Multimodal imaging of dark without pressure lesions in paediatric retinal vasculitis: A cross-sectional study.

The objective of this study was to assess the structural-functional relationship in choroideremia (CHM) patients using optical coherence tomography (OCT) and autofluorescence (AF) images. In this study, 53 eyes of 28 CHM patients were included. Demographic, ocular and clinical fundus features were recorded. Fundus AF and OCT images were analysed. Patients were classified into two groups based on AF features: group 1, CHM patients where the foveal island was present and group 2, CHM patients where the foveal island was absent. Inner and outer retinal layer thicknesses, retinal pigment epithelium (RPE) and subfoveal choroidal thickness (SFCT) were measured and correlated with visual acuity (VA). There were 26 eyes in group 1 and 27 eyes in group 2. Mean age in groups 1 and 2 were 51.7 ± 13.4 and 63.6 ± 11.6 years, respectively. Age (p = 0.001) and VA (p < 0.001) between the two groups were significantly different. The retinal and SFCT showed significant differences that were analysed for each eye between the two groups. Reduced VA was noted with increasing age (r = 0.483; p ≤ 0.001), thin total retina (r = -0.378; p = 0.005), inner (r = -0.512; p < 0.001), outer (r = -0.59; p < 0.001) retinal thicknesses and thin RPE (r = -0.653; p < 0.001). Multivariate analysis showed RPE thickness (p = 0.001) as the most important index that affected VA. RPE thinning contributes to poor VA in patients with advanced CHM. Further studies are needed to evaluate the role of retinal thickness and SFCT and its relationship to VA.

Geographic atrophy (GA) is the atrophic late-stage manifestation of age-related macular degeneration (AMD), which may result in severe vision loss and blindness. The purpose of this study was to develop a reliable, effective approach for GA segmentation in both spectral-domain optical coherence tomography (SD-OCT) and fundus autofluorescence (FAF) images using a level set-based approach and to compare the segmentation performance in the two modalities. To identify GA regions in SD-OCT images, three retinal surfaces were first segmented in volumetric SD-OCT images using a double-surface graph search scheme. A two-dimensional (2-D) partial OCT projection image was created from the segmented choroid layer. A level set approach was applied to segment the GA in the partial OCT projection image. In addition, the algorithm was applied to FAF images for the GA segmentation. Twenty randomly chosen macular SD-OCT (Zeiss Cirrus) volumes and 20 corresponding FAF (Heidelberg Spectralis) images were obtained from 20 subjects with GA. The algorithm-defined GA region was compared with consensus manual delineation performed by certified graders. The mean Dice similarity coefficients (DSC) between the algorithm- and manually defined GA regions were 0.87 ± 0.09 in partial OCT projection images and 0.89 ± 0.07 in registered FAF images. The area correlations between them were 0.93 (P < 0.001) in partial OCT projection images and 0.99 (P < 0.001) in FAF images. The mean DSC between the algorithm-defined GA regions in the partial OCT projection and registered FAF images was 0.79 ± 0.12, and the area correlation was 0.96 (P < 0.001). A level set approach was developed to segment GA regions in both SD-OCT and FAF images. This approach demonstrated good agreement between the algorithm- and manually defined GA regions within each single modality. The GA segmentation in FAF images performed better than in partial OCT projection images. Across the two modalities, the GA segmentation presented reasonable agreement.

High-Definition and 3-dimensional Imaging of Macular Pathologies with High-speed Ultrahigh-Resolution Optical Coherence Tomography

