Objective To evaluate the application value of optical coherence tomography angiography (OCTA) in obstructive sleep apnea syndrome (OSAS). Methods A comprehensive search of both domestic and international databases was conducted to identify clinical studies on the use of OCTA in OSAS, from the establishment of the databases to May 2024. A meta-analysis was performed using Revman 5.4 software. Results A total of 134 studies were initially identified, with 14 studies meeting the inclusion criteria, encompassing 999 subjects (739 in the OSAS group and 260 in the healthy group). Meta-analysis results indicated that the superficial capillary plexus (SCP) density in the fovea (MD=–2.05, 95%CI –3.75 to –0.35, P=0.02) and parafovea (MD=–1.56, 95%CI –2.44 to –0.68, P=0.000 5) was significantly lower in the OSAS group compared with the healthy group. In the mild to moderate OSAS group, SCP density was significantly lower in the fovea (MD=–2.41, 95%CI –4.32 to –0.49, P=0.01), parafovea (MD=–1.17, 95%CI –2.01 to –0.32, P=0.007), and perifovea (MD=–1.73, 95%CI –2.69 to –0.77, P=0.000 4) compared with the healthy group. In the severe OSAS group, SCP density in the perifovea (MD=–1.33, 95%CI –2.53 to –0.13, P=0.03) was significantly lower than that of the healthy group. SCP density in the whole area (MD=0.36, 95%CI 0.05 to 0.68, P=0.02) was significantly higher in the mild to moderate OSAS group compared with the severe OSAS group. In the deep capillary plexus (DCP) density, the OSAS group showed significantly lower densities in the whole area (MD=–2.16, 95%CI –3.51 to –0.81, P=0.002), fovea (MD=–2.38, 95%CI –4.38 to –0.37, P=0.02), and parafovea (MD=–2.33, 95%CI –3.93 to –0.73, P=0.004) compared with the healthy group. The mild to moderate OSAS group also showed significantly lower densities in the whole area (MD=–2.02, 95%CI –3.33 to –0.72, P=0.002) and parafovea (MD=–1.65, 95%CI –3.04 to –0.26, P=0.02) compared with the healthy group. The severe OSAS group had significantly lower DCP density in the whole area (MD=–2.26, 95%CI –3.85 to –0.66, P=0.006) and parafovea (MD=–1.47, 95%CI –2.31 to –0.62, P=0.000 7) compared with the healthy group. DCP density in the whole area (MD=0.54, 95%CI 0.02 to 1.07, P=0.04) was significantly higher in the mild to moderate OSAS group compared with the severe OSAS group. Regarding the retinal nerve fiber layer (RNFL) thickness, the inferior quadrant (MD=4.01, 95%CI 0.69 to 7.32, P=0.02) and temporal quadrant (MD=4.35, 95%CI 1.88 to 6.82, P=0.000 6) were significantly thicker in the mild to moderate OSAS group compared with the severe OSAS group. In terms of the foveal avascular zone (FAZ) area, the severe OSAS group showed a significantly larger FAZ area (MD=0.06, 95%CI 0.03 to 0.08, P<0.000 01) compared with the healthy group. Conclusion OCTA-related ocular biomarkers may be associated with the occurrence and progression of OSAS and have potential applications in the diagnosis and treatment of OSAS.
Intravascular optical coherence tomography (IVOCT) has emerged as a high-resolution and minimal-invasive imaging technique that provides high-speed visualization of coronary arterial vessel walls and clearly displays the vessel lumen and lesions under the intima. However, morphological gray-scale images cannot provide enough information about the tissue components to accurately characterize the plaque tissues including calcified, fibrous, lipidic and mixed plaques. Quantitative IVOCT (qIVOCT) is necessary to provide the physiological contrast mechanisms and obtain the characteristic parameters of tissues with clinical diagnostic value. In this paper, the progress of qIVOCT is reviewed. The current methods for quantitatively measuring optical, elastic and hemodynamic parameters of vessel wall and plaque tissues using IVOCT gray-scale images and raw backscattered signals are introduced and potential development is forecast.
