Purpose: To investigate the relationship between choriocapillaris (CC) hypoperfusion and photoreceptor alterations in eyes with nonproliferative diabetic retinopathy (NPDR). Methods: In this prospective, observational, case–control study, 30 eyes (30 patients) with NPDR and 30 healthy eyes from 30 controls were enrolled at the University G. d'Annunzio, Chieti-Pescara, Italy. This study cohort underwent an ophthalmologic examination, including optical coherence tomography and optical coherence tomography angiography. The main outcome measures were as follows: 1) “normalized” reflectivity of en face image segmented at the ellipsoid zone level, which was calculated to quantify the photoreceptor damage, and 2) CC perfusion density. Secondary outcome measures were as follows: 1) superficial retinal capillary plexus (SCP), intermediate retinal capillary plexus (ICP), and deep retinal capillary plexus (DCP) perfusion density (based on the area of vessels); 2) SCP, ICP, and DCP vessel length density (based on a map with vessels of 1-pixel width); and 3) SCP, ICP, and DCP vessel diameter. Results: Mean ± SD age was 58.9 ± 11.1 years (range 38–79 years) in the NPDR group and 61.7 ± 11.3 years (range 39–87 years) in the control group (P > 0.05 for all the comparisons). Compared with controls, NPDR eyes displayed a lower “normalized” reflectivity (0.96 ± 0.25 in controls and 0.73 ± 0.19 in the NPDR group, P < 0.0001). Moreover, the NPDR group was characterized by an impaired perfusion in both the retinal and choroidal vasculature. In multiple regression analysis, ellipsoid zone “normalized” reflectivity displayed a significant direct association with CC perfusion density in patients with NPDR (P = 0.025 and P = 0.476, in NPDR and controls, respectively). Conclusion: Eyes with NPDR are affected by macular hypoperfusion and photoreceptor damage, the latter investigated as ellipsoid zone “normalized” reflectivity. The diabetic choroidopathy seems to be strongly associated with photoreceptor damage.

(1) Background: To evaluate superficial capillary plexus (SCP), deep capillary plexus (DCP), choriocapillaris (CC), perfusion density (PD), and vessel length density (VLD) in macular and near/mid periphery regions in patients with retinitis pigmentosa (RP) using widefield swept source optical coherence tomography angiography (WSS-OCTA). (2) Methods: Twelve RP patients (20 eyes) and 20 age-matched subjects (20 eyes) were imaged with the SS-OCTA system (PLEX Elite 9000, Carl Zeiss Meditec Inc., Dublin, CA, USA). Quantitative analysis was performed in the macular and peripheral regions. The main outcome measures were SCP, DCP, CC, PD, and VLD in central and peripheral areas. (3) Results: Mean visual acuity, central macular thickness, and microperimetry were significantly reduced in RP patients compared to normal subjects (p < 0.05). The perfusion density and VLD of SCP, DCP, and CC were significantly reduced in RP patients compared to normal controls both in the central and peripheral retina (p < 0.05). A significant direct correlation was found in RP patients between PD of the 1.5 mm central retina both in DCP and CC and microperimetry at 4° and 8°. (4) Conclusions: Widefield SS-OCTA shows an impairment of retinal and choroidal perfusion density and vessel length density in central and peripheral retina of RP patients. The reduction of flow features correlates with the macular function.

Purpose: To report variation of choroidal thickness (CT) and choroidal vascularity index (CVI) in subjects with drusen and subjects with reticular pseudodrusen (RPD) compared with healthy individuals using the Spectral-domain (SD)-Optical Coherence Tomography with enhanced depth imaging (EDI) system. Design: A prospective, observational, cross-sectional study. Subjects: Eighty-four participants. Methods: The patients were imaged using the Heidelberg Spectralis device (Heidelberg Engineering, Heidelberg, Germany) with EDI mode. EDI-OCT images were exported and then imported into image analysis ImageJ software (National Institutes of Health, Bethesda) and a semiautomated algorithm was used for subsequent quantitative analysis. Main outcome measures: This study evaluated two choroidal parameters: (i) choroidal thickness (CT); (ii) choroidal vascularity index (CVI). Results: CT analysis was performed in three different regions: (i) foveal region, (ii) parafoveal region; (iii) perifoveal region. All the analyzed regions were significantly decreased in RPD pattern, as compared with both the drusen group ( p < .005) and healthy eyes ( p < .005). CVI was significantly decreased in the RPD pattern, as compared with healthy eyes ( p < 0.001). However, the drusenoid pattern did not have statistical significance in comparison with the control group suggesting the lower incidence of this pattern on choroidal vasculopathy. Conclusions: We report CT and CVI difference in RPD and drusen eyes. The RPD pattern seems to be a consequence of an alteration in the choroidal vascularity resulting in severe ischemia and excessive hypoxia inducing an increased risk of late AMD compared to the drusenoid pattern.