Previous studies have demonstrated that optical coherence tomography (OCT) could be used to delineate alterations in the microstructure of cartilage, and have suggested that changes in the polarization state of light as detected by OCT could provide information on the birefringence properties of articular cartilage as influenced by disease. In this study we have used both OCT and polarization sensitive optical coherence tomography (PS-OCT) technologies to evaluate normal and abnormal bovine articular cartilage according to established structural, organizational, and birefringent characteristics of degenerative joint disease (DJD) in order to determine if this technology can be used to differentiate various stages of DJD as a minimally invasive imaging tool. Fresh bovine femoral-tibial joints were obtained from an abattoir, and 45 cartilage specimens were harvested from 8 tibial plateaus. Whole ex vivo specimens of normal and degenerative articular cartilage were imaged by both OCT and PS-OCT, then fixed and processed for histological evaluation. OCT/PS-OCT images and corresponding histology sections of each specimen were scored according to a modified Mankin structural grading scale and compared. OCT and PS-OCT imaging allowed structural evaluation of intact articular cartilage along a 6 mm surface length to a depth of 2 mm with a transverse resolution of 12 microm and an axial resolution of 10 microm. The OCT and PS-OCT images demonstrated characteristic alterations in the structure of articular cartilage with a high correlation to histological evaluation (kappa = 0.776). The OCT images were able to demonstrate early to advanced structural changes of articular cartilage while the optical phase retardation images obtained by PS-OCT imaging were able to discriminate areas where disorganization of the cartilage matrix was present, however, these characteristics are much different than those reported where OCT images alone were used to characterize tissue birefringence. No evidence of differences in OCT or PS-OCT images were detected between specimens of similar structural characteristics where proteoglycan was judged present or absent by safranin-O Fast Green staining. The combined use of OCT and PS-OCT technologies to obtain images from a single system is able to demonstrate and discriminate between characteristics of very early stages of surface irregularities not previously reported for OCT imaging, to deep clefts and collagen matrix disorganization for tissue at depths of up to 2 mm with good correlation to histology. PS-OCT and accumulated optical phase retardation images of articular cartilage as constructed from alterations in Stokes vector parameters appear to give a valuable but different assessment of alterations in tissue birefringence and organization than have been reported for OCT images obtained with the use of polarized or non-polarized light sources. This is the first time that alterations in the polarization state of light reflected from within the tissue have been demonstrated to be consistent with changes observed in the orientation and organization of the collagen matrix in advanced stages of DJD. The degree of phase transformation of light reflected from within the tissue as determined by PS-OCT imaging does not appear to be altered by the presence or absence of proteoglycan.

Microaneurysms (MAs) are pathognomonic signs that help clinicians to detect diabetic retinopathy (DR) in the early stages. Automatic detection of MA in retinal images is an active area of research due to its application in screening processes for DR which is one of the main reasons of blindness amongst the working-age population. The focus of these works is on the automatic detection of MAs in en face retinal images like fundus color and Fluorescein Angiography (FA). On the other hand, detection of MAs from Optical Coherence Tomography (OCT) images has 2 main advantages: first, OCT is a non-invasive imaging technique that does not require injection, therefore is safer. Secondly, because of the proven application of OCT in detection of Age-Related Macular Degeneration, Diabetic Macular Edema, and normal cases, thanks to detecting MAs in OCT, extensive information is obtained by using this imaging technique. In this research, the concentration is on the diagnosis of MAs using deep learning in the OCT images which represent in-depth structure of retinal layers. To this end, OCT B-scans should be divided into strips and MA patterns should be searched in the resulted strips. Since we need a dataset comprising OCT image strips with suitable labels and such large labelled datasets are not yet available, we have created it. For this purpose, an exact registration method is utilized to align OCT images with FA photographs. Then, with the help of corresponding FA images, OCT image strips are created from OCT B-scans in four labels, namely MA, normal, abnormal, and vessel. Once the dataset of image strips is prepared, a stacked generalization (stacking) ensemble of four fine-tuned, pre-trained convolutional neural networks is trained to classify the strips of OCT images into the mentioned classes. FA images are used once to create OCT strips for training process and they are no longer needed for subsequent steps. Once the stacking ensemble model is obtained, it will be used to classify the OCT strips in the test process. The results demonstrate that the proposed framework classifies overall OCT image strips and OCT strips containing MAs with accuracy scores of 0.982 and 0.987, respectively.

