Enlargement Of Foveal Avascular Zone Research Articles

Quantitative microvascular analysis in different stages of retinitis pigmentosa using optical coherence tomography angiography

As retinitis pigmentosa (RP) is chronic and progressive, the chronological sequence of microvascular changes is important for understanding its pathophysiology. We aimed to investigate retinal and choroidal microvascular changes according to the RP stages. The stages of RP were classified into three stages according to the integrity and width of the inner segment ellipsoid zone: early, ≥ 2500 μm; moderate, < 2500 μm; advanced, absence. Using optical coherence tomography angiography, quantitative microvascular parameters were analyzed. In total, 91 eyes from 49 patients were included. For the superficial capillary plexus (SCP) and deep capillary plexus (DCP), perfusion densities (PDs) in the early stage (SCP: 37.32 ± 8.11%; DCP: 21.19 ± 9.15%) were greater than those in moderate (SCP: 34.16 ± 6.65%, P = 0.011; DCP: 15.67 ± 8.85%, P = 0.031) and advanced stages (SCP: 33.71 ± 9.02%, P = 0.030; DCP: 12.83 ± 6.29%, P < 0.001). The choroidal vascularity index in the early stage (0.58 ± 0.03) was greater than those in the moderate (0.57 ± 0.02, P = 0.017) and advanced stage (0.56 ± 0.02, P = 0.033). The area and perimeter of foveal avascular zone (FAZ) in advanced stage (0.44 ± 0.26 mm2, 2.96 ± 0.86 mm, respectively) were larger than those in early (0.26 ± 0.11 mm2, P = 0.020; 2.19 ± 0.53 mm, P = 0.006, respectively) and moderate stage (0.28 ± 0.13 mm2, P = 0.043; 2.24 ± 0.67 mm, P = 0.013, respectively). During RP disease progression, retinal and choroidal microvascular vessel density decreases in the early stage, followed by FAZ enlargement in the advanced stage.

Optical coherence tomography angiography of the foveal avascular zone after successful macula‐off rhegmatogenous retinal detachment repair

Aims/Purpose: To investigate the size and shape of the foveal avascular zone (FAZ) after successful macula‐off rhegmatogenous retinal detachment (RRD) repair using swept source OCT angiography (SS OCTA).Methods: A prospective comparative cross‐sectional study including 21 eyes of 21 patients with macula‐off RRD that were successfully repaired. The size of the superficial FAZ was assessed by its area, length of perimeter, and Feret's diameter, and the shape by the circularity, axial ratio, roundness and solidity. The correlations between each parameter and the clinical and OCT findings were statistically determined. The unaffected fellow eyes were used as controls.Results: The mean initial BCVA was 1.92 ± 0.41 Log MAR (20/2000 Snellen's equivalent). The mean BCVA at OCTA acquisition (3 months) was 0.78 ± 0.39 Log MAR (20/100 Snellen's equivalent) (p &lt; 0.001). FAZ was significantly larger (323.09 ± 129.03 μm2 vs. 245.27 ± 93.15 μm2; p = 0.038), with longer perimeter (2.31 ± 0.35 mm vs. 2.07 ± 0.31 mm; p = 0.048), and irregular shaped (mean circularity: 0.73 ± 0.72 vs. 0.78 ± 0.5; p = 0.019 and mean solidity: 0.90 ± 0.02 vs. 0.93 ± 0.02; p = 0.002) in operated eyes than in the control group. The average Feret's diameter was 0.77 ± 0.10 mm versus 0.71 ± 0.88 mm (p = 0.076). The average axial ratio was 1.25 ± 0.20 versus 1.22 ± 0.22 (p = 0.531), and the average roundness was 0.81 ± 0.11 versus 0.83 ± 0.11 (p = 0.531). Mean central foveal thickness (CFT) was significantly lower in operated eyes than in control eyes (178.23 ± 40.59 μm vs. 247.44 ± 38.2 μm (p &lt; 0.001)). There was a significant inverse correlation between FAZ area and post‐operative outer nuclear layer thickness (r = −0.520, p = 0.016) and CFT (r = −0.571, p = 0.007) in operated eyes. There was no significant correlation between the post‐operative visual acuity and FAZ parameters.Conclusions: Enlargement and irregularities of FAZ after successful macula‐off RRD repair, as demonstrated by SS OCTA, might suggest an ischaemic macular damage caused by RRD that may affect post‐operative functional outcome.

