Search Results (157)

Background: This study aimed to evaluate prognostic factors of early filtering blebs using anterior segment swept-source optical coherence tomography (AS SS-OCT) in patients with uveitic and neovascular glaucoma. Methods: This retrospective cohort study included 22 eyes from 22 patients who underwent trabeculectomy (11 eyes each with uveitic or neovascular glaucoma). Intrableb characteristics were assessed using AS SS-OCT at 1 month, postoperatively. Surgical success was defined as intraocular pressure (IOP) ≤ 18 mmHg and ≥30% IOP reduction without medication at 12 months. Logistic regression was used to identify the prognostic factors associated with IOP control. Results: Sixteen eyes (72.7%) achieved surgical success, while six (27.3%) were unsuccessful. Eyes with successful IOP control at 12 months showed thicker and less reflective bleb walls with microcysts compared with unsuccessful cases of IOP control, in the early postoperative phase (all p < 0.033). However, IOP at the time of OCT did not significantly differ between the groups (p = 0.083). Multivariate logistic regression analysis revealed that higher bleb wall reflectivity at 1-month post-trabeculectomy was significantly associated with a higher surgical failure rate at 12 months after trabeculectomy (hazard ratio = 1.072, p = 0.032). Conclusions: Early intrableb assessment using AS SS-OCT may be beneficial for managing filtering blebs after trabeculectomy in uveitic and neovascular glaucoma. Higher bleb wall reflectivity in the early post-trabeculectomy phase may indicate poor features of the filtering bleb, suggesting the need for timely interventions for refractory cases. Full article

Background: Patients with primary angle-closure disease (PACD), those with no history of acute angle-closure glaucoma or laser iridotomy, rarely present with prominent corneal endothelial cell density (CECD) loss. To identify factors associated with decreased CECD in PACD, anterior segment parameters were compared in patients with PACD and normal CECD and patients with PACD and decreased CECD, using anterior segment optical coherence tomography (AS-OCT). Patients and Methods: Ten patients with PACD and CECD of less than 1500/mm² without a history of cataract surgery, acute angle-closure glaucoma, or prior laser glaucoma procedures were identified at the Kyorin Eye Center from January 2018 to July 2023. Patients with an obvious corneal guttata or apparent corneal edema were also excluded. Seventeen patients with PACD and normal CECD (normal CECD group) were used as the control. Simultaneous biometry of all anterior segment structures, including the cornea, anterior chamber, and iris, were assessed using a swept-source AS-OCT system. Results: Corneal curvature radius was significantly larger in the decreased CECD group compared with the corneal refractive power in the normal CECD group (p = 0.022, Mann–Whitney test). However, no significant differences were detected in other anterior segment morphology parameters. Multiple regression analysis with CECD as the dependent variable revealed that a large corneal curvature radius was a significant explanatory variable associated with corneal endothelial loss. Conclusions: Flattened corneal curvature may be a risk factor for corneal endothelial loss in patients with PACD. Full article

Optical coherence tomography (OCT) is a non-invasive imaging technique that provides high-resolution, real-time visualization of soft and hard periodontal tissues. It offers micrometer-level resolution (typically ~10–15 μm) and a scan depth ranging from approximately 0.5 to 2 mm, depending on tissue type and system configuration. The field of view generally spans a few millimeters, which is sufficient for imaging gingiva, sulcus, and superficial bone contours. Over the past two decades, its application in periodontology has gained increasing attention due to its ability to detect structural changes in gingival and alveolar tissues without the need for ionizing radiation. Various OCT modalities, including time-domain, Fourier-domain, and swept-source OCT, have been explored for periodontal assessment, offering valuable insights into tissue morphology, disease progression, and treatment outcomes. Recent innovations include the development of three-dimensional (3D) OCT imaging and OCT angiography (OCTA), enabling the volumetric visualization of periodontal structures and microvascular patterns in vivo. Compared to conventional imaging techniques, such as radiography and cone beam computed tomography (CBCT), OCT offers superior soft tissue contrast and the potential for dynamic in vivo monitoring of periodontal conditions. Recent advancements, including the integration of artificial intelligence (AI) and the development of portable OCT systems, have further expanded its diagnostic capabilities. However, challenges, such as limited penetration depth, high costs, and the need for standardized clinical protocols, must be addressed before widespread clinical implementation. This narrative review provides an updated overview of the principles, applications, and technological advancements of OCT in periodontology. The current limitations and future perspectives of this technology are also discussed, with a focus on its potential role in improving periodontal diagnostics and personalized treatment approaches. Full article