ObjectiveTo examine the postoperative morphological changes in outer retinal wave-like changes (ORC) in eyes with rhegmatogenous retinal detachment (RRD). MethodsA retrospective clinical study. From March 2020 to March 2024, 64 eyes of 64 RRD patients diagnosed at The Second Affiliated Hospital of Zunyi Medical University were included. The cohort included 39 males (39 eyes) and 25 females (25 eyes), with a mean age of (45.3±15.7) years and a mean retinal detachment duration of (16.6±13.5) days. Macular involvement was observed in 51 eyes. Scleral buckling surgery (SB), pars plana vitrectomy (PPV), and SB+PPV were performed in 17, 44, and 3 eyes respectively. Best corrected visual acuity (BCVA) and spectral domain optical coherence tomography examinations were performed in all affected eyes. BCVA examination was performed using the standard logarithmic visual acuity chart, and the visual acuity was converted to logarithm of the minimum angle of resolution (logMAR) during statistics. Combined with the ORC situation before the operation, the morphological repositioning of outer retinal folds (ORF) after the operation was classified into types Ⅰ, Ⅱ and Ⅲ. One week and one and three months after the operation, relevant examinations were performed using the same equipment and methods as before the operation. The structural characteristics of ORC and the morphology of ORF after surgery were observed. The comparison between groups was conducted using the independent sample t test or the Mann-Whitney U test. ResultsAmong the 64 eyes, preoperative ORC was present in 46 eyes (71.9%, 46/64) and absent in 18 eyes (28.1%, 18/64). The 18 eyes without ORC had retinal detachment durations of either ≤4 days or ≥42 days. Postoperatively, ORF was observed in 51 eyes (79.7%, 51/64) and absent in 13 eyes (20.3%, 13/64). Among the 51 eyes with macular holes involved, 24 eyes (47.1%, 24/51) had ORF after the operation and 27 eyes (52.9%, 27/51) had no ORF. Among the 46 and 18 eyes with and without ORC, the ORF after surgery was 28 (60.9%, 28/46) and 1 (5.6%, 1/18) eyes, respectively. There was a statistically significant difference in the reduction rate of ORF after surgery between eyes with and without ORC (χ2=15.974, P＜0.001). Among the 46 eyes with ORC, the proportions of ORF to types Ⅰ, Ⅱ and Ⅲ after surgery were 24 (52.2%, 24/46), 20 (43.5%, 20/46), and 2 (4.3%, 2/46) eyes, respectively. There was no statistically significant difference in the incidence of ORF after different surgical methods in eyes with ORC (P＞0.05). One week and one month after the surgery, the logMAR BCVA of the affected eyes with and without ORF was 0.97±0.47, 0.69±0.34 and 0.85±0.32, 0.54±0.21, respectively. The BCVA of those without ORF was better than that of those with ORF, but the differences were not statistically significant (t=0.237, 0.408; P＞0.05). ConclusionsThe occurrence of ORC in RRD eyes has a certain relationship with the time of retinal detachment. For RRD eyes with ORC before the operation, the repositioning morphology after the operation is more likely to show changes in ORF. The transformation from ORC to ORF after ORC surgery has no correlation with the surgical method.
We aimed to establish an optical coherence tomography (OCT) system to measure the strain of blood vessels. A general OCT system was constructed firstly and its reliability was confirmed by comparing the OCT imaging of the porcine coronary and the corresponding histological slices. The strain of the porcine coronary was induced by static flow pressure and correlation algorithm was used to calculate the strain field of blood vessels within OCT images. The results suggest that bright-dark stratification of blood vessels displayed in OCT images is consistent with the intima and media layers of histological image. Furthermore, the strain of media layer is greater than that of the intima layer under the same static pressure. The optical coherence imaging system could not only measure the histological structure of the blood vessels, but also qualify the vessel strain under flow pressure.
