The Disorganization of Retinal Inner Layers Is Correlated to Müller Cells Impairment in Diabetic Macular Edema: An Imaging and Omics Study.

The disorganization of retinal inner layers (DRIL) is an optical coherence tomography (OCT) biomarker strictly associated with visual outcomes in patients with diabetic macular edema (DME) whose pathophysiology is still unclear. The aim of this study was to characterize in vivo, using retinal imaging and liquid biopsy, DRIL in eyes with DME. This was an observational cross-sectional study. Patients affected by center-involved DME were enrolled. All patients underwent spectral domain optical coherence tomography (SD-OCT) and proteomic analysis of aqueous humor (AH). The presence of DRIL at OCT was analyzed by two masked retinal experts. Fifty-seven biochemical biomarkers were analyzed from AH samples. Nineteen eyes of nineteen DME patients were enrolled. DRIL was present in 10 patients (52.63%). No statistically significant difference was found between DME eyes with and without DRIL, considering the AH concentration of all the analyzed biomarkers except for glial fibrillary acidic protein (GFAP), a biomarker of Müller cells dysfunction (p = 0.02). In conclusion, DRIL, in DME eyes, seems to strictly depend on a major dysfunction of Müller cells, explaining its role not only as imaging biomarker, but also as visual function Müller cells-related parameter.

RADIATION MACULOPATHY IS ANTICIPATED BY OCT HYPERREFLECTIVE RETINAL FOCI: A Large, Prospective, Confirmation Study.

PURPOSE: To investigate, by means of spectral domain optical coherence tomography, retinal reflectivity changes as an early biomarker anticipating radiation-induced macular edema (ME) in patients treated by iodine-125 (I-125) brachytherapy. METHODS: Thirty patients planned for I-125 brachytherapy because of uveal melanoma were prospectively included and followed every 4 months for five years. Reflectivity alterations, namely hyperreflective retinal foci, were characterized and counted by two independent masked examiners by means of spectral domain optical coherence tomography imaging. Hyperreflective retinal foci were defined as discrete intraretinal reflectivity changes ≤30 µm, with reflectivity similar to nerve fiber layer and without back shadowing. RESULTS: Macular edema occurred in 17 patients (24.2 ±15.1 months) (group 1) after irradiation. Thirteen patients showed no signs of ME at the 5-year follow-up (group 2). The number of hyperreflective retinal foci was statistically higher in sequential visits until the evidence of ME in group 1 vs group 2 (P < 0.0001). In group 1, hyperreflective retinal foci at the follow-up before the evidence of ME were significantly related to the OCT central subfield thickness at ME appearance (P = 0.0002, r2=0.6129). The intergrader agreement was almost perfect (intraclass correlation coefficient = 0.80). CONCLUSION: Hyperreflective retinal foci may be considered as an early in vivo imaging biomarker of retinal inflammatory response to ocular irradiation, anticipating the development of radiation maculopathy.

Intraocular fluid biomarkers (liquid biopsy) in human diabetic retinopathy.

PURPOSE: This article aims to review the impact of detecting and quantifying intraocular biomarkers (liquid biopsy) in both aqueous and vitreous humor in eyes of people affected by diabetes mellitus. METHODS: This is a detailed review about aqueous and/or vitreous humor sampling in human diabetic eyes for proteomic and/or metabolomic analysis contributing to the understanding of the pathophysiology and treatment effects of diabetic retinopathy. RESULTS: Aqueous and vitreous humor molecular biomarkers proved to be directly correlated to each other and valuable to study retinal conditions. Moreover, proteomic and metabolomic analysis showed that the biomarkers of neuroinflammation, neurodegeneration, and vasculopathy are detectable in intraocular fluids and that their concentration changes in different stages of disease, and in response to treatment of all diabetic retinopathy aspects, mainly diabetic macular edema and proliferative retinopathy. CONCLUSIONS: Liquid biopsy offers the possibility to improve our knowledge of intraocular eye disease induced by diabetes mellitus. The exact quantification of intraocular biomarkers contributes to the precision medicine approach even in the diabetic retinopathy scenario. The diffusion of this approach should be encouraged to have quantifiable information directly from the human model, which may be coupled with imaging data.

RETINAL VASCULAR ABNORMALITIES RELATED TO NEUROFIBROMATOSIS TYPE 1: Natural History and Classification by Optical Coherence Tomography Angiography in 473 Patients.

