Infrared Reflectance Imaging Research Articles

Differences in structural optical coherence tomography and infrared enface images between non-exudative macular neovascularizations secondary to AMD and pachychoroid disease.

To provide an analysis of structural optical coherence tomography (OCT) and enface infrared reflectance (IR) differences between non-exudative macular neovascularizations (NE MNVs) secondary to age-related macular degeneration (AMD) and NE MNVs secondary to pachychoroid spectrum. Patients diagnosed with NE-MNV documented by OCTA and dye angiography in the context of either AMD or pachychoroid spectrum were retrospectively included in AMD group and PACHY group respectively. Only treatment-naïve NE MNVs showing persistence of non-exudative status for at least 1 year after diagnosis were considered. Availability of good quality structural OCT B scan and IR enface acquisitions both at baseline and at 1 year follow up was also required. The study population included 15 eyes of 15 patients in AMD group and 13 eyes of 13 patients in PACHY group. AMD group showed at baseline a significantly wider pigment epithelium detachment (PED) apex angle (p = 0.02), higher homogeneity of the PED (p = 0.015), higher PED shadowing(p = 0.03). Both groups experienced a widening of apex angle (flattening of the PED) during follow-up. Ten (76.9%) patients in PACHY group showed a hyporeflective halo at the margins of the PED at baseline compared to 3/15 (20.0%) patients in AMD group (0.007), with no significant changes at 1 year follow up (p = 0.47). NE-MNVs in pachychoroid eyes are characterized by sharper and more inhomogeneous PEDs with a lighter choroidal shadowing compared to NE-MNVs in AMD eyes. Moreover, they often show a hyporeflective halo around the lesion with IR imaging.

Multimodal Imaging Characteristics and Diagnostic Value of Choroidal Nodules in Patients with Neurofibromatosis Type 1.

Yasunari nodules are choroidal lesions observed in patients diagnosed with neurofibromatosis type 1 (NF-1) and characterized by relatively irregular dome-shaped, plaque-like, or patchy boundaries. The present study examines the multimodal imaging characteristics of Yasunari nodules and their value in the diagnosis of NF-1. Medical records including optical coherence tomography (OCT), enhanced depth imaging OCT, infrared reflectance (IR) imaging, OCT angiography, and color fundus images of NF-1 patients who were examined at the Department of Ophthalmology in Dokuz Eylül University Faculty of Medicine between January 2022 and December 2023 were retrospectively reviewed for the presence of Yasunari nodules. A total of 54 eyes of 27 patients were included in the study. At least one choroidal nodule was detected on IR imaging in 52 eyes (96.3%). In 31 (72.1%) of the 43 eyes (79.6%) with available high-quality OCT angiography images, choroidal nodules were observed as areas showing a flow deficit in the choriocapillaris layer. Of the total 54 eyes included, Lisch nodules without choroidal nodules were observed in 2 eyes (3.7%). In 16 eyes (29.6%), Lisch nodules were not detected despite the presence of choroidal nodules. Both Lisch nodules and choroidal nodules were detected in the other 36 eyes (66.7%). Yasunari nodules are frequently observed in NF-1 cases and can be easily detected with multimodal imaging techniques, especially IR imaging. The ability to visualize choroidal nodules before the appearance of Lisch nodules demonstrates the importance of Yasunari nodules in the diagnosis of NF-1.

Visualization of Keratopathy Associated With the Antibody-Drug Conjugate Belantamab Mafodotin Using Infrared Imaging in Patients With Multiple Myeloma.

The treatment of patients with relapsed/refractory multiple myeloma (RRMM) with the antibody-drug conjugate belantamab mafodotin is affected by ocular adverse effects, most frequently keratopathy with corneal microcyst-like epithelial changes (MECs). To assess ocular side effects, the "Keratopathy and Visual Acuity (KVA) scale," based on the extent of keratopathy subjectively graded on slit-lamp examination and the change in best corrected visual acuity from baseline, was created. Advanced corneal imaging techniques have been explored to further characterize MECs and identify objective imaging biomarkers. We examined whether infrared reflectance imaging of the anterior segment (AS-IR) could contribute to the assessment, monitoring, and documentation of corneal toxicity in patients treated with belantamab mafodotin. In addition to the KVA examination, AS-IR imaging was performed. AS-IR images were evaluated for presence of visible hyporeflective lesions and their spatial and temporal distribution between visits and compared with keratopathy identified on slit-lamp examination. To standardize the assessment, a scoring system for lesions on AS-IR was implemented for additional analysis. Nine patients undergoing treatment with belantamab mafodotin for up to 9 months were examined. All patients exhibited hyporeflective lesions on AS-IR imaging, indicative of corneal toxicity corresponding to MECs observed on slit-lamp examination. AS-IR lesions showed early occurrence, variable quantity and size, and distinct distribution patterns, correlating with clinical findings during treatment. As shown for belantamab mafodotin, AS-IR imaging represents a fast, noninvasive, supplemental method for documentation, monitoring, and assessment of corneal adverse effects during treatment with antibody-drug conjugates, which may enable more standardized analyses.

