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.
Objective To observe the hemodynamic changes in the retina and choroid after scleral buckling surgery in eyes with rhegmatogenous retinal detachment (RRD). MethodsA prospective clinical observational study. A total of 25 eyes of 25 patients with RRD who underwent scleral buckling surgery in Tianjin Eye Hospital from February to April 2024 were included in the study. Among them, 10 were male and 15 were female. Age was 17-68 years old. All cases were monocular. The surgical eye and the contralateral healthy eye were divided into the affected eye group and the contralateral healthy eye group respectively. Best corrected visual acuity (BCVA), scanning source optical coherence tomography angiography (SS-OCTA), and axial length (AL) measurements were performed 3 months after surgery. SS-OCTA examination of macular area was performed by VG200 of Visual Microimaging (Henan) Technology Co., LTD. Scanning range 21 mm×26 mm. According to the partitioning method of the early treatment group of glycosuria retinopathy, the retina within 21 mm of the macular fovea was divided into concentric circles with the macular fovea as the center and diameters of 1-3, 3-6, 6-12, 12-21 mm, respectively. The built-in software of the device was used to record the central area (12 mm×12 mm in the fovea of the macula) and the peripheral area (12-21 mm range) retinal superficial capillary plexus (SCP), deep capillary plexus (DCP), radial peripapillary capillaries (RPC) blood density and choroidal vascular index (CVI), choroidal vascular volume (CVV), and 1-3, 3-6, 6-12, 12-21 mm above concentric circles (S), nasal side (N), temporal side (T), and lower side (I) SCP, DCP, and RPC blood flow density. Quantitative data between the two groups were compared by independent sample t test or Wilcoxon signed rank test. The correlation between retinal and choroid blood flow parameters and postoperative BCVA was analyzed by Spearman correlation analysis. ResultsCompared with the opposite healthy eye group, SCP blood density in the central area (Z=−4.372), DCP blood density in the central area (Z=−2.829), and CVI in the peripheral area (Z=−2.138) were decreased in the affected eye group, and the differences were statistically significant (P＜0.05). SCP: in the affected eye group, the blood flow density in T3-6 mm, T6-12 mm, N6-12 mm and T12-21 mm regions decreased, while the blood flow density in I6-12 mm regions increased, with statistical significance (P＜0.05). DCP: blood flow density in S6-12 mm, I6-12 mm, S12-21 mm and I12-21 mm regions decreased significantly, and the differences were statistically significant (P＜0.05). RPC: blood flow density decreased significantly in T6-12 mm and I12-21 mm, and the differences were statistically significant (P＜0.05). CVI: T6-12 mm, S12-21 mm, T12-21 mm, I12-21 mm significantly decreased, and T1-3 mm, S12-21 mm significantly increased, the differences were statistically significant (P＜0.05). Correlation analysis showed that AL growth was positively correlated with CVV in central region (r=0.408, P=0.040) . The number of pad pressure was negatively correlated with the blood density of central DCP (r=−0.422, P=0.030). ConclusionsAfter scleral buckling operation, the blood flow density and choroidal blood flow parameters in RRD affected eyes are lower than those in contralateral healthy eyes in some areas. The increase of AL is positively correlated with CVV in the central region, and the wider the range of pad pressure, the worse the recovery of DCP blood density.
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.
A three-dimensional (3D) model of human anterior chamber is reconstructed to explore the effect of different corneal temperatures on the heat transfer in the chamber. Based on the optical coherence tomography imaging of the volunteers with normal anterior chamber, a 3D anterior chamber model was reconstructed by the method of UG parametric design. Numerical simulation of heat transfer and aqueous humor flow in the whole anterior chamber were analyzed by the finite volume methods at different corneal temperatures. The results showed that different corneal temperatures had obvious influence on the temperature distribution and the aqueous flow in the anterior chamber. The temperature distribution is linear and axial symmetrical around the pupillary axis. As the temperature difference increases, the symmetry becomes poorer. Aqueous floated along the warm side and sank along the cool side which forms a vortexing flow. Its velocity increased with the addition of temperature difference. Heat fluxes of cornea, lens andiris were mainly affected by the aqueous velocity. The higher the velocity, the bigger more absolute value of the above-mentioned heat fluxes became. It is practicable to perform the numerical simulation of anterior chamber by the optical coherence tomography imaging. The results are useful for studying the important effect of corneal temperature on the heat transfer and aqueous humor dynamics in the anterior chamber.
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.
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.
The segmentation of the intracoronary optical coherence tomography (OCT) images is the basis of the plaque recognition, and it is important to the following plaque feature analysis, vulnerable plaque recognition and further coronary disease aided diagnosis. This paper proposes an algorithm about multi region plaque segmentation based on kernel graph cuts model that realizes accurate segmentation of fibrous, calcium and lipid pool plaques in coronary OCT image, while boundary information has been well reserved. We segmented 20 coronary images with typical plaques in our experiment, and compared the plaque regions segmented by this algorithm to the plaque regions obtained by doctor's manual segmentation. The results showed that our algorithm is accurate to segment the plaque regions. This work has demonstrated that it can be used for reducing doctors' working time on segmenting plaque significantly, reduce subjectivity and differences between different doctors, assist clinician's diagnosis and treatment of coronary artery disease.
