Optical Coherence Tomography Scans Research Articles

Intraoperative OCT to check the correct postimplant position of PreserfloTM.

This study was designed to examine the capacity of intraoperative optical coherence tomography (OCT) to predict the postimplant position of the glaucoma drainage device PreserfloTM. 13 eyes (mean age 65.42 (14.89) years) underwent PreserfloTM (Santen, Osaka, Japan) placement. Before surgery, participants were subjected to a comprehensive ophthalmic examination (intraocular pressure (IOP), cup to disk ratio (C/D), visual field, OCT, endothelial cell count). Anterior segment OCT scans were obtained intraoperatively using a Rescan 700 OCT system (Carl Zeiss Meditec, Inc., Oberkochen, Germany). One day postsurgery, anterior segment OCT using the Spectralis OCT (Heidelberg Engineering GmbH) was performed in a sitting position to capture the same chamber cross-section as before. The main outcome variables were tube-endothelium distance (T-E) and tube length (TL) in the anterior chamber measured using both OCT systems. Correlation between intraoperative and office measurements was examined through Pearson correlation (r) and intraclass correlation coefficients (ICC). Mean intraoperative and in-office T-E were 625.26 (SD 366.60) versus 561.16 (SD 364.62) µm respectively (p = 0.540). Intraoperative and in-office anterior chamber TL were 1386 (SD 701.82) and 1433.91 (SD 713.55) µm, respectively (p = 0.029). Excellent correlation was observed between both sets of T-E (r = 0.992; p = 0.008) and TL (r = 0.984; p = 0.016) values. Both OCT systems showed good agreement yielding ICCs of 0.992 (p < 0.001) for T-E and 0.995 (p = 0.001) for TL. Excellent correlation was observed between our intraoperative and postoperative OCT measurements. These results support the usefulness of intraoperative OCT to confirm the correct position of an implanted PreserfloTM microshunt.

Retinal layer thinning for monitoring disease-modifying treatment in relapsing multiple sclerosis—Evidence for applying a rebaselining concept

Background: Employing a rebaselining concept may reduce noise in retinal layer thinning measured by optical coherence tomography (OCT). Methods: From an ongoing prospective observational study, we included patients with relapsing multiple sclerosis (RMS), who had OCT scans at disease-modifying treatment (DMT) start (baseline), 6–12 months after baseline (rebaseline), and ⩾12 months after rebaseline. Mean annualized percent loss (aL) rates (%/year) were calculated both from baseline and rebaseline for peripapillary-retinal-nerve-fiber-layer (aLpRNFLbaseline/aLpRNFLrebaseline) and macular-ganglion-cell-plus-inner-plexiform-layer (aLGCIPLbaseline/aLGCIPLrebaseline) by mixed-effects linear regression models. Results: We included 173 RMS patients (mean age 31.7 years (SD 8.8), 72.8% female, median disease duration 15 months (12-94) median baseline-to-last-follow-up-interval 37 months (18-71); 56.6% moderately effective DMT (M-DMT), 43.4% highly effective DMT (HE-DMT)). Both mean aLpRNFLbaseline and aLGCIPLbaseline significantly increased in association with relapse (0.51% and 0.26% per relapse, p < 0.001, respectively) and disability worsening (1.10% and 0.48%, p < 0.001, respectively) before baseline, but not with DMT class. Contrarily, neither aLpRNFLrebaseline nor aLGCIPLrebaseline was dependent on relapse or disability worsening before baseline, while HE-DMT significantly lowered aLpRNFLrebaseline (by 0.31%, p < 0.001) and aLGCIPLrebaseline (0.25%, p < 0.001) compared with M-DMT. Conclusions: Applying a rebaselining concept significantly improves differentiation of DMT effects on retinal layer thinning by avoiding carry-over confounding from previous disease activity.

Pre-Clinical Studies of a Novel Bispecific Fusion Protein Targeting C3b and VEGF in Neovascular and Nonexudative AMD Models.

