Retinal capillary and choriocapillaris assessment using a beam modifier optical coherence tomography angiography module to increase lateral optical resolution.

PURPOSE: To assess a new optical coherence tomography angiography (OCTA) technology and its contribution to retinal vascularization and choriocapillaris (CC) exploration. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

ABNORMALITIES IN THE RETINAL CAPILLARY PLEXUSES IN COATS DISEASE IN ADULTHOOD ON OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

PURPOSE: To describe and quantify the abnormalities of the retinal capillary plexuses using optical coherence tomography angiography in Coats disease. METHODS: Retrospective study. Eleven eyes of 11 patients with Coats disease (9 men and two women aged 32-80 years) compared with nine fellow eyes and 11 healthy control eyes. Horizontal bands of contiguous 3 × 3 mm optical coherence tomography angiograms of the superficial vascular plexus and deep capillary complex were acquired from the optic disk to 6 mm temporal to the fovea, through areas with telangiectasia visible on fluorescein angiography in 9 cases. RESULTS: The vascular density was significantly decreased in both plexuses in eyes with Coats disease compared with normal and fellow eyes within the 6 mm temporal to the fovea (superficial vascular plexus: 21.5 vs. 29.4%, P = 0.00004 and vs. 30.3%, P = 0.00008; deep capillary complex, 16.5 vs. 23.9%, P = 0.00004 and vs. 24.7%, P = 0.00008, respectively). The fractal dimension was also significantly decreased in eyes with Coats disease (superficial vascular plexus: 1.796 vs. 1.848 P = 0.001 and vs. 1.833, P = 0.003; deep capillary complex: 1.762 vs. 1.853, P = 0.003 and vs. 1.838, P = 0.004, respectively). CONCLUSION: Retinal plexuses' vascular density was decreased in Coats disease, including in areas with no visible telangiectasia.

Refractive error after combined phaco-vitrectomy: A multicentric study.

PURPOSE: To study the post-operative refractive error (RE) of patients undergoing combined phaco-vitrectomy and to find out which intraocular lens (IOL)-power formula had the best refractive outcomes. METHODS: In this retrospective multicentric study we compared the preoperative expected target with the postoperative RE of patients undergoing combined phaco-vitrectomy due to vitreomacular traction, macular pucker, full thickness macular hole or lamellar macular hole. A multinomial logistic regression was performed to compare the postoperative REs and the differences between expected and postoperative REs among the SRK-T, Olsen's and Holladay-2 formulas. The correlation between the difference in REs and IOL-power was also studied. RESULTS: Sixty-seven eyes with a mean axial length of 23.73 ± 1.21 mm were included. Forty-two (63%), 14 (21%) and 11 (16%) eyes were implanted with an IOL that was calculated respectively with SRK-T, Olsen's and the Holladay-2 formula. The mean preoperative expected- and post-operative REs were -0.16 ± 0.12D and -0.48 ± 0.17, respectively (p = 0.045). SRK-T and Holladay-2 formulas led to a significant myopic shift whereas Olsen's caused a significant hyperopic error, independently from the IOL power. CONCLUSION: Independently from the IOL power, none of the analyzed formulas is precise at calculating the post-operative RE.

Hyperreflective cystoid spaces in diabetic macular oedema: prevalence and clinical implications.

AIMS: To analyse the prevalence and evolution of hyper-reflective cystoid spaces with decorrelation signal detected using optical coherence tomography angiography (OCTA) in diabetic macular oedema (DMO). METHODS: A retrospective study of consecutive eyes with DMO imaged using OCTA over a 1-year period was conducted. All eyes with hyper-reflective cystoid spaces at baseline and at least 3 months of follow-up were included in a longitudinal analysis. RESULTS: The prevalence of hyperreflective cystoid spaces with decorrelation signal was of 37% (61/165) in DMO eyes. Hyperreflective foci within hyperreflective cystoid spaces were observed in 85% of eyes. The longitudinal study included 33 eyes (10 observed and 23 treated with intravitreal anti-vascular endothelial growth factor), with a median follow-up of 15 months. The hyperreflective cystoid spaces resolved in 85% of eyes. The mean best-corrected visual acuity remained stable during the follow-up, even in the eyes achieving a resolution of the hyperreflective cystoid spaces. Hard exudates appeared in the area of resolved hyperreflective cystoid spaces in 33% of eyes. CONCLUSION: Hyperreflective cystoid spaces detected by OCTA affected more than one-third of the DMO eyes. Their disappearance was not associated with any functional improvement and led to the formation of new hard exudate deposits in about one-third of the eyes.