PURPOSE: To analyze and classify neurofibromatosis Type 1 (NF1)-related retinal vascular abnormalities (RVAs), their natural history and correlation with disease severity, in a large cohort of patients. METHODS: This was an observational longitudinal study with prospective enrollment. Four hundred and seventy-three patients affected by NF1 and 150 age-matched healthy subjects were consecutively enrolled. Retinal vascular abnormalities were detected by means of near-infrared reflectance and studied by optical coherence tomography angiography. The superficial vascular plexus and the deep vascular complex (DVC) were quantitatively and qualitatively analyzed. RESULTS: We identified RVAs in 82 of 473 (17%) NF1 patients, but in none of the 150 healthy subjects. A comparison revealed that NF1 patients with RVAs showed a higher number of NF1 diagnostic criteria (4.3 ± 1.5 vs. 3.9 ±1.5, respectively; P = 0.02) than patients without RVAs. Three different RVA types were identified on optical coherence tomography angiography: macrovascular angiomatosis of the sole superficial vascular plexus; macrovascular angiomatosis of the superficial vascular plexus combined with microvascular angiomatosis of the deep vascular complex; and combined macrovascular angiomatosis of both superficial vascular plexus and deep vascular complex. The prospective analysis of optical coherence tomography angiography images showed no significant longitudinal evolution of RVAs (mean follow-up: 3.7 ± 2.8 years). A single patient developed a de novo single RVA, and two RVAs showed detectable changes during follow-up. CONCLUSION: In NF1 patients, RVAs are a characteristic sign that correlates with a more severe systemic disease expression, usually remaining stable during time. Optical coherence tomography angiography allows for the identification of different RVAs subtypes.

Clinical-Radiological Patterns and Histopathological Outcomes in Non-Thyroid Extraocular Muscle Enlargement: Retrospective Case Series and Current Concepts.

PURPOSE: To report a single-center experience with non-thyroid causes of extraocular muscle enlargement (EME), describing the association between clinical-radiological findings at presentation and the final histopathological diagnosis. METHODS: Retrospective consecutive case series of 59 patients with single or multiple EME on orbital imaging, in the absence of an etiological diagnosis at the time of presentation. All patients were submitted to orbital muscle biopsy in order to achieve a final etiological diagnosis. Patients with a confirmed diagnosis of thyroid-associated orbitopathy and vascular causes of EME which were angiographically and clinically diagnosed were excluded. Orbital ultrasound and radiologic evaluation (CT and/or MRI) were performed before surgery in all cases. Main outcomes measured included initial clinical-radiological findings and final histopathological features of EME. RESULTS: A diagnosis of lymphoma was confirmed in 13 cases (22%). Sixteen cases (27%) were diagnosed as orbital inflammatory disease including nonspecific idiopathic orbital inflammatory disease in 9 cases, IgG4-related disease in 4 cases, and sclerosing idiopathic orbital inflammatory disease in 3 cases. In 11 patients (18%), a diagnosis of metastatic tumor was made, whereas sarcoidosis, vascular malformations, Erdheim-Chester, and necrobiotic xanthogranuloma were diagnosed in 8 eyes (13.5%). Three patients (5%) with single muscle enlargement developed Graves disease 10 months later. Four patients (6.7%) were diagnosed with granulomatosis with polyangiitis. In 2 cases (3.3%), the diagnosis was unknown, with inconclusive biopsy results. Differential patterns for inflammatory/vascular, lymphomatous and metastatic EME were identified based on age and gender distribution and clinical-radiological characteristics at presentation. CONCLUSIONS: Initial clinical and radiological features may orientate the differential diagnosis of non-thyroid EME.

HYPERREFLECTIVE RETINAL SPOTS IN NORMAL AND DIABETIC EYES: B-Scan and En Face Spectral Domain Optical Coherence Tomography Evaluation.