KNP-301 is a bi-specific fragment crystallizable region (Fc) fusion protein, which inhibits both C3b and vascular endothelial growth factor (VEGF) simultaneously for patients with late-stage age-related macular degeneration (AMD). The present study evaluated in vitro potency, in vivo efficacy, intravitreal pharmacokinetics (IVT PK), and injectability of KNP-301. C3b and VEGF binding of KNP-301 were assessed by surface plasmon resonance (SPR) and enzyme-linked immunosorbent assay (ELISA), and cellular bioassays. A laser-induced choroidal neovascularization (CNV) model and a sodium iodate-induced nonexudative AMD model were used to test the in vivo efficacy of mouse surrogate of KNP-301. Utilizing fluorescein angiography (FA) and spectral-domain optical coherence tomography (SD-OCT) scans, the reduction in disease lesions were analyzed in a CNV mouse model. In the nonexudative AMD mouse model, outer nuclear layer (ONL) was assessed by immunofluorescence staining. Lastly, intravitreal pharmacokinetic study was conducted with New Zealand white rabbits via IVT administration of KNP-301 and injectability of KNP-301 was examined by a viscosity test at high concentrations. KNP-301 bound C3b selectively, which resulted in a blockade of the alternative pathway, not the classical pathway. KNP-301 also acted as a VEGF trap, impeding VEGF-mediate signaling. Our dual-blockade strategy was effective in both neovascular and nonexudative AMD models. Moreover, KNP-301 had an advantage of potentially less frequent dosing due to the long half-life in the intravitreal chamber. Our viscosity assessment confirmed that KNP-301 meets the criteria of the IVT injection. Unlike current therapies, KNP-301 is expected to cover patients with late-stage AMD of both neovascular and nonexudative AMD, and its long-term PK profile at the intravitreal chamber would allow convenience in the dosing interval of patients.

Longitudinal Changes in Choroidal Vascularity in Myopic and Non-Myopic Children.

The purpose of this study was to evaluate longitudinal changes in choroidal vascular characteristics in childhood, and their relationship with eye growth and refractive error. Analysis of high-resolution optical coherence tomography (OCT) scans, collected over an 18-month period as part of the Role of Outdoor Activity in Myopia (ROAM) study, was conducted in 101 children (41 myopic, 60 non-myopic, age 10-15 years). OCT images were automatically analyzed and binarized using a deep learning software tool. The output was then used to compute changes in macular choroidal vascularity index (CVI), choroidal luminal, and stromal thickness over 18-months. Associations of these variables with refractive error and axial length were analyzed. CVI decreased significantly, whereas luminal and stromal thickness increased significantly over 18 months (all P < 0.001). The magnitude of change was approximately double in stromal tissue compared to luminal tissue (luminal β = 2.6 µm/year; 95% confidence interval [CI] = -1.0 to 4.1 µm/year; stromal β = 5.2 µm/year; 95% CI = 4.0, 6.5 µm/year). A significant interaction between baseline axial length and change in CVI over time (P = 0.047) was observed, with a greater CVI reduction in those with shorter axial lengths. Significant associations were observed between the change in CVI, luminal thickness, stromal thickness, and change in axial length over time (all P < 0.05). Faster axial eye growth was associated with smaller reductions in CVI, and less increase in choroidal luminal and stromal thickness. The changes in choroidal vascularity, particularly in the stromal component, may thus be a marker for eye growth. This knowledge of the longitudinal changes in choroidal vascularity in childhood and their relationship with eye growth may assist clinicians in the future to better predict eye growth and myopia progression in childhood.

Inducible RPE-specific GPX4 knockout causes oxidative stress and retinal degeneration with features of age-related macular degeneration