ObjectiveTo observe the changes of chorioidal thickness (ChT) in patients with central serous chorioretinopathy (CSC) in different mode of vortic venous dilation. MethodsA prospective cross-sectional observational study. A total of 80 patients with 89 eyes (CSC group) diagnosed in Department of Ophthalmology, General Hospital of Central Theater Command from April to October 2023 were included in the study. Among them, 64 males had 71 eyes and 17 females had 18 eyes. A total of 15 healthy volunteers matched in age and sex were selected as the control group. Among them, 14 men had 26 eyes and one woman had two eyes. The macular region was examined by ultra-wide-angle scanning frequency source optical coherence tomography (OCTA) with BM400K BMizar made by TowardPi (Beijing) Medical Technology Co., LTD. Scanning rate 1 536 A scanning×1 280 B scanning, scanning range 24 mm×20 mm. The accompanying software delineated nine subfields (superotemporal, upper, superonasal, temporal, central, nasal, inferotemporal, lower, inferonasal regions) to record ChT. En-face OCTA mode was utilized to observe the anatomy and functional anastomosis of the vortex veins above and below the choroidal blood layer. Eyes in the CSC group were further categorized into upper-dominant, symmetrical, and lower-dominant groups based on the difference in vortex vein expansion shown in the choroidal layer of the en-face image, with 36, 35, and 18 eyes respectively. Statistical analysis included the use of independent samples t-test or Mann-Whitney test for comparison between two groups, one-way analysis of variance or Kruskal-Wallis H test for comparison between multiple groups, and the χ test or Fisher test for categorical variables. ResultsCompared with the control group, ChT in the CSC group was thickened in the foveal area and different areas of the macula, with the greatest difference in the fovea, and the differences were statistically significant (t=3.345, 5.018, 2.902, 4.667, 7.276, 3.307, 3.868, 4.795, 2.583; P＜0.05). Compared with the ChT of the control group, there was no statistically significant difference in the superotemporal, region of the upper-dominant group (t=1.510, P＞0.05); in other regions, the differences were statistically significant (t=3.207, 5.163, 2.526, 4.310, 6.285, 2.656, 3.812, 2.173; P＜0.05). The differences in the foveal area and other areas in the symmetrical group were statistically significant (t=4.488, 5.554, 3.457, 5.314, 7.256, 3.507, 5.584, 6.019, 2.994; P＜0.05). In the superotemporal, and superonasal, regions of the lower dominant group, the differences were not statistically significant (t=1.150, 1.465; P＜0.05); in other regions, the differences were statistically significant (t=2.278, 4.168, 5.244, 2.783, 5.040, 3.432, 2.095; P＜0.05). ConclusionThe dilated distribution of vortex veins on en-face ultra-wide-angle OCTA has a corresponding relationship with ChT. In eyes with CSC, the superior vortex vein drainage system may be the primary route for choroidal drainage.
Objective To explore the pathological diagnostic value of optical coherence tomography (OCT) in lung cancer. Methods This study selected patients who underwent general anesthesia and electronic bronchoscope biopsy at the Respiratory Endoscopy Center of Sichuan Provincial People’s Hospital from January 1, 2023, to December 1, 2023. White-light bronchoscopy (WLB), auto-fluorescence bronchoscopy (AFB), and OCT examinations were performed in all patients. Lesions were assessed for benign or malignant characteristics based on AFB and OCT before biopsy. The final pathological results were determined according to pathology report. Results A total of 124 patients were included in the study. The accuracy of OCT in differentiating the nature of lesions was 93.55%, significantly higher than AFB (accuracy 83.06%). The accuracy, sensitivity, and specificity of OCT were all higher than AFB. For squamous carcinoma, adenocarcinoma, and small cell lung cancer, the accuracy rates of OCT imaging characteristics were 91.94%, 94.35%, and 94.35%, respectively. Conclusion OCT can improve the accuracy of pre-bronchoscopic tissue pathology biopsy in determining the nature of lesions and provide rapid pathological typing basis, potentially further promoting the development of non-invasive histological biopsy.
