Lesions in Acute Coronary Syndrome

Effect of Colchicine on Coronary Plaque Stability in Acute Coronary Syndrome as Assessed by Optical Coherence Tomography: The COLOCT Randomized Clinical Trial.

Colchicine has been approved to reduce cardiovascular risk in patients with coronary heart disease on the basis of its potential benefits demonstrated in the COLCOT (Colchicine Cardiovascular Outcomes Trial) and LoDoCo2 (Low-Dose Colchicine 2) studies. Nevertheless, there are limited data available about the specific impact of colchicine on coronary plaques. This was a prospective, single-center, randomized, double-blind clinical trial. From May 3, 2021, until August 31, 2022, a total of 128 patients with acute coronary syndrome aged 18 to 80 years with lipid-rich plaque (lipid pool arc >90°) detected by optical coherence tomography were included. The subjects were randomly assigned in a 1:1 ratio to receive either colchicine (0.5 mg once daily) or placebo for 12 months. The primary end point was the change in the minimal fibrous cap thickness from baseline to the 12-month follow-up. Among 128 patients, 52 in the colchicine group and 52 in the placebo group completed the study. The mean age of the 128 patients was 58.0±9.8 years, and 25.0% were female. Compared with placebo, colchicine therapy significantly increased the minimal fibrous cap thickness (51.9 [95% CI, 32.8 to 71.0] μm versus 87.2 [95% CI, 69.9 to 104.5] μm; difference, 34.2 [95% CI, 9.7 to 58.6] μm; P=0.006), and reduced average lipid arc (-25.2° [95% CI, -30.6° to -19.9°] versus -35.7° [95% CI, -40.5° to -30.8°]; difference, -10.5° [95% CI, -17.7° to -3.4°]; P=0.004), mean angular extension of macrophages (-8.9° [95% CI, -13.3° to -4.6°] versus -14.0° [95% CI, -18.0° to -10.0°]; difference, -6.0° [95% CI, -11.8° to -0.2°]; P=0.044), high-sensitivity C-reactive protein level (geometric mean ratio, 0.6 [95% CI, 0.4 to 1.0] versus 0.3 [95% CI, 0.2 to 0.5]; difference, 0.5 [95% CI, 0.3 to 1.0]; P=0.046), interleukin-6 level (geometric mean ratio, 0.8 [95% CI, 0.6 to 1.1] versus 0.5 [95% CI, 0.4 to 0.7]; difference, 0.6 [95% CI, 0.4 to 0.9]; P=0.025), and myeloperoxidase level (geometric mean ratio, 1.0 [95% CI, 0.8 to 1.2] versus 0.8 [95% CI, 0.7 to 0.9]; difference, 0.8 [95% CI, 0.6 to 1.0]; P=0.047). Our findings suggested that colchicine resulted in favorable effects on coronary plaque stabilization at optical coherence tomography in patients with acute coronary syndrome. URL: https://www.clinicaltrials.gov; Unique identifier: NCT04848857.

Fractal geometry of culprit coronary plaque images within optical coherence tomography in patients with acute coronary syndrome vs stable angina pectoris.

The main cause of acute coronary syndrome (ACS) is plaque rupture and thrombus formation. However, it has not been fairly successful to identify vulnerable plaque to rupture using conventional parameters of intravascular imaging modalities. Fractal analysis is one of the mathematical models to examine geometrical features of picture image using a specific parameter called as fractal dimension (FD) which suggests geometric complexity of the image. This study examined FD of the optical coherence tomography (OCT)-derived images of the culprit plaque in patients with ACS vs stable angina pectoris (SAP) to evaluate the feasibility of FD for identifying vulnerable coronary plaques prone to provoke ACS distinguished from stable plaques only provoking SAP. We examined 65 cases (34 ACS patients, 31 SAP patients) in which the culprit lesion was imaged by OCT before percutaneous coronary intervention in patients with ACS and SAP. The culprit plaque lesion in the ACS group had a significantly larger mean lipid arc (203.8 ± 39.4° vs 152.3 ± 34.5°, p < 0.001) and a larger lipid plaque length (12.6 ± 5.1mm vs 7.7 ± 2.7mm, p < 0.001) and a thinner fibrous cap thickness (75.3 ± 22.3μm vs 134.8 ± 53.2μm, p < 0.001) than those in the SAP group. The prevalence of OCT-derived macrophage infiltration (Mph) in the entire culprit coronary vessel as well as that of the OCT-derived thin-cap fibroatheroma (TCFA) at the culprit lesion were significantly greater in the ACS group than those in the SAP group, respectively (Mph: 61.8% vs 35.5%, p = 0.048; TCFA: 44.1% vs 6.4%, p < 0.001). The FD of culprit plaque in the ACS group was significantly greater than in the SAP group (2.401 ± 0.073 vs 2.341 ± 0.051, p < 0.001). In multivariate regression analysis, the presence of Mph was a significant determinant of FD (regression coefficient estimate 0.049, CI 0.018-0.079, p = 0.002). The FD of OCT-derived image of culprit coronary plaque in the ACS group was significantly greater than that in the SAP group, indicating that the culprit plaque in ACS were structurally more complex. Therefore, fractal analysis of coronary OCT images might be clinically useful for identifying coronary plaques prone to provoke ACS.

