Tear levels of apoptotic, matrix-degrading and antioxidant biomarkers in patients with and without keratoconus: A cross sectional study

PURPOSE

To assess the tear levels of a set of apoptotic, matrix-degrading and antioxidant biomarkers, including Metalloproteinase 9 (MMP9), High Mobility Group Box 1 (HMGB1) and Superoxide Dismutase 3-Extracellular (SOD3).

METHODS

Sandwich-ELISA commercial kits were used to test the expression of the three tear biomarkers in the lacrimal fluid of eligible participants. Linear logistic regression analysis was performed todetermine whether the set of tear biomarkers could be associated with clinically manifest keratoconus. ROC curve analysis using 10-fold cross-validation was performedto evaluate the prediction accuracy of the model.

RESULTS

Eighty-one participants aged 30-48 years old were enrolled in this study; 48 were patients with keratoconus and 33 were age-matched healthy subjects. The linear combination of the three tear biomarkers levels (AUC = 0.811; CI 95 %: 0.712-0.911) accurately indicated the existence of keratoconus; higher levels of MMP9 (Odd Ratio: 1.069; CI 95 %: 1.029-1.130) and HMGB1 (OR: 1.011; CI 95 %: 1.003-1.022) and lower levels of SOD3 (OR: 0.994; CI 95 %: 0.989-0.997) were significantly associated with a higher probability of keratoconus.

CONCLUSION

Multivariable analysis of the set of tear levels of MMP9, HMGB1 and SOD3 biomarkers confirmed a chronic state of inflammation in the ocular surface of patients with keratoconus.

Longitudinal Structural and Functional Evaluation of Dark-without-Pressure Fundus Lesions in Patients with Autoimmune Diseases

OBJECTIVES

The main objective of this study was to report and investigate the characteristics and longitudinal changes in dark-without-pressure (DWP) fundus lesions in patients with autoimmune diseases using multimodal imaging techniques.

METHODS

In this retrospective observational case series, five patients affected by ocular and systemic autoimmune disorders and DWP were examined. DWP was assessed by multimodal imaging, including color fundus photography (CFP), near-infrared reflectance (NIR), blue reflectance (BR), blue autofluorescence (BAF), optical coherence tomography (OCT), OCT-angiography (OCT-A), fluorescein angiography (FA) and indocyanine green angiography (ICGA), and functional testing, including standard automated perimetry (SAP) and electroretinography (ERG). Follow-up examinations were performed for four out of five patients (range: 6 months-7 years).

RESULTS

DWP fundus lesions were found in the retinal mid-periphery and were characterized by the hypo-reflectivity of the ellipsoid zone on OCT. DWP appeared hypo-reflective in NIR, BR and BAF, and exhibited hypo-fluorescence in FA in two patients while showing no signs in one patient. ICGA showed hypo-fluorescent margins in one patient. SAP and ERG testing did not show alterations attributable to the DWP lesion. Follow-up examinations documented rapid dimensional changes in DWP even in the short term (1 month).

CONCLUSIONS

This study suggests a possible association between autoimmune diseases and DWP. New FA and ICGA features were described. The proposed pathogenesis hypotheses may operate as a basis for further investigation of a lesion that is still largely unknown. Large population studies would be necessary to confirm whether there is a higher incidence of DWP in this patient category.

Targeted next-generation sequencing analysis in Italian patients with keratoconus

OBJECTIVE

To report variants in 26 candidate genes and describe the clinical features of Italian patients with keratoconus (KC).

SUBJECTS/METHODS

Sixty-four patients with a confirmed diagnosis of KC were enrolled in this genetic association study. Patients were classified into two study groups according to whether they had a confirmed diagnosis of progressive or stable KC. A purpose-developed Next Generation Sequencing (NGS) panel was used to identify and analyse the coding exons and flanking exon/intron boundaries of 26 genes known to be associated with KC and corneal dystrophies. Interpretation of the pathogenic significance of variants was performed using in silico predictive algorithms.

RESULT

The targeted NGS research identified a total of 167 allelic variants of 22 genes in the study population; twenty-four patients had stable keratoconus (n. 54 variants) and forty patients had progressive disease (n. 113 variants). We identified genetic variants of certain pathogenic significance in five patients with progressive KC; in addition, eight novel genetic variants were found in eight patients with progressive KC. Mutations of FLG, LOXHD1, ZNF469, and DOCK9 genes were twice more frequently identified in patients with progressive than stable disease. Filaggrin gene variants were found in 49 patients (76% of total), of whom 32 patients (80% of progressive KC group) had progressive disease.