Retinal Sensitivity Correlates With the Superficial Vessel Density and Inner Layer Thickness in Diabetic Retinopathy.

Purpose: The purpose of this paper was to present our study on the relationship between the parafoveal sensitivity measured using microperimetry and the vessel density (VD) assessed by optical coherence tomography-angiography (OCT-A) in eyes with diabetic retinopathy (DR). Methods: The observational case series was conducted in a tertiary ophthalmology center. Eyes with DR and without macular edema were consecutively included. All eyes underwent microperimetry and OCT-A. The correlation between the regional retinal sensitivity and the corresponding local capillary changes and structural alterations seen on OCT-A was assessed in each retinal quadrant. Results: Thirty-seven eyes of 21 patients were included. The mean retinal sensitivity was 28.7 ± 2 decibel (dB). The mean parafoveal VD was 43.2 ± 4.2% in the superficial capillary plexus (SCP) and 48.1 ± 3.3% in the deep capillary complex (DCC). In the multivariate linear regression model, the mean retinal sensitivity was positively correlated with the VD in the SCP in the parafoveal ring (P = 0.01) and with the inner nuclear layer (INL) thickness (P = 0.01). The qualitative analysis of each quadrant showed the presence of areas of capillary dropout with a normal sensitivity. Conversely, all areas of decreased sensitivity (<25 dB) were associated with a decreased VD in the SCP and the DCC. Conclusions: The parafoveal sensitivity positively correlated with the VD in the SCP in DR eyes. Areas with a low retinal sensitivity were always co-located with a loss of capillaries in the SCP and the DCC despite preserved outer retinal layers.

Impact of image averaging on vessel detection using optical coherence tomography angiography in eyes with macular oedema and in healthy eyes.

PURPOSE: To assess the repeatability of multiple automatic vessel density (VD) measurements and the effect of image averaging on vessel detection by optical coherence tomography angiography (OCTA). METHODS: An observational study was conducted in a series of healthy volunteers and patients with macular oedema. Five sequential OCTA images were acquired for each eye using the OptoVue HD device. The effect of the averaging of the 5 acquisitions on vessel detection was analysed quantitatively using a pixel-by-pixel automated analysis. In addition, two independent retina experts qualitatively assessed the change in vessel detection in averaged images segmented in 9 boxes and compared to the first non-averaged image. RESULTS: The automatic VD measurement in OCTA images showed a good repeatability with an overall mean intra-class correlation coefficient (ICC) of 0.924. The mean ICC was higher in healthy eyes compared to eyes with macular oedema (0.877 versus 0.960; p < 0.001) and in the superficial vascular plexus versus the deep vascular complex (0.967 versus 0.888; p = 0.001). The quantitative analysis of the effect of the averaging showed that averaged images had a mean gain of 790.4 pixels/box, located around or completing interruptions in the vessel walls, and a mean loss of 727.2 pixels/box. The qualitative analysis of the averaged images showed that 99.6% of boxes in the averaged images had a gain in vessel detection (i.e., vessels detected in the averaged image but not in the non-averaged image). The loss of pixels was due to a reduction in background noise and motion artifacts in all cases and no case of loss of vessel detection was observed. CONCLUSION: The automatic VD measurement using the OptoVue HD device showed a good repeatability in 5 acquisitions in a row setting. Averaging images increased vessel detection, and in about a third of boxes, decreased the background noise, both in healthy eyes and, in a greater proportion, in eyes with macular oedema.

Swept-source OCT reduces the risk of axial length measurement errors in eyes with cataract and epiretinal membranes.