Multimodal and multi-omics-based deep learning model for screening of optic neuropathy

PurposeTo examine the use of multimodal data and multi-omics strategies for optic nerve disease screening. MethodsThis was a single-center retrospective study. A deep learning model was created from fundus photography and infrared reflectance (IR) images of patients with diabetic optic neuropathy, glaucomatous optic neuropathy, and optic neuritis. Patients who were seen at the Ophthalmology Department of First Affiliated Hospital of Nanchang University in Jiangxi Province from November 2019 to April 2023 were included in this study. The data were analyzed in single and multimodal modes following the traditional omics, Resnet101, and fusion models. The accuracy and area-under-the-curve (AUC) of each model were compared. ResultsA total of 312 images fundus and infrared fundus photographs were collected from 156 patients. When multi-modal data was used, the accuracy of the traditional omics mode, Resnet101, and fusion models with the training set were 0.97, 0.98, and 0.99, respectively. The accuracy of the same models with the test sets were 0.72, 0.87, and 0.88, respectively. We compared single- and multi-mode states by applying the data to the different groups in the learning model. In the traditional omics model, the macro-average AUCs of the features extracted from fundus photography, IR images, and multimodal data were 0.94, 0.90, and 0.96, respectively. When the same data were processed in the Resnet101 model, the scores were 0.97 equally. However, when multimodal data was utilized, the macro-average AUCs in the traditional omics, Resnet101, and fusion modesl were 0.96, 0.97, and 0.99, respectively. ConclusionThe deep learning model based on multimodal data and multi-omics strategies can improve the accuracy of screening and diagnosing diabetic optic neuropathy, glaucomatous optic neuropathy, and optic neuritis.

Multimodal Ophthalmic Imaging in Spinocerebellar Ataxia Type 7.

The aim of this case series and narrative literature review is to highlight the importance of multimodal imaging in the ophthalmological examination of patients with spinocerebellar ataxia type 7 and provide a summary of the most relevant imaging techniques. Three patients with SCA7 were included in this case series. A literature review revealed twenty-one publications regarding ocular manifestations of SCA7, and the most relevant aspects are summarized. The role of different imaging techniques in the follow-up of SCA7 patients is analyzed, including color vision testing, corneal endothelial topography, color fundus photography (CFP) and autofluorescence, near infrared reflectance imaging, spectral domain optical coherence tomography (SDOCT), visual field examination, and electrophysiological tests. SDOCT provides a rapid and non-invasive imaging evaluation of disease progression over time. Additional examination including NIR imaging can provide further information on photoreceptor alteration and subtle disruption of the RPE, which are not evident with CFP at an early stage. Electrophysiological tests provide essential results on the state of cone and rod dystrophy, which could be paramount in guiding future genetic therapies. Multimodal imaging is a valuable addition to comprehensive ophthalmological examination in the diagnosis and management of patients with SCA7.

Optical Coherence Tomography Features of Macular Hyperpigmented Lesions without Intraretinal Hyperreflective Foci in Age-Related Macular Degeneration

