To explore the relationships between vessel density (VD) in the retinal vascular plexuses with the thickness and structural changes of their corresponding retinal layers in patients with diabetic ...retinopathy (DR).
Retrospective analysis of 17 eyes of 17 Type 1 diabetes (T1D) patients with severe non-proliferative or proliferative DR and no current or past macular edema. Seventeen age- and sex-matched healthy subjects were included as controls. Using optical coherence tomography (OCT) and OCT-angiography (OCTA), VD was measured in the superficial vascular plexus (SVP) and deep vascular complex (DVC) that includes the intermediate (ICP) and deep capillary plexuses (DCP), and compared to the retinal thickness (RT) of the inner (from the inner limiting membrane to the inner plexiform layer) and intermediate (inner nuclear and outer plexiform layer) retinal layers. The correlation between the inner and intermediate RT and the VD of the corresponding vascular networks (SVP and DVC, respectively) was assessed. All OCT and OCTA examinations were performed using the RTVue XR Avanti (Optovue, Fremont, CA).
The inner RT and VD in all plexuses were significantly reduced in T1D patients compared to healthy subjects. The capillary drop-out patterns were polygonal and well-defined in the SVP while the ICP and DCP showed a more diffuse capillary rarefaction and a VD that varied in the same proportion. The inner RT significantly correlated with VD in the SVP (r = 0.71 in healthy subjects and r = 0.62 in T1D patients, p <0.01). The intermediate RT did not significantly correlate with VD in the DVC.
In T1D subjects, OCTA allowed observing different capillary drop-out patterns in the SVP and in the ICP-DCP, with different structural changes in the corresponding retinal layers, suggesting that they should be considered as distinct anatomical and functional entities.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To compare the changes in retinal perfusion on ultra-wide-field fluorescein angiography with the changes in diabetic retinopathy lesions observed on ultra-wide-field fundus color photographs after 3 ...monthly anti-vascular endothelial growth factor injections.
Retrospective interventional cohort study analyzing the files of 14 patients with DR (18 eyes). UWF color photos and FA were analyzed at baseline (M0) and 1 month after the third anti-VEGF injection (M3). The main outcomes included the count of the number of red dots (microaneurysms, hemorrhages) and assessment of DR severity score (DRSS); the analysis of non-perfusion areas and disappearance or reappearance of arterioles or venules in the non-perfusion areas on FA.
Eighteen eyes of 14 diabetic patients, with mean age of 63 ± 5 years, were included. The DRSS score improved by at least one stage in 11/18 (61%) eyes. The mean number of red dots significantly decreased at M3 (n = 80 ± 85) compared with M0 (n = 139 ± 130) (P < 0.0001). No reperfusion of arterioles or venules was observed in or around nonperfusion areas.
After anti-vascular endothelial growth factor injections, the improvement in the DRSS score based on color fundus photographs can occur without retinal reperfusion on ultra-wide-field fluorescein angiography.
Optical coherence tomography angiography is evolving towards wider fields of view. As single widefield acquisitions have a lower resolution, preventing an accurate segmentation of vascular plexuses ...in the periphery, we examined the retinal vascularisation from the macula to the periphery in all retinal quadrants, using 3 × 3-mm volume scans, to obtain montages with sufficient image resolution up to 11 mm from the foveal centre. Images were qualitatively and quantitatively analysed, using C- and B-scan approaches to calculate the capillary density (CD) and the interplexus distance (IPD). Three vascular plexuses (i.e., superficial vascular plexus: SVP, intermediate capillary plexus: ICP, and deep capillary plexus: DCP) were observed up to the mid-periphery in all sectors. The CD of the SVP decreased from about 5 mm of eccentricity, along with ganglion cell density decrease. The CD of the ICP progressively decreased from the fovea towards the periphery, along with the retinal thinning and then vanished from 8 to 9 mm of eccentricity, becoming undetectable beyond. This ICP disappearance resulted in an increased IPD between the SVP and the DCP in an area known to be frequently affected by capillary drop-out in diabetic retinopathy. The DCP only showed a slightly decreased CD towards the retinal periphery.
To assess topographic variations of choroidal thickness (CT) in the fovea and beyond in healthy eyes.
This cross-sectional study included healthy subjects ≤ 55 years of age with axial lengths (22-26 ...mm) and refractive error margins (-4D, +4D) in normal ranges. Images were acquired using swept-source optical coherence tomography angiography (OCT-A). Corneal thickness (CT) maps from 12 × 12-mm radial scans and 9 × 9-mm OCT-A B-scans were analyzed.
The study included 64 eyes of 33 subjects (mean age, 37 years). Mean CT was >300 µm in all locations except the nasal outer macula. The subfoveal CT was >395 µm in 30% of cases; in 38.7% of cases, >50% of the CT map was thicker than 395 µm. The mean thickest choroidal point was 395.2 µm (range, 164-548 µm), located superior and temporal to the macula in 72.2% of cases and subfoveally in 1.8% of cases. The CT pattern was symmetrical (58%) or asymmetrical (42%) along a horizontal axis correlating with choroidal vein distribution. Half of the asymmetrical patterns were thicker in the inferior quadrants, with an oblique temporal watershed of venous drainage, and the other half were thicker superiorly. The mean vascularity index was ∼75% regardless of the mean CT.