Aim: The aim of this study was to evaluate choroidal and peripapillary retinal nerve fiber layer (RNFL) thicknesses in individuals with vasovagal syncope (VVS). Method: A total of 67 consecutive patients with VVS and 61 healthy control subjects were enrolled this study. The choroidal thickness (CT) at the fovea, the nasal to fovea thickness, and the temporal to fovea thickness were measured, alongside pRNLFT measurements assessed by swept-source optical coherence tomography (SS-OCT). Results: The mean foveal CT (408.7 ± 92.5 μm vs. 342.1 ± 60.2 μm, p < 0.01), the mean nasal CT (385.2 ± 88.3 μm vs. 329.2 ± 47.6 μm, p < 0.001), and the mean temporal CT (379.5 ± 51.6 μm vs. 321.48 ± 43.2 μm, p < 0.03) were statistically thicker in patients with VVS compared to the healthy controls. There was no statistically significant difference in the global pRNFLT measurements and all quadrants between the study groups. Conclusions: The CT in all regions was found to be thicker in patients with VVS compared to the healthy controls, while there were no differences in pRNFLT values. These results suggest that choroidal circulation might be affected by local neurotransmitter alterations in patients with VVS. Full article

Swept-source optical coherence tomography (SS-OCT) is a widely used imaging technique, particularly in medical diagnostics, due to its ability to provide high-resolution cross-sectional images. However, one of the main challenges in SS-OCT systems is the nonlinearity in wavelength sweeping, which leads to degraded depth resolution after Fourier transform. Correcting for this nonlinearity typically requires complex re-sampling and chirp compensation methods. In this paper, we introduce the first ultrafast time-stretch optical coherence tomography (TS-OCT) system that utilizes reservoir computing (RC) to perform direct temporal signal analysis without relying on Fourier transform techniques. By focusing solely on the temporal characteristics of the interference signal, regardless of frequency chirp, we demonstrate a more efficient solution to address the nonlinear wavelength sweeping issue. By leveraging the dynamic temporal processing capabilities of RC, the proposed system effectively bypasses the challenges faced by Fourier analysis, maintaining high-resolution depth measurement without being affected by chirp-introduced spectral broadening. The system operates by categorizing the interference signals generated by variations in sample position. This classification-based approach simplifies the data processing pipeline. We developed an RC-based model to interpret the temporal patterns in the interferometric signals, achieving high classification accuracy. A proof-of-the-concept experiment demonstrated that this method allows for precise depth resolution, independent of system chirp. With an A-scan rate of 50 MHz, the classification model yielded 100% accuracy with a root mean square error (RMSE) of 0.2416. This approach offers a robust alternative to Fourier-based analysis, particularly in systems prone to nonlinearities during signal acquisition. Full article