Objective To observe the anastomotic status of the vortex veins in patients with central serous chorioretinopathy (CSC). MethodsA cross-sectional study of clinical practice. From July 2021 to July 2022, 50 cases (50 eyes) of monocular CSC patients diagnosed through ophthalmic examination at the First Affiliated Hospital of Zhengzhou University were included in the study. Among them, there were 37 males (74.0%, 37/50) and 13 females (26.0%, 13/50), with the mean age of (44.30±9.59) years old. The course of disease from the onset of symptoms to the time of treatment was less than 3 months. The affected eye and contralateral eye of CSC patients were divided into the affected eye group and contralateral eye group, respectively. Fifty healthy volunteers of the same age and gender were selected as the normal control group with 50 eyes. The macular area scanning source optical coherence tomography (OCT) vascular imaging examination was performed with Visual Microimaging (Henan) Technology Co., Ltd. VG200D. Horizontal watershed vortex veins anastomosis rate and asymmetric vortex-venous dilation rate were observed by en face OCT. The device comes with software to calculate the central foveal choroidal thickness (SFCT), mean choroidal thickness (MCT), and choroidal vascular index (CVI). One-way analysis of variance and χ2 test were used to compare the three groups. When variances were unequal between groups, nonparametric tests were performed. ResultsThe SFCT values of the affected eye group, contralateral eye group, and normal control group were (567.12±129.02), (513.26±133.17), (327.64±97.40) μm, respectively; MCT were (407.38±97.54), (388.24±94.13), (275.46±60.55) μm, respectively; CVI were 0.34±0.05, 0.32±0.04, and 0.27±0.04, respectively; anastomosis rates of vortex veins were 98% (49/50), 78% (39/50), and 40% (20/50), respectively; asymmetric dilation rates of vortex veins were 96% (48/50), 88% (44/50), and 48% (24/50), respectively. The differences of SFCT (F=53.974), MCT (Z=51.415), CVI (F=28.082), vortex vein anastomosis rate (χ2=43.056), asymmetric dilation rate of vortex veins (χ2=37.728) among three groups were statistically significant (P＜0.001). Compared with the contralateral eye group, the SFCT, MCT, CVI, vortex vein anastomosis rate, and vortex vein asymmetric dilation rate in the affected eye group were significantly higher than those in the contralateral eye group. Among them, the differences of SFCT (t=2.054), CVI (t=2.211), and vortex vein anastomosis rate (χ2=9.470) were statistically significant (P＜0.05); the differences of MCT (Z=7.490), asymmetric dilation rate of vortex veins（χ2=2.714) were not statistically significant (P=1.000, 0.140). ConclusionsSFCT, MCT, and CVI in the affected and contralateral eyes of monocular CSC patients significantly increase. The anastomotic rate and asymmetric dilation rate of the vortex vein in the opposite eye were lower than those in the affected eye.
The aim of this study was to investigate the feasibility of anterior segment optical coherence tomography to assess the anterior segment morphology of hyperopia in school-aged children. 320 eyes of 160 school-aged children, 6-12 years of age, were examined with anterior segment optical coherence tomography and were divided into four groups according to the cycloplegic spherical equivalence of refractive error. The mentioned four groups were: emmetropia group, low hyperopia group, moderate hyperopia group and high hyperopia group. The measurements of central corneal thickness, anterior chamber depth, angle opening distance, trabecular iris space area and scleral angle were compared in pairs among objects in the four groups. The results showed that high hyperopia and moderate hyperopia had shallower anterior chamber depth and narrower anterior chamber angle compared to those in emmetropia group. The study also showed that anterior segment optical coherence tomography as a non-contact technology could become a new technology for accessing the anterior segment morphology of hyperopia in school-aged children.