Age-related macular degeneration (AMD) is one of the leading causes of vision loss in the elderly. This disease involves oxidative stress burden in the retina leading to death of retinal pigment epithelial (RPE) cells and photoreceptors. The retina is susceptible to oxidative stress, in part due to high metabolic activity and high concentration of polyunsaturated fatty acids that undergo lipid peroxidation chain reactions. Antioxidant enzymes exist in the retina to combat this stress, including glutathione peroxidase 4 (GPX4). GPX4 specifically reduces oxidized lipids, protecting against lipid peroxidation-induced oxidative stress, which is noted in dry AMD. We hypothesize that Gpx4 knockout within the RPE will result in an environment of chronic oxidative stress yielding degeneration akin to AMD. C57BL/6J mice with a floxed Gpx4 gene were mated with Rpe65Cre/ER mice. Offspring containing Rpe65Cre ± alleles and either Gpx4 WT or Gpx4 fl/fl alleles were administered tamoxifen to induce Gpx4 knockout in Gpx4 fl/fl mice. At sequential timepoints, retinal phenotypes were assessed via in vivo imaging utilizing confocal scanning laser ophthalmoscopy and optical coherence tomography (OCT), and visual function was probed by electroretinography. Retinas were studied post-mortem by immunohistochemical analyses, electron microscopy, plastic sectioning, and quantitative polymerase chain reaction and Western analyses. The RPE-specific Gpx4 knockout model was validated via Western analysis indicating diminished GPX4 protein only within the RPE and not the neural retina. Following Gpx4 knockout, RPE cells became dysfunctional and died, with significant cell loss occurring 2 weeks post-knockout. Progressive thinning of the photoreceptor layer followed RPE degeneration and was accompanied by loss of visual function. OCT and light microscopy showed hyperreflective foci and enlarged, pigmented cells in and above the RPE layer. Electron microscopy revealed decreased mitochondrial cristae and loss of basal and apical RPE ultrastructure. Finally, there was increased carboxyethylpyrrole staining, indicating oxidation of docosahexaenoic acid, and increased levels of mRNAs encoding oxidative stress-associated genes in the RPE and photoreceptors. Overall, we show that RPE-localized GPX4 is necessary for the health of the RPE and outer retina, and that knockout recapitulates phenotypes of dry AMD.

PROGRESSION OF PERIPAPILLARY AND MACULAR CHORIORETINAL ATROPHY IN MULTIFOCAL CHOROIDITIS IS ASSOCIATED WITH PERIATROPHIC INFLAMMATORY PLUMES.

To investigate peripapillary atrophy and macular chorioretinal scars in eyes affected by multifocal choroiditis and panuveitis. This retrospective cohort study reviewed the medical records, fundus photographs, and spectral-domain optical coherence tomographic scans of 31 eyes from 19 patients. Patients had a mean age of 45 years (range 24-69 years). The average follow-up duration was 7 years (range, 2.5-14.5 years), with 14 patients undergoing immunosuppressive treatment. In the group of 31 eyes, 20 showed peripapillary plumes of ill-defined hyperreflectivity at the termination border of the retinal pigment epithelium. These plumes, extending from bare Bruch membrane to the outer nuclear layer, sometimes undermined the adjacent retinal pigment epithelium. They responded to corticosteroid treatment and resembled the material under the retinal pigment epithelium in acute lesions. Among 20 eyes with these peripapillary inflammatory lesions, 16 (80%) experienced increased atrophy, in contrast to none in the eyes without these lesions ( P < 0.001). Similar patterns were observed at the edges of macular chorioretinal atrophy. This observation occurred in patients using immunosuppressive medication who were otherwise thought to be under adequate control. In patients with multifocal choroiditis and panuveitis, previously unrecognized plumes of smoldering inflammatory activity at the borders of chorioretinal atrophy appears to be linked to atrophy expansion. The recognition of this phenomenon may require a reappraisal of treatment of multifocal choroidopathies to help mitigate the expansion of atrophy in these eyes.

Use of artificial intelligence for recognition of biomarkers in intermediate age-related macular degeneration

Advances in imaging and artificial intelligence (AI) have revolutionized the detection, quantification and monitoring for the clinical assessment of intermediate age-related macular degeneration (iAMD). The iAMD incorporates a broad spectrum of manifestations, which range from individual small drusen, hyperpigmentation, hypopigmentation up to early stages of geographical atrophy. Current high-resolution imaging technologies enable an accurate detection and description of anatomical features, such as drusen volumes, hyperreflexive foci and photoreceptor degeneration, which are risk factors that are decisive for prediction of the course of the disease; however, the manual annotation of these features in complex optical coherence tomography (OCT) scans is impractical for the routine clinical practice and research. In this context AI provides a solution by fully automatic segmentation and therefore delivers exact, reproducible and quantitative analyses of AMD-related biomarkers. Furthermore, the application of AI in iAMD facilitates the risk assessment and the development of structural endpoints for new forms of treatment. For example, the quantitative analysis of drusen volume and hyperreflective foci with AI algorithms has shown a correlation with the progression of the disease. These technological advances therefore improve not only the diagnostic precision but also support future targeted treatment strategies and contribute to the prioritized target of personalized medicine in the diagnostics and treatment of AMD.