Purpose To evaluate the optical coherence tomography (OCT) features of hyperpigmented lesions in the absence of intraretinal hyperreflective foci (IHRF) on OCT in eyes with age-related macular degeneration (AMD). Methods We retrospectively analyzed OCT images of eyes with intermediate AMD (iAMD) and macular hyperpigmentation (HP) on color fundus photograph (CFP) but without IHRF on OCT in the corresponding location. The most prominent or definite HP was selected for analysis. The infrared reflectance (IR) image registered with the CFP, and the location corresponding to the HP lesion were defined on the IR image. The location of the HP on the corresponding OCT B-scan was assessed for retinal pigment epithelium (RPE) elevation, acquired vitelliform lesion (AVL), abnormal retinal pigment epithelium + basal lamina (RPE + BL) band reflectivity, RPE + BL band thickening, as well as interdigitation zone (IZ), ellipsoid zone (EZ) and external limiting membrane (ELM) disruption. Results 49 eyes (39 patients) were included in this study. Forty-six (94%) of the hyperpigmented lesions showed a thickened RPE + BL band. RPE + BL band reflectivity was increased in 37 (76%) of the lesions. RPE + BL band thickening, however, was not correlated with RPE + BL band reflectivity (p-value = 0.31). Either thickening or hyperreflectivity of the RPE + BL band was present in all cases. Twenty (41%) lesions had evidence of ELM disruption, 42 (86%) demonstrated EZ disruption and 48 (98%) had IZ disruption. Five (10%) HPs demonstrated AVL. Among cases with RPE elevation (15 cases, 31%), 10 were classified as drusen, 2 as drusenoid PEDs, and 3 as fibrovascular PEDs. Conclusions Thickening and/or hyperreflectivity of the RPE + BL band commonly correspond to regions of macular hyperpigmentation without IHRF in eyes with iAMD.

Investigation of the choroidal structure in non-neovascular age-related macular degeneration patients with reticular pseudodrusen

BackgroundThis study aimed to compare choroidal thickness, total choroidal area (TCA), luminal area (LA), stromal area (SA) and choroidal vascularity index (CVI) in patients with reticular pseudodrusen (RPD) and drusen. MethodsA total of 100 eyes of 100 patients with non-neovascular age related macular degeneration (AMD) with five or more medium drusen (63–125 µm) and RPD in two or more quadrants were recruited to the study. 48 eyes of 48 patients with RPD were assigned as Group 1 and 52 eyes of 52 patients with drusen were assigned as Group 2. 40 right eyes of 40 healthy subjects were included as controls. Patients with neovascular AMD or advanced non-neovascular AMD were excluded from the study. After a detailed ophthalmic examination, infrared reflectance images and OCT with enhanced depth imaging mode was obtained from all patients. TCA, SA, LA and CVI were calculated using the Image J program. The data were analyzed for statistics using SPSS software. ResultsThe female/male ratio was 56/44 in the patient groups and 20/20 in the control group. The mean age was 73.63±6.14 (61–91) years for Group 1 and 69.43± 6.97 (59–87) years for Group 2 (p=0.005). The mean age of Group 3 patients was 71.14±8.17 (60–79) years and was statistically similar to Groups 1 and 2 (p=0.09 and p=0.12, respectively). Choroidal thickness, TCA, SA and LA were significantly lower in Group 1 (p<0.001). CVI and foveal thicknesses were not significantly different between Group 1 and 2 (p=0.214 and p=0.384 respectively). CVI was significantly lower in Group 3 (p<0.01). RPD was most commonly seen in the superior quadrant followed by temporal, nasal, and inferior quadrants. ConclusionsTCA, SA and LA, which reflect choroidal vasculature, were decreased in patients with RPD. These parameters can help evaluate the pathophysiology of the disease.

Retromode Scanning Laser Ophthalmoscopy for Choroidal Nevi: A Preliminary Study.

The purpose of the present study was to document pathological findings on retromode imaging in choroidal nevi and evaluate its diagnostic validity, using the confocal scanning laser ophthalmoscope Nidek Mirante (cSLO). A total of 41 choroidal nevi from 41 patients were included. All patients underwent multicolor fundus (mCF), infrared reflectance (IR), green fundus autofluorescence (FAF), dark-field (DF) and retromode (RM) imaging and optical coherence tomography (OCT) scans. We investigated retromode images to evaluate choroidal nevus features by comparing the results with those of mCF, IR, FAF, DF and OCT. In 100% of available images, retromode scanning laser ophthalmoscopy was able to detect choroidal nevi with a characteristic "hypo-retro-reflective" pattern, even the cases not visible on mCF, IR and FAF images. It also made it possible to delineate the margins of lesions with the highest rate of sharpness and accuracy among the imaging modalities examined. These findings seem to demonstrate how RM-SLO is an innovative diagnostic tool to detect and follow up choroidal nevi in a fast, reliable and non-invasive way.