Retinal optical coherence tomography biomarkers in dementia

Due to the general aging of society, the prevalence and incidence of dementia are expected to increase considerably. In order to timely identify patients and assess their need for treatment and/or supportive measures, comprehensive and easy access screening methods are required, which, however, are yet to be developed. To date, several biomarkers for the presence of dementia on high-resolution spectral domain optical coherence tomography (OCT) and OCT angiography (OCT-A) images were identified. To summarize previously identified OCT biomarkers in dementia and to assess their suitability for comprehensive screening examinations. Aliterature search was conducted on PubMed until March 2023 for the keywords "dementia", "mild cognitive impairment", "OCT", "OCT angiography" and "retinal biomarkers". Relevant publications were identified and summarized. Numerous unspecific alterations on OCT imaging and OCT‑A were identified in patients with (predementia) dementia according to many population and clinical studies. These include areduced thickness of the peripapillary retinal nerve fiber layer, the ganglion cell complex and the central retinal region. Additionally, areduced vascular density and an enlarged foveal avascular zone (FAZ) were identified on OCT‑A imaging. The currently known OCT biomarkers are too unspecific, and there is to date no OCT or OCT-A-based signature distinguishing between different types of dementia. Further longitudinal studies with larger sample sizes are warranted to develop and evaluate such distinct OCT signatures for different types of dementia and their respective early disease stages and to assess their prognostic value. Only then is the inclusion in comprehensive screening investigations feasible.

The Relationship Between Artificial Intelligence–Assisted OCT Angiography–Derived Foveal Avascular Zone Parameters and Visual-Field Defect Progression in Eyes with Open-Angle Glaucoma

To investigate clinical factors associated with foveal avascular zone (FAZ) parameters obtained using OCT angiography (OCTA) with assistance from a previously developed artificial intelligence (AI) platform in eyes with open-angle glaucoma (OAG). Retrospective longitudinal. This study followed up 885 eyes of 558 patients with OAG for ≥ 2 years; all eyes underwent≥ 5 Humphrey visual-field (VF) tests and had 3.0×3.0 mm macular OCTA scans available. Average total deviation (TD) in the superior, superocentral, inferocentral, and inferior sectors of the Humphrey 24-2 program was calculated. We collected 3.0×3.0 mm macular OCTA images from each patient and used a previously developed AI platform with these images to obtain FAZ parameters, including FAZ area, FAZ circularity index (CI), and FAZ perimeter. Multivariable linear mixed-effects models were used to analyze the relationship between FAZ parameters, TD or TD slope in each quadrant, and systemic factors, adjusting for potential confounding factors, including axial length. Ophthalmic and systemic variables, FAZ parameters, and TD or TD slope in each quadrant. The multivariable model showed that FAZ parameters were correlated with both TD and TD slope in the inferocentral quadrant (β=-0.244 - 0.168, P < 0.001). Both upper-half and lower-half FAZ parameters were better associated with TD-inferocentral and TD-inferocentral slope than TD-superocentral or TD-superocentral slope in terms of β size and statistical significance, indicating that there was no evident vertical anatomical correspondence between TD in the central quadrant and FAZ parameters. Foveal avascular zone area enlargement was associated with female gender (β=0.242, P= 0.003). Loss of FAZ circularity was associated with both aging and comorbid sleep apnea syndrome (SAS) (yes: 1, no: 0) (β=-0.188, P < 0.001; β=-0.261, P= 0.031, respectively). Foveal avascular zone perimeter elongation was associated with aging and female gender (β=0.084, P= 0.040; β=0.168, P= 0.042, respectively). Artificial intelligence-assisted OCTA-measured FAZ enlargement and irregular shape might be good markers ofocular hypoperfusion and associated inferocentral VF defect progression in eyes with OAG. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Microvascular involvement in migraine: an optical coherence tomography angiography study.