3D Features Fusion for Automated Segmentation of Fluid Regions in CSCR Patients: An OCT-based Photodynamic Therapy Response Analysis.

Central Serous Chorioretinopathy (CSCR) is a significant cause of vision impairment worldwide, with Photodynamic Therapy (PDT) emerging as a promising treatment strategy. The capability to precisely segment fluid regions in Optical Coherence Tomography (OCT) scans and predict the response to PDT treatment can substantially augment patient outcomes. This paper introduces a novel deep learning (DL) methodology for automated 3D segmentation of fluid regions in OCT scans, followed by a subsequent PDT response analysis for CSCR patients. Our approach utilizes the rich 3D contextual information from OCT scans to train a model that accurately delineates fluid regions. This model not only substantially reduces the time and effort required for segmentation but also offers a standardized technique, fostering further large-scale research studies. Additionally, by incorporating pre- and post-treatment OCT scans, our model is capable of predicting PDT response, hence enabling the formulation of personalized treatment strategies and optimized patient management. To validate our approach, we employed a robust dataset comprising 2,769 OCT scans (124 3D volumes), and the results obtained were significantly satisfactory, outperforming the current state-of-the-art methods. This research signifies an important milestone in the integration of DL advancements with practical clinical applications, propelling us a step closer towards improved management of CSCR. Furthermore, the methodologies and systems developed can be adapted and extrapolated to tackle similar challenges in the diagnosis and treatment of other retinal pathologies, favoring more comprehensive and personalized patient care.

Exploring the relationship between 24-2 visual field and widefield optical coherence tomography data across healthy, glaucoma suspect and glaucoma eyes.

To utilise ganglion cell-inner plexiform layer (GCIPL) measurements acquired using widefield optical coherence tomography (OCT) scans spanning 55° × 45° to explore the link between co-localised structural parameters and clinical visual field (VF) data. Widefield OCT scans acquired from 311 healthy, 268 glaucoma suspect and 269 glaucoma eyes were segmented to generate GCIPL thickness measurements. Estimated ganglion cell (GC) counts, calculated from GCIPL measurements, were plotted against 24-2 SITA Faster visual field (VF) thresholds, and regression models were computed with data categorised by diagnosis and VF status. Classification of locations as VF defective or non-defective using GCIPL parameters computed across eccentricity- and hemifield-dependent clusters was assessed by analysing areas under receiver operating characteristic curves (AUROCCs). Sensitivities and specificities were calculated per diagnostic category. Segmented linear regression models between GC counts and VF thresholds demonstrated higher variability in VF defective locations relative to non-defective locations (mean absolute error 6.10-9.93 dB and 1.43-1.91 dB, respectively). AUROCCs from cluster-wide GCIPL parameters were similar across methods centrally (p = 0.06-0.84) but significantly greater peripherally, especially when considering classification of more central locations (p < 0.0001). Across diagnoses, cluster-wide GCIPL parameters demonstrated variable sensitivities and specificities (0.36-0.93 and 0.65-0.98, respectively), with the highest specificities observed across healthy eyes (0.73-0.98). Quantitative prediction of VF thresholds from widefield OCT is affected by high variability at VF defective locations. Prediction of VF status based on cluster-wide GCIPL parameters from widefield OCT could become useful to aid clinical decision-making in appropriately targeting VF assessments.

Developing a privacy-preserving deep learning model for glaucoma detection: a multicentre study with federated learning

BackgroundDeep learning (DL) is promising to detect glaucoma. However, patients’ privacy and data security are major concerns when pooling all data for model development. We developed a privacy-preserving DL model...

The effect of heart rate variability on the choroidal vascularity of the optical coherence tomography and angiography in central serous chorioretinopathy.

