In Vivo Correlation Between Macular Pigment Optical Volume and Retinal Layers Thickness.

Purpose: This study aims to investigate the potential in vivo relationship between macular pigment (MP) and retinal layers thickness in healthy subjects and dry, non-advanced age-related macular degeneration (AMD). Methods: An observational, cross-sectional study was conducted. Healthy subjects >40 years and patients with early or intermediate AMD were recruited. Structural OCT and macular pigment optical volume (MPOV) were collected for each subject. Retinal layers parameters were calculated based on the standard early treatment diabetic retinopathy study (ETDRS) map. Additionally, MPOV within 1°, 2°, and 9° of eccentricity was assessed and associated with retinal layers thickness and volume. Linear mixed-effects models were used to test the relationship between MP and structural OCT parameters, while adjusting for known possible confounding factors. Results: A total of 144 eyes of 91 subjects (60.4% females) were evaluated, comprising 43% normal eyes and 57% with early/intermediate AMD. Among the retinal layers, only the outer nuclear layer (ONL) thickness and volume appeared to be associated to higher MP levels. Specifically, the central ONL thickness was identified as a significant predictor of the MPOV 1°(P = 0.04), while the parafoveal ONL thickness (inner ETDRS subfield) was identified as a significant fixed effect on the MPOV 9° (P = 0.037). Age and the presence of drusen or subretinal drusenoid deposits were also tested without showing significant correlations. Conclusions: Among the retinal layers examined, only the ONL thickness demonstrated a significant association with MPOV. Consequently, ONL thickness might serve as a potential biomarker related to MP levels.

Progressive Choriocapillaris Changes on Optical Coherence Tomography Angiography Correlate With Stage Progression in AMD.

Purpose: We investigated the association between inner choroid flow deficit percentage (IC-FD%) using swept-source optical coherence tomography angiography (SS-OCTA) and progression of AMD. Methods: Retrospective, observational study including 64 eyes (42 participants) with early or intermediate AMD at baseline. Participants had two or more consecutive swept-source optical coherence tomography angiography covering a period of at least 18 months. Demographics, visual acuity, and AMD staging based on Beckman classification were reviewed. OCT was analyzed for hyperreflective foci, subretinal drusenoid deposits, hyporeflective drusen cores, and subfoveal choroidal thickness. IC-FD% was measured within the central 3- and 6-mm using a 16-µm slab, after compensation and binarization (Phansalkar method). Mixed-effects Cox regression models assessed the association between imaging biomarkers and AMD progression. Results: During follow-up (37 ± 9 months), 4 eyes with early AMD (31%) progressed to intermediate AMD and 30 (59%) eyes with intermediate AMD developed late AMD (19 geographic atrophy; 11 wet AMD). Baseline hyporeflective drusen core was associated with geographic atrophy development (P < 0.01), whereas greater IC-FD% (3-mm) was associated with wet AMD (P = 0.03). Time-varying analysis showed that faster subfoveal choroidal thickness reduction and IC-FD% (6-mm) increase were associated with geographic atrophy onset (P < 0.05), whereas IC-FD% (3-mm) increase was associated with wet AMD (P = 0.03). Notably, greater IC-FD% increases in the 3 mm (area under the curve = 0.72) and 6 mm (area under the curve = 0.89) were better predictive of wet AMD and geographic atrophy development, respectively. Conclusions: Our longitudinal IC-FD% assessment emphasizes the role of progressive choriocapillaris changes as a biomarker for AMD progression. Our findings support that widespread choriocapillaris alterations (6 mm) may precede progression to geographic atrophy, whereas more central choriocapillaris loss (3 mm) may provide an ischemic stimulus for wet AMD.

Decreased Macular Choriocapillaris Perfusion Correlates with Contrast Sensitivity Function in Dry Age-related Macular Degeneration.