CONCLUSIONS

Targeted NGS research provided new insights into the causative effect of candidate genes in the clinical phenotype of keratoconus. Filaggrin mutations were found to represent a genetic risk factor for development of progressive disease in Italy.

Real-time monitoring of riboflavin concentration using different clinically available ophthalmic formulations for epi-off and epi-on corneal cross-linking

PURPOSE

To assess the feasibility of theranostics to determine the riboflavin concentration in the cornea using clinically available ophthalmic formulations during epithelium-off (epi-off) and transepithelial (epi-on) corneal cross-linking procedures.

METHODS

Thirty-two eye bank human donor corneas were equally randomized in eight groups; groups 1 to 3 and groups 4 to 8 underwent epi-off and epi-on delivery of riboflavin respectively. Riboflavin ophthalmic solutions were applied onto the cornea according to the manufacturers' instructions. The amount of riboflavin into the cornea was estimated, at preset time intervals during imbibition time, using theranostic UV-A device (C4V CHROMO4VIS, Regensight srl, Italy) and expressed as riboflavin score (d.u.). Measurements of corneal riboflavin concentration (expressed as µg/cm3) were also performed by spectroscopy absorbance technique (AvaLight-DH-S-BAL, Avantes) for external validation of theranostic measurements.

RESULTS

At the end of imbibition time in epi-off delivery protocols, the average riboflavin score ranged from 0.77 ± 0.38 (the average corneal riboflavin concentration was 213 ± 190 µg/cm3) to 1.79 ± 0.07 (554 ± 103 µg/cm3). In epi-on delivery protocols, the average riboflavin score ranged from 0.17 ± 0.01 to 0.67 ± 0.19 (corneal riboflavin concentration ranged from 6 ± 5 µg/cm3 to 122 ± 39 µg/cm3) at the end of imbibition time. A statistically significant linear correlation (P ≤ 0.05) was found between the theranostic and spectrophotometry measurements in all groups.

CONCLUSIONS

Real-time theranostic imaging provided an accurate strategy for assessing permeation of riboflavin into the human cornea during the imbibition phase of corneal cross-linking, regardless of delivery protocol. A large variability in corneal riboflavin concentration exists between clinically available ophthalmic formulations both in epi-off and epi-on delivery protocols.

Evidence for multi-fragmentation and mass shedding of boulders on rubble-pile binary asteroid system (65803) Didymos

Asteroids smaller than 10 km are thought to be rubble piles formed from the reaccumulation of fragments produced in the catastrophic disruption of parent bodies. Ground-based observations reveal that some of these asteroids are today binary systems, in which a smaller secondary orbits a larger primary asteroid. However, how these asteroids became binary systems remains unclear. Here, we report the analysis of boulders on the surface of the stony asteroid (65803) Didymos and its moonlet, Dimorphos, from data collected by the NASA DART mission. The size-frequency distribution of boulders larger than 5 m on Dimorphos and larger than 22.8 m on Didymos confirms that both asteroids are piles of fragments produced in the catastrophic disruption of their progenitors. Dimorphos boulders smaller than 5 m have size best-fit by a Weibull distribution, which we attribute to a multi-phase fragmentation process either occurring during coalescence or during surface evolution. The density per km2 of Dimorphos boulders ≥1 m is 2.3x with respect to the one obtained for (101955) Bennu, while it is 3.0x with respect to (162173) Ryugu. Such values increase once Dimorphos boulders ≥5 m are compared with Bennu (3.5x), Ryugu (3.9x) and (25143) Itokawa (5.1x). This is of interest in the context of asteroid studies because it means that contrarily to the single bodies visited so far, binary systems might be affected by subsequential fragmentation processes that largely increase their block density per km2. Direct comparison between the surface distribution and shapes of the boulders on Didymos and Dimorphos suggest that the latter inherited its material from the former. This finding supports the hypothesis that some asteroid binary systems form through the spin up and mass shedding of a fraction of the primary asteroid.