To investigate the correlation between the autonomic nervous system and choroidal vascularity in patients with central serous chorioretinopathy (CSC), using heart rate variability (HRV) analysis, optical coherence tomography (OCT) and OCT angiography (OCTA). We retrospectively analyzed data of 25 patients with unilateral CSC (50 eyes, including the unaffected fellow eyes) and 25 healthy controls. The assessment involved a 5-minute HRV analysis encompassing both frequency and time domains, especially low frequency (LF), high frequency (HF), and LF/HF ratio. In OCT (12 × 9mm) and en-face OCTA (3 × 3mm) scans, we measured parameters including choroidal vascularity index (CVI), choroidal vessel density in the middle and deep layers, and choriocapillaris flow void. Regression analysis was conducted to elucidate the associations between HRV parameters and OCT/OCTA measurements. Normalized LF(LFnorm) and LF/HF ratios were higher in patients with CSC than in healthy controls. LFnorm and the log-transformed ratio of LF to HF [log(LF/HF)] demonstrated a significant and borderline correlation with CVI in the linear regression analysis (P = 0.040, R2 = 0.171, and P = 0.059, R2 = 0.147, respectively). Both CVI and deep choroid vessel density showed a more significant association with LFnorm and log (LF/HF) in the non-linear quadratic regression analysis than in the linear analysis (all, P < 0.04, R2 > 0.25). The frequency-domain parameters of HRV, including LFnorm and log (LF/HF), demonstrated a significant association with indicators reflective of large choroidal vessel luminal area on macular OCT/OCTA scans. This observation implies complicated modulation of choroidal blood flow by the autonomic nervous system in CSC.

Best Vitelliform Macular Dystrophy Presenting with Choroidal Neovascular Membrane in an Adolescent: A Case Report and a Review of the Literature

Abstract An 11-year-old boy presented to the retina outpatient clinic with a -5-year history of poor vision in the left eye. The best corrected visual acuity at presentation was 6/5 and 6/36, respectively, in the right and left eyes. Ocular examination revealed normal anterior segments in both eyes. Binocular indirect ophthalmoscopy of the right eye revealed a pink disc with a cup disc ratio (CDR) of 0.3, normal vessels while the macula had a yellowish lesion with a scrambled egg appearance and surrounding dome-shaped subretinal fluid with a flat retina and no treatable peripheral retinal lesions. The left eye had a pink disc with CDR O.3, normal vessels with a hyperpigmented lesion at the macula surrounded by a small cuff of subretinal fluid with a flat retina and no treatable peripheral retinal lesions. Optical coherence tomography scan revealed subretinal fluid in both eyes with an active choroidal neovascular membrane in the left eye. He was advised on the need for left intravitreal anti-vascular endothelial growth factor injections.

Response of the human choroid to short-term changes in eyelid and periocular temperature

ABSTRACT Clinical relevance Choroidal thickness measurement is gaining popularity in clinical practice and research as an early indicator of myopia progression. Understanding the influence of temperature on choroidal thickness changes will improve the reliability of the measures. Background It has been suggested that environmental temperature may affect choroidal thickness and blood flow, with potential implications for ocular disease and refractive development. This study investigates the effect of changes in eyelid/ocular adnexa temperature on choroidal thickness. Methods In a paired-eye study, 20 young, healthy subjects received a warm stimulus (heat pack) over one closed eye and simultaneously a cold stimulus (ice pack) over the other for 10 min. Eyelid temperatures were monitored with thermal probes, and optical coherence tomography scans of the retina and choroid were taken before and after heating and cooling, and then every 5 min during a 15-min recovery period. Retinal and choroidal thicknesses were measured across the macular region (6 mm), including the subfoveal (1 mm), parafoveal (1–3 mm), and perifoveal (3–5 mm) regions, and compared between the cooled and warmed eyes. Results When the thermal stimuli were applied, eyelid surface temperatures changed predictably and remained significantly different (by approximately 10–15°C) between the eyes after 2 min (p < .001). Relative to the warmed eye, macular choroidal thickness in the cooled eye increased significantly after 10 min of treatment (p = .004). This choroidal thickening response occurred in the subfoveal, parafoveal, and perifoveal regions (all p < .05). Upon removal of the thermal stimuli, choroidal thickness rapidly returned to the baseline and was no longer different between the cooled and warmed eye (p = .641). Conclusion Cooling the anterior eye by application of a cold stimulus directly onto the closed eyelid caused a small but significant increase in choroidal thickness relative to warming the anterior eye, demonstrating that the choroid can modulate its thickness rapidly and transiently in response to local temperature changes.