The aim of this study was to evaluate the microvasculature of the macula and the optic nerve in patients affected by migraine with aura (MA) and without aura (MO) by optical coherence tomography angiography (OCTA), comparing the findings with healthy controls (HC). We collected data from ocular and orthotic examinations, including eye motility, intraocular pressure measurement, best-corrected visual acuity (BCVA) measurement, objective refraction measurement, fundus examination, macular and optic disk OCTA examination. All subjects were imaged with solix fullrange OCT. The following OCTA parameters were recorded: macular vessel density (VD), inside disc VD, peripapillary VD, disc whole image VD, fovea choriocapillaris VD, fovea VD, parafovea VD, peripapillary thickness, fovea thickness, parafovea thickness, macular full retinal thickness, and foveal avascular zone (FAZ) parameters. Clinical and demographical data about migraine patients were collected by a neurologist. We included 56 eyes from 28 patients with a diagnosis of MO, 32 eyes from 16 patients with a diagnosis of MA, and 32 eyes from 16 HC subjects. The FAZ area was 0.230 ± 0.099 mm2 in the MO group, 0.248 ± 0.091 mm2 in the MA group and 0.184 ± 0.061 mm2 in the control group. The FAZ area was significantly larger in the MA group than in the HC group (p = 0.007). The foveal choriocapillaris VD was significantly lower in MA patients (63.6 ± 2.49%) when compared with MO patients (65.27 ± 3.29%) (p = 0.02). An impairment of retinal microcirculation can be detected in patients with MA, as demonstrated by the enlargement of FAZ. Moreover, the study of choroid circulation may reveal microvascular damage in patients with migraine with aura. OCTA is a useful non-invasive screening tool for the detection of microcirculatory disturbance in patients with migraine.

Analysis of Vascular Changes of Fundus in Behcet's Uveitis by Widefield Swept-source Optical Coherence Tomography Angiography and Fundus Fluorescein Angiography.

To investigate vascular changes of fundus in quiescent Behçet's uveitis(BU) based on widefield swept-source optical coherence tomography angiography(SS-OCTA) and fluorescein angiography (FA). This case-control study included 33 quiescent BU patients(57eyes)and 35 healthy people(60 eyes) as the control. All participants underwent the widefield SS-OCTA, and BU patients additionally underwent the FA. The quantitative analysis of the widefield SS-OCTA assessed the vessel density(VD) of 9 anatomic locations in the fundus. Vascular leakage and retinal nonperfusion on FA were assessed in BU patients. Compared with the control group using Mann-Whitney U test, BU patients had enlargement of foveal avascular zone (FAZ) (P=0.005, P=0.04, respectively) and decreased VD within a 300μm width around the FAZ(FAZ300μm) (P=0.001, P<0.0001, respectively) both in the superficial and deep retina. Larger FAZ size and lower FAZ300μm were correlated with higher logarithm of the minimum angle of resolution best-corrected visual acuity in BU (P≤0.003, P<0.0001, respectively). VD of choriocapillaris(CC), as the most widely involved of all layers of the retina and choroid, was lower in 6 locations(P≤ 0.03∼0.0001) in the peripheral fundus of BU compared to the controls. Vascular leakage and retinal nonperfusion in the peripheral fundus was observed in 54.4% and 66.7% of the patients on FA. Fovea and peripheral fundus were prone to the damage of ischemia as evidenced by significantly decreased VD of capillaries. Combination of SS-OCTA with FA could accurately evaluate the changes in the retinal and choroidal vasculature in BU.