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Purpose: To investigate iris vasculature changes following scleral buckling (SB) surgery in eyes with rhegmatogenous retinal detachment (RRD) with anterior-segment (AS) optical coherence tomography angiography (OCTA). Methods: In this prospective study, enrolled subjects were imaged with an SS-OCTA system (PLEX Elite 9000, Carl Zeiss Meditec Inc., Dublin, CA, USA). Image acquisition of the iris was obtained using an AS lens and a manual focusing adjustment in the iris using the retina imaging software. The quantitative analysis was performed in eight different iris regions: (i) superior, (ii) supero-temporal, (iii) supero-nasal, (iv) nasal, (v) temporal, (vi) inferior, (vii) infero-temporal, (viii) infero nasal which, were defined as squares with area of 1.5 mm2. Results: Fifteen eyes of 15 patients (six females; nine males) were included. Anterior segment optical coherence tomography angiography (AS-OCTA) parameters of the iris were statistically compared at baseline (preoperatively), 1 week, 1 month and 6 months after SB. At post-operative 1 week, perfusion density (PD) showed a significant decrease from 66.8 ± 13.2% to 58.55 ± 12.0% in the iris supero-nasal region (p = 0.016). However, at the 1-month follow-up visit, iris PD was significantly lower in all the analyzed iris regions, apart from the superior one. Conclusions: This study is the first description of AS-OCTA in patients undergoing SB. Our results showed a uniform reduction of the iris vessel network at 1 month after surgery, supporting the clinical use of AS-OCTA to identify early iris perfusion changes as potential predictive biomarkers of vascular disorders.

Purpose To assess the different impact of two enface OCTA image simultaneously acquired by means of a new prototype of Spectral-Domain Optical Coherence Tomography Angiography (SD-OCTA) on quantitative retinal vascular metrics. Methods In this prospective observational cross-sectional study 28 healthy subjects were enrolled. Macular (3x3 mm) OCTA images were acquired for all participants using Solix Fullrange OCT (Optovue Inc, Freemont CA, USA). The main outcome measurements were: Perfusion density (PD), vessel length density (VLD), and vessel diameter index (VDI) of both superficial capillary plexus (SCP) and deep capillary plexus (DCP), and choriocapillaris (CC) total flow-deficits area. Quantitative retinal vascular metrics were measured on binarized and skeletonized OCTA images by comparing not averaged and fast automated multiple averaged en face OCTA images. Results In both SCP and DCP, PD significantly increased (p = 0,005 and p = 0,030, respectively), and VLD significantly decreased (p<0,001 and p = 0,004, respectively), and VDI increased (p<0,001 and p = 0,068, respectively), and total CC flow deficits area significantly decreased (p<0,001) by averaging multiple OCTA images. Conclusions In this study, we found a significant difference of quantitative retinal metrics by comparing two different image acquisition modes using a novel and fully automated averaging OCTA system in young healthy subjects.

The aim of our study is to evaluate the serum circulating levels of some miRNA, such as hsa-let-7b-5p, hsa-let-7a-5p, hsa-miR-320b, hsa-miR-23a-3p, hsa-miR-27a-3p, hsa-miR-15a-5p, and hsa-miR-495-3, in diabetic patients without diabetic retinopathy (DR), diabetic patients with DR, and, healthy subjects in order to find reliable and reproducible biomarkers for DR. A total of 45 subjects underwent serum sampling for miRNAs evaluation and a complete ophthalmologic examination, including microperimetry and widefield swept source optical coherence tomography angiography (OCTA). Total circulating RNA was isolated from patients using the miRNeasy Serum/Plasma Kit. Serum miRNA expression levels were significantly different in the three groups. In detail, circulating hsa-miR-15a-5p levels were significantly reduced in both diabetic patients without DR and diabetic patients with DR (p = 0.027). Serum hsa-miR-495-3p was lower in diabetic patients with DR and diabetic patients without DR (p = 0.049). Hsa-miR-23a-3p serum expression levels were significantly lower in diabetic patients with DR and diabetic patients without DR (p = 0.013). Significant associations of miRNAs with anatomical/perfusion parameters and functional parameters were observed in the diabetic groups. We find evidence of damage in progression biomarkers in DR that are evidently early in patients with diabetes without DR. Serum miRNAs levels are considered to have strong potential as a novel biomarker for the early detection of DR in subjects suffering from diabetes and could represent noninvasive target therapies to block the progression of the disease at the early stages.