One-third of healthy eyes of patients younger than age 55 had a thick choroid (>395 µm). In these normal eyes, the thickest choroidal point was not subfoveal, CT symmetry above and below the fovea depended on choroidal vein distribution, and choroidal vascularity index was independent from CT. No patients demonstrated fundus autofluorescence abnormalities, and the choriocapillaris remained visible even in thick choroids. These features could be interesting when differentiating normal versus pathological states.
To assess a new optical coherence tomography angiography (OCTA) technology and its contribution to retinal vascularization and choriocapillaris (CC) exploration.
A new module, named "Beam expander" ...(BE), which increases the lateral resolution of OCTA, was used in combination with a prototype software in the PLEX® Elite 9000 Swept-Source OCT instrument (ZEISS, Dublin, CA). This prospective study involved 22 healthy subjects imaged with and without BE. Qualitative analysis of superficial capillary plexus (SCP), deep capillary complex (DCC) retinal and CC angiograms were performed. Perfusion density (PD), vessel density (VD), and foveal avascular zone (FAZ) measurements were also compared.
Qualitative analysis of single SCP and DCC retinal angiograms acquired with BE showed significantly better vessel sharpness (respectively, p = 0.0002, and p<0.0001), and greater peripheral image quality (p = 0.028 and p = 0.007) compared to standard OCTA images. Mean VD of whole retina single scans was significantly higher for BE angiograms compared to classic angiograms (28.16 ±1.29 mm-1 and 23.36 ±0.92 mm-1, respectively, p<0.0001). Repeatability of VD, PD and FAZ raw size were found to be similar between the two methods (intraclass correlation coefficient: 0.671, 0.604 and 0.994 with BE versus 0.764, 0.638 and 0.990 without BE). CC image quality was found to be significantly superior with BE, and flow deficits were more visible in all BE scans compared to standard scans.
An increase in lateral resolution of the OCT beam resulted in higher quality of retinal and choriocapillaris OCTA images in healthy subjects. These results provide significant insights into the future OCTA imaging enhancements.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Aims
To compare functional and anatomical outcomes of continued anti-vascular endothelial growth factor (VEGF) therapy versus dexamethasone (DEX) implant in eyes with refractory diabetic macular ...edema (DME) after three initial anti-VEGF injections in a real-world setting.
Methods
To be included in this retrospective multicenter, case–control study, eyes were required: (1) to present with early refractory DME, as defined by visual acuity (VA) gain ≤ 5 letters or reduction in central subfield thickness (CST) ≤ 20%, after a loading phase of anti-VEGF therapy (three monthly injections) and (2) to treat further with (a) anti-VEGF therapy or (b) DEX implant. Main outcome measures were change in visual acuity (VA) and central subfield thickness (CST) at 12 months. Due to imbalanced baseline characteristics, a matched anti-VEGF group was formed by only keeping eyes with similar baseline characteristics as those in the DEX group.
Results
A total of 110 eyes from 105 patients were included (anti-VEGF group: 72 eyes, DEX group: 38 eyes). Mean change in VA at 12 months was − 0.4 ± 10.8 letters (anti-VEGF group), and + 6.1 ± 10.6 letters (DEX group) (
P
= 0.004). Over the same period, mean change in CST was + 18.3 ± 145.9 µm (anti-VEGF group) and − 92.8 ± 173.6 µm (DEX group) (
P
< 0.001). Eyes in the DEX group were more likely to gain ≥ 10 letters (OR 3.71, 95% CI 1.19–11.61,
P
= 0.024) at month 12.
Conclusions
In a real-world setting, eyes with DME considered refractory to anti-VEGF therapy after three monthly injections which were switched to DEX implant and had better visual and anatomical outcomes at 12 months than those that continued treatment with anti-VEGF therapy.
Type 2 diabetes mellitus (T2DM), characterized by hyperglycemia and dyslipidemia, leads to nonproliferative diabetic retinopathy (NPDR). NPDR is associated with blood-retina barrier disruption, ...plasma exudates, microvascular degeneration, elevated inflammatory cytokine levels, and monocyte (Mo) infiltration. Whether and how the diabetes-associated changes in plasma lipid and carbohydrate levels modify Mo differentiation remains unknown. Here, we show that mononuclear phagocytes (MPs) in areas of vascular leakage in DR donor retinas expressed perilipin 2 (PLIN2), a marker of intracellular lipid load. Strong upregulation of PLIN2 was also observed when healthy donor Mos were treated with plasma from patients with T2DM or with palmitate concentrations typical of those found in T2DM plasma, but not under high-glucose conditions. PLIN2 expression correlated with the expression of other key genes involved in lipid metabolism (ACADVL, PDK4) and the DR biomarkers ANGPTL4 and CXCL8. Mechanistically, we show that lipid-exposed MPs induced capillary degeneration in ex vivo explants that was inhibited by pharmaceutical inhibition of PPARγ signaling. Our study reveals a mechanism linking dyslipidemia-induced MP polarization to the increased inflammatory cytokine levels and microvascular degeneration that characterize NPDR. This study provides comprehensive insights into the glycemia-independent activation of Mos in T2DM and identifies MP PPARγ as a target for inhibition of lipid-activated MPs in DR.