Fast boulder fracturing by thermal fatigue detected on stony asteroids

Spacecraft observations revealed that rocks on carbonaceous asteroids, which constitute the most numerous class by composition, can develop millimeter-to-meter-scale fractures due to thermal stresses. However, signatures of this process on the second-most populous group of asteroids, the S-complex, have been poorly constrained. Here, we report observations of boulders' fractures on Dimorphos, which is the moonlet of the S-complex asteroid (65803) Didymos, the target of NASA's Double Asteroid Redirection Test (DART) planetary defense mission. We show that the size-frequency distribution and orientation of the mapped fractures are consistent with formation through thermal fatigue. The fractures' preferential orientation supports that these have originated in situ on Dimorphos boulders and not on Didymos boulders later transferred to Dimorphos. Based on our model of the fracture propagation, we propose that thermal fatigue on rocks exposed on the surface of S-type asteroids can form shallow, horizontally propagating fractures in much shorter timescales (100 kyr) than in the direction normal to the boulder surface (order of Myrs). The presence of boulder fields affected by thermal fracturing on near-Earth asteroid surfaces may contribute to an enhancement in the ejected mass and momentum from kinetic impactors when deflecting asteroids.

The natural course of an iridoschisis: A case report

BACKGROUND

Iridoschisis is a rare ophthalmological disorder that presents with the separation of the anterior fibers of the iris from the posterior ones at the level of the stromal layer. Fibers resulting from the disintegration of the anterior iris layers can be encountered in the anterior chamber of the affected eyes. This condition mostly affects females and has been associated with both open-angle and angle-closure glaucoma. The pathogenesis has not been clarified yet, and the treatment is still a matter of discussion.

OBJECTIVE

We want to contribute to the understanding of the pathogenesis and natural course of the disease as well as to document with multimodal imaging a new case of this very rare disease.

CASE REPORT

We present a case of a 71-year-old woman affected by iridoschisis in both eyes followed by 3 consecutive visits every 4 months. We performed an extensive ophthalmologic examination, including gonioscopy, endothelial cell microscopy, and optical coherence tomography of the anterior segment.

CONCLUSION

In our report, we documented a possible natural course of iridoschisis, characterized by an acute worsening followed by a phase of stability, and formulated some hypotheses on the pathogenesis of this rare disease.

Spatial targeted delivery of riboflavin with a controlled corneal iontophoresis delivery system in theranostic-guided UV-A light photo-therapy

Seven human donor eye globes underwent corneal cross-linking using theranostic UV-A device with accessory corneal iontophoresis system for patterned delivery of a 0.22% riboflavin solution. Theranostic-guided UV-A light illumination assessed riboflavin distribution and treated corneas at 10 mW/cm2 for 9 min with a 5.0-mm beam size. Corneal topography maps were taken at baseline and 2-h post-treatment. Analysis utilized corneal topography elevation data, with results showing controlled riboflavin delivery led to a consistent gradient, with 40% higher levels centrally (248 ± 79 μg/cm3) than peripherally (180 ± 72 μg/cm3 at ±2.5 mm from the center). Theranostic-guided UV-A light irradiation resulted in significant changes in corneal topography, with a decrease in best-fit sphere value (-0.7 ± 0.2 D; p < 0.001) and consistent downward shift in corneal elevation map (-11.7 ± 3.7 μm). The coefficient of variation was 2.5%, indicating high procedure performance in achieving significant and reliable corneal flattening.

Real-World Use of Off-Label MVASI in the Treatment of Patients With Neovascular AMD and DME

Purpose

The purpose of this study was to evaluate the efficacy and safety of bevacizumab-awwb in the off-label treatment of neovascular age-related macular degeneration (n-AMD) and diabetic macular edema (DME).

Methods

All patients with n-AMD and DME treated in the maintenance phase according to the "treat and extend" strategy, who underwent forced drug substitution from bevacizumab to bevacizumab-awwb from October 2022 to April 2023 at the Tor Vergata Polyclinic in Rome, were evaluated in a retrospective study. The primary outcome was changes in central retinal thickness (CRT) over time following drug substitution. The secondary outcomes were variations in drug durability, best corrected visual acuity (BCVA) and retinal fluid, and the incidence of drug-related local and systemic serious adverse events.

Results

Of 80 eyes of 76 patients with n-AMD and 55 eyes of 44 patients with DME included, before and after drug substitution, the average CRT did not statistically differ; the proportion of patients within time intervals of q8, q12, and q16 was not different; and the mean BCVA remained constant. Of a cumulative 3496 bevacizumab-awwb treatments (2154 for patients with n-AMD and 1342 for patients with DME), no local severe complications were detected. Out of a total of 544 patients (342 affected by n-AMD and 202 affected by DME), no serious adverse events were reported.