PURPOSE: To investigate the relationships between contrast sensitivity (CS), choriocapillaris perfusion and other structural optical coherence tomography (OCT) biomarkers in dry age-related macular degeneration (AMD). DESIGN: Cross-sectional, observational study. PARTICIPANTS: One hundred AMD eyes (22 early, 52 intermediate and 26 late) from 74 patients and 45 control eyes from 37 age-similar subjects. METHODS: All participants had visual acuity (VA) assessment, quantitative contrast sensitivity function (qCSF) testing, macular OCT, and 6x6-mm swept-source OCT angiography (OCTA) scans on the same day. OCT volumes were analyzed for subretinal drusenoid deposits and hyporeflective drusen cores, and to measure thickness of the outer nuclear layer (ONL). OCTA scans were utilized to calculate drusen volume, inner choroid flow deficit percentage (IC-FD%), and to measure the area of choroidal hypertransmission defects (HTD). IC-FD% was measured from a 16 µm-thick choriocapillaris slab after compensation and binarization with Phansalkar's method. Generalized linear mixed-effects models were used to evaluate the associations between functional and structural variables. MAIN OUTCOME MEASURES: To explore the associations between qCSF-measured CS, ICFD% and various AMD imaging biomarkers. RESULTS: AMD exhibited significantly reduced qCSF metrics eyes across all stages compared to controls. Univariate analysis revealed significant associations between various imaging biomarkers, reduced qCSF metrics and VA in both groups. Multivariate analysis confirmed that higher IC-FD% in the central 5 mm was significantly associated with decreases in all qCSF metrics in AMD eyes (ß= -0.74 to -0.25, all p<0.05), but not with VA (p>0.05). ONL thickness in the central 3 mm correlated with both VA (ß= 2.85, p<0.001) and several qCSF metrics (ß= 0.01-0.90, all p<0.05), especially in AMD eyes. Further, larger HTD areas were associated with decreased VA (ß=-0.89, p<0.001) and reduced CS at low-intermediate frequencies across AMD stages (ß= -0.30 to -0.29, p<0.001). CONCLUSIONS: The significant association between IC-FD% in the central 5 mm and qCSF-measured CS reinforces the hypothesis that decreased macular choriocapillaris perfusion contributes to visual function changes in AMD, which are more pronounced in CS than in VA.

Cognitive rehabilitation effects on grey matter volume and Go-NoGo activity in progressive multiple sclerosis: results from the CogEx trial.

BACKGROUND: Research on cognitive rehabilitation (CR) and aerobic exercise (EX) to improve cognition in progressive multiple sclerosis (PMS) remains limited. CogEx trial investigated the effectiveness of CR and EX in PMS: here, we present MRI substudy volumetric and task-related functional MRI (fMRI) findings. METHODS: Participants were randomised to: 'CR plus EX', 'CR plus sham EX (EX-S)', 'EX plus sham CR (CR-S)' and 'CR-S plus EX-S' and attended 12-week intervention. All subjects performed physical/cognitive assessments at baseline, week 12 and 6 months post intervention (month 9). All MRI substudy participants underwent volumetric MRI and fMRI (Go-NoGo task). RESULTS: 104 PMS enrolled at four sites participated in the CogEx MRI substudy; 84 (81%) had valid volumetric MRI and valid fMRI. Week 12/month 9 cognitive performances did not differ among interventions; however, 25-62% of the patients showed Symbol Digit Modalities Test improvements. Normalised cortical grey matter volume (NcGMV) changes at week 12 versus baseline were heterogeneous among interventions (p=0.05); this was mainly driven by increased NcGMV in 'CR plus EX-S' (p=0.02). Groups performing CR (ie, 'CR plus EX' and 'CR plus EX-S') exhibited increased NcGMV over time, especially in the frontal (p=0.01), parietal (p=0.04) and temporal (p=0.04) lobes, while those performing CR-S exhibited NcGMV decrease (p=0.008). In CR groups, increased NcGMV (r=0.36, p=0.01) at week 12 versus baseline correlated with increased California Verbal Learning Test (CVLT)-II scores. 'CR plus EX-S' patients exhibited Go-NoGo activity increase (p<0.05, corrected) at week 12 versus baseline in bilateral insula. CONCLUSIONS: In PMS, CR modulated grey matter (GM) volume and insular activity. The association of GM and CVLT-II changes suggests GM plasticity contributes to cognitive improvements. TRIAL REGISTRATION NUMBER: NCT03679468.

Comprehensive dosimetric characterization of novel silicon carbide detectors with UHDR electron beams for FLASH radiotherapy.