To study the relationship between the location of cystoid spaces and retinal capillary nonperfusion areas in diabetic cystoid macular edema (DCME).
In this retrospective study, 24 eyes of 21 patients ...with chronic DCME were followed using optical coherence tomography angiography. The capillary density of the superficial capillary plexus and deep capillary plexus was measured using AngioAnalytics software in all DCME eyes and in 20 healthy controls. Diabetic cystoid macular edema improved spontaneously or after treatment in 11 eyes.
The intraretinal cystoid spaces were surrounded by capillary-flow void areas in the superficial capillary plexus in 71% of cases and in the deep capillary plexus in 96% of cases. The deep capillary plexus had lost its regular pattern in all cases. The capillary density was decreased in both plexus (mean decrease of -23.0% in the superficial capillary plexus and -12.4% in the deep capillary plexus vs. normal). In the 11 cases with DCME resolution, the capillary did not reperfuse in areas of resolved cystoid spaces, and the capillary density did not change significantly.
In chronic DCME, cystoid spaces were located within capillary dropout areas. No reperfusion occurred after DCME resolution. The impact of the severity of this nonperfusion on the risk of recurrence of DCME remains to be clarified.This is an open access article distributed under the terms of the Creative Commons Attribution-Noncommercial-Noderivatives License 4.0 (CC BY-NC-ND), which permits downloading and sharing the work provided it is properly cited. The work cannot be changed in any way or used commercially.
To study the characteristics of subfoveal abnormalities secondary to idiopathic epiretinal membranes (ERM) using improved-resolution spectral-domain optical coherence tomography (SD OCT) and their ...evolution after surgery.
Retrospective, observational cohort study.
The files of 344 patients operated on consecutively for ERM over a 2-year period in a single tertiary ophthalmologic center were reviewed. Patients with vitreomacular traction syndrome, secondary ERM, or both were excluded.
In all, 293 eyes with idiopathic ERM were included in the final analysis. Fundus photographs were reviewed to assess the presence of a yellow foveal spot, and SD OCT analysis was performed.
Presence or absence of a subfoveal abnormality and its SD OCT characteristics before and after surgery at 1 month, 3 months, and at final visit; best-corrected visual acuity (BCVA) and central macular thickness at baseline, 1 month, 3 months, and at the final visit.
Before surgery, a subfoveal detachment (SD) corresponding to the yellow deposit was present in 59 of 293 eyes (20%). No difference was found for the postoperative BCVA between the 59 eyes with SD before surgery and the 234 eyes without SD (0.253 ± 0.14 logarithm of the minimum angle of resolution logMAR vs. 0.262 ± 0.24 logMAR, respectively; P = 0.6). Sixty-eight percent (n = 40/59) of SD disappeared after surgery during a mean follow-up of 4.8 ± 3.2 months, most of them (62%) before month 3. Among eyes with preoperative SD, no difference was found for the postoperative BCVA between eyes with disappeared SD and those with persistent SD.
Subfoveal detachments secondary to idiopathic ERM were observed in 20% of these eyes. They disappeared after surgery in more than two thirds of cases, usually early during postoperative course. Subfoveal detachments do not affect visual outcome and should not interfere with surgical decision making.
To report the feasibility and information provided by intraoperative optical coherence tomography (iOCT) during vitreomacular surgery in highly myopic eyes.
Retrospective observational case series on ...consecutive highly myopic eyes that underwent vitreomacular surgery with iOCT for epiretinal membrane (ERM), macular hole, and myopic foveoschisis. The main outcome was the qualitative and quantitative assessment of retinal changes: detection of persistent epiretinal structures, new openings, central macular thickness, and macular hole diameters after each step of the surgical procedure. Quantitative measurements (in pixels) were manually obtained on iOCT video screen captures.
Twenty-two eyes were included: six ERMs, 10 macular holes, and 6 with myopic foveoschisis. An unsuspected postpeeling macular opening was detected by iOCT in 2/22 eyes. Intraoperative optical coherence tomography also allowed for detecting the presence of residual fragments of the vitreous cortex in 6/12 eyes after surgically induced posterior vitreous detachment. Intraoperative optical coherence tomography detected residual fragments of the internal limiting membrane in 5/21 eyes after internal limiting membrane peeling, and residual fragments of ERM in 3/15 eyes with ERM. Quantitative analysis did not find any significant change in central macular thickness and macular hole diameters before and after ERM and internal limiting membrane peeling.
In highly myopic eyes, iOCT could help assess undetected macular openings and otherwise posterior vitreous status and epiretinal structure peeling.
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