Correlation of posterior segment lesions with anterior segment biometric parameters and FBN1 genotype in patients with Marfan syndrome

Objective: To investigate the characteristics of posterior segment lesions in Marfan syndrome (MFS) patients and their relationship with anterior segment biometric parameters and FBN1 genotype. Methods: A cross-sectional study was conducted. A total of 121 MFS patients, 76 males and 45 females, with an average age of (11.72±11.66) years, who visited the Department of Ophthalmology, Eye & ENT Hospital of Fudan University from January 2013 to March 2023 were included. The presence of posterior scleral staphyloma was observed using B-mode ultrasound, and macular lesions were identified and classified using the atrophy-traction-neovascularization system based on ultra-widefield fundus images, color fundus images, and optical coherence tomography scans. Anterior segment biometric parameters, including axial length of the eye, average corneal curvature, corneal astigmatism, horizontal corneal diameter, anterior chamber depth, and lens thickness, were collected, and the direction and extent of lens dislocation were observed. Molecular genetic analysis of FBN1 gene mutations in patients was performed using next-generation sequencing based on a panel of ocular genetic diseases, and the impact of the genotype and anterior segment biometric parameters on the posterior segment manifestations was analyzed. Results: Sixty patients exhibited posterior segment lesions, including retinal detachment (4 cases, 3.31%), macular lesions (47 cases, 38.84%), and posterior scleral staphyloma (54 cases, 44.63%). There was statistically significant difference in axial length of the eye between patients with and without posterior scleral staphyloma [23.09 (22.24, 24.43) and 27.04 (25.44, 28.88) mm], between patients with and without macular lesions [23.16 (22.24, 24.61) and 27.04 (25.74, 28.78) mm], and between patients with and without atrophic macular lesions [23.16 (22.24, 24.61) and 27.04 (25.74, 28.79) mm] (all P<0.001). There was statistically significant difference in anterior chamber depth between patients with and without macular lesions [3.11 (2.75, 3.30) and 3.34 (3.09, 3.60) mm] (P<0.05). There was also statistically significant difference in corneal astigmatism between patients with and without posterior scleral staphyloma [2.15 (1.20, 2.93) and 1.40 (1.00, 2.20) diopters] (P<0.05). The location and region of the FBN1 gene mutation not only showed statistically significant difference from the positive rates of posterior scleral staphyloma and macular lesions (all P<0.05), but also influenced the occurrence of atrophic macular lesions (both P<0.05). Patients with FBN1 mutations located in the transforming growth factor β regulatory sequence had the highest proportion of posterior scleral staphyloma and macular lesions (both 10/11). Conclusions: Posterior scleral staphyloma and macular lesions have a relatively high incidence in MFS patients and tend to progress to more severe grades. The age, axial length of the eye, anterior chamber depth, corneal astigmatism, and location and region of the FBN1 gene mutation are factors affecting the posterior segment lesions in MFS patients.

Prevalence Screening for Familial Optic Disc Drusen: A Cross-Sectional Study

ABSTRACT Optic disc drusen (ODD) may present in multiple individuals and generations within a family, indicating hereditary predisposition. Individuals are often unaware of their ODD, and consequently, the prevalence of ODD within families remains largely unknown. The aim of this study was to estimate the prevalence and consider the inheritance pattern of familial ODD and to investigate ODD-related symptoms and their association to ODD location and size. In this cross-sectional study, 22 ODD patients, aged 10 years or older, were included. Of these, 13 ODD probands had 24 family members participating. The presence, size, and anatomical location of ODDs and the presence of hyperreflective lines were ascertained using enhanced depth imaging optical coherence tomography (EDI-OCT) scan. Visual symptoms were ascertained, and these were correlated with ODD burden in terms of ODD location and size. Familial ODD was found in eight of the 13 screened families. Hyperreflective lines were present in all individuals with ODD, including both probands and their family members, and in seven out of the 14 family members without ODD. Visual symptoms were reported in 14–50% and associated significantly with superficial ODD location. We found familial ODD in eight of the 13 screened families. Our results aligned with the previously suggested autosomal dominant inheritance pattern with incomplete penetrance, assuming that hyperreflective lines represent a less expressed form of ODD. This emphasizes that ODD runs in families and supports the hypothesis that genetic factors may contribute to the etiology.