ObjectiveTo compare and observe the fundus imaging characteristics of eyes with glucocorticoid-related central serous chorioretinopathy (CSC). MethodsA retrospective clinical study. A total of 149 CSC patients with 166 eyes diagnosed at Department of Ophthalmology of The First Affiliated Hospital of Zhengzhou University from March 2021 to October 2024 were included in the study. The duration of the disease from the appearance of symptoms to treatment was less than 3 months. All affected eyes underwent best-corrected visual acuity (BCVA), fundus color photography, swept-source optical coherence tomography (SS-OCT), and fundus fluorescein angiography (FFA) examinations. BCVA was tested using an international standard vision chart and converted into logarithm of the minimum angle of resolution (logMAR) visual acuity for statistical analysis. The SS-OCT instrument measured subfoveal choroidal thickness (SFCT), central macular thickness (CMT), choroidal vascular volume (CVV), and the width and height of flat irregular pigment epithelial detachment (FIPED). FIPED, subretinal fibrin, and choroidal layer strong reflective spots were identified from SS-OCTA B-scan images; multiple leakages (leak points >3) were identified from FFA images. Based on the presence or absence of a clear history of glucocorticoid administration before the onset, patients were divided into glucocorticoid-related and non-glucocorticoid-related groups, comprising 41 patients with 53 eyes and 108 patients with 113 eyes, respectively. Clinical and fundus imaging characteristics of the two groups were compared. The comparison of quantitative data between the two groups was performed using independent samples t test or non-parametric independent samples Wilcoxon test; the comparison of qualitative data was performed using χ2 test. ResultsCompared with the non-glucocorticoid-related group, the glucocorticoid-related group had a smaller male-to-female ratio and a higher bilateral incidence, and the differences were statistically significant (χ2=4.925, 17.849; P＜0.05). The logMAR BCVA for the glucocorticoid-related and non-glucocorticoid-related groups were 0.45±0.33 and 0.21±0.21, respectively; SFCT were (644.43±131.91) and (507.26±121.79) μm; CMT were (389.51±233.45) and (362.59±140.85) μm; CVV were (4.44±1.07) and (3.67±0.82) mm3; FIPED incidence were 58.49% (31/58) and 20.35% (23/113), respectively; FIPED width and height were (1 122.01±533.98) and (742.90±388.79) μm, and (99.13±92.17) and (33.01±15.99) μm; subretinal fibrin were observed in 24 (45.28%, 24/53) and 15 (13.27%, 15/113) eyes; choroidal strong reflections were found in 38 (71.70%, 38/53) and 45 (39.82%, 45/113) eyes; multiple leak points were identified in 35 (66.03%, 35/53) and 40 (35.40%, 40/113) eyes, respectively. Compared with the non-glucocorticoid-related group, the glucocorticoid-related group had worse BCVA (Z=−4.984), thicker SFCT (t=6.586), larger CVV (t=5.160), higher incidence of FIPED (χ2=23.908), and greater width and height of FIPED (t=2.895, Z=−3.703). The glucocorticoid-related group also had a significantly increased incidence of subretinal fibrin, choroidal strong reflections, and multiple leak points, with all differences being statistically significant (χ2=20.565, 14.663, 13.675; P＜0.05); however, the comparison of CMT showed no statistically significant difference (Z=−0.651, P＞0.05). ConclusionCompared with non-glucocorticoid-related CSC, glucocorticoid-related CSC patients have poorer vision, are more likely to affect both eyes, show no gender bias; choroidal vascular dilation is more significant, and damage to the outer retina and retinal pigment epithelium is more severe.
Optical coherence tomography (OCT) is a non-invasive, rapid optical medical imaging modality and has become a hot topic in biomedical research. In recent years, several functional OCTs have emerged, including Doppler OCT, polarization-sensitive OCT, spectroscopic OCT, and optical coherence tomographic elastography, etc. These newer advances in functional OCT broaden the potential clinical application of OCT by providing novel ways to observe and understand tissue activity that cannot be accomplished by other current imaging methodologies.