BACKGROUND: The extremely fast delivery of doses with ultra high dose rate (UHDR) beams necessitates the investigation of novel approaches for real-time dosimetry and beam monitoring. This aspect is fundamental in the perspective of the clinical application of FLASH radiotherapy (FLASH-RT), as conventional dosimeters tend to saturate at such extreme dose rates. PURPOSE: This study aims to experimentally characterize newly developed silicon carbide (SiC) detectors of various active volumes at UHDRs and systematically assesses their response to establish their suitability for dosimetry in FLASH-RT. METHODS: SiC PiN junction detectors, recently realized and provided by STLab company, with different active areas (ranging from 4.5 to 10 mm2) and thicknesses (10-20 µm), were irradiated using 9 MeV UHDR pulsed electron beams accelerated by the ElectronFLASH linac at the Centro Pisano for FLASH Radiotherapy (CPFR). The linearity of the SiC response as a function of the delivered dose per pulse (DPP), which in turn corresponds to a specific instantaneous dose rate, was studied under various experimental conditions by measuring the produced charge within the SiC active layer with an electrometer. Due to the extremely high peak currents, an external customized electronic RC circuit was built and used in conjunction with the electrometer to avoid saturation. RESULTS: The study revealed a linear response for the different SiC detectors employed up to 21 Gy/pulse for SiC detectors with 4.5 mm2/10 µm active area and thickness. These values correspond to a maximum instantaneous dose rate of 5.5 MGy/s and are indicative of the maximum achievable monitored DPP and instantaneous dose rate of the linac used during the measurements. CONCLUSIONS: The results clearly demonstrate that the developed devices exhibit a dose-rate independent response even under extreme instantaneous dose rates and dose per pulse values. A systematic study of the SiC response was also performed as a function of the applied voltage bias, demonstrating the reliability of these dosimeters with UHDR also without any applied voltage. This demonstrates the great potential of SiC detectors for accurate dosimetry in the context of FLASH-RT.

Advanced neuroimaging techniques to explore the effects of motor and cognitive rehabilitation in multiple sclerosis.

INTRODUCTION: Progress in magnetic resonance imaging (MRI) technology and analyses is improving our comprehension of multiple sclerosis (MS) pathophysiology. These advancements, which enable the evaluation of atrophy, microstructural tissue abnormalities, and functional plasticity, are broadening our insights into the effectiveness and working mechanisms of motor and cognitive rehabilitative treatments. AREAS COVERED: This narrative review with selected studies discusses findings derived from the application of advanced MRI techniques to evaluate structural and functional neuroplasticity modifications underlying the effects of motor and cognitive rehabilitative treatments in people with MS (PwMS). Current applications as outcome measure in longitudinal trials and observational studies, their interpretation and possible pitfalls and limitations in their use are covered. Finally, we examine how the use of these techniques could evolve in the future to improve monitoring of motor and cognitive rehabilitative treatments. EXPERT COMMENTARY: Despite substantial variability in study design and participant characteristics in rehabilitative studies for PwMS, improvements in motor and cognitive functions accompanied by structural and functional brain modifications induced by rehabilitation can be observed. However, significant enhancements to refine rehabilitation strategies are needed. Future studies in this field should strive to implement standardized methodologies regarding MRI acquisition and processing, possibly integrating multimodal measures. This will help identifying relevant markers of treatment response in PwMS, thus improving the use of rehabilitative interventions at individual level. The combination of motor and cognitive strategies, longer periods of treatment, as well as adequate follow-up assessments will contribute to enhance the quality of evidence in support of their routine use.

Artificial Intelligence (AI) for Early Diagnosis of Retinal Diseases.