Assessment of intraretinal hyperreflective foci using multimodal imaging in eyes with age-related macular degeneration.

This study aimed to investigate the correspondence between intraretinal hyperreflective foci (IHRF) identified on optical coherence tomography (OCT) B-scans with hyperpigmentation on colour fundus photography (CFP) or hyperreflectivity on infrared reflectance (IR) images in eyes with age-related macular degeneration (AMD). Flash CFP, IR images and OCT B-scans obtained at the same visit were evaluated. Individual IHRF identified on OCT B-scans were assessed for the qualitative presence or absence of a hypotransmission tail into the choroid. The corresponding IR image obtained at the time of OCT acquisition was analysed for the presence or absence of hyperreflectivity in this region. The IR images were manually registered to the CFP image, and CFP images were inspected for the presence or absence of hyperpigmentation at the location of IHRF. From 122 eyes, a total of 494 IHRF were evaluated. For the primary analysis of qualitative presence or absence of hyperpigmentation on CFP and hyperreflectivity on IR at the locations corresponding to IHRF on OCT, 301 (61.0%) of the IHRFs demonstrated evidence of hyperpigmentation on CFP, while only 115 (23.3%) showed evidence of hyperreflectivity on IR. The qualitative determination of the presence or absence of an abnormality on CFP or IR were significantly different (p < 0.0001). 327 (66.2%) of the IHRF showed hypotransmission, and 80.4% of these IHRF showed hyperpigmentation on CFP, though only 23.9% (p < 0.0001) demonstrated hyperreflectivity on IR. Less than two-thirds of IHRF evident on OCT manifest as hyperpigmentation on colour photos, though IHRF with posterior shadowing are more likely to be evident as pigment. IR imaging appears to be even more poorly sensitive for visualizing IHRF.

Reticular Pseudodrusen: Interreader Agreement of Evaluation on OCT Imaging in Age-Related Macular Degeneration

PurposeTo determine the interreader agreement for reticular pseudodrusen (RPD) assessment on combined infrared reflectance (IR) and OCT imaging in the early stages of age-related macular degeneration across a range of different criteria to define their presence.DesignInterreader agreement study.ParticipantsTwelve readers from 6 reading centers.MethodsAll readers evaluated 100 eyes from individuals with bilateral large drusen for the following: (1) the presence of RPD across a range of different criteria and (2) the number of Stage 2 or 3 RPD lesions (from 0 to ≥ 5 lesions) on an entire OCT volume scan and on a selected OCT B-scan. Supportive information was available from the corresponding IR image.Main Outcome MeasuresInterreader agreement, as assessed by Gwet’s first-order agreement coefficient (AC1).ResultsWhen evaluating an entire OCT volume scan, there was substantial interreader agreement for the presence of any RPD, any or ≥ 5 Stage 2 or 3 lesions, and ≥ 5 definite lesions on en face IR images corresponding to Stage 2 or 3 lesions (AC1 = 0.60–0.72). On selected OCT B-scans, there was also moderate-to-substantial agreement for the presence of any RPD, any or ≥ 5 Stage 2 or 3 lesions (AC1 = 0.58–0.65) and increasing levels of agreement with increasing RPD stage (AC1 = 0.08, 0.56, 0.78, and 0.99 for the presence of any Stage 1, 2, 3, and 4 lesions, respectively). There was substantial agreement regarding the number of Stage 2 or 3 lesions on an entire OCT volume scan (AC1 = 0.68), but only fair agreement for this evaluation on selected B-scans (AC1 = 0.30).ConclusionsThere was generally substantial or near-substantial—but not near-perfect—agreement for assessing the presence of RPD on entire OCT volume scans or selected B-scans across a range of differing RPD criteria. These findings underscore how interreader variability would likely contribute to the variability of findings related to the clinical associations of RPD. The low levels of agreement for assessing RPD number on OCT B-scans underscore the likely challenges of quantifying RPD extent with manual grading.Financial Disclosure(s)Proprietary or commercial disclosure may be found after the references. To determine the interreader agreement for reticular pseudodrusen (RPD) assessment on combined infrared reflectance (IR) and OCT imaging in the early stages of age-related macular degeneration across a range of different criteria to define their presence. Interreader agreement study. Twelve readers from 6 reading centers. All readers evaluated 100 eyes from individuals with bilateral large drusen for the following: (1) the presence of RPD across a range of different criteria and (2) the number of Stage 2 or 3 RPD lesions (from 0 to ≥ 5 lesions) on an entire OCT volume scan and on a selected OCT B-scan. Supportive information was available from the corresponding IR image. Interreader agreement, as assessed by Gwet’s first-order agreement coefficient (AC1). When evaluating an entire OCT volume scan, there was substantial interreader agreement for the presence of any RPD, any or ≥ 5 Stage 2 or 3 lesions, and ≥ 5 definite lesions on en face IR images corresponding to Stage 2 or 3 lesions (AC1 = 0.60–0.72). On selected OCT B-scans, there was also moderate-to-substantial agreement for the presence of any RPD, any or ≥ 5 Stage 2 or 3 lesions (AC1 = 0.58–0.65) and increasing levels of agreement with increasing RPD stage (AC1 = 0.08, 0.56, 0.78, and 0.99 for the presence of any Stage 1, 2, 3, and 4 lesions, respectively). There was substantial agreement regarding the number of Stage 2 or 3 lesions on an entire OCT volume scan (AC1 = 0.68), but only fair agreement for this evaluation on selected B-scans (AC1 = 0.30). There was generally substantial or near-substantial—but not near-perfect—agreement for assessing the presence of RPD on entire OCT volume scans or selected B-scans across a range of differing RPD criteria. These findings underscore how interreader variability would likely contribute to the variability of findings related to the clinical associations of RPD. The low levels of agreement for assessing RPD number on OCT B-scans underscore the likely challenges of quantifying RPD extent with manual grading.