Prevalence of intracerebral thrombus detected by optical coherence tomography in patients with posterior circulation stroke or transient ischemic attack

BackgroundThe incidence of thrombosis in patients with intracranial atherosclerotic stenosis (ICAS) remains unclear. Optical coherence tomography (OCT) has the potential to explore the vessel wall structure of posterior-circulation ICAS because...

Impact of morphofunctional assessment with quantitative flow ratio and optical coherence tomography in patients with acute coronary syndromes.

Combining morphological and physiological evaluations might improve the risk stratification of patients who undergo percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) culprit lesions. We aimed to investigate the clinical utility of morphofunctional evaluation after PCI for identifying ACS patients with increased risk of subsequent clinical events. We retrospectively studied 298 consecutive ACS patients who had undergone optical coherence tomography (OCT)-guided PCI. We performed OCT-based morphological analysis and quantitative flow ratio (QFR)-based physiological assessment immediately after PCI. The non-culprit segment (NCS) was defined as the most stenotic untreated segment in the culprit vessel. The primary outcome was target vessel failure (TVF), a composite of cardiac death, target vessel-related myocardial infarction, and ischaemia-driven target vessel revascularisation. During a median follow-up period of 990 days, 42 patients experienced TVF. Cox regression analysis revealed that the presence of thin-cap fibroatheroma (TCFA) in the NCS and a low post-PCI QFR, or the presence of TCFA in the NCS and a high ΔQFR in the NCS (QFRNCS), were independently associated with TVF. The subgroup with TCFA in the NCS and a low post-PCI QFR had a significantly higher incidence of TVF (75%) than the other subgroups, and those with TCFA in the NCS and a high ΔQFRNCS had a significantly higher incidence of TVF (86%) than the other subgroups. The integration of TCFA in NCS, post-PCI QFR, and ΔQFRNCS with traditional risk factors significantly enhanced the identification of subsequent TVF cases. Combining post-PCI OCT and QFR evaluation may enhance risk stratification for ACS patients after successful PCI, particularly in predicting subsequent TVF.

Impact of Calcium Angle on Coronary Stent Expansion and Eccentricity Index Using Optical Coherence Tomography in Patients Undergoing Intravascular Lithotripsy

Impact of Calcium Angle on Coronary Stent Expansion and Eccentricity Index Using Optical Coherence Tomography in Patients Undergoing Intravascular Lithotripsy

Wide-Field Optical Coherence Tomography in Patients with Diabetic Macular Edema.

Background: The goal of the study was to analyze variations in central, perifoveal, and peripheral retinal thickness (RT) and choroidal thickness (CT) in patients with diabetic macular edema (DME) measured with ultra-wide-field optical coherence tomography (UWF-OCT). Additionally, correlations between RT and CT in the central, perifoveal, and peripheral sectors and the presence of selected systemic factors were evaluated. Methods: A total of 74 consecutive adult diabetic patients with DME and 75 healthy controls were included. Study participants were divided into three groups: DME patients without panretinal photocoagulation (PRP; 84 eyes), DME patients after PRP (56 eyes), and healthy controls (125 eyes). RT and CT were analyzed in three zones: a central circle of 3 mm diameter (central), a ring contained between a centered 9 mm circle and the central 3 mm circle (perifoveal), and a second, more peripheral ring between centered 18 mm and 9 mm circles (peripheral). Additionally, DME subgroups were analyzed according to the correlation of RT and CT with age, axial length, best corrected visual acuity (BCVA), diabetes duration, insulin therapy duration, body mass index (BMI), glycosylated hemoglobin (HbA1c) values, intravitreal injection (IVI) count, and the advancement of retinopathy assessed by the simplified diabetic retinopathy severity scale (DRSS). Results: The increase in RT in the far peripheral sectors in DME patients was not significant. The increases in central and perifoveal RT and lower values of CT in PRP-naive DME patients were strongly associated with poorer BCVA. Patients with DME after PRP presented with BCVA improvements significantly related to the number of IVIs. The amount of DME and RT in peripheral sectors were both independent of systemic factors such as BMI, duration of diabetes, duration of insulin intake, retinopathy severity, and HbA1c levels. Conclusions: Peripheral retinal sectors in DME patients are less affected in terms of increase in their thickness compared to central ones. Functional and morphological associations of DME with UWF-OCT testing refer to central and perifoveal sectors.