PURPOSE: To evaluate hyperreflective retinal spots (HRS), in normal subjects and diabetic patients without and with macular edema (diabetic macular edema, DME), on linear B-scans and corresponding en face image of spectral-domain optical coherence tomography. METHODS: Retrospective evaluation of images of 54 eyes/subjects (16 normal subjects, 19 diabetic patients without DME, and 19 with DME). On horizontal B-scan spectral-domain optical coherence tomography, passing through the center of the fovea, the following characteristics of HRS were evaluated: location (inner retina or outer retina), size (≤30 or >30 µm), reflectivity (similar to nerve fiber layer or to retinal pigment epithelium-Bruch complex), and presence or absence of back shadowing. On en face spectral-domain optical coherence tomography, the following patterns were evaluated: 1) isolated HRS (not corresponding to any visible lesion); 2) HRS corresponding to a segment of retinal capillary or microaneurysm wall; and 3) HRS corresponding to hard exudate. All gradings were performed twice by two graders in a masked fashion. RESULTS: Size ≤30 µm, reflectivity similar to nerve fiber layer, and absence of back shadowing were associated with absence of vessels or any other lesion on en face image (P = 0.0001 for all). Size >30 µm, reflectivity similar to retinal pigment epithelium-Bruch complex, presence of back shadowing, and location in the outer retina were all associated with presence of hard exudate on en face imaging (P < 0.0001 for all). Multiple logistic regression analysis showed that HRS present in the inner retina (P < 0.0001), size >30 µm (P = 0.0029), and presence of back shadowing (P < 0.0001) are directly associated with presence of microaneurysms on en face image. Intragrader and intergrader repeatability were excellent for all evaluations. CONCLUSION: Hyperreflective retinal spots ≤30 µm, reflectivity similar to nerve fiber layer, and absence of back shadowing may represent activated microglial cells; HRS >30 µm, reflectivity similar to retinal pigment epithelium-Bruch complex, presence of back shadowing, and location in the outer retina may represent hard exudate; HRS >30 µm, presence of back shadowing, and location in the inner retina may represent microaneurysms. These hypotheses may be tested in further studies.

HYPERREFLECTIVE INTRARETINAL SPOTS IN RADIATION MACULAR EDEMA ON SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY.

PURPOSE: To better pathophysiologically characterize macular edema secondary to eye irradiation, analyzing the presence of optical coherence tomography (OCT) hyperreflective spots. METHODS: Twenty-five consecutive eyes affected by radiation maculopathy, secondary to irradiation for a primary uveal melanoma, without macular involvement in the irradiation field, were consecutively enrolled. All subjects underwent full ophthalmologic examination, including fluorescein angiography, color fundus photography, and spectral domain OCT, even in en face modality. Optical coherence tomography central subfield thickness was stratified into the following 3 categories: <400 µm, 400 to 600 µm, and >600 µm. Spectral domain OCT images were analyzed to measure and localize hyperreflective spots by two independent masked graders. RESULTS: Hyperreflective spots were documented in all eyes (100%). Hyperreflective spots significantly increased in number according to OCT central subfield thickness (<400 µm, 400-600 µm, >600 µm, P < 0.05). The intergrader agreement was at least substantial for all measurements (intraclass correlation coefficient: 0.80). CONCLUSION: Spectral domain OCT documents discrete intraretinal reflectivity changes (hyperreflective spots) in all (studied) eyes affected by radiation maculopathy. Hyperreflective spots increase in number with increasing central subfield thickness and could be considered as a new clinical biomarker of intraretinal inflammation in patients affected by macular edema secondary to irradiation for uveal melanoma.

Expression of GNAQ, BAP1, SF3B1, and EIF1AX Proteins in the Aqueous Humor of Eyes Affected by Uveal Melanoma.

Purpose: The purpose of this study was to quantify specific aqueous humor (AH) proteins in eyes affected by posterior uveal melanoma (UM). Methods: Thirty-six eyes affected by primary UM were included. Tumor thickness and largest basal diameter were specific clinical characteristics. Tumors were staged with the American Joint Commission on Cancer Eighth Edition (AJCC) classification. During the brachytherapy (Iodine-125) surgical procedure, both the AH sample collection and the 25-gauge transscleral fine needle aspiration biopsy (FNAB) were performed. AH samples were analyzed by immunoprecipitation and SDS PAGE techniques to quantify GNAQ, BAP1, SF3B1, and EIF1AX proteins. Cytologic material underwent fluorescence in situ hybridization for chromosome 3. The AH of 36 healthy eyes was used as the control group. Cluster analysis of groups was also performed. Results: Compared with the control group, significantly higher protein levels of: GNAQ (P = 0.02), BAP1 (P = 0.01), and SF3B1 (P = 0.02) were detected in eyes with UM. Cluster analysis of UM group revealed 2 clusters, one showing higher expression of GNAQ and BAP1 protein and one of EIF1AX protein. Moreover, the 2 clusters corresponded with the chromosome 3 status of UM. Conclusions: Specific and selected proteins may be detected in the AH of eyes affected by UM. These findings confirm the possibilities provided by AH analysis in UM.