Drusen morphometrics on optical coherence tomography in eyes with age-related macular degeneration and normal aging.

To compare drusen size metrics (apical height and basal width) on optical coherence tomography (OCT) B-scans with their size assessed on color photos in eyes with age-related macular degeneration (AMD) and normal aging. A total of 508 drusen were evaluated in this analysis. Flash color fundus photos (CFP), infrared reflectance (IR) images, and OCT B-scans obtained at the same visit were evaluated. Individual drusen were identified on CFPs and the diameters of the drusen were measured in planimetric grading software. CFPs were manually registered to the IR image with their corresponding OCT volume. After confirming correspondence between the CFP and OCT, the apical height and basal width of the same drusen were measured on OCT B-scans. Drusen were divided into small, medium, large, and very large categories based on their diameter on the CFP images (< 63, 63 to 124, 125 to 249, and [Formula: see text] 250μm, respectively). The OCT apical height of small drusen on CFP ranged from 20 to 31μm, while medium drusen ranged from 31 to 46μm, large drusen ranged from 45μm to 111µm, and very large drusen ranged from 55μm to 208μm. The OCT basal width measured < 99μm in small drusen, from 99 to 143μm in medium drusen, from 141 to 407µm in large drusen, and > 209µm in very large drusen. Drusen of different size categories on color photographs may also be separated according to their apical height and basal width on OCT. The apical height and basal width ranges defined in this analysis may be of value in the design of an OCT-based grading scale for AMD.

Characteristics of subretinal particles detected after pars plana vitrectomy for rhegmatogenous retinal detachment

BackgroundTo determine the incidence and characteristics of the multiple subretinal particles (SRPs) present after pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment (RRD).MethodsThe medical records of 224 eyes of 224 patients that underwent PPV for RRD were reviewed. The presence of SRPs in the subretinal fluid blebs and the presence of subretinal deposits were determined by optical coherence tomography (OCT) and fundus autofluorescence (FAF). The characteristics of the FAF and infrared reflectance (IR) images of a scanning laser ophthalmoscope in eyes with SRPs (SRPs group) were compared to that of eyes without SRPs (control group).ResultsSRPs were observed in 27 eyes (12%), and they were completely resolved in 20 eyes (74%) after 6 months. The incidence of macula-off RRD (85%) and preoperative precipitates (41%) were significantly higher in the SRPs group than that in the control group (64%, P = 0.046; 12%, P = 0.002). The axial length was significantly shorter in the SRPs group than that in the control group (25.04 ± 1.54 mm, 26.00 ± 1.78 mm, P = 0.012). The preoperative and postoperative best-corrected visual acuity were not significantly different between the two groups (P = 0.702, P = 0.337). The subretinal fluid bleb determined by OCT were hyperfluorescent in the FAF images in 24 eyes (89%), and the subretinal deposits were hypofluorescent with solid appearance by OCT other than fluid in 3 eyes (11%). The hypofluorescent subretinal deposits in the FAF images were bright in the IR images in 2 eyes.ConclusionsThe SRPs consist of lipofuscin-related hyperfluorescent subretinal fluid and the subretinal deposits containing bright IR melanin particles of proliferating retinal pigment epithelial cells.