AIMS: To compare the biometric data from partial coherence interferometry (PCI) and swept-source OCT (SS-OCT) in patients with age-related cataract and epiretinal membrane (ERM): ERM, ERM with foveoschisis and macular pseudohole. METHODS: 49 eyes of 49 subjects including 36 ERM, 9 ERM foveoschisis and 4 macular pseudohole were analysed to evaluate the axial length (AL) measurements and the presence of AL measurement errors, defined basing on the shape of the biometric output graphs and on the concordance of AL values between instruments. Eyes with ERM were divided in four stages according to OCT features (i.e. presence/absence of the foveal pit, presence of ectopic inner foveal layers, disrupted retinal layers). RESULTS: The devices provided similar mean AL measurements in all subgroups, with differences <0.1 mm in 41/49 cases (83.6%). AL measurement errors were observed in ERM stages 3 and 4, characterized by ectopic inner foveal layers, and were significantly more frequent with the PCI (8/17, 47%) as compared with the SS-OCT device (2/17, 12%), p = 0.02. The refractive prediction error in cases with AL measurement errors was significantly greater using the PCI compared to the SS-OCT device (p<0.05). CONCLUSION: Both devices provide reliable biometric data in the majority of patients and can be used in the preoperative assessment of patients with age-related cataract and ERM. In eyes with ectopic inner foveal layers, attention should be paid as AL measurement and refractive prediction errors may occur, more frequently with the PCI device.

Surgical outcomes in patients with lamellar macular holes selected based on the optical coherence tomography consensus definition.

PURPOSE: The surgical indication for lamellar macular holes (LMH) is controversial due to a misclassification of different macular diseases. A consensus based on an optical coherence tomography (OCT) definition has recently been suggested. The aim of this study was to investigate the surgical outcomes of patients with LMH selected based on this OCT-based consensus definition. METHODS: Retrospective review of patients who underwent surgery for LMH with a follow-up of at least 3 months. Anatomical OCT criteria for the diagnosis of LMH were the presence of an irregular foveal contour with foveal cavitation and a loss of retinal tissue. Cases of macular pseudoholes and epiretinal membrane foveoschisis were excluded. Surgery consisted in pars plana vitrectomy with centripetal peri-hole peeling of epiretinal proliferation and internal limiting membrane. Pre- and postoperative visual acuities (VA) were compared, and changes in OCT anatomical features, including the restoration of the foveal profile and outer retinal layers, were assessed. RESULTS: Eleven eyes of 11 patients were included, of which 9 eyes (81.8%) showed proliferation on preoperative OCT. The mean VA improved from 0.44 ± 0.19 LogMAR (20/55 Snellen equivalent) to 0.16 ± 0.08 LogMAR (20/28 Snellen equivalent), after a mean follow-up of 7.2 ± 2.9 months (P = 0.02). Postoperatively, all eyes showed a restored foveal profile. The mean central foveal thickness increased from 127.6 ± 29.9 µm to 209.0 ± 44.0 µm (P = 0.001). At baseline, ellipsoid zone disruption and external limiting membrane disruption were found in 9 and 7 eyes, respectively. Postoperatively, the ellipsoid zone and external limiting membrane were restored in respectively 6/9 eyes (66.7%) and 5/7 eyes (71.4%). No cases of postoperative full-thickness macular hole were found. CONCLUSION: In patients with LMH carefully selected based on the recent OCT-based criteria and showing a loss of retinal tissue, the foveal architecture was restored and the VA was improved after vitrectomy with peri-hole peeling for epiretinal proliferation.

Near-infrared fundus autofluorescence alterations correlate with swept-source optical coherence tomography angiography findings in patients with retinitis pigmentosa.

Thirty-eight patients from 37 families with retinitis pigmentosa (RP) underwent macular 6 × 6-mm swept-source optical coherence tomography angiography (SS-OCTA) and 30° near-infrared fundus autofluorescence (NIR-FAF) acquisitions in one eye. Superficial vascular complex (SVC), deep capillary complex (DCC) and choriocapillaris (CC) angiograms were registered with NIR-FAF acquisitions to comparatively assess subjects with and without central area of preserved NIR-FAF (APA). On the subset of patients showing an APA, the vessel densities for SVC and DCC and flow deficits for CC were assessed in three directions (superior, inferior and temporal) from the fovea and compared to healthy 1:1 age-matched controls. Nine patients with no APA had evidence of severe central OCTA alterations at all levels, especially in the DCC. In the other 29 subjects presenting APA, all OCTA parameters were similar to healthy eyes within the APA, where the retina preserves its structural integrity. Outside the APA, both the DCC and CC were significantly reduced in all directions. These alterations are probably related to the outer retinal atrophy outside the APA. Comparing OCTA to other imaging modalities is helpful to determine the potential interest of OCTA findings as an outcome measure for disease status and progression.