Background/Objectives: Swept-Source Optical Coherence Tomography (SS-OCT) is a novel optical biometry technology with limited published data on its reliability compared to the gold standard, partial coherence interferometry (PCI). This study aims to assess the agreement between an SS-OCT biometer (Argos) and a PCI device (IOLMaster 500) in terms of biometry values, intraocular lens (IOL) power calculation and mean prediction error (ME). Methods: In this prospective comparative study, axial length (AL), anterior chamber depth (ACD), flat (K1), steep (K2) and mean (Km) keratometry values, astigmatism power, J0, and J45 vector components, white-to-white distance (WTW), and IOL power calculations for nine IOL models using four formulas were compared in cataract patients. Refractive outcomes were assessed in eyes implanted with SN60WF and Panoptix IOLs, with ME calculated for each module and formula for both IOLs postoperatively. Results: This study included 133 eyes (mean age: 66.0 ± 10.95 years). Argos measured significantly higher ACD and steeper keratometry values than IOLMaster, albeit without significant differences in AL, astigmatism power, WTW, J0, and J45. Mean IOL power differences were within the clinically acceptable threshold (0.50 D), except for SN6ATx with Hoffer Q and Haigis, and Clareon with Haigis. For Panoptix and SN60WF, IOLMaster demonstrated a more hyperopic ME than Argos with SRK/T, Holladay 1, and Hoffer Q; however, this was without clinically significant differences. Conclusions: Argos and IOLMaster 500 presented differences in ACD, keratometry values, and IOL power calculation. However, both devices showed non-clinically significant differences in IOL power calculation and ME in the majority of formulas. Full article

Objectives: to evaluate the feasibility and utility of intraoperative optical coherence tomography (iOCT) utilizing an immersive augmented reality surgical headset (Beyeonics iOCT, Beyeonics Vision Ltd., Haifa, Israel) digital visualization platform with swept-source integrated OCT in ophthalmic surgery. Methods: As part of the Institutional Review Board-approved prospective DISCOVER study, the Beyeonics iOCT was utilized in multiple ophthalmic surgical procedures to evaluate the feasibility and utility of iOCT with this platform. The Beyeonics iOCT is a three-dimensional surgical visualization system that utilizes a swept-source integrated OCT within the digital microscope system. Surgeon feedback on system performance and integration into the surgical workflow was gathered via a prespecified survey. Results: Thirteen eyes of thirteen patients were included in this study. The surgical procedures consisted of four cataract surgeries, two lamellar corneal transplants, one pterygium removal, and six vitreoretinal surgeries. Surgeons were able to successfully view and review the iOCT images within the surgical Head-Mounted Display, eliminating the need for an external display. Utility feedback from surgeons included iOCT assisting with confirming wound architecture, corneal graft orientation, and retinal structure. All surgeries were completed without reverting to a conventional microscope, and no intraoperative adverse events occurred. Conclusions: The new visualization platform with integrated swept-source iOCT demonstrated feasibility and potential utility in multiple ophthalmic surgical platforms. Additional research related to outcomes, ergonomics, and enhanced software analysis is needed in the future. Full article

Objectives: This review explores the role of swept-source optical coherence tomography (OCT) in diagnosing and monitoring optic nerve neuropathy in Wernicke’s encephalopathy (WE) due to hyperemesis gravidarum, including a case of neuropathy from intractable vomiting in pregnancy. Methods: A literature search was conducted in the PubMed database to select high-quality reviews and original articles on the use of swept-source OCT for assessing optic nerve involvement in WE due to hyperemesis gravidarum. Results: WE is a potentially fatal neuropsychiatric syndrome caused by thiamine deficiency due to various causes, like alcoholism, malnutrition, and prolonged parenteral nutrition. This condition can cause neurological disorders such as imbalance, altered mental status, nystagmus, and ophthalmoplegia. Sometimes, there is also a deterioration of visual acuity with swelling of the optic disc. OCT is a non-invasive imaging tool that can detect optic nerve involvement in WE by assessing peripapillary retinal nerve fiber layer (pRNFL) thickness. In the acute phase, optic disc edema and increased pRNFL thickness may be observed, while chronic-phase changes include optic nerve atrophy and pRNFL thinning. WE may occur in the course of hyperemesis gravidarum in pregnant women. We present a case of a 23-year-old woman at 14 weeks of gestation with WE due to severe hyperemesis gravidarum, manifesting as visual impairment and neurological deficits. MRI confirmed the diagnosis, while OCT revealed transient pRNFL thickening followed by optic nerve atrophy. Conclusions: Early diagnosis and thiamine supplementation are crucial to preventing severe complications. OCT is a valuable tool for detecting and tracking optic nerve changes in WE. Full article