ObjectiveTo observe the histopathological changes in peripheral retinal lesions under intraoperative optical coherence tomography (iOCT). Methods A retrospective case series study. Eighty-eight patients (194 eyes) who underwent vitreoretinal surgery in the Department of Ophthalmology at the East Ward of the First Affiliated Hospital of Zhengzhou University from October 2021 to May 2022 in 94 eyes were included in the study. Among them, 49 cases were male and 39 cases were female, with the mean age of (50.93±17.55) years. Ninety-four eyes included 32 eyes with retinal detachment, 6 eyes with proliferative diabetic retinopathy, 28 eyes with vitreous hemorrhage, 8 eyes with ocular trauma, 14 eyes with the macular lesion, 1 eye with uveitis, 1 eye with family exudative vitreoretinopathy (FEVR), 1 eye with acute retinal necrosis (ARN), and 3 eyes with lens dislocation. All affected eyes were examined with iOCT during vitreoretinal surgery. The iOCT scanning of the peripheral retina was performed with the help of episcleral pressure. The pre-equatorial and serrated edge anterior and posterior of retinas were scanned according to the characteristics of different fundus diseases. Various abnormal fundus manifestations were recorded. Results In 94 eyes, 53 eyes (56.38%, 53/94) have different types of retinopathy in the peripheral retina. Of these, 7 eyes (7.45%) have retinal cystoid degeneration; 19 eyes (20.21%) have lattice degeneration; and 8 eyes (8.51%) have pigment degeneration; 9 eyes (9.57%) have pavement-like degeneration; 7 eyes (7.45%) have small occult holes; 1 eye (1.06%) has familial exudative vitreoretinopathy (FEVR) serrated edge "dyke-like" proliferative degeneration; 4 eyes (4.26%) have vitreous and retinopathy adhesions; and one eye (1.06%) has ARN. Conclusion With clear refractive media, iOCT can provide clear scans of different peripheral retinal lesions.
Optical coherence tomography (OCT) is a new technique applied in cardiovascular system. It can detect vessel intimal, small structure of plaque surface and discover small lesions with its high axial resolution and quantification character. Especially with the application of OCT in characterization of coronary atherosclerotic plaque, diagnosis and treatment strategy making, optimizing percutaneous coronary intervention therapy and assessment after stent planting make the OCT become an efficient tool for cardiovascular disease diagnosis and treatment. This paper presents a novel coronary vessel intimal sequence extraction method based on prior boundary constraints in OCT image. On the basis of conventional Chan-Vese model, we modified the evolutionary weight function to control the evolutionary rate of boundary by adding local information of boundary curve. At the same time, we added the gradient energy term and intimal boundary constraint term based on priori boundary condition to further control the evolutionary of boundary curve. At last, coronary vessel intimal is extracted in a sequence way. The comparison with vessel intimal, manual segmented by clinical scientists (golden standard), indicates that our coronary vessel intimal extraction method is robust to intimal boundary blur, distortion, guide wire shadow and plaque disturbs. The results of this study can be applied to clinical aid diagnosis and precise diagnosis and treatment.
Objective To observe the curative effect of a personalized surgical scheme based on scanning source optical coherence tomography (SS-OCT) image features in the treatment of congenital optic disc pit (ODP) with maculopathy (ODP-M). MethodsA prospective interventional cohort study. From September 2019 to May 2024, 15 patients with 15 eyes who were diagnosed with ODP-M by ophthalmology examination in Department of Ophthalmonogy of The First Affiliated Hospital of Zhengzhou University were included in the study. Best corrected visual acuity (BCVA) and SS-OCT were performed in all affected eyes. Standard E word visual acuity chart was used for BCVA examination, which was converted into logarithm of the minimum angle of resolution (logMAR) BCVA for record. The center retinal thickness (CRT) was measured by SS-OCT examination of macular area using VG200D of Henan SVision Imaging Technology Co., LTD. According to the morphological characteristics of ODP and the splitting, edema and detachment of macular region, combined with the degree of pulling of the boundary membrane between the posterior vitreous cortex and macular region, a personalized surgical method was designed. Class I: pars plana vitrectomy combined with macular boundary film stripping, ODP boundary film packing and vitreous cavity gas filling. Class Ⅱ: pars plana vitrectomy combined with non-retained macular boundary film stripping or ODP inner boundary film packing, vitreous cavity gas filling. Class Ⅰ and Class Ⅱ operations were performed in 10 and 5 eyes of 15 eyes, respectively. The postoperative follow-up time was ＞6 months. Follow-up time was performed with the same equipment before surgery. BCVA changes, CRT reduction rate and complications were observed. BCVA and CRT were compared before and after operation by paired sample t test. ResultsThere were 15 eyes in 15 cases, 4 eyes in 4 males and 11 eyes in 11 females. The age was (28.87±16.5) years. logMAR BCVA of the affected eye was 0.94±0.51. CRT was (697.80±301.80) μm. At the last follow-up, the logMAR BCVA was 0.53±0.49. CRT was (392.53±167.55) μm. Compared with before operation, BCVA and CRT were significantly improved, and the difference was statistically significant (t=3.23, 3.25; P=0.006, 0.006). After surgery, transient intraocular hypertension occurred in 2 eyes, and the intraocular pressure returned to normal level after 3 to 7 days without special treatment. Two eyes underwent an unexpected second operation. Among them, one eye underwent Class Ⅰ surgery, the tunnel at ODP was closed after surgery, and there was a small amount of subretinal fluid in the macular area. Class Ⅱ surgery was performed in 1 eye with retinal reattachment. ConclusionPersonalized surgical treatment of ODP-M based on SS-OCT image features can reduce CRT and improve visual acuity.