Artificial intelligence (AI) has emerged as a transformative tool in the field of ophthalmology, revolutionizing disease diagnosis and management. This paper provides a comprehensive overview of AI applications in various retinal diseases, highlighting its potential to enhance screening efficiency, facilitate early diagnosis, and improve patient outcomes. Herein, we elucidate the fundamental concepts of AI, including machine learning (ML) and deep learning (DL), and their application in ophthalmology, underscoring the significance of AI-driven solutions in addressing the complexity and variability of retinal diseases. Furthermore, we delve into the specific applications of AI in retinal diseases such as diabetic retinopathy (DR), age-related macular degeneration (AMD), Macular Neovascularization, retinopathy of prematurity (ROP), retinal vein occlusion (RVO), hypertensive retinopathy (HR), Retinitis Pigmentosa, Stargardt disease, best vitelliform macular dystrophy, and sickle cell retinopathy. We focus on the current landscape of AI technologies, including various AI models, their performance metrics, and clinical implications. Furthermore, we aim to address challenges and pitfalls associated with the integration of AI in clinical practice, including the "black box phenomenon", biases in data representation, and limitations in comprehensive patient assessment. In conclusion, this review emphasizes the collaborative role of AI alongside healthcare professionals, advocating for a synergistic approach to healthcare delivery. It highlights the importance of leveraging AI to augment, rather than replace, human expertise, thereby maximizing its potential to revolutionize healthcare delivery, mitigate healthcare disparities, and improve patient outcomes in the evolving landscape of medicine.

Structural and functional correlates of disability, motor and cognitive performances in multiple sclerosis: Focus on the globus pallidus.

OBJECTIVES: To explore structural and functional alterations of external (GPe) and internal (GPi) globus pallidus in people with multiple sclerosis (pwMS) compared to healthy controls (HC) and analyze their relationship with measures of clinical disability, motor and cognitive impairment. METHODS: Sixty pwMS and 30 HC comparable for age and sex underwent 3.0T MRI, including conventional, diffusion tensor MRI and resting state (RS) functional MRI. Expanded Disability Status Scale (EDSS) scores were rated and timed 25-foot walk (T25FW) test, nine-hole peg test (9HPT), and paced auditory serial addition test (PASAT) were administered. Two operators segmented the GP into GPe and GPi. Volumes, T1/T2 ratio, diffusivity indices and seed-based RS functional connectivity (FC) of the GP and its components were assessed. RESULTS: PwMS had no atrophy or altered diffusivity measures of the GP. Compared to HC, pwMS had higher T1/T2 ratio in both GP regions, which correlated with EDSS score (r = 0.26-0.39, p = 0.01-0.05). RS FC analysis highlighted component-specific functional alterations in pwMS: the GPe had decreased RS FC with fronto-parietal cortices, whereas the GPi had decreased intra-GP RS FC and increased RS FC with the thalamus. Worse EDSS, 9HPT, T25FW and PASAT scores were associated with GP RS FC modifications (r=-0.51‒0.51, p < 0.001). CONCLUSIONS: Structural GP involvement in MS was homogeneous across its portions. Increased T1/T2 ratio values, possibly representing iron accumulation, were related to more severe disability. RS FC alterations of the GPe and GPi were consistent with their roles within the basal ganglia network and correlated with worse functional status, suggesting less efficient communication between structures.

Quantitative Contrast Sensitivity Function and the Effect of Aging in Healthy Adult Eyes: A Normative Database.

BACKGROUND AND OBJECTIVE: We sought to establish normative quantitative contrast sensitivity function (qCSF) values in healthy adult eyes and investigate the effect of age on qCSF. PATIENTS AND METHODS: Healthy eyes underwent qCSF testing (adaptive sensory technology) and Snellen's visual acuity (VA). Descriptive statistics and mixed-effects multivariable linear regressions were evaluated. RESULTS: A total of 334 eyes (290 patients) with median age 61 years (range 21 to 88) had qCSF values as follows: area under the log contrast sensitivity function curve: 1.18; contrast acuity: 1.32; contrast sensitivity (CS) at 1 cycle per degree (cpd): 1.32; CS at 1.5 cpd: 1.37; CS at 3 cpd: 1.38; CS at 6 cpd: 1.20; CS at 12 cpd: 0.69; CS at 18 cpd: 0.22. Linear reductions in qCSF values per decade of age ranged from -0.02 to -0.07 vs 0.01 for visual acuity (VA). Age had a greater effect on the majority of qCSF values than VA (beta standardized regression coefficient ranged from -0.309 to -0.141 for qCSF values vs 0.177 for VA). CONCLUSIONS: We herein establish a normative database for qCSF and quantify the effect of age on qCSF values, adding evidence towards the validation of qCSF as a clinical endpoint. [Ophthalmic Surg Lasers Imaging Retina 2024;55:212-219.].

