Marianna Berton

Hyperreflective Intraretinal Spots in Diabetics without and with Nonproliferative Diabetic Retinopathy: An In Vivo Study Using Spectral Domain OCT

Purpose. To evaluate the presence of hyperreflective spots (HRS) in diabetic patients without clinically detectable retinopathy (no DR) or with nonproliferative mild to moderate retinopathy (DR) without macular edema, and compare the results to controls. Methods. 36 subjects were enrolled: 12 with no DR, 12 with DR, and 12 normal subjects who served as controls. All studied subjects underwent full ophthalmologic examination and spectral domain optical coherence tomography (SD-OCT). SD-OCT images were analyzed to measure and localize HRS. Each image was analyzed by two independent, masked examiners. Results. The number of HRS was significantly higher in both diabetics without and with retinopathy versus controls (P < 0.05) and in diabetics with retinopathy versus diabetics without retinopathy (P < 0.05). The HRS were mainly located in the inner retina layers (inner limiting membrane, ganglion cell layer, and inner nuclear layer). The intraobserver and interobserver agreement was almost perfect (κ > 0.9). Conclusions. SD-OCT hyperreflective spots are present in diabetic eyes even when clinical retinopathy is undetectable. Their number increases with progressing retinopathy. Initially, HRS are mainly located in the inner retina, where the resident microglia is present. With progressing retinopathy, HRS reach the outer retinal layer. HRS may represent a surrogate of microglial activation in diabetic retina.

Proteome analysis of retinal glia cells-related inflammatory cytokines in the aqueous humour of diabetic patients.

Retinal glia cells (RGC) activation and release of inflammatory cytokines have been associated with development of diabetic retinopathy (DR). In this study, we evaluated by protein array the presence of aqueous humour (AH) cytokines secreted by RGC in patients with diabetes without DR and with mild DR.

HYPERREFLECTIVE RETINAL SPOTS AND VISUAL FUNCTION AFTER ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR TREATMENT IN CENTER-INVOLVING DIABETIC MACULAR EDEMA.

Background: To assess and correlate early modifications in hyperreflective retinal spots (HRS), retinal sensitivity (RS), fixation stability, and best-corrected visual acuity (BCVA) after anti-vascular endothelial growth factor treatment in naive center-involving diabetic macular edema. Methods: Cross-sectional comparative case–control series. Twenty diabetic patients underwent 3 consecutive intravitreal anti-vascular endothelial growth factor injections in the study eye (20 fellow eyes served as control), full ophthalmologic examination including spectral domain optical coherence tomography (Retinascan RS-3000; Nidek, Gamagori, Japan), and microperimetry (MP1; Nidek) at baseline (Visit-V1), 1 month after each injection (V2, V3, V4), and at 6 months (V5). Central retinal thickness, inner and outer retinal thickness, number of HRS, BCVA, RS, and bivariate contour ellipse area were evaluated by analysis of variance test with Bonferroni post hoc test. Correlation analyses were performed by Spearman correlation. Results: In treated eyes, central retinal thickness and inner retinal thickness significantly decreased at V2, V3, V4 versus V1 (P < 0.03 at least for all); the mean number of HRS significantly decreased in both inner and outer retina at all follow-up visits versus V1 (P < 0.008 at least for all); mean RS and bivariate contour ellipse area remained statistically unchanged during the follow-up; BCVA significantly improved at V3, V4, and V5 versus V1 (P = 0.009 at least for all). In fellow eyes, central retinal thickness, HRS, RS, and BCVA did not change at any follow-up. The number of HRS correlated inversely with RS, directly with bivariate contour ellipse area, and not significantly with BCVA. Conclusion: A significant decrease in HRS in the retina after anti-vascular endothelial growth factor treatment is documented. A decrease in HRS correlates with functional parameters, specifically RS. New parameters may be used for treatment evaluation in center-involving diabetic macular edema.

Small fiber peripheral neuropathy in Wilson disease: an in vivo documentation by corneal confocal microscopy.

PURPOSE Wilson disease (WD) is a disorder of hepatic copper metabolism leading to copper accumulation in hepatocytes and in extrahepatic organs, as the brain and cornea. The aim of this study was to investigate central corneal changes and in particular to assess the parameters of corneal subbasal nerve plexus (SBNP) in patients affected by WD, using corneal confocal microscopy (CCM). METHODS A total of 24 patients affected by WD and 24 healthy control subjects were included in this cross-sectional comparative study. One eye of each subject was examined to quantify different corneal parameters. Mean cell diameter and mean cell density of the epithelium; number of fibers (NF), nerve fiber length density (NFLD), number of branchings (NBr), number of beadings (NBe), and fiber tortuosity (FT) of the SBNP; mean cell density of keratocytes of the anterior, medium, and posterior stroma; and mean cell density, polimegatism, and pleomorphism of the endothelium, and central corneal sensitivity were analyzed. RESULTS Wilson disease induced significant alterations in SBNP, and corneal epithelium. The NFLD (P < 0.0001), NF (P = 0.001), NBe (P = 0.025), and NBr (P < 0.0001) were significantly lower, whereas FT (P < 0.0001) was significantly higher in WD subjects compared to controls. Moreover mean epithelial cell diameter (P < 0.0001) and mean epithelial cell density (P < 0.0001) were significantly higher and lower compared to controls, respectively. CONCLUSIONS The CCM showed significant corneal changes in SBNP, with concomitant corneal epithelium changes in WD, demonstrating the presence of small fiber peripheral neuropathy in these patients. The CCM may contribute to diagnosis and monitoring of the peripheral nervous system involvement in WD.