To explore discrepancies on fundus autofluorescence (FAF) obtained with two widely used devices in patients with CNGB3-associated achromatopsia, with respect to the central foveal signal. Secondly, to explore continuity of the foveal ellipsoid zone (EZ) in these patients. Patients who had undergone blue (488 nm; Heidelberg Spectralis) and green (532 nm; Optos) FAF imaging during the same visit were included. The central foveal signal was graded qualitatively as brighter or darker compared to the wider foveal/parafoveal region. Optical coherence tomography images from the same visit were also graded (masked to FAF grading) with respect to foveal EZ continuity. Forty-one patients (24 females; mean age, 32 ± 19 years) were included. For blue FAF, the central foveal signal was graded darker in all cases. For green FAF, the central fovea was brighter in 11 patients (27%), indicating discordance with blue FAF. The discordant group were significantly younger (P = 0.022). The EZ line was gradable in 40 patients: 22 (55%) had continuous foveal EZ in both eyes; these were younger than those with an interrupted EZ in one or both eyes (P < 0.0001). All patients discordant for FAF images had continuous foveal EZ. Discordance occurred between the FAF modalities in more than one-quarter of patients; these patients were significantly younger, and all had a continuous EZ line. Investigating mechanisms of discordance could yield pathophysiological insights. FAF platforms are not interchangeable; these findings could inform the design of natural history studies and therapeutic trials for this condition.

Aims/Purpose: The detection of subretinal fluid (SRF) and intraretinal fluid (IRF) in optical coherence tomography (OCT) images plays a crucial role in the diagnosis and treatment of certain eye diseases. In this study, we investigated the performance of a Transfer Learning artificial intelligence (AI) technique, which we used to perform the model adaptation from the domain of Heidelberg OCT images to Optopol devices.Methods: A data set of 133 Optopol OCT images. 69 images indicating subretinal or intraretinal fluid and 64 fluid‐free images, were analysed. The AI algorithm that was initially trained on OCT images from Heidelberg device was fine‐tuned to perform the biomarker segmentation in Optopol (Revo NX, SOCT Copernicus REVO, REVO FC) OCT images. Manual assessments by the medical experts were used to evaluate the algorithm's performance.Results: Our findings demonstrate the promising performance of the domain‐adapted model. in detecting SRF and IRF, when initially trained on OCT images from a different device. The algorithm achieved an accuracy of 80% while classifying the presence versus absence of the fluids on the balanced test data set.Conclusions: The study demonstrates a successful application of a transfer learning technique for detection of subretinal and intraretinal fluids in OCT images acquired with the Optopol devices, indicating its potential for enhancing eye diagnostics. Further studies utilizing larger data sets, further biomarkers and diverse OCT devices are warranted to validate the algorithm's robustness and generalizability.

Autologous translocation of the choroid and retina pigment epitelial cells(RPE) in age-related macular degeneration: Monitoring the viability of choroid and RPE patch with indocyanine green angiography(ICGA) and fundus autofluorescence(FAF).

Purpose: The purpose was to compare between color fundus photography (CFP) images and fundus autofluorescence (FAF) images of cases with geographical atrophy (GA) about size. To evaluate the relation between different phenotypes of FAF changes and best corrected visual acuity (BCVA) in cases with late dry age-related macular degeneration (AMD) (GA). Materials and Methods: This study was conducted on 18 eyes of 18 patients aged 55 years. Patients unwilling to participate in the study, suffering from hereditary fundus diseases, had previous laser photocoagulation treatment for any cause, were excluded. BCVA using Snellen chart was measured. Retinal imaging including CFP with 50° field camera: Topcon TRC-50 IX - and FAF using spectralis Heidelberg retinal angiograph (HRA) + optical coherence tomography (HRA, Heidelberg Engineering, Germany) were done. All images were optimized and then manually measured using image analysis software (Adobe Photoshop version CS6; Inc., San Jose, California, USA). Images of fundus autofluorescence in cases of late dry AMD were classified to phenotypes at the junctional zone according to the classification of abnormal FAF patterns. Results: According to sex distribution, 33.3% (6 eyes) were males and 66.7% (12 eyes) were females . The mean age of the study participants was 72.89 ± 9.09 years. About surface area of GA, the mean surface area of GA by FAF was 71094.56 ± 21490.53 pixels and by color fundus camera were 46236.56 ± 13153.46 pixels. About FAF phenotypes in late dry AMD cases, Twelve eyes (66.7%) had diffuse pattern, 11.1% (2 eyes) had a none pattern (no specific pattern), and 22.2% (4 eyes) had focal pattern. Color fundus camera underestimated the surface area of GA in cases of late dry AMD. BCVA was best in cases with no specific pattern of autofluorescence at the junctional zone of the GA, followed by cases with focal pattern of hyperautofluorescence while cases with diffuse increases of autofluorescence at the junctional zone showed the worst VA. Conclusions: CFP underestimated the size of the GA, as compared with FAF measured sizes. BCVA was best in cases with no specific pattern of autofluorescence at the junctional zone of the GA, followed by cases with focal pattern of hyperautofluorescence while cases with diffuse increases of autofluorescence at the junctional zone showed the worst VA.