Conclusions

In our cohort of patients with n-AMD and DME in the maintenance phase, bevacizumab-awwb seems to represent a viable and cost-effective intravitreal therapy with comparable efficacy and safety to the originator.

Translational Relevance

This study provides a preliminary assessment of the efficacy and safety of intravitreal bevacizumab-awwb, which is widely used off-label in retinal vascular diseases.

Assessment of the Predictive Ability of Theranostics for Corneal Cross-linking in Treating Keratoconus: A Randomized Clinical Trial

PURPOSE

To validate the ability of theranostic imaging biomarkers in assessing corneal cross-linking (CXL) efficacy in flattening the maximum keratometry (Kmax) index.

DESIGN

Prospective, randomized, multicenter, masked clinical trial (ClinicalTrails.gov identifier, NCT05457647).

PARTICIPANTS

Fifty patients with progressive keratoconus.

INTERVENTION

Participants were stratified to undergo epithelium-off (25 eyes) and epithelium-on (25 eyes) CXL protocols using an ultraviolet A (UV-A) medical device with theranostic software. The device controlled UV-A light both for performing CXL and assessing the corneal riboflavin concentration (riboflavin score) and treatment effect (theranostic score). A 0.22% riboflavin formulation was applied onto the cornea for 15 minutes and 20 minutes in epithelium-off and epithelium-on protocols, respectively. All eyes underwent 9 minutes of UV-A irradiance at 10 mW/cm2.

MAIN OUTCOME MEASURES

The primary outcome measure was validation of the combined use of theranostic imaging biomarkers through measurement of their accuracy (proportion of correctly classified eyes) and precision (positive predictive value) to classify eyes correctly and predict a Kmax flattening at 1 year after CXL. Other outcome measures included change in Kmax, endothelial cell density, uncorrected and corrected distance visual acuity, manifest spherical equivalent refraction and central corneal thickness 1 year after CXL.

RESULTS

Accuracy and precision of the theranostic imaging biomarkers in predicting eyes that had >0.1 diopter (D) of Kmax flattening at 1 year were 91% and 95%, respectively. The Kmax value significantly flattened by a median of -1.3 D (IQR, -2.11 to -0.49 D; P < 0.001); both the uncorrected and corrected distance visual acuity improved by a median of -0.1 logarithm of the minimum angle of resolution (logMAR; IQR, -0.3 to 0.0 logMAR [P < 0.001] and -0.2 to 0.0 logMAR [P < 0.001], respectively). No significant changes in endothelial cell density (P = 0.33) or central corneal thickness (P = 0.07) were noted 1 year after surgery.

CONCLUSIONS

The study demonstrated the efficacy of integrating theranostics in a UV-A medical device for the precise and predictive treatment of keratoconus with epithelium-off and epithelium-on CXL protocols. Concentration of riboflavin and its UV-A light mediated photoactivation in the cornea are the primary factors determining CXL efficacy.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Estimated prevalence of keratoconus in the largest metropolitan area of Italy

PURPOSE

To estimate the prevalence of keratoconus in a population of subjects undergoing first eye examination in an eye clinic in Italy.

METHODS

A single-center, cross-sectional, study was conducted involving patients who underwent first eye examination at an eye clinic in Rome between September 2021 and June 2022. The prevalence of keratoconus was determined by Placido-disk corneal topography using the maximum keratometry (Kmax) value and the Cone Magnitude and Location Index (CLMI) for keratoconus screening. Subjective analysis was performed by two experienced corneal specialists, who classified the outcome into two groups: normal and keratoconus. Risk factors, including family history of keratoconus, allergy or atopy, thyroid disease, eye rubbing habit and gender were also examined.

RESULTS

A total of 512 subjects between 7 and 81 years old were evaluated. The inter-observer agreement to classify subjects in normal or keratoconus group was excellent (k = 1.0); the estimated prevalence in the specific population was 2.1%. Presence of positive family history (9% of keratoconus vs 5% normal), concomitant allergy or atopy (27% vs 9%) and eye rubbing habit (18% vs 4%) were associated with a higher risk of disease.

CONCLUSION

This study reported a high estimated prevalence of keratoconus in a metropolitan area of Italy, as found in recent studies in the Mediterranean and Middle East countries. Screening for keratoconus is highly recommendable and easily feasible with corneal topography under expert supervision and may be indicated primarily in young population to improve early detection and prompt therapeutic management for halting disease progression.