Aqueous humor biomarkers of müller cell activation in diabetic eyes

PURPOSE To identify early biomarkers of retinal Müller cell activation in diabetic eyes with or without clinically detectable signs of diabetic retinopathy (DR). METHODS This study was a cross-sectional comparative case series. The aqueous humor (AH) of 34 eyes was collected in 12 healthy controls, 11 diabetic patients without DR, and 11 diabetic patients with nonproliferative DR. Full ophthalmic examination and spectral-domain optical coherence tomography were performed in all eyes. Glial fibrillary acidic protein (GFAP), aquaporin 1 (AQP1), and aquaporin 4 (AQP4) were quantified in AH samples as biomarkers of Müller cell activity by ELISA. Statistical analysis was performed with ANOVA followed by Tukey-Kramer post hoc test. RESULTS There was no significant difference in the age among the three groups. Mean concentration of GFAP, AQP1, and AQP4 significantly increased in diabetic eyes versus controls (P < 0.05, for each comparison). Glial fibrillary acidic protein and AQP1 showed an approximate 2-fold increase, whereas AQP4 showed an approximate 25-fold increase in diabetics with DR versus controls. In diabetics without DR, AQP4 showed an approximate 6-fold increase versus controls. CONCLUSIONS Glial fibrillary acidic protein, AQP1, and AQP4-biomarkers of Müller cell activity-are significantly increased in human eyes with diabetes, confirming that Müller cells are precociously affected by diabetes mellitus.

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 &mgr;m), 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 &mgr;m, 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 &mgr;m, 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 &mgr;m (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 &mgr;m, reflectivity similar to nerve fiber layer, and absence of back shadowing may represent activated microglial cells; HRS >30 &mgr;m, reflectivity similar to retinal pigment epithelium–Bruch complex, presence of back shadowing, and location in the outer retina may represent hard exudate; HRS >30 &mgr;m, presence of back shadowing, and location in the inner retina may represent microaneurysms. These hypotheses may be tested in further studies.

Predictive algorithms for early detection of retinopathy of prematurity

To evaluate sensitivity, specificity and the safest cut‐offs of three predictive algorithms (WINROP, ROPScore and CHOP ROP) for retinopathy of prematurity (ROP).

A decade-long telemedicine screening program for diabetic retinopathy in the north-east of Italy

AIM To describe a decade long telemedicine screening for diabetic retinopathy (DR) in the metropolitan area of Padova (North-East Italy) and to report about prevalence/incidence of DR and maculopathy, rate of progression to STDR and optimal screening interval in patients with no DR at first examination. METHODS Observational, longitudinal, cohort study; 9347 patients with Type 1 and Type 2 diabetes mellitus (DM) underwent 17,344 fundus exams (three-45° color photos per eye) in two diabetes clinics and were graded in the Reading Centre, by certified personnel. The incidence of STDR, progression of maculopathy and risk factors were evaluated by log Rank test (Kaplan-Meier method). A receiver operating curve was used to determine the optimal screening interval in patients who at the first examination had no DR. RESULTS The overall prevalence of DR was 27.6%:12.5% mild non proliferative (NPDR), 11.3% moderate NPDR, 2.9% severe NPDR and 0.9% proliferative (PDR). The overall prevalence of maculopathy was 5.7%: 2.8% mild, 2.2% moderate, and 0.7% severe maculopathy. The 10-year incidence of STDR was: 0.6% in no DR, 5.5% in mild NPDR and 21.1% in moderate NPDR at first examination. The 10-year incidence of maculopathy was: 2.1% mild, 1.7% moderate and 0.2% severe. The incidence of STDR in patients with type 1 and type 2 DM and duration>10years was 8.21% and 8.15%;in type 1 DM with duration <10years was 5.5% and in type 2 DM and duration <10years was 1.91%.In patients with no DR at first screening, the best (sensitivity-specificity) follow-up interval is 2.5years. CONCLUSIONS Screening every 2.5-year in patients without DR at the first examination seems to be adequate. Duration of disease is a relevant risk factor for progression to STDR, however patients with type 1 DM and duration <10years have greater incidence of STDR than patients with type 2 DM and similar disease duration. Epidemiologic data from this decade-long screening program in the North East of Italy may serve for implementing a national screening program.