The aim of this study was to report the findings from enhanced depth imaging (EDI) and swept-source optical coherence tomography (OCT) in a choroidal osteoma. A case study of a patient with choroidal osteoma is presented and discussed. A 25-year-old woman presented with an asymptomatic peripapillary mass. Fundus examination revealed a yellow–orange, well-defined geographical lesion. B‑scan ultrasonography, corroborated by fundus autofluorescence (FAF) and OCT findings, pointed to the diagnosis of choroidal osteoma. Calcified areas of the tumor were iso-autofluorescent on FAF and hyporeflective on OCT, revealing the morphological patterns of cancellous bone, including a sponge-like pattern and lines indicating lamellae, Haversian canals, and cement lines. Decalcified patches of the tumor were hypofluorescent on FAF and hyperreflective on OCT and showed overlying retinal damage—most prominently depigmentation and retinal pigment epithelium disruptions. A central area of the tumor revealed unusual characteristics; hyperreflectivity on OCT indicating decalcification but isofluorescence on FAF and sharing the same color as the rest of the retina on fundus photography. The area also differed from the other decalcified areas with its cumulus cloud-like appearance. Compared with EDI-OCT, SS-OCT images showed some increased definition of the bony features of the tumor, especially in its deeper layers, as well as a mild reduction of the shadowing caused by overlying retinal vessels. The morphological features of a choroidal osteoma are demonstrated using EDI- and SS-OCT. Calcified and decalcified areas of the tumor were differentiated, as well as another area showing unexpected characteristics. In our case, SS-OCT imaging revealed very similar features to EDI-OCT.

To investigate morphological variations in the macular area with optical coherence tomography (OCT) after vitrectomy for diabetic fibrovascular proliferation. We reviewed 108 cases using OCT 7-15 months after vitrectomy. Of these, 32 received OCT within 3 months postoperatively. Morphological variations were categorized and correlated with visual outcome. Only 24 cases (21.4%) had no obvious abnormalities. The most frequent findings were epiretinal membrane (52.8%), macular thickening (37.0%) and macular cysts (28.7%). Multivariate regression showed that diffuse macular thickening, loss of foveal depression and diffuse retinal thinning were significantly associated with poor visual acuity. Sequential OCT (< 3 and >or= 7 months) revealed that epiretinal membrane and oedema outside of fovea changed significantly between two examinations. OCT may identify diverse morphological changes in the macular area after diabetic vitrectomy for fibrovascular proliferation. Macular appearance may change over time, and certain types of morphological changes may be associated with poor visual function.

Aim: To investigate and compare the presentation of granulomatous lesions in optical coherence tomography (OCT) images and compare this to previous studies of nonmelanoma skin tumors. Methods: Two patients with granulomas, tophi and granuloma annulare (GA), respectively, were photographed digitally, OCT-scanned and biopsied in the said order. Normal skin was OCT-scanned for comparison, but not biopsied. The OCT images from each lesion were compared with their histologic images as well as with OCT images with similar characteristics obtained from nonmelanoma skin tumors. Results: The OCT images of the tophi showed hyperreflective, rounded cloud-like structures in dermis, their upper part sharply delineated by a hyporeflective fringe. The deeper areas appeared blurred. The crystalline structures were delineated by a hyporeflective fringe. OCT images of GA showed two different structures in dermis: a hyporeflective rounded one, and one that was lobulated and wing-like. Conclusion: Granulomatous tissue surrounding urate deposits appeared as a clear hyporeflective fringe surrounding a light, hyperreflective area. The urate crystals appeared as hyperreflective areas, shielding the deeper part of dermis, meaning OCT could only visualize the upper part of the lesions. The lobulated, wing-like structure in GA may resemble diffuse GA or a dense lymphocytic infiltrate as seen on histology. The rounded structure in GA may represent an actual granuloma or either diffuse GA or a dense lymphocytic infiltrate as described above. This case suggests that OCT images granulomatous tissue as absorbent, hyporeflective areas, and urate crystals appear as reflective areas, obscuring the underlying tissue. In GA a new image shape looking like a wing has been found. The frequency, specificity and sensitivity of this new pattern in OCT imaging will require further studies.