The Epidemiology of Anal Human Papillomavirus (HPV) in HIV-Positive and HIV-Negative Women and Men: A Ten-Year Retrospective Observational Study in Rome (Italy).

Human papillomaviruses (HPVs) commonly infect the anogenital mucosa; most infections are transient, but a fraction of those caused by high-risk (HR) types persist and may lead to anogenital cancer. The epidemiology of HPV genotypes in anal infections in groups at different risk for anal cancer has not been well described in Italy. This retrospective study reports the results of HPV DNA testing and complete genotyping performed on anal swabs from 691 female and male patients attending proctology clinics in Rome during 2012-2021; one-third had repeated testing. Cumulative HPV positivity in 1212 anal swabs was approximately 60%, was not age related, and showed an increasing trend over the study period. HPV rates differed significantly by sex and HIV status: HIV-negative women had the lowest (43.6%) and HIV-positive men the highest (83.5%) HPV prevalence. HIV-positive men had more oncogenic HPV genotypes detected, more multiple infections, and the highest frequency of persistent infections. Two-thirds of all infections were vaccine-preventable. This study found that anal HPV infection rates are still elevated and even increasing in groups at low and high risk of developing anal cancer. Prevention programs need to be improved to reduce rates of anal infection in young women and men.

Lesion area progression in eyes with neovascular age-related macular degeneration treated using a proactive or a reactive regimen.

BACKGROUND: To compare the change in lesion area over 4 years of follow-up in eyes with neovascular age-related macular degeneration (nAMD) treated with anti-vascular endothelial growth factor (VEGF) agents using either a proactive or a reactive regimen in routine clinical practice. METHODS: This was a multicentre, retrospective comparative study. Totally, 202 treatment-naïve nAMD eyes (183 patients) received anti-VEGF therapy according to a proactive (n = 105) or reactive (n = 97) regimen. Eyes were included if they had received anti-VEGF injections for a period of at least 4 years and had baseline fluorescein angiography and annual optical coherence tomography (OCT) imaging. Two masked graders independently delineated the lesion's margins from serial OCT images and growth rates were calculated. RESULTS: At baseline, the mean [SD] lesion area was 7.24 [5.6] mm2 in the proactive group and 6.33 [4.8] mm2 in the reactive group respectively (p = 0.22). After four years of treatment, the mean [SD] lesion area in the proactive group was 5.16 [4.5] mm2 showing a significant reduction compared to the baseline (p < 0.001). By contrast, the mean [SD] lesion area kept expanding in the reactive group during the follow-up and was 9.24 [6.0] mm2 at four years (p < 0.001). The lesion area at 4 years was significantly influenced by treatment regimen, baseline lesion area, and proportion of visits with active lesions. CONCLUSIONS: Eyes treated using a reactive strategy had an increased lesion area and worse visual outcomes at 4 years. By contrast, the proactive regimen was associated with fewer recurrences of active disease, shrinkage of the lesion area, and better vision at four years.

Liquid plug propagation in computer-controlled microfluidic airway-on-a-chip with semi-circular microchannels.

This paper introduces a two-inlet, one-outlet lung-on-a-chip device with semi-circular cross-section microchannels and computer-controlled fluidic switching that enables a broader systematic investigation of liquid plug dynamics in a manner relevant to the distal airways. A leak-proof bonding protocol for micro-milled devices facilitates channel bonding and culture of confluent primary small airway epithelial cells. Production of liquid plugs with computer-controlled inlet channel valving and just one outlet allows more stable long-term plug generation and propagation compared to previous designs. The system also captures both plug speed and length as well as pressure drop concurrently. In one demonstration, the system reproducibly generates surfactant-containing liquid plugs, a challenging process due to lower surface tension that makes the plug formation less stable. The addition of surfactant decreases the pressure required to initiate plug propagation, a potentially significant effect in diseases where surfactant in the airways is absent or dysfunctional. Next, the device recapitulates the effect of increasing fluid viscosity, a challenging analysis due to higher resistance of viscous fluids that makes plug formation and propagation more difficult particularly in airway-relevant length scales. Experimental results show that increased fluid viscosity decreases plug propagation speed for a given air flow rate. These findings are supplemented by computational modeling of viscous plug propagation that demonstrates increased plug propagation time, increased maximum wall shear stress, and greater pressure differentials in more viscous conditions of plug propagation. These results match physiology as mucus viscosity is increased in various obstructive lung diseases where it is known that respiratory mechanics can be compromised due to mucus plugging of the distal airways. Finally, experiments evaluate the effect of channel geometry on primary human small airway epithelial cell injury in this lung-on-a-chip. There is more injury in the middle of the channel relative to the edges highlighting the role of channel shape, a physiologically relevant parameter as airway cross-sectional geometry can also be non-circular. In sum, this paper describes a system that pushes the device limits with regards to the types of liquid plugs that can be stably generated for studies of distal airway fluid mechanical injury.