TAPSE/SPAP ratio stratifies mortality risk in mild-to-moderate idiopathic pulmonary fibrosis

BACKGROUND: Due to paucity of literature data, we aimed at evaluating the prognostic role of the ratio of tricuspid annular plane systolic excursion (TAPSE) to systolic pulmonary artery pressure (SPAP) in idiopathic pulmonary fibrosis (IPF) patients without severe pulmonary hypertension and at assessing its correlation with effective arterial elastance index (EaI). METHODS: Multi-instrumental data obtained in 60 IPF patients (73.2 ± 6.8 years) and 60 matched controls were retrospectively analysed. Primary endpoint was all-cause mortality, while secondary endpoint was the composite of all-cause mortality and re-hospitalisations for all-causes over medium-term follow-up. RESULTS: ;At baseline, TAPSE/SPAP was significantly lower in patients with IPF than in controls (0.36 ± 0.25 vs. 0.77 ± 0.18 mm/mmHg; P < 0.001). TAPSE/SPAP was inversely correlated with EaI (r = -0.96) in IPF patients. During follow-up (3.5 ± 1.5 years), 21 patients died and 25 were re-hospitalised due to cardiopulmonary causes. TAPSE/SPAP was independently associated with both primary (HR 0.79, 95%CI 0.65-0.97) and secondary (HR 0.94, 95%CI 0.92-0.97) endpoints. A TAPSE/SPAP ratio of <0.20 and <0.44 mm/mmHg showed the greatest sensitivity and specificity for predicting primary (AUC 0.98) and secondary (AUC 0.99) endpoints, respectively. CONCLUSIONS: TAPSE/SPAP is a strong predictor of adverse outcomes in mild-to-moderate IPF. The strong correlation between TAPSE/SPAP and EaI might be an expression of a systemic fibrotic process which involves the heart, lungs and circulation.

Short Wavelength Automated Perimetry, Standard Automated Perimetry, and Optical Coherence Tomography in Dominant Optic Atrophy

Background: Blue-yellow axis dyschromatopsia is well-known in Autosomal Dominant Optic Atrophy (ADOA) patients, but there were no data on the correlation between retinal structure and short-wavelength automated perimetry (SWAP) values in this pathology. Methods: In this cross-sectional case-control study, we assessed the correlation between best corrected visual acuity (BCVA), standard automated perimetry (SAP), SWAP, and optical coherence tomography (OCT) parameters of 9 ADOA patients compared with healthy controls. Correlation analysis was performed between BCVA, mean deviation, pattern standard deviation (PSD), and fovea sensitivity (FS) values and the OCT thickness of each retinal layer and the peripapillary retinal nerve fiber layer (pRNFL). Results: The following significant and strong correlations were found: between BCVA and ganglion cell layer (GCL) and the global (G) pRNFL thicknesses; between SAP FS and GCL and the G-pRNFL thicknesses; between SWAP PSD and total retina, GCL, inner plexiform layer, inner nuclear layer, inner retinal layer and the temporal pRNFL thicknesses. We found a constant shorter duration of the SITA-SWAP compared with the SITA-STANDARD strategy. Conclusions: SWAP, SAP, and BCVA values provided relevant clinical information about retinal involvement in our ADOA patients. The perimetric functional parameters that seemed to correlate better with structure involvement were FS on SAP and PSD on SWAP.

Accuracy of an Air-Puff Dynamic Tonometry Biomarker to Discriminate the Corneal Biomechanical Response in Patients With Keratoconus

PURPOSE

The aim of this study was to assess accuracy of the mean corneal stiffness ( kc , N/m) parameter to discriminate between patients with keratoconus and age-matched healthy subjects.

METHODS

Dynamic Scheimpflug imaging tonometry was performed with Corvis ST (Oculus Optikgeräte GmbH, Germany) in patients with keratoconus (n = 24; study group) and age-matched healthy subjects (n = 32; control). An image processing algorithm was developed to analyze the video sequence of the Corvis ST air-puff event and to determine the geometric and temporal parameters that correlated with the corneal tissue biomechanical properties. A modified 3-element viscoelastic model was used to derive the kc parameter, which represented the corneal tissue resistance to deformation under load. Receiver operating characteristic curves were used to assess the overall diagnostic performance for determining the area under the curve, sensitivity, and specificity of the kc in assessing the corneal tissue deformation to the Corvis ST air-puff event in keratoconus and control eyes. The Corvis Biomechanical Index ( CBI ) was analyzed for external validation.