Purpose: To evaluate peripapillary acute zonal occult outer retinopathy in a 67-year-old man. Methods: Images were obtained using fundus photography, fluorescein angiography (FA) and indocyanine green angiography (ICGA), fundus autofluorescence (FAF) imaging, and optical coherence tomography (OCT). Visual field testing and multifocal electroretinogram (mfERG) were also performed to evaluate retinal function. Results: Fundus photographs showed subtle pigmentary changes in the peripapillary region, while FAF imaging showed clearly defined hypofluorescent areas in the peripapillary region. Intense hyperfluorescent lesions were also seen underneath hypofluorescent areas. A transmission defect with a granular hyperfluorescence was visible on FA, and ICGA showed hypofluorescence within the lesion. The outer border of the peripapillary zone appeared to block the underlying choroidal fluorescence. The photoreceptor inner segment/outer segment line was absent on OCT images from this area in both eyes, and hyperreflective punctate drusen-like materials were present at the outer border of the peripapillary zone. Visual field testing by Goldmann perimetry showed blind-spot enlargement, and mfERG showed corresponding amplitude reductions. Conclusions: We speculate that the intense hyperautofluorescent material at the outer border of the peripapillary zone might be accumulated drusenoid lipofuscin.

BackgroundThis manuscript describes a case of a patient with presumed ocular tuberculosis masquerading as multiple evanescent white dot syndrome.Case presentationA 32-year-old male patient presented with a complaint of reduced visual acuity in the left eye. Retinal fundus exam of the left eye revealed gray-whitish deep lesions predominantly nasal to the optic disc. The lesions were more clearly identifiable on fundus autofluorescence (FAF) imaging, fluorescein angiography (FA) and en face optical coherence tomography (OCT). FA also indicated retinal vasculitis and papillitis. Swept-source OCT B-scan demonstrated loss of the ellipsoid layer in the regions corresponding to the lesions detected by FAF. A positive tuberculin skin test (TST) confirmed presumed tuberculosis, and a related WDS diagnosis was made. Specific antituberculosis therapy was instituted with favorable anatomical recovery and visual outcome.ConclusionMultiple evanescent white dot syndrome (MEWDS) may be manifestation of presumed ocular tuberculosis, and multimodal retinal exams can provide a better understanding of atypical diseases and their follow-up.

To determine the fundus autofluorescence (FAF) lifetimes and spectral characteristics of individual drusen and hyperpigmentation independent of those with retinal pigment epithelium (RPE) in geographic atrophy (GA) areas in late-stage age-related macular degeneration (AMD). Three consecutive patients with complete RPE and outer retinal atrophy (cRORA) exhibiting drusen that were calcified or associated with hyperpigmentation were investigated with multimodal non-invasive ophthalmic imaging including colour fundus photography (CFP), optical coherence tomography (OCT), near-infrared reflectance (NIR), blue FAF and fluorescence lifetime imaging ophthalmoscopy (FLIO). Fluorescence lifetimes were measured in two spectral channels (short-wavelength spectral channel (SSC): 500-560 nm and long-wavelength spectral channel (LSC): 560-720 nm). Drusen lacking RPE coverage, as confirmed by CFP and OCT, had longer FAF lifetimes than surrounding cRORA by 127 ± 66 ps (SSC) and 113 ± 48 ps (LSC, both p = 0.008 in Wilcoxon test, N = 9) and by 209 ± 100 ps (SSC) and 121 ± 56 ps (LSC, p < 0.001, N = 14) in two patients. Hyperpigmentation in CFP in a third patient shows strong FAF with prolonged lifetimes. In the SSC, persistent FAF was found inside cRORA. A crescent-shaped hyperfluorescence in an area of continuous RPE but lacking outer retina was seen in one eye with a history of anti-VEGF treatment. Short-wavelength fluorescence in cRORA points to fluorophores beyond RPE organelles. Fluorescence properties of drusen within cRORA differ from invivo drusen covered by RPE. These limited findings from three patients give new insight into the sources of FAF that can be further elucidated in larger cohorts.