Test-retest repeatability and agreement of the quantitative contrast sensitivity function test: towards the validation of a new clinical endpoint.

PURPOSE: The purpose of this study is to investigate test-retest reliability and agreement of the quantitative contrast sensitivity function test (qCSF) in the retina clinic. METHODS: A total of 121 right eyes of 121 patients were tested and consecutively re-tested with qCSF in the retina clinic. Outcomes included area under the logarithm of contrast sensitivity function curve (AULCSF), contrast acuity, and contrast sensitivity thresholds at 1-18 cycles per degree (cpd). Test-retest means were compared with paired t-test, variability was compared with the Brown-Forsythe test, and intraclass correlation coefficient (ICC) and Bland Altman plots evaluated reliability and agreement. RESULTS: Mean test-retest differences for all qCSF metrics ranged from 0.02 to 0.05 log units without statistically significant differences in variability. Standard deviations ranged from 0.08 to 0.14. Coefficients of repeatability ranged from 0.16 to 0.27 log units. ICC > 0.9 for all metrics except 1cpd (ICC = 0.84, all p < 0.001); AULCSF ICC = 0.971. CONCLUSION: qCSF-measured contrast sensitivity shows great test-retest repeatability and agreement in the retina clinic.

CORRELATION BETWEEN MICROPERIMETRY AND IMAGING IN EXTENSIVE MACULAR ATROPHY WITH PSEUDODRUSEN-LIKE APPEARANCE.

PURPOSE: To determine the correlation between microperimetry and imaging findings in extensive macular atrophy with pseudodrusen-like appearance (EMAP). METHODS: This cross-sectional, observational study included 44 consecutive patients with EMAP (88 eyes) and 30 healthy subjects (60 eyes). Both groups underwent visual acuity assessment, mesopic and scotopic microperimetry, fundus photography, autofluorescence, optical coherence tomography, and optical coherence tomography angiography. Retinal sensitivity was also subdivided in macular (0-4°) and paramacular areas (8-10°). Scotopic sensitivity loss was defined as the difference between scotopic and mesopic sensitivities for each tested point. Eyes with EMAP were further classified into the three stages described by Romano et al: 19 eyes in Stage 1, 31 in Stage 2, and 38 in Stage 3. RESULTS: Mesopic and scotopic retinal sensitivity were significantly reduced in patients with EMAP compared with controls, particularly in the macular area (all P < 0.001). Mesopic retinal sensitivity progressively declined in more advanced EMAP stages (all P < 0.01), but no scotopic differences were observed between Stages 2 and 3 ( P = 0.08). Remarkably, scotopic sensitivity loss was significantly higher in Stage 1 ( P < 0.05).On multivariate analysis, mesopic dysfunction was associated with larger atrophic areas ( P < 0.01), foveal involvement ( P = 0.03), and fibrosis ( P = 0.02). Conversely, no independent variable was associated with a reduced scotopic retinal sensitivity (all P > 0.05). CONCLUSION: The findings highlight that patients with EMAP suffer from a severe cone- and rod-mediated dysfunction on microperimetry. The predominant rod impairment in the early cases (Stage 1) emphasizes the importance of dark-adapted scotopic microperimetry as a clinical end point and suggests defective transportation across the RPE-Bruch membrane complex in its pathogenesis.