RAVIR: A Dataset and Methodology for the Semantic Segmentation and Quantitative Analysis of Retinal Arteries and Veins in Infrared Reflectance Imaging.

The retinal vasculature provides important clues in the diagnosis and monitoring of systemic diseases including hypertension and diabetes. The microvascular system is of primary involvement in such conditions, and the retina is the only anatomical site where the microvasculature can be directly observed. The objective assessment of retinal vessels has long been considered a surrogate biomarker for systemic vascular diseases, and with recent advancements in retinal imaging and computer vision technologies, this topic has become the subject of renewed attention. In this paper, we present a novel dataset, dubbed RAVIR, for the semantic segmentation of Retinal Arteries and Veins in Infrared Reflectance (IR) imaging. It enables the creation of deep learning-based models that distinguish extracted vessel type without extensive post-processing. We propose a novel deep learning-based methodology, denoted as SegRAVIR, for the semantic segmentation of retinal arteries and veins and the quantitative measurement of the widths of segmented vessels. Our extensive experiments validate the effectiveness of SegRAVIR and demonstrate its superior performance in comparison to state-of-the-art models. Additionally, we propose a knowledge distillation framework for the domain adaptation of RAVIR pretrained networks on color images. We demonstrate that our pretraining procedure yields new state-of-the-art benchmarks on the DRIVE, STARE, and CHASE_DB1 datasets. Dataset link: https://ravirdataset.github.io/data.

Automated diagnosis of age-related macular degeneration using multi-modal vertical plane feature fusion via deep learning.

To develop a computer-aided diagnostic (CADx) system of age-related macular degeneration (AMD) through feature fusion between infrared reflectance (IR) and optical coherence tomography (OCT) modalities in order to explore the superiority of multi-modality CADx system and the optimal feature fusion patterns between multi-modality inputs. This is a dual center retrospective study. We retrospectively collected 2006 pairs of IR and OCT images to develop the algorithms. Two single-modality models and three multi-modality models were constructed for the comparison of the diagnostic efficacy. The multi-modality models were designed utilizing a novel feature fusion method, namely, vertical plane feature fusion (VPFF). The results were validated using an independent external validation dataset and compared by three ophthalmologists. In the test set of the ZJU dataset, our best model named OCT_MAIN demonstrated diagnostic efficiency with an overall accuracy of 0.9608 and area under the curve of 0.9944 for the normal category, 0.9659 for the dry AMD category, and 0.9930 for the wet AMD category. The external validation exhibited an overall accuracy of 0.9159. Its diagnostic efficiency was comparable to that of the senior ophthalmologist. The VPFF method was successfully employed to develop a multi-modal intelligent diagnostic system for the AMD classification. This is a valuable complement and optimization to the existing CADx system, which reveals a wide application prospect and research potential.

Policy-Driven, Multimodal Deep Learning for Predicting Visual Fields from the Optic Disc and OCT Imaging

To develop and validate a deep learning (DL) system for predicting each point on visual fields (VFs) from disc and OCT imaging and derive a structure-function mapping. Retrospective, cross-sectional database study. A total of 6437 patients undergoing routine care for glaucoma in 3 clinical sites in the United Kingdom. OCT and infrared reflectance (IR) optic disc imaging were paired with the closest VF within 7 days. EfficientNet B2 was used to train 2 single-modality DL models to predict each of the 52 sensitivity points on the 24-2 VF pattern. A policy DL model was designed and trained to fuse the 2 model predictions. Pointwise mean absolute error (PMAE). A total of 5078 imaging scans to VF pairs were used as a held-out test set to measure the final performance. The improvement in PMAE with the policy model was 0.485 (0.438, 0.533) decibels (dB) compared with the IR image of the disc alone and 0.060 (0.047, 0.073) dB with to the OCT alone. The improvement with the policy fusion model was statistically significant (P < 0.0001). Occlusion masking shows that the DL models learned the correct structure-function mapping in a data-driven, feature agnostic fashion. The multimodal, policy DL model performed the best; it provided explainable maps of its confidence in fusing data from single modalities and provides a pathway for probing the structure-function relationship in glaucoma.