OCT of Outer Retinal Hyperreflectivity, Neovascularization, and Pigment in Macular Telangiectasia Type 2.

PURPOSE: To investigate whether outer retina hyperreflectivity (ORHR) and outer retina neovascularization (ORNV) are visible in eyes with macular telangiectasia type 2 (MacTel 2) before pigment proliferation is visible. DESIGN: Retrospective study in a cohort of patients from the MacTel Project. PARTICIPANTS: Thirty-nine MacTel 2 eyes without pigment on color fundus photography (CFP) at presentation were studied over a mean of 36.6 months (range, 13.8-50.4 months; standard deviation, ±10 months). METHODS: All patients routinely underwent Snellen best-corrected visual acuity (VA) measurement, CFP, spectral-domain OCT, and OCT angiography (OCTA). MAIN OUTCOME MEASURES: Pigment in the macula on CFP, best-corrected VA, presence of ORHR, presence of ORNV, presence and surface of ellipsoid zone (EZ) loss, and occurrence of ORHR, ORNV, and pigment. RESULTS: At presentation, 13 eyes showed no EZ loss, and no ORHR nor change was observed during the follow-up. In the 19 eyes with only EZ loss at baseline, ORHR appeared in 6 eyes, and one of them also showed visible pigment on CFP. Among the 7 eyes with ORHR and ORNV at baseline, pigment proliferation became visible in 4 eyes. Overall, at the end of follow-up, 14 eyes showed ORNV and 13 showed ORHR, of which 5 showed pigment on CFP. In all cases, ORHR on spectral-domain OCT corresponded to ORNV on OCTA. Hyperreflectivity and neovascularization developed within an EZ loss area or at its edge. At the end of follow-up, although the EZ loss area was larger in eyes with ORHR, pigment, or both than in eyes without any pigment migration (0.33 mm2 vs. 0.94 mm2; P = 0.01), VA was similar in both groups (0.32 logarithm of the minimum angle of resolution [logMAR] vs. 0.35 logMAR; Snellen equivalent, 20/40 vs. 20/50; P = 0.64). CONCLUSIONS: Spectral-domain OCT and OCTA showed that in MacTel 2 eyes, ORHR was associated with ORNV on OCTA and most often did not correspond to pigmentation on CFP. When ORNV developed, hyperreflectivity appeared along the abnormal capillary tracts after a mean follow-up of 36 months. In most cases, the presence of ORHR was not associated with rapid vision loss.

Staphyloma-related chorioretinal folds.

PURPOSE: To report a case of bilateral idiopathic chorioretinal folds that seemed to be related to an atypical staphyloma. OBSERVATIONS: A 49-year old man without medical history consulted for slight vision loss and metamorphopsia in the left eye. The ophthalmologic examination revealed moderate myopia and bilateral chorioretinal folds in the posterior pole, confirmed by multimodal imaging. Orbital and systemic examinations ruled out all the known etiologies of chorioretinal folds. 3-D optical coherence tomography and B-scan suggested that the folds were related to an atypical staphyloma that developed in the temporal part of the fundus, while sparing the peripapillary area. The peripapillary area, spared by the staphyloma process, appeared as a "dome-shaped disc" compared to the staphylomatous area. CONCLUSION AND IMPORTANCE: This case suggests that myopic patients with unusual staphyloma located outside the peripapillary area could develop chorioretinal folds.

Retinal Capillary Plexus Pattern and Density from Fovea to Periphery Measured in Healthy Eyes with Swept-Source Optical Coherence Tomography 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.

Central serous chorioretinopathy: risk factors for serous retinal detachment in fellow eyes.