Measurement of retinal blood flow precision in the human eye with multimodal adaptive optics imaging.

Impaired retinal blood flow (RBF) autoregulation plays a key role in the development and progression of several ocular diseases, including glaucoma and diabetic retinopathy. Clinically, reproducible RBF quantitation could significantly improve early diagnosis and disease management. Several non-invasive techniques have been developed but are limited for retinal microvasculature flow measurements due to their low signal-to-noise ratio and poor lateral resolution. In this study, we demonstrate reproducible vessel caliber and retinal blood flow velocity measurements in healthy human volunteers using a high-resolution (spatial and temporal) multimodal adaptive optics system with scanning laser ophthalmoscopy and optical coherence tomography.

Wide-Field Optical Coherence Tomography Imaging Improves Rate of Change Detection in Progressing Glaucomatous Eyes Compared With Standard-Field Imaging.

To compare rates of retinal nerve fiber layer change over time in healthy, eyes with nonprogressing glaucoma and eyes with progressing glaucoma using single wide-field (SWF) and optic nerve head (ONH) cube scan optical coherence tomography (OCT) images. Forty-five eyes of 25 healthy individuals and 263 eyes of 161 glaucoma patients from the Diagnostic Innovations in Glaucoma Study were included. All eyes underwent 24-2 visual field testing and OCT (Spectralis SD-OCT) ONH and macular imaging. SWF images (up to 43° × 28°) were created by stitching together ONH cube scans centered on the optic disc and macular cube scans centered on the fovea. Visual field progression was defined as guided progression analysis likely progression and/or a significant (P < 0.01) mean deviation slope of less than -1.0dB/year. Mixed effects models were used to compare rates of change. Highly myopic eyes were included. Thirty glaucomatous eyes were classified as progressing. In eyes with glaucoma, mean global rate of change was -1.22 µm/year (P < 0.001) using SWF images and -0.83 µm/year (P = 0.003) using ONH cube scans. Rate of change was significantly greater in eyes with progressing glaucoma compared with eyes with nonprogressing glaucoma (-1.51 µm/year vs. -1.24 µm/year; P = 0.002) using SWF images and was similar using ONH cube scans (P = 0.27). In this cohort that includes eyes with and without high axial myopia, the mean rate of retinal nerve fiber layer thinning measured using SWF images was faster in eyes with progressing glaucoma than in eyes with nonprogressing glaucoma. Wide-field OCT images including the ONH and macula can be effective for monitoring glaucomatous progression in patients with and without high myopia.