The neurovascular retinal involvement in a large population of patients recovered from COVID-19: an OCT and OCT angiography study.

BACKGROUND: This study aimed to assess the neuronal and microvascular retinal and choroidal involvement in COVID-19 recovered patients using optical coherence tomography (OCT) and OCT angiography (OCTA). METHODS: This observational cross-sectional study recruited patients recovered from COVID-19 and a group of healthy controls for comparisons. OCT (peripapillary scan and macular map) and OCTA (macular map) were performed to obtain: the central subfield thickness (CST), the macular volume (MV), the peripapillary retinal nerve fibre layer (pRNFL) thickness, the vessel area density (VAD), vessel length fraction (VLF), vessel diameter index (VDI) and fractal dimension (FD) of the superficial vascular plexus (SVP), intermediate capillary plexus (ICP) and deep capillary plexus (DCP), and the vessel density (VD), stromal density (SD) and vascular/stromal (V/S) ratio of the choriocapillaris (CC) and choroid (Ch). Data regarding disease severity, administered therapy and prior comorbidities were collected. RESULTS: We recruited 676 eyes from 338 patients and 98 eyes from 49 healthy controls. VAD of all the three retinal plexuses, VLF and VDI of ICP and DCP and VD of CC were significantly reduced in patients versus controls. No differences were found in CST, MV and pRNFL. A multivariate analysis showed that oxygen therapy, previous cardio/cerebrovascular events and hypertension negatively influenced vascular parameters. CONCLUSION: A microvascular retinal and choriocapillaris damage may be identified secondary to SARS-CoV-2 infection, even after recovery. OCTA may represent a reproducible and non-invasive tool to assess microangiopathy in these patients, with particular regard to those with previous cardio/cerebrovascular events, hypertension and those who received oxygen therapy.

Proptosis secondary to bilateral extraocular muscle enlargement in Noonan syndrome with hypertrophic cardiomyopathy: A case report.

PURPOSE: To report and investigate proptosis in a young girl with Noonan syndrome. METHODS: Observational case report. RESULTS: A 16-year-old girl affected by Noonan syndrome underwent a complete ophthalmological examination showing bilateral proptosis with hypofunction of lateral rectus and superior oblique muscles. Visual acuity, color discrimination and fundus examination were unremarkable. The orbital MRI showed bilateral proptosis and symmetrical enlargement of extraocular muscles, with bellies thickening and tendon sparing. The young patient also complained restrictive hypertrophic cardiomyopathy. CONCLUSIONS: Proptosis is an uncommon ocular manifestation of Noonan syndrome and its pathophysiology has never been clarified. The MRI evidence of extraocular muscles enlargement associated with hypertrophic cardiomyopathy, led us to hypothesize a common altered pathway beneath these features, more specifically the MAP kinase pathway, since extraocular and cardiac muscles share a mesenchymal embryological origin.

Comparison of 50° handheld fundus camera versus ultra-widefield table-top fundus camera for diabetic retinopathy detection and grading.

OBJECTIVES: To compare the performance of a handheld fundus camera with standard 50° visual field to ultra-widefield (UWF) table-top fundus camera in diabetic retinopathy (DR) detection and grading. METHODS: Patients affected by diabetes mellitus and referred to our diabetic retinopathy clinic were enroled and underwent fundus photography in mydriasis. All photos were taken using the ultra-widefield table-top fundus camera Zeiss Clarus™ 500 (four fields per eye) and the Optomed Aurora® handheld fundus camera (3 fields per eye). The following parameters were analysed: the gradability of the images, the grade of DR, and diabetic maculopathy (DM), the presence of hypertensive retinopathy (HR) and the presence of other ocular diseases. RESULTS: We enroled 759 eyes of 384 diabetic patients and analysed 5313 fundus photos. The handheld fundus camera obtained a sensitivity of 84.2% and specificity of 95.4% for referable cases. Moreover, it obtained, compared to UWF, an almost perfect agreement with linear weighting for DR, DM and HR (k = 0.877, k = 0.854, and k = 0.961, respectively). The lowest sensitivity was achieved for proliferative DR (58.7% sensitivity, 100% specificity). CONCLUSIONS: Optomed Aurora® handheld fundus camera imaging showed a strong agreement compared to UWF in grading DR, considering all DR and DM grades, in mydriasis. However, the use of UWF imaging increases the detection of referable eyes.