BACKGROUND/AIMS: To assess risk factors for serous retinal detachment (SRD) in the fellow eye of patients with central serous chorioretinopathy (CSC) based on clinical data and multimodal imaging findings, including baseline late-phase indocyanine green angiography (ICGA). METHODS: Consecutive patients with unilateral CSC were retrospectively assessed. Inclusion criteria were the availability of late-phase ICGA and a spectral-domain optical coherence tomography (OCT) macular cube for both eyes at baseline and over 3 months. Subsequent OCT of fellow eyes was reviewed to detect the development of SRD during the follow-up. Baseline medical data and multimodal imaging findings were analysed using Kaplan-Meier survival curves (log-rank test). RESULTS: Sixty-eight patients with unilateral CSC were included. An SRD was detected in 19% of fellow eyes during a mean follow-up of 25.8±18.7 months. Hyperfluorescent plaques on midphase ICGA, hypofluorescent foci on late-phase ICGA, retinal pigment epithelium changes on fundus autofluorescence and fluorescein angiography abnormalities were associated with the occurrence of SRD (log-rank test; p<0.001, p=0.02, p=0.002 and p=0.001, respectively). CONCLUSION: These results suggest that the fellow eyes with specific findings on multimodal imaging in patients with unilateral CSC should be carefully followed up for possible incidence of CSC.

RAPID MACULAR CAPILLARY LOSS IN PATIENTS WITH UNCONTROLLED TYPE 1 DIABETES.

PURPOSE: To analyze the evolution of macular vessel density (VD) over 1 year, during early worsening of diabetic retinopathy, in patients with uncontrolled Type 1 diabetes (T1D). METHODS: Retrospective study of 12 eyes of 9 patients with T1D with early worsening of diabetic retinopathy imaged with optical coherence tomography angiography. The following data were collected at the time of pan retinal photocoagulation initiation and after 6 and 12 months: vessel density within three retinal plexuses-superficial vascular plexus, intermediate capillary plexus, and deep capillary plexus; foveal avascular zone area, acircularity index, and flow density (FD)-300; central macular thickness; and HbA1c levels. RESULTS: A history of rapid reduction in blood glucose was found in seven of nine cases. Vessel density was significantly decreased at 12 months in all plexuses: from 44.68 ± 4.75 to 40.23 ± 7.13 in the superficial vascular plexus (P = 0.008), from 42.72 ± 4.86 to 37.12 ± 8.64 in the intermediate capillary plexus (P = 0.03), and from 22.68 ± 3.93 to 19.66 ± 4.92 in the deep capillary plexus (P = 0.004). Intermediate capillary plexus and deep capillary plexus changes were strongly correlated (r = 0.86, P < 0.001) and were significant as early as 6 months. The mean foveal avascular zone area increased (P = 0.05) and the FD-300 decreased (P = 0.03). No significant change in acircularity index, central macular thickness, and visual acuity were observed over time. CONCLUSION: Early worsening of diabetic retinopathy induces a rapid macular capillary dropout mainly affecting the intermediate capillary plexus and deep capillary plexus.

Retinal microvasculature in pituitary adenoma patients: is optical coherence tomography angiography useful?

PURPOSE: To examine retinal vascular changes in the peripapillary and macular areas in patients with pituitary adenoma (PA) using optical coherence tomography angiography (OCTA). METHODS: Cross-sectional, retrospective study of 17 consecutive PA patients and 16 healthy subjects. All patients underwent a neuro-ophthalmological examination to assess the presence of optic neuropathy (ON). Static automated perimetry (SAP), macular and optic disc structural OCT [retinal nerve fibre layer (RNFL) and ganglion cell complex (GCC) thicknesses] and OCTA were performed. Pituitary adenoma (PA) patients with ON were compared to those without ON and to healthy subjects. RESULTS: Optic neuropathy (ON) was found in 16 eyes of nine PA patients. Peripapillary vessel density (ppVD) and macular vessel density (VD) in the superficial vascular plexus were significantly decreased in PA eyes with ON, compared to healthy eyes (45.21 ± 5.69 versus 50.52 ± 2.14% and 43.79 ± 5.03% versus 48.96 ± 2.94%, respectively). No significant difference in VD was observed in the macular deep vascular complex (DVC) between groups. Pituitary adenoma (PA) patients with ON had a mean ppVD reduction by 10.51% compared to healthy subjects. RNFL and GCC thicknesses were significantly reduced in PA eyes with ON compared to the other groups. Peripapillary VD (ppVD) significantly correlated with RNFL thickness and SAP mean deviation. CONCLUSIONS: Optical coherence tomography angiography showed a significant decrease in ppVD and superficial macular VD in PA eyes with ON compared to healthy eyes, according to RNFL and GCC thinning. Together with the absence of DVC alterations, it may provide further insights into neurovascular coupling.

Widefield OCT-Angiography and Fluorescein Angiography Assessments of Nonperfusion in Diabetic Retinopathy and Edema Treated with Anti-Vascular Endothelial Growth Factor.