Detecting early changes in choroidal vascularity and thickness using optical coherence tomography in patients with corneal crosslinking for keratoconus.

To investigate changes in choroidal thickness and vascularity in keratoconus patients treated with corneal crosslinking. This study evaluated 28 eyes of 22 patients with keratoconus who underwent corneal crosslinking. The choroidal thicknesses were evaluated on enhanced depth imaging optical coherence tomography at the preoperative and postoperative 3d, 1, and 3mo. Choroidal thickness in the four cardinal quadrants and the fovea were evaluated. The choroidal vascularity index was also calculated. There was no significant difference in central choroidal thickness between the preoperative and postoperative 3d, 1mo (P>0.05). There was a significant increase in the 3mo (P=0.034) and a significant decrease in the horizontal choroidal vascularity index on the postoperative 3d (P=0.014), there was no statistically significant change in vertical axes and other visits in horizontal sections (P>0.05). This study sheds light on choroidal changes in postoperative corneal crosslinking for keratoconus. While it suggests the procedure's relative safety for submacular choroid, more extensive research is necessary to confirm these findings and their clinical significance.

Atherosclerotic plaque structure according to optical coherence tomography in patients with coronary artery disease living in extreme weather conditions

Aim. To evaluate the plaque structural features in patients with coronary artery disease (CAD) permanently residing in the Far North of the Tyumen region in com­parison with patients in the South of the Tyumen region.Material and methods. This pilot case-control study included 32 patients with stable CAD (mean age 62,7±8,9 years, 24 (75%) men). The main group consisted of 16 patients permanently residing in the Far North of Tyumen region (non-indi­ge­nous population), while the comparison group consisted of 16 patients permanently residing in the South of the Tyumen region. In all patients, CAD was verified using paraclinical diagnostic methods. All patients underwent optical coherence tomography (OCT), according to which the plaque type was analyzed. The following plaque types were distinguished: fibrous, fibroatheroma, calcified fibroatheroma, thin-cap fibroatheroma (TCFA). TCFA was defined as the presence of a fibrous cap ≤65 μm thick and an arc of the necrotic core of at least 90о. In addition, a lipid-rich plaque was isolated, which was determined by a lipid arc of more than 180о.Results. According to clinical and angiographic characteristics, patients in the compared groups were statistically comparable. A total of 134 plaques were analyzed from 32 patients (main group — 65 plaques; control group — 69 plaques (p&gt;0,05)). The most common plaque type in both groups was calcified fibroatheroma (46,2% in the Far North group and 50,7% in the South group, p=0,609). TCFA was significantly more often detected in patients living in far north (33,8% vs 17,4%, p=0,031). In this group of patients, thin (&lt;65 µm) fibrous plaque cap was also more often determined (35,4% vs 18,8%, p=0,034). Lipid-rich plaques in both groups was determined with the same frequency (56,9% vs 62,3%, p=0,598).Conclusion. In patients with verified CAD living in extreme weather conditions, according to OCT, TCFA was more often determined, which could potentially be associated with a higher risk of adverse cardiovascular events.

The Usefulness of Intravascular Ultrasound and Optical Coherence Tomography in Patients Treated with Rotational Atherectomy: An Analysis Based on a Large National Registry.

Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have been shown to improve the clinical outcomes of percutaneous coronary interventions (PCIs) in selected subsets of patients. The aim was to investigate whether the use of OCT or IVUS during a PCI with rotational atherectomy (RA-PCI) will increase the odds for successful revascularization, defined as thrombolysis in myocardial infarction (TIMI) 3 flow. Data were obtained from the national registry of PCIs (ORPKI) maintained by the Association of Cardiovascular Interventions (AISN) of the Polish Cardiac Society. The dataset includes PCIs spanning from January 2014 to December 2021. A total of 6522 RA-PCIs were analyzed, out of which 708 (10.9%) were guided by IVUS and 86 (1.3%) by OCT. The postprocedural TIMI 3 flow was achieved significantly more often in RA-PCIs guided by intravascular imaging (98.7% vs. 96.6%, p < 0.0001). Multivariable analysis revealed that using IVUS and OCT was independently associated with an increased chance of achieving postprocedural TIMI 3 flow by 67% (odds ratio (OR), 1.67; 95% confidence interval (CI): 1.40-1.99; p < 0.0001) and 66% (OR, 1.66; 95% CI: 1.09-2.54; p = 0.02), respectively. Other factors associated with successful revascularization were as follows: previous PCI (OR, 1.72; p < 0.0001) and coronary artery bypass grafting (OR, 1.09; p = 0.002), hypertension (OR, 1.14; p < 0.0001), fractional flow reserve assessment during angiogram (OR, 1.47; p < 0.0001), bifurcation PCI (OR, 3.06; p < 0.0001), and stent implantation (OR, 19.6, p < 0.0001). PCIs with rotational atherectomy guided by intravascular imaging modalities (IVUS or OCT) are associated with a higher procedural success rate compared to angio-guided procedures.

Granulomatosis with polyangiitis, complicated by ocular adnexa lesion and vascular changes in retina and choroid (literature review with a clinical case)

Granulomatosis with polyangiitis (GPA) is manifested as ocular pathology in almost a third of patients, which can either be detected at the onset of the disease or occur in the late stages. The pathological process involves the orbit, sclera, episclera, cornea, conjunctiva, eyelids, nasolacrimal system, optic nerve, retina and choroid. Lesion of eye and its surrounding structures determines the severity of the pathological process, the patient’s quality of life and prognosis. The article presents a clinical case of a 38-year-old man with an unfavorable course of GPA, lesion to upper and lower respiratory tract, kidneys, and musculoskeletal system. The authors consider ocular manifestations in the context of a systemic disease. An ophthalmological examination of the patient revealed changes in sclera and choroid, which had not previously been described in detail in the literature. The patient underwent cataract phacoemulsification in the right eye with implantation of a posterior chamber intraocular lens. The dynamics of clinical manifestations of eye lesion in the near future is positive, but in the long term it remains doubtful due to pronounced changes in the orbit and adnexa of the eye against the background of ongoing small vessels vasculitis. Early consultation with an ophthalmologist and optical coherence tomography in patients with GPA are necessary at any stage of the disease. The clinical case is presented with consideration to the CARE 2021 recommendations.

Correspondence on ‘Detection and Correlation of Changes on Perimetry and Optical Coherence Tomography in Patients on Chronic Usage of Hydroxychloroquine: A Cross-sectional Study’

Correspondence on ‘Detection and Correlation of Changes on Perimetry and Optical Coherence Tomography in Patients on Chronic Usage of Hydroxychloroquine: A Cross-sectional Study’

Longitudinal Changes of Cornea Volume Measured by Means of Anterior Segment-Optical Coherence Tomography in Patients with Stable and Progressive Keratoconus.