Posterior Eye Shape in Myopia

PurposeTo explore prevalence and associated factors of abnormalities of the posterior eye shape in dependence of axial length. DesignPopulation-based study. ParticipantsOut of the participants (n=3468) of the Beijing Eye Study, we included all eyes with an axial length of ≥25 mm, and a randomized sample of eyes with an axial length of <25 mm. MethodsUsing 30°-wide, serial horizontal, and fovea-centered radial, optical coherence tomographic (OCT) images, we examined location and depth of the most posterior point of the retinal pigment epithelium/Bruch´s membrane line (PP-RPE/BML). Main Outcome ParametersPrevalence and depth of an extrafoveal PP-RPE/BML. ResultsThe study included 366 eyes (314 individuals;age:63.7±9.7 years). On the radial OCT scans, the PP-RPE/BML was located in the foveola in 190 (51.9%;95%CI:46.9,56.9) eyes, in 121 (33.1%;95%CI:28.1,38.1) eyes in the 6 o´clock part of the vertical meridian at a mean distance of 1.73±0.70mm from the foveola, and in 54 (14.8%;95%CI:11.1,18.4) eyes in the 12 o´clock part of the vertical meridian at a distance of 2.01±0.66mm from the foveola. Deeper PP-RPE/BML depth increased with longer axial length (beta:0.28;B:12.3;95%CI:7.5,17.1;P<0.001), female sex (beta:0.17;B:30.2;95%CI:10.7,49.6;P=0.002), and higher corneal astigmatism (beta:0.12;B:13.9;95%CI:1.50,26.3;P=0.03). On the horizontal OCT scans, the PP-RPE/BML was located in the foveola in 304 (83.1%;95%CI:79.2,86.9) eyes, between the foveola and the optic disc in 36 (9.8%;95%CI:6.8,12.9) eyes (mean depth: 119±142μm; mean distance:1.59±0.76mm from the foveola), and temporal to the foveola in 26 (7.1%;95%CI:4.5,9.8) eyes (depth:71±46μm; distance:1.20±0.60mm). Higher prevalence of an extrafoveal PP-RPE/BML correlated with longer axial length (OR:1.55;95%CI:1.28,1.89;P<0.001), higher corneal astigmatism (OR:1.78;95%CI:1.14,2.79;P=0.01) and female sex (OR:2.74;95%CI:1.30,5.77;P=0.008). The curvature of the RPE/BM line at the posterior pole was similar to the RPE/BM line curvature outside of the posterior pole in 309 (84.4%;95%CI:80.7,88.2) eyes, and it was steeper (i.e., smaller curvature radius) in 57 (15.6%;95%CI:12.1,19.1) eyes. In these eyes, axial length was longer (24.41±1.78mm versus 27.74±1.88mm;P<0.001). ConclusionsWith longer axial length, the foveola is more often located outside of the geometrical posterior pole. It may be of importance for biometric axial length measurements. An extrafoveal location of the PP-RPE/BML may be due to an axial elongation-associated, meridionally asymmetric enlargement of Bruch´s membrane in the fundus midperiphery.

Choroidal and retinal vascular changes in HLA-B27-associated anterior uveitis.

To quantitatively analyze choroidal and retinal vascular changes in HLA-B27-associated anterior uveitis. A retrospective study. Medical records of 51 eyes with unilateral HLA-B27-associated anterior uveitis, their fellow eyes and 47 sex and age-matched healthy eyes were retrospectively reviewed. Their choroidal and retinal vasculature were analyzed using swept-source (SS) optical coherence tomography (OCT) and OCT angiography (OCTA) scans. Deep capillary plexus (DCP) vessel density (VD) (p < 0.001), choroidal vascularity index (CVI) (p = 0.012), and choriocapillary flow deficit (CCFD) (p < 0.001) of uveitic and fellow eye group were significantly higher than those of control group. On the contrary, superficial capillary plexus (SCP) VD (p < 0.001) of uveitic and fellow eye group were significantly lower than of control group. The vascular parameters of uveitis and fellow eye group showed no significant difference between uveitic and resolution period. Certain choroidal and retinal vascular parameters were significantly changed in both HLA-B27-associated anterior uveitis without posterior segment involvement and the quiet fellow eyes, suggesting their possible effects as a systemic inflammatory disorder.

Modelo computacional basado en la tomografía de coherencia óptica (TCO) para identificar y cuantificar la radiodermatitis aguda (RA): estudio observacional prospectivo

BackgroundAcute radiation dermatitis (ARD) is the most widely reported radiotherapy-induced adverse event. Currently, there is no objective or reliable method to measure ARD. ObjectiveOur main objective was to identify and quantify the effects of radiotherapy with a computational model using optical coherence tomography (OCT) skin scanning. Secondary objectives included determining the ARD impact of different radiotherapeutic schemes and adjuvant topical therapies. MethodsWe conducted a prospective, single-center case series study in a tertiary referral center of patients with breast cancer who were eligible for whole breast radiotherapy (WBRT). ResultsA total of 39 women were included and distributed according to the radiotherapeutic schemes (15, 20, and 25 fractions). A computational model was designed to quantitatively analyze OCT findings. After radiotherapy, OCT scanning was more sensitive revealing vascularization changes in 84.6% of the patients (vs 69.2% of the patients with ARD by clinical examination). OCT quantified an increased vascularization at the end of WBRT (P<.05) and a decrease after 3 months (P=.032). Erythematous skin changes by OCT were more pronounced in the 25-fraction regime. ConclusionAn OCT computational model allowed for the identification and quantification of vascularization changes on irradiated skin, even in the absence of clinical ARD. This may allow the design of standardized protocols for ARD beyond the skin color of the patients involved.