PURPOSE: To assess change in retinal nonperfusion (NP) after anti-vascular endothelial growth factor (VEGF) therapy for diabetic macular edema (DME) using 2 different imaging modalities: swept-source widefield (SS-WF) OCT angiography (OCTA) and ultra-widefield (UWF) fluorescein angiography (FA). DESIGN: Observational case series. PARTICIPANTS: Ten eyes of 9 patients with severe nonproliferative diabetic retinopathy (NPDR) or proliferative DR (PDR) initiating 3 monthly anti-VEGF intravitreal injections for DME. METHODS: All eyes were imaged with UWF color fundus photographs (CFPs), UWF FA, and SS-WF OCTA at baseline (M0) and 1 month after the third anti-VEGF injection (M3). All images were aligned and divided into 16 boxes for analysis of NP areas by 2 blinded retina specialists. MAIN OUTCOME MEASURES: The number of discrepancies between SS-WF OCTA and UWF FA regarding the detection of NP areas and small vessels passing through NP areas; assessment of DR severity on UWF CFP; and change in each NP area between M0 and M3: number of boxes/eye with presence of at least 1 NP area, number of arterioles or venules that disappeared or reappeared, and number of NP areas in which capillaries disappeared or reappeared. RESULTS: The diabetic retinopathy (DR) severity score improved by at least 1 stage in 8 of 10 eyes, with a significant decrease in the mean number of microaneurysms and retinal hemorrhages on UWF CFP at M3 versus M0 (n = 40±28 vs. 121±57; P = 0.0020) and regression of fundus neovascularization when present. All NP areas detected on FA were seen on SS-WF OCTA, but additional NP areas were detected on SS-WF OCTA at M0 in 29% (46/160) of boxes. No reperfusion of arterioles or venules was observed at M3 on FA or SS-WF OCTA. Retinal capillaries were only visible on OCTA, and no reperfusion in NP areas was observed even when a reduction in dark areas was visible on FA. CONCLUSIONS: No reperfusion of vessels or capillary network was detected in NP areas using 2 imaging techniques, UWF FA and SS-WF OCTA, in eyes with DR after 3 anti-VEGF injections. The detection rate of NP areas was higher with SS-WF OCTA than with UWF FA.

Reduced vessel density in the superficial and deep plexuses in diabetic retinopathy is associated with structural changes in corresponding retinal layers.

PURPOSE: 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). METHODS: 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). RESULTS: 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. CONCLUSIONS: 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.

ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR THERAPY CAN IMPROVE DIABETIC RETINOPATHY SCORE WITHOUT CHANGE IN RETINAL PERFUSION.

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

VESSEL DENSITY OF SUPERFICIAL, INTERMEDIATE, AND DEEP CAPILLARY PLEXUSES USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

PURPOSE: To provide values of retinal vessel density (VD) in the three retinal capillary plexuses, foveal avascular zone (FAZ) area, and retinal layer thickness in a cohort of healthy subjects. METHODS: The optical coherence tomography angiography maps of 148 eyes of 84 healthy subjects, aged 22 to 76 years, were analyzed for measuring VD of the retinal capillary plexuses, using the Optovue device comprising a projection artifact removal algorithm. Foveal avascular zone metrics were measured, and the relationship between optical coherence tomography angiography findings and age, sex, and image quality was studied. RESULTS: The deep capillary plexus showed the lowest VD (31.6% ± 4.4%) in all macular areas and age groups compared with the superficial vascular plexus (47.8% ± 2.8%) and intermediate capillary plexus (45.4% ± 4.2%). The mean VD decreased by 0.06%, 0.06%, and 0.08% per year, respectively, in the superficial vascular plexus, intermediate capillary plexus, and deep capillary plexus. Mean FAZ area, FAZ acircularity index, and capillary density in a 300-µm area around the FAZ were 0.25 ± 0.1 mm, 1.1 ± 0.05, and 50.8 ± 3.4%, respectively. The yearly increase in FAZ area was 0.003 mm (P < 0.001). CONCLUSION: The deep capillary plexus, a single monoplanar capillary plexus located in the outer plexiform layer, has the lowest VD, a significant finding that might be used to evaluate retinal vascular diseases. Vascular density decreased with age in the three capillary plexuses.