Choroidal hyperreflective nodules detected by infrared reflectance images as a new diagnostic criterion for Neurofibromatosis ‐1

AbstractPurposeTo investigate the possibility of including the presence of choroidal abnormalities detected by infrared reflectance as a new diagnostic criterion for neurofibromatosis type 1 (NF1).MethodsA cross‐sectional study was carried out in 24 eyes of 12 patients diagnosed with NF1 using the criteria of the National Institutes of Health (NIH). A group of 12 healthy individuals of equivalent age and sex served as control. The presence and number of visualized choroidal abnormalities were evaluated by Heidelberg optical coherence tomography (OCT) with infrared reflectance (NIR) as well as the presence of iridian Lisch nodules by slit lamp examination.ResultsNIR by OCT shows the presence of choroidal hyperreflective nodules in all the patients diagnosed with NF1, while these choroidal abnormalities are not observed in any control. This finding is more frequent than the presence of iridian Lisch nodules.ConclusionsHyperreflective nodules detected by NIR appear more frequently than Lisch nodules in NF1. The study suggests that it could be considered as a new diagnostic criterion for NF1.

Evaluation of distributional homogeneity of pharmaceutical formulation using laser direct infrared imaging

The distributional homogeneity of chemicals is a key parameter of solid pharmaceutical formulations. Indeed, it may affect the efficacy of the drug and consequently its safety.Chemical imaging offers a unique insight enabling the visualisation of the different constituents of a pharmaceutical tablet. It allows identifying ingredients poorly distributed offering the possibility to optimize the process parameters or to adapt characteristics of incoming raw materials to increase the final product quality.Among the available chemical imaging tools, Raman imaging is one of the most widely used since it offers a high spatial resolution with well-resolved peaks resulting in a high spectral specificity. However, Raman imaging suffers from sample autofluorescence and long acquisition times. Recently commercialised, laser direct infrared reflectance imaging (LDIR) is a quantum cascade laser (QCL) based imaging technique that offers the opportunity to rapidly analyse samples.In this study, a typical pharmaceutical formulation blend composed of two active pharmaceutical ingredients and three excipients was aliquoted at different mixing timepoints. The collected aliquots were tableted and analysed using both Raman and LDIR imaging. The distributional homogeneity indexes of one active ingredient image were then computed and compared. The results show that both techniques achieved similar conclusions. However, the analysis times were drastically different. While Raman imaging required a total analysis time of 4 h per tablet to obtain the distribution map of acetylsalicylic acid with a step size of 100 µm, it only took 7.5 min to achieve the same result with LDIR.The results obtained in the present study show that LDIR is a promising technique for the analysis of pharmaceutical formulations and that it could be a valuable tool when developing new pharmaceutical formulations.

Infrared reflectance image-guided laser photocoagulation of telangiectatic capillaries in persistent diabetic macular edema

This study aimed to assess detection rate of telangiectatic capillaries (TelCaps) with infrared reflectance (IR) and optical coherence tomography (OCT) images and to evaluate the clinical efficacy of IR image-guided focal laser photocoagulation of TelCaps in persistent diabetic macular edema (DME). This retrospective case series included 28 eyes of 28 patients with TelCap and persistent DME refractory to intravitreal anti-vascular endothelial growth factor or corticosteroids. The presence of TelCaps was confirmed using IR and OCT images. All patients were followed up for more than 12 months after direct focal laser photocoagulation of the TelCaps. The TelCap closure rate, changes in best-corrected visual acuity, and central subfield thickness were analyzed. On IR imaging, TelCap appeared as a characteristic hyperreflectivity within a hyporeflective spherical lesion in 85.7% of the eyes. After focal laser photocoagulation, the TelCap closure rate was 57.1% at 3 months and 71.4% at 12 months. A significant improvement in visual acuity and reduction in central subfield thickness were observed at three and 12 months after focal laser photocoagulation (all p < 0.05). The characteristic hyperreflectivity within hyporeflective lesions on the IR image in conjunction with OCT helps identify the TelCap. Our results suggest that IR imaging and OCT-guided focal laser photocoagulation of TelCaps can improve functional and anatomical outcomes in persistent DME.