Keratoconus is a corneal disease which results in progressive thinning and protrusion of the cornea leading to irregular astigmatism. The purpose of this study was to evaluate longitudinal changes in corneal volume (CV) occurring over time in keratoconus eyes. Consecutive patients affected by keratoconus were evaluated by means of anterior segment-optical coherence tomography (AS-OCT) at two different time points: baseline (T0) and after 1 year (T1). Anterior and posterior refractive value; corneal thickness at the thinnest point (TP) and corneal volume (CV) calculated within discs of 3, 5 and 8 mm of diameter; anterior chamber depth (ACD); and anterior chamber volume (ACV) were obtained. Enrolled patients were divided into 3 groups (groups 1, 2, 3) according to the increasing disease severity and into 2 groups (groups A, B) according to the progression or stability of the disease. Overall, 116 eyes of 116 patients (76 males and 40 females, mean age 34.76 ± 13.99 years) were included. For the entire group of keratoconus patients, in comparison with T0, mean TP decreased at T1 from 458.7 ± 52.2 µm to 454.6 ± 51.6 µm (p = 0.0004); in parallel, mean value of CV calculated at 5 mm and 8 mm decreased significantly (from 10.78 ± 0.8 at T0 to 10.75 ± 0.79 at T1 (p = 0.02), and from 32.03 ± 2.01 mm3 at T0 to 31.95 ± 1.98 at T1 (p = 0.02), respectively). Conversely, there were no statistically significant differences in CV at 3 mm from T0 to T1 (p = 0.08), as well as for ACD and ACV. Regarding the course of the disease, patients belonging to group A showed statistically significant differences from T0 to T1 for TP, and for CV at 3 mm, 5 mm and 8 mm (p < 0.0001, p < 0.0001, p < 0.001 and p = 0.0058 respectively). There were no statistically significant differences for ACD (p = 0.6916) and ACV calculated at 3, 5 and 8 mm (p = 0.7709, p = 0.3765, p = 0.2475, respectively) in group A. At the same time, no statistically significant differences for ACD (p = 0.2897) and ACV calculated at 3, 5 and 8 mm (p = 0.9849, p = 0.6420, p = 0.8338, respectively) were found in group B. There were statistically significant positive correlations between changes of TP and CV at 3 mm (r = 0.6324, p < 0.0001), 5 mm (r = 0.7622, p < 0.0001) and 8 mm (r = 0.5987 p < 0.0001). In conclusion, given the strong correlation with TP, CV might be considered an additional AS-OCT parameter to be used in association with conventional parameters when detecting longitudinal changes in keratoconic eyes.

Comparability of Measurement of Astigmatism between URk-800F Auto Refracto-keratometer and MS-39 Anterior Segment Optical Coherence Tomography in Patients with Refractive Error.

Accurate refractive error assessment is the first and the most important step of ocular examination. A reliable screening method of refractive status is important for early detection and prevention of blinding complications of uncorrected refractive error. To evaluate the comparability of astigmatism measured by an auto-refractometer (URk-800F) with the measurements of the gold standard anterior segment optical coherence tomography (AS-OCT). This cross-sectional observational study was conducted in a tertiary eye centre in Kathmandu from February 2023 to June 2023. A total of 100 patients with best corrected visual acuity of ≥ 20/20, spherical refractive error with cylindrical error of more than and equal to -0.75 and no pathology detected on slit lamp examination were taken by consecutive sampling method. Ethical approval was taken for the study. The data were entered into Microsoft Excel and analysed using Bland-Altman analysis. The mean cylindrical power and axis was -2.33 D and 88 degrees for the right eye and -2.32 D and 122 degrees for the left eye respectively, as measured by MS-39 AS-OCT. For URK 800-F Auto-refracto Keratometer, the mean cylindrical power and axis was -2.31 D and 89 degrees for the right eye and -2.27 D and 124 degrees for the left eye. The findings of this study conclude that an auto-refractometer can be used as an effective tool for identification of spherical refractive error as well as measurement of accurate cylindrical power and cylindrical axis in low resource primary care settings.

Макулярные телеангиэктазии 2-го типа

Purpose. To summarize the data on the etiology, pathogenesis, diagnostic methods, and treatment of macular telangiectasia type 2 (MacTel 2) currently known. Material and methods. For this review, a search was conducted on PubMed and eLIBRARY resources, covering scientific publications by domestic and foreign authors from 1980 to 2021. The primary focus of the search was on the topic of MacTel 2. Results. Based on the current understanding of the disease process, it is recognized that dysfunction or loss of Muller cells represents an early stage that contributes to the development of MacTel 2. The review addresses the issues of diagnosis and differential diagnosis, pathogenesis, classification, clinical presentation, and treatment of MacTel 2. Detailed discussion is provided on the changes detected by optical coherence tomography in patients with MacTel 2, which can be valuable for the differential diagnosis of this condition and selection of appropriate patient management strategies. Conclusion. The emergence of new technologies enables the identification of specific changes occurring in the retina in MacTel 2, which require detailed analysis and can be used for differential diagnosis and disease prognosis. Key words: macular telangiectasia type 2, retinal degenerative disease, Muller cells, optical coherence tomography, differential diagnosis

Plaque Morphology by Optical Coherence Tomography in Patients Undergoing Percutaneous Coronary Intervention for Saphenous Vein Graft Lesions: A Prospective Observational Pilot study

Plaque Morphology by Optical Coherence Tomography in Patients Undergoing Percutaneous Coronary Intervention for Saphenous Vein Graft Lesions: A Prospective Observational Pilot study