Validation of an Automated Artificial Intelligence Algorithm for the Quantification of Major OCT Parameters in Diabetic Macular Edema.

Artificial intelligence (AI) and deep learning (DL)-based systems have gained wide interest in macular disorders, including diabetic macular edema (DME). This paper aims to validate an AI algorithm for identifying and quantifying different major optical coherence tomography (OCT) biomarkers in DME eyes by comparing the algorithm to human expert manual examination. Intraretinal (IRF) and subretinal fluid (SRF) detection and volumes, external limiting-membrane (ELM) and ellipsoid zone (EZ) integrity, and hyperreflective retina foci (HRF) quantification were analyzed. Three-hundred three DME eyes were included. The mean central subfield thickness was 386.5 ± 130.2 µm. IRF was present in all eyes and confirmed by AI software. The agreement (kappa value) (95% confidence interval) for SRF presence and ELM and EZ interruption were 0.831 (0.738-0.924), 0.934 (0.886-0.982), and 0.936 (0.894-0.977), respectively. The accuracy of the automatic quantification of IRF, SRF, ELM, and EZ ranged between 94.7% and 95.7%, while accuracy of quality parameters ranged between 99.0% (OCT layer segmentation) and 100.0% (fovea centering). The Intraclass Correlation Coefficient between clinical and automated HRF count was excellent (0.97). This AI algorithm provides a reliable and reproducible assessment of the most relevant OCT biomarkers in DME. It may allow clinicians to routinely identify and quantify these parameters, offering an objective way of diagnosing and following DME eyes.

Outer Retinal and Choroidal Changes in Adolescents with Long-Lasting Type 1 Diabetes.

This study aimed to assess outer retinal layer (ORL), retinal pigment epithelium (RPE), choroid (Ch) and choriocapillaris (CC) modifications in adolescents with long-lasting (>10 years) type 1 diabetes (T1D) without (noDR) or with diabetic retinopathy (DR). ORL and RPE thickness were measured at optical coherence tomography (OCT) macular scans. Vascular parameters of Ch and CC were quantified after elaboration of macular OCT-angiography (OCTA) images. Insulin dose and auxological and metabolic parameters were correlated with OCT and OCTA findings in patients. ORL thickness was higher in DR eyes than in noDR and healthy controls (HC), and RPE thickness was higher in noDR and DR eyes than in HC, with statistical significance for some sectors in noDR versus HC. No OCTA parameters of CC and Ch differed among groups, and no significant correlation was observed with auxological and metabolic parameters. In conclusion, ORL and RPE were both increased in adolescents with long-lasting T1D. Such changes were not associated with insulin dose and glycemia control, nor to any choroid or choriocapillaris flow change clinically detectable at OCTA, and they could be potential imaging biomarkers of disease progression.

Circulating miR-146a predicts glucocorticoid response in thyroid eye disease.

Objective: Thyroid eye disease (TED) is an immune-mediated disorder of the eye. Intravenous glucocorticoid (GC) is the first-line treatment for patients with active moderate-to-severe TED. However, the response rate is between 50% and 80%. There are still no simple and reliable markers of responsiveness to GC therapy. We aimed to explore the possible role of miR-146a and miR-21 as predictors of responsiveness to GC treatment in TED. Methods: We carried out a prospective longitudinal study on 30 consecutive adult patients with active moderate-to-severe TED and eligible for GC therapy. All patients received the standard GC treatment with methylprednisolone i.v. In cases of progressive worsening of Gorman Score for diplopia or with duction restriction <30° in at least two consecutive controls, patients also underwent orbital radiotherapy. Response to GC treatment was defined as a decrease of two or more points in the clinical activity score (CAS) or CAS <4/10 at 24 weeks. Circulating miRNAs were extracted from patients' serum and quantified by real-time PCR. Results: Twenty-three (77%) patients responded to GC. Thyroid surgery, higher CAS, greater proptosis and higher pre-treatment circulating levels of miR-146a emerged as predictive factors of responsiveness to GC. A ROC analysis revealed that miR-146a could predict responsiveness to GC with a positive predictive value of 100%. Conclusion: This is the first study investigating the role of pre-treatment circulating miR-21 and miR-146a to predict responsiveness to GC in TED. miR-146a emerged as a simple, objective, new marker of GC sensitivity that could be used to avoid ineffective administration of GC therapy to TED patients.