Reflectance Imaging Spectroscopy (RIS) for Operation Night Watch: Challenges and Achievements of Imaging Rembrandt's Masterpiece in the Glass Chamber at the Rijksmuseum.

Visible and infrared reflectance imaging spectroscopy is one of the several non-invasive techniques used during Operation Night Watch for the study of Rembrandt’s iconic masterpiece The Night Watch (1642). The goals of this project include the identification and mapping of the artists’ materials, providing information about the painting technique used as well as documenting the painting’s current state and ultimately determining the possible conservation plan. The large size of the painting (3.78 m by 4.53 m) and the diversity of the technical investigations being performed make Operation Night Watch the largest research project ever undertaken at the Rijksmuseum. To construct a complete reflectance image cube at a high spatial resolution (168 µm2) and spectral resolution (2.54 to 6 nm), the painting was imaged with two high-sensitivity line scanning hyperspectral cameras (VNIR 400 to 1000 nm, 2.54 nm, and SWIR 900 to 2500 nm, 6 nm). Given the large size of the painting, a custom computer-controlled 3-D imaging frame was constructed to move each camera, along with lights, across the painting surface. A third axis, normal to the painting, was added along with a distance-sensing system which kept the cameras in focus during the scanning. A total of 200 hyperspectral image swaths were collected, mosaicked and registered to a high-resolution color image to sub-pixel accuracy using a novel registration algorithm. The preliminary analysis of the VNIR and SWIR reflectance images has identified many of the pigments used and their distribution across the painting. The SWIR, in particular, has provided an improved visualization of the preparatory sketches and changes in the painted composition. These data sets, when combined with the results from the other spectral imaging modalities and paint sample analyses, will provide the most complete understanding of the materials and painting techniques used by Rembrandt in The Night Watch.

Association of Reading Performance in Geographic Atrophy Secondary to Age-Related Macular Degeneration With Visual Function and Structural Biomarkers

As a disabling and frequent disease, geographic atrophy secondary to age-related macular degeneration (AMD) constitutes an important study subject. Emerging clinical trials require suitable end points. The characterization and validation of reading performance as a functional outcome parameter is warranted. To prospectively evaluate reading performance in geographic atrophy and to assess its association with established visual function assessments and structural biomarkers. The noninterventional, prospective natural history Directional Spread in Geographic Atrophy study included patients with geographic atrophy secondary to AMD who were recruited at the University Hospital in Bonn, Germany. Participants were enrolled from June 2013 to June 2016. Analysis began December 2019 and ended January 2021. Reading acuity and reading speed were assessed using Radner charts. Longitudinal fundus autofluorescence and infrared reflectance images were semiautomatically annotated for geographic atrophy, followed by extraction of shape-descriptive variables. Linear mixed-effects models were applied to investigate the association of those variables with reading performance. A total of 150 eyes of 85 participants were included in this study (median [IQR] age, 77.9 [72.4-82.1] years; 51 women [60%]; 34 men [40%]). Reading performance was impaired with a median (IQR) monocular reading acuity of 0.9 (0.4-1.3) logarithm of the reading acuity determination and a reading speed of 52.8 (0-123) words per minute. In the multivariable cross-sectional analysis, best-corrected visual acuity, area of geographic atrophy in the central Early Treatment Diabetic Retinopathy Study (ETDRS) subfield, classification of noncenter vs center-involving geographic atrophy, and area of geographic atrophy in the inner-right ETDRS subfield showed strongest associations with reading acuity (cross-validated R2for reading acuity = 0.69). Regarding reading speed, the most relevant variables were best-corrected visual acuity, low-luminance visual acuity, area of geographic atrophy in the central ETDRS subfield, in the inner-right ETDRS subfield, and in the inner-upper ETDRS subfield (R2 for reading speed = 0.67). In the longitudinal analysis, a similar prediction accuracy for reading performance was determined (R2 for reading acuity = 0.73; R2 for reading speed = 0.70). Prediction accuracy did not improve when follow-up time was added as an independent variable. Binocular reading performance did not differ from reading performance in the better-seeing eye. The association of reading acuity and speed with visual functional and structural biomarkers supports the validity of reading performance as a meaningful end point in clinical trials. These findings suggest that measures in clinical and low-vision care for patients with geographic atrophy should focus primarily on the better-seeing eye.