There is growing interest in optical coherence tomography (OCT) imaging at a wavelength of 1060 nm. However, potential contrast agents for OCT imaging at this specific wavelength has not been thoroughly investigated. In this study, we present the synthesis and optical characterization of gold nanocages with a small edge length (~65 nm) and a surface plasmon resonance peak around 1060 nm. These nanocages represent a class of potential contrast agents for OCT at 1060 nm. OCT imaging experiments were conducted on phantoms and in vivo mouse tissues using a 1060 nm swept-source OCT system, demonstrating significant enhancement in imaging contrast due to the presence of the gold nanocages. Full article

Background and Objectives: Despite the growing amount of new research, the pathophysiology of glaucoma remains unclear. The aim of this study was to determine the relationship between intracranial pressure (ICP), ocular blood flow and structural optic nerve parameters. Materials and Methods: A prospective clinical study was conducted involving 24 patients with open-angle glaucoma and 25 healthy controls. Routine clinical examination was performed. Swept-source optical coherence tomography (SS-OCT) and OCT angiography (OCTA) images were taken (DRI-OCT Triton, Topcon). The vessel density (VD) values of the ONH were calculated around the optic nerve head (ONH). An orbital Doppler device (Vittamed 205, Kaunas, Lithuania) was used for non-invasive ICP measurements. Color Doppler imaging (CDI) (Mindray M7, Shenzhen, China) was used for retrobulbar blood flow measurements in the ophthalmic artery (OA), central retinal artery (CRA) and short posterior ciliary arteries (SPCAs). Results: ICP was 8.35 ± 2.8 mmHg in the glaucoma group and 8.45 ± 3.19 mmHg in the control group (p = 0.907). In the glaucoma group, the VD of the superficial vascular plexus in the inferior-nasal (NI) sector of the ONH showed a correlation with ICP (r = 0.451, p = 0.05). In contrast, the control group exhibited weaker correlations. CRA peak systolic velocity (PSV) demonstrated significant moderate correlations with VD in multiple retinal layers, including the avascular retina layer in the temporal (T) sector (r = 0.637, p = 0.001). Conclusions: Lower ICP was significantly associated with the lower VD of the superficial plexus layer in the inferior-nasal sector in the glaucoma group, with the control group exhibiting weaker correlations in all sectors. Further longitudinal studies with larger sample sizes are needed to establish associations between intracranial pressure, ocular blood flow and ONH parameters. Full article

Objectives: In this study, the objective was to assess the correlation between macular function and peripapillary retinal nerve fiber layer (pRNFL) thickness following successful rhegmatogenous retinal detachment (RRD) surgery, as well as the subsequent recovery of visual acuity. Methods: This was a cross-sectional study including 64 eyes from patients with RRD who underwent successful treatment with 23G pars plana vitrectomy (PPV), endophotocoagulation and sulfur-hexafluoride (SF6) were included and compared to a control group consisting of 136 healthy eyes. A complete ophthalmological examination was performed on all participants, including assessment of macular sensitivity using macular integrity assessment (MAIA) microperimetry and pRNFL thickness using DRI-Triton swept-source (SS)–optical coherence tomography (OCT). Results: In the RRD group, retinal sensitivity was decreased. The temporal (T) sector of the total retina (TR) protocol was thicker, while the superior (S) and inferior (I) sectors of the pRNFL protocol were thinner. Within the RRD group, positive correlations were observed between the nasal (N), I sectors and total thickness of TR protocol and MAIA inferior outer (IO) sector; the I sector and total thickness of the TR protocol and MAIA inferior inner (II) sector; the I sector of the pRNFL protocol and MAIA IO sector. Negative correlations were shown between the S, T sectors and total thickness of the pRNFL protocol and MAIA central (C) sector; the N sector and total thickness of the pRNFL protocol and MAIA central temporal (CT) sector. Conclusions: RRD leads to a decrease in pRNFL thickness accompanied by reduced macular sensitivity. These changes may be attributed to factors such as the specific location of the RRD, the distribution pattern of the RNFL and the chosen surgical approach. Full article