RESULTS

The kc parameter was significantly different between keratoconus and controls ( P < 0.001), ranging from 24.9 ±3.0 to 34.2 ±3.5 N/m, respectively. It was highly correlated with CBI (r = -0.69; P < 0.001); however, the kc parameter had greater specificity (94%) than CBI (75%), whereas the 2 biomarkers had similar area under the curve (0.98 vs. 0.94) and sensitivity (96% vs. 92%) in predicting the occurrence of keratoconus.

CONCLUSIONS

The kc parameter extracted by video processing analysis of dynamic Scheimpflug tonometry data was highly accurate in discriminating patients with clinically manifest keratoconus compared with controls.

The Dimorphos ejecta plume properties revealed by LICIACube

The Double Asteroid Redirection Test (DART) had an impact with Dimorphos (a satellite of the asteroid Didymos) on 26 September 20221. Ground-based observations showed that the Didymos system brightened by a factor of 8.3 after the impact because of ejecta, returning to the pre-impact brightness 23.7 days afterwards2. Hubble Space Telescope observations made from 15 minutes after impact to 18.5 days after, with a spatial resolution of 2.1 kilometres per pixel, showed a complex evolution of the ejecta3, consistent with other asteroid impact events. The momentum enhancement factor, determined using the measured binary period change4, ranges between 2.2 and 4.9, depending on the assumptions about the mass and density of Dimorphos5. Here we report observations from the LUKE and LEIA instruments on the LICIACube cube satellite, which was deployed 15 days in advance of the impact of DART. Data were taken from 71 seconds before the impact until 320 seconds afterwards. The ejecta plume was a cone with an aperture angle of 140 ± 4 degrees. The inner region of the plume was blue, becoming redder with increasing distance from Dimorphos. The ejecta plume exhibited a complex and inhomogeneous structure, characterized by filaments, dust grains and single or clustered boulders. The ejecta velocities ranged from a few tens of metres per second to about 500 metres per second.

Selective Hydrofunctionalization of N-Allenyl Derivatives with Heteronucleophiles Catalyzed by Brønsted Acids

In this study, we present a novel and environmentally sustainable protocol for the γ-hydrofunctionalization of N-allenyl compounds using various heteronucleophiles catalyzed solely by simple Brønsted acids. The method displays remarkable attributes, highlighting its sustainability, efficiency, regio- and stereoselectivity, as well as its versatile applicability to diverse heteroatom-containing enamides. Notably, our approach eliminates the need for metal catalysts and toxic solvents, representing a significant advancement in greener chemistry practices. We demonstrate the broad scope of our protocol by successfully scaling up reactions to gram-scale syntheses, underscoring its robustness for potential industrial implementation. The resulting γ-heterosubstituted enamides offer new possibilities for further synthetic transformations, yielding highly functionalized compounds with diverse applications. Mechanistic investigations reveal the pivotal role of CSA as a catalyst, enabling alcohol addition via a covalent activation mode.

Non-Invasive High-Resolution Imaging of In Vivo Human Myelinated Axons

This work aims to reveal the microscopic (2-3 micrometer resolution) appearance of human myelinated nerve fibers in vivo for the first time. We analyzed the myelinated retinal nerve fibers of a male patient without other neurological disorders in a non-invasive way using the transscleral optical phase imaging method with adaptive optics. We also analyzed the fellow eye with non-myelinated nerve fibers and compared the results with traditional ocular imaging methods such as optical coherence tomography. We documented the microscopic appearance of human myelin and myelinated axons in vivo. This method allowed us to obtain better details than through traditional ocular imaging methods. We hope these findings will be useful to the scientific community to evaluate neuro-retinal structures through new imaging techniques and more accurately document nerve anatomy and the pathophysiology of this disease.

Assessing Feasibility of Cognitive Impairment Testing Using Social Robotic Technology Augmented with Affective Computing and Emotional State Detection Systems

Social robots represent a valid opportunity to manage the diagnosis, treatment, care, and support of older people with dementia. The aim of this study is to validate the Mini-Mental State Examination (MMSE) test administered by the Pepper robot equipped with systems to detect psychophysical and emotional states in older patients. Our main result is that the Pepper robot is capable of administering the MMSE and that cognitive status is not a determinant in the effective use of a social robot. People with mild cognitive impairment appreciate the robot, as it interacts with them. Acceptability does not relate strictly to the user experience, but the willingness to interact with the robot is an important variable for engagement. We demonstrate the feasibility of a novel approach that, in the future, could lead to more natural human-machine interaction when delivering cognitive tests with the aid of a social robot and a Computational Psychophysiology Module (CPM).