Case Report: Multiple Retinal Astrocytic Hamartomas in Congenital Disorder of Glycosylation-Ia.

Congenital disorder of glycosylation-Ia (CDG-Ia) is a rare autosomal recessive genetic disorder, characterized by systemic and ophthalmological abnormalities. Here, we report multiple retinal astrocytic hamartomas as a new retinal finding in an adolescent affected by congenital disorder of CDG-Ia. A 15-year-old boy affected by CDG-Ia underwent full ophthalmic examination, full field electroretinography (ERG) evaluation and retinal multimodal imaging, including: fundus photography, spectral domain optical coherence tomography (SD-OCT) and blue fundus autofluorescence (FAF). Blue FAF showed multiple papillary and iuxtapapillary bilateral hyper-FAF lesions, corresponding to hyperreflective thickening of the retinal nerve fiber layer, with internal optical empty spaces and posterior dense optical shadowing at SD-OCT. These imaging findings were consistent with retinal astrocytic hamartomas. Scotopic ERG response was significantly reduced in both eyes. Macular edema and absence of the retinal outer segments layer were also detectable. Retinal multi-modal imaging provides additional insights about retinal involvement of patients affected by CDG-Ia. In particular, this case shows the presence of multiple retinal astrocytic hamartomas.

Handheld Fundus Camera for Diabetic Retinopathy Screening: A Comparison Study with Table-Top Fundus Camera in Real-Life Setting.

The aim of the study was to validate the performance of the Optomed Aurora® handheld fundus camera in diabetic retinopathy (DR) screening. Patients who were affected by diabetes mellitus and referred to the local DR screening service underwent fundus photography using a standard table-top fundus camera and the Optomed Aurora® handheld fundus camera. All photos were taken by a single, previously unexperienced operator. Among 423 enrolled eyes, we found a prevalence of 3.55% and 3.31% referable cases with the Aurora® and with the standard table-top fundus camera, respectively. The Aurora® obtained a sensitivity of 96.9% and a specificity of 94.8% in recognizing the presence of any degree of DR, a sensitivity of 100% and a specificity of 99.8% for any degree of diabetic maculopathy (DM) and a sensitivity of 100% and specificity of 99.8% for referable cases. The overall concordance coefficient k (95% CI) was 0.889 (0.828-0.949) and 0.831 (0.658-1.004) with linear weighting for DR and DM, respectively. The presence of hypertensive retinopathy (HR) was recognized by the Aurora® with a sensitivity and specificity of 100%. The Optomed Aurora® handheld fundus camera proved to be effective in recognizing referable cases in a real-life DR screening setting. It showed comparable results to a standard table-top fundus camera in DR, DM and HR detection and grading. The Aurora® can be integrated into telemedicine solutions and artificial intelligence services which, in addition to its portability and ease of use, make it particularly suitable for DR screening.

Corneal Confocal Microscopy as a Quantitative Imaging Biomarker of Diabetic Peripheral Neuropathy: A Review.

Distal symmetric polyneuropathy (DPN), particularly chronic sensorimotor DPN, represents one of the most frequent complications of diabetes, affecting 50% of diabetic patients and causing an enormous financial burden. Whilst diagnostic methods exist to detect and monitor this condition, they have significant limitations, mainly due to their high subjectivity, invasiveness, and non-repeatability. Corneal confocal microscopy (CCM) is an in vivo, non-invasive, and reproducible diagnostic technique for the study of all corneal layers including the sub-basal nerve plexus, which represents part of the peripheral nervous system. We reviewed the current literature on the use of CCM as an instrument in the assessment of diabetic patients, particularly focusing on its role in the study of sub-basal nerve plexus alterations as a marker of DPN. CCM has been demonstrated to be a valid in vivo tool to detect early sub-basal nerve plexus damage in adult and pediatric diabetic patients, correlating with the severity of DPN. Despite its great potential, CCM has still limited application in daily clinical practice, and more efforts still need to be made to allow the dissemination of this technique among doctors taking care of diabetic patients.