Light-emitting electronic devices are widely used at present, and this increases the risk of myopia. Thus, the early identification of myopia and the prevention of further exacerbation has become an essential issue in ophthalmology. Recently, choroidal imaging has been used to assist in the early identification and prevention of high myopia due to the fact that swept-source optical coherence tomography (SS-OCT) is an essential diagnostic tool in ophthalmology. This study presents a novel method to judge high myopia using the SS-OCT image dataset obtained from a university hospital. In order to relate the proposed method to the region of the SS-OCT image, the curvature analysis of an arbitrary segmented curve similar to the region of the SS-OCT is first illustrated by quadratic functions and matrix operations. Next, the curvature formula is derived and then applied to the choroidal curve obtained manually in each patient’s choroidal image. In particular, we applied the curvature analysis and its results to find the maximal curvature and average curvature of each patient’s choroidal curve. Finally, we used the maximal curvature and average curvature to evaluate high myopia. The accuracy of the proposed maximal curvature method and average curvature method in the experimental results to verify the proposed method. Full article

Retinal detachment (RD) is a vision-threatening ocular emergency that necessitates rapid diagnosis and intervention. This review examines the evolving role of optical coherence tomography (OCT) in RD by synthesizing the literature on preoperative biomarkers and advanced image modalities that inform diagnosis, prognosis, and surgical planning. We evaluated studies employing spectral-domain OCT, swept-source OCT, OCT angiography, adaptive optics OCT, and en face OCT to assess photoreceptor integrity, retinal detachment height, intraretinal cystic cavities, outer retinal corrugations and undulation, and macular involvement. The incorporation of OCT assessment into clinical practice may facilitate more precise surgical timing, technique selection, and postoperative monitoring. Further research is needed to standardize imaging protocols and validate specific prognostic biomarkers for optimal surgical outcomes. Key aspects include uniform imaging protocols, validating OCT-derived biomarkers such as ellipsoid zone integrity, and correlating OCT metrics with functional outcomes. Full article

Background/Objectives: This study aimed to evaluate long-term postoperative outcomes following the use of small-diameter grafts in Descemet Membrane Endothelial Keratoplasty (DMEK) procedures. Methods: Thirty-four eyes were evaluated after DMEK surgery. Best-corrected visual acuity (BCVA), endothelial cell density (ECD), endothelial cell loss (ECL), central corneal thickness (CCT), mean keratometry (MK), mean astigmatism (MA), astigmatism asymmetry (AA), and higher-order aberrations (HOA) were assessed at baseline and 12, 24 and 36 months after surgery using anterior segment swept-source OCT (CASIA2, Tomey, Japan). Results: BCVA gradually improved during the 12-month follow-up, after which the stabilisation of this parameter was documented. Compared with the donor values, the cumulative median ECL reached approximately 63.95% over 36 months. No significant changes in total keratometry between baseline recordings and 36-month data were observed. Total astigmatism power significantly decreased between baseline and the 12th month and subsequently between the 12th and 24th month, with consecutive stabilisation of astigmatism power from the 24th month to the 36th month of follow-up. Significant reductions in HOA were observed until the 12th month, followed by the stabilisation of these parameters. Conclusions: The use of smaller grafts in DMEK demonstrates high effectiveness in maintaining high visual and refractive quality while offering potential advantages in tissues. Full article

This study demonstrates the use of a dual-sample arm swept-source optical coherence tomography (SS-OCT) instrument coupled with air-puff stimulation to assess corneal displacement in an ex vivo porcine eye model. The air-puff SS-OCT system enables correction of corneal deformation for eye globe retraction, providing a comprehensive quantitative analysis of corneal apex deformation dynamics under varying intraocular pressure (IOP) levels and air-puff stimulus strengths. Spatio-temporal characterization of those stimuli was performed. The results showed that the cornea stiffened with increased IOP, and reducing the stimulus amplitude decreased the correlation between parameters describing corneal dynamics and IOP. However, maximum displacement and corneal response time exhibited very strong correlations regardless of the strength of the applied air-puff. These findings suggest that softening air-puff stimulation may impact the accuracy of non-contact tonometers in measuring IOP and corneal biomechanical properties. Full article