Stereoselective Synthesis of α-Disubstituted β-Homoprolines

An efficient enantioselective synthesis of chiral α-disubstituted β-homoprolines was developed, starting with the stereodivergent allylation of chiral N-tert-butanesulfinyl imines derived from 4-bromobutanal with indium or zinc and using well-established and reliable synthetic transformations. This methodology allows the easy introduction of different substituents at the α-position of the pyrrolidine scaffold and is characterized by the possibility of switching the absolute configuration of the newly formed stereocenter either by changing the configuration of the tert-butanesufinamide chiral auxiliary or by using a different stereodivergent allylation protocol with the same auxiliary.

Putting a "C60 Ball" and Chain to Chlorin e6 Improves Its Cellular Uptake and Photodynamic Performances

Chlorin e6 (Ce6) and fullerene (C60) are among the most used photosensitizers (PSs) for photodynamic therapy (PDT). Through the combination of the chemical and photophysical properties of Ce6 and C60, in principle, we can obtain an "ideal" photosensitizer that is able to bypass the limitations of the two molecules alone, i.e., the low cellular uptake of Ce6 and the scarce solubility and absorption in the red region of the C60. Here, we synthesized and characterized a Ce6-C60 dyad. The UV-Vis spectrum of the dyad showed the typical absorption bands of both fullerene and Ce6, while a quenching of Ce6 fluorescence was observed. This behavior is typical in the formation of a fullerene-antenna system and is due to the intramolecular energy, or electron transfer from the antenna (Ce6) to the fullerene. Consequently, the Ce6-C60 dyad showed an enhancement in the generation of reactive oxygen species (ROS). Flow cytometry measurements demonstrated how the uptake of the Ce6 was strongly improved by the conjugation with C60. The Ce6-C60 dyad exhibited in A431 cancer cells low dark toxicity and a higher PDT efficacy than Ce6 alone, due to the enhancement of the uptake and the improvement of ROS generation.

Paving the Way for Predicting the Progression of Cognitive Decline: The Potential Role of Machine Learning Algorithms in the Clinical Management of Neurodegenerative Disorders

Alzheimer's disease (AD) is the most common form of neurodegenerative disorder. The prodromal phase of AD is mild cognitive impairment (MCI). The capacity to predict the transitional phase from MCI to AD represents a challenge for the scientific community. The adoption of artificial intelligence (AI) is useful for diagnostic, predictive analysis starting from the clinical epidemiology of neurodegenerative disorders. We propose a Machine Learning Model (MLM) where the algorithms were trained on a set of neuropsychological, neurophysiological, and clinical data to predict the diagnosis of cognitive decline in both MCI and AD patients.

METHODS

We built a dataset with clinical and neuropsychological data of 4848 patients, of which 2156 had a diagnosis of AD, and 2684 of MCI, for the Machine Learning Model, and 60 patients were enrolled for the test dataset. We trained an ML algorithm using RoboMate software based on the training dataset, and then calculated its accuracy using the test dataset.

RESULTS

The Receiver Operating Characteristic (ROC) analysis revealed that diagnostic accuracy was 86%, with an appropriate cutoff value of 1.5; sensitivity was 72%; and specificity reached a value of 91% for clinical data prediction with MMSE.

CONCLUSION

This method may support clinicians to provide a second opinion concerning high prognostic power in the progression of cognitive impairment. The MLM used in this study is based on big data that were confirmed in enrolled patients and given a credibility about the presence of determinant risk factors also supported by a cognitive test score.

Bioelectrical impedance analysis in patients with posterior vitreous detachment

OBJECTIVE

The purpose of the study is to assess body hydration in patients with posterior vitreous detachment (PVD) by bioelectrical impedance analysis (BIA). PVD, one of the most common eye diseases, is associated in both research and the collective image with reduced daily water intake, but this finding is not supported by strong evidence in the literature.

PATIENTS AND METHODS

Based on Spectral Domain Optical Coherence Tomography (SD-OCT) evaluation, different PVD stages are identified: absent posterior vitreous detachment, partial posterior vitreous detachment (P-PVD), or complete posterior vitreous detachment (C-PVD). BIA is a simple, non-invasive bedside method used to assess body composition. Patients underwent BIA and completed a floaters symptoms. 30 patients were enrolled and divided into two groups according to the degree of vitreous detachment, in P-PVD (n=12) and C-PVD (n=18). Patients underwent BIA and completed a floaters symptoms questionnaire. BIA measured the Resistance (R), Reactance (Xc), Phase Angle (PhA), Total Body Water (TBW), Extracellular Water (ECW), Fat Mass (FM), Fat-Free Mass (FFM), and Body Cell Mass Index (BCMI). Finally, patients received a test to assess adherence to the Mediterranean diet (Mediterranean Diet Test Score, MDTS) with the addition of daily water intake.