MULTIMODAL RETINAL IMAGING REVEALS NEW PATHOGENIC INSIGHTS IN CENTRAL AREOLAR CHOROIDAL DYSTROPHY: A CASE SERIES.

PURPOSE: To describe novel imaging findings in a family affected by central areolar choroidal dystrophy. METHODS: Case series with multimodal retinal imaging assessment. RESULTS: A 19-year-old asymptomatic woman was referred for bilateral macular defects of the retinal pigment epithelium. Blue-light autofluorescence of her right eye revealed a speckled pattern in the macular area with a ring of decreased autofluorescence using near-infrared autofluorescence. Multimodal assessment of her left eye disclosed a single parafoveal spot of decreased pigmentation that was clearly visible as hyperautofluorescent using blue-light autofluorescence and as hypoautofluorescent using near-infrared autofluorescence. Optical coherence tomography angiography revealed several tiny areas of flow voids in correspondence of the retinal pigment epithelium alterations of both eyes. Three family members were recently diagnosed with presumed age-related macular degeneration and demonstrated well-demarcated areas of retinal pigment epithelium atrophy surrounded by yellowish deposits and a hypopigmented halo. Next-generation genetic analysis for inherited macular dystrophies was performed on the index case and the affected family members and revealed a p.Arg172Gln missense mutation in PRPH2 gene, leading to the diagnosis of central areolar choroidal dystrophy. CONCLUSION: Multimodal imaging can reveal new pathogenic insights in central areolar choroidal dystrophy. Of notice, near-infrared autofluorescence and optical coherence tomography angiography are able to detect retinal pigment epithelium hypopigmentation and choriocapillaris rarefaction, respectively, since the earliest stages of the disease.

Single-Ion Counting with an Ultra-Thin-Membrane Silicon Carbide Sensor.

In recent times, ion implantation has received increasing interest for novel applications related to deterministic material doping on the nanoscale, primarily for the fabrication of solid-state quantum devices. For such applications, precise information concerning the number of implanted ions and their final position within the implanted sample is crucial. In this work, we present an innovative method for the detection of single ions of MeV energy by using a sub-micrometer ultra-thin silicon carbide sensor operated as an in-beam counter of transmitted ions. The SiC sensor signals, when compared to a Passivated Implanted Planar Silicon detector signal, exhibited a 96.5% ion-detection confidence, demonstrating that the membrane sensors can be utilized for high-fidelity ion counting. Furthermore, we assessed the angular straggling of transmitted ions due to the interaction with the SiC sensor, employing the scanning knife-edge method of a focused ion microbeam. The lateral dimension of the ion beam with and without the membrane sensor was compared to the SRIM calculations. The results were used to discuss the potential of such experimental geometry in deterministic ion-implantation schemes as well as other applications.

Unveiling the Hidden: Early Manifestations of Extensive Macular Atrophy with Pseudodrusen-like appearance.

PURPOSE: To describe novel microperimetry and imaging findings in two patients affected by extensive macular atrophy with pseudodrusen-like appearance (EMAP) without signs of retinal pigment epithelium (RPE) atrophy. METHODS: Case series. Both patients underwent mesopic and dark-adapted two-color scotopic microperimetry, followed by multimodal imaging assessment including ultra-widefield photography, fundus autofluorescence (AF), high-resolution optical coherence tomography (Hi-Res OCT), OCT angiography and high-magnification module (HMM). RESULTS: Albeit normal visual acuity, both patients had a significant reduction of retinal sensitivity - especially under scotopic cyan conditions. One patient had macular pigment abnormalities, while the combination of blue and near-infrared AF modalities highlighted different patterns of pseudodrusen-like lesions.Of notice, Hi-Res OCT revealed a marked separation between the RPE and Bruch's membrane, containing a hyperreflective material with two different reflectivities. OCT angiography excluded the presence of macular neovascularization and documented several choriocapillaris flow voids. HMM images showed severe alteration of photoreceptors' mosaic in the perifovea. CONCLUSIONS: Our comprehensive assessment of two stage 1 EMAP patients revealed a predominant damage of perifoveal rods over areas of RPE-Bruch's membrane separation. These findings underscore the importance of basal laminar deposits in the initial stages of EMAP, contributing to a deeper understanding of its underlying mechanisms.