RESULTS

Relevant data were obtained from the BIA evaluation: the values of R and Xc were lower in the P-PVD group than C-PVD group (respectively 417.08±58.12 Ω vs. 476.94±51.29 Ω p=0.006 and 41.33±8.23 Ω vs. 50.61±7.98 Ω p=0.004). Instead, patients in the P-PVD group reported higher values of TBW and ECW than C-PVD group (respectively 44.13±7.57 L vs. 37.96±6.27 L p=0.021 and 21.03±4.06 L vs. 17.24±2.63 L p=0.004).

CONCLUSIONS

In the present study, we reported a significant correlation between vitreous pathology and anthropometric and BIA measurements.

Predicting corneal cross-linking treatment efficacy with real-time assessment of corneal riboflavin concentration

PURPOSE

To assess predictability of tissue biomechanical stiffening induced by UV-A light-mediated real-time assessment of riboflavin concentration during corneal crosslinking (CXL) of human donor tissues.

SETTING

Studio Italiano di Oftalmologia, Rome, Italy.

DESIGN

Laboratory study.

METHODS

20 sclerocorneal tissues were randomly stratified to undergo CXL with either the epithelium intact (n = 12) or removed (n = 8). Samples underwent corneal soaking with 0.22% riboflavin formulation (RitSight) with dosing time of t = 10 minutes and t = 20 minutes in epithelium-off and epithelium-on protocols, respectively. All tissues underwent 9-minute UV-A irradiance at 10 mW/cm 2 using theranostic device (C4V CHROMO4VIS). The device used controlled UV-A light irradiation to induce both imaging and treatment of the cornea, providing a real-time measure of corneal riboflavin concentration and treatment efficacy (ie, theranostic score) during surgery. Tissue biomechanics were assessed with an air-puff device (Corvis), which was performed before and after treatment. A 3-element viscoelastic model was developed to fit the corneal deformation response to air-puff excitation and to calculate the mean corneal stiffness parameter (k c ).

RESULTS

Significant corneal tissue stiffening ( P < .05) was induced by the theranostic UV-A device in either CXL treatment protocol. Significant correlation was found between the theranostic score and the increase in k c ( R = 0.75; P = .003). The score showed high accuracy (94%) and precision (94%) to predict correctly samples that had improved tissue biomechanical strengthening.

CONCLUSIONS

Real-time assessment of corneal riboflavin concentration provided a predictive and precise approach for significant improvement of tissue strength on individual corneas, regardless of CXL treatment protocol.

Long-Term Zonal Average Analysis of Corneal Tomography in Keratoconus Eyes

PURPOSE

The scope of this study was to investigate keratoconus progression using zonal average analysis of corneal tomography.

METHODS

The corneal tomographies of patients participating in initial baseline and all scheduled follow-up visits up to 4 years were analyzed. Data were exported in custom software, which delineated 4 zones of analysis and calculated the average values of the anterior and posterior curvature and the average thickness for each zone at each visit. In particular, a 3.1 mm 2 area containing the K max , termed "keratoconus cone zone," was defined for assessing disease progression during the follow-up.

RESULTS

A total of 201 patients were enrolled in this prospective study. At 4 years, 31% of the eyes (n = 62) had an average increase of ≥1.0 D in the keratoconus cone zone in baseline visit, whereas only 11% of the eyes (n = 22) had ≥1.0 D K max increase in the same period. The zonal anterior average curvature (+1.1 D; P < 0.001) and thickness (-14 μm; P < 0.001) values of the keratoconus cone zone progressed significantly during the follow-up. A high correlation was found between the 4-year changes of K max and central corneal thickness values and the change of the average anterior curvature and thickness values in the keratoconus cone zone. The posterior cornea did not show significant average changes (<-0.2 D; P > 0.05) during the follow-up.

CONCLUSIONS

Single-point tomography indexes for keratoconus progression did not capture the overall structure and shape changes of the cornea. It would be recommended to update criteria for keratoconus management including the zonal average analysis of curvature and thickness values for tracking disease progression over observation periods longer than 1 year.