Retinal Vascular Findings in Sickle Cell Retinopathy

Sickle cell disease (SCD) is a common inherited blood disease that develops due to hemoglobin (Hb) dot mutation that reduces the oxygen-carrying ability of erythrocytes. In hypoxia, this mutated abnormal Hb causes "sickling" of erythrocytes, and subsequent episodes of hypoxia, acidosis, inflammation, vaso-occlusive crises, and hemolysis cause progressive damage to many organs, including the brain, kidneys, lungs, bones, heart, and eyes. Systemic and ocular findings vary in SCD. Sickle Cell C Disease and Sickle beta-Thalassemia forms of SCD have mild systemic diseases; however, both cause severe ocular diseases. In the posterior segment of the eye, SCD can cause optic neuropathy, retinopathy, maculopathy, and choroidopathy. Retinal vascular findings include tortuosity in retinal vessels, “silver wire” arterioles, angioid streaks, arterial and venous occlusions, arteriovenous anastomoses, and retinal neovascularizations (NVs). Fundus fluorescein angiography (FFA), optical coherence tomography (OCT), and OCT angiography are used in the diagnosis. NVs and the enlargement and irregularity of foveal avascular zone (FAZ) in FFA, macular temporal retinal thinning in OCT, FAZ enlargement, and the reduction in densities of macular capillary in OCT angiography are the main findings. This article is aimed to review the retinal vascular findings encountered in Sickle Cell Retinopathy.

Internal limiting membrane detachment in acute Central Retinal Artery Occlusion: clinical features, multimodal imaging, outcomes & prognostic biomarker

PurposeTo report the clinical features, multi-modal imaging characteristics and their corroboration, and prognostic value of internal limiting membrane detachment (ILMD), a novel OCT biomarker in acute CRAO.DesignRetrospective observational case-control study at institutional tertiary eye care centers.Methods60 eyes of 60 patients of acute CRAO with optical coherence tomography (OCT) at baseline were included. Eyes were grouped in (a) With ILMD; (b) With no-ILMD. Multimodal imaging correlation, BCVA change and binary logistic regression were studied.ResultsEighteen eyes (30%) were noted to have ILMD. At presentation, ILMD on OCT corroborated with macular non-perfusion with enlarged foveal avascular zone both on OCT-angiography (OCTA) and fundus fluorescein angiography (FFA). On follow-up, ILMD had resolved in all cases with fragmentation, disruption and atrophy of the retinal layers. Logistic regression showed poor baseline visual acuity was significantly associated with the odds of ILMD [Odds Ratio (OR) 31.02, p = 0.0018, 95% confidence interval: 1.81–529] while controlling for potential confounders including age (p = 0.60), gender (p = 0.316) duration of symptoms (p = 0.114), follow-up duration (p = 0.450) and final BCVA (p = 0.357). Eyes with ILMD and no-ILMD had a baseline BCVA of 2.62 LogMAR (light perception) and 2.05 LogMAR (Snellen equivalent 20/2000), respectively. On follow up, none of the eyes with ILMD showed any improvement. In contrast, nine (21.4%) eyes in no-ILMD had a vision of 20/400 and above with a mean final visual acuity of 1.87 + 0.78 LogMAR (p = 0.000).ConclusionILMD correlated with macular non-perfusion and poor baseline visual acuity which showed no improvement on follow-up, suggesting it to be poor prognostic biomarker.

Optical coherence tomography angiography quantitative analysis of retinal and choroidal microvasculature in patients with dyslipidemia.

The purpose of this investigation was to report swept source-optical coherence tomography angiography (SS-OCTA) quantitative information of retinal and choroidal microvascularization in patients with dyslipidemia (DL). We performed a retrospective study. The study enrolled 37 eyes of 20 patients with DL and 40 eyes of 23 healthy subjects. OCTA quantitative parameters (vessel density (VD) and foveal avascular zone (FAZ) area of superficial capillary plexus (SCP), middle capillary plexus (MCP), deep capillary plexus (DCP) and choriocapillaris (CC)) in 6 mm × 6 mm and 4,5 mm × 4,5 mm cubes were recorded. No differences in VD in SCP, MCP and DCP were demonstrated between DL group and control group (p > 0,05). Conversely, VD in the central region at CC was diminished in patients with DL in both cubes (p < 0,05). Moreover, total VD in CC was decreased in the DL group in 6 mm × 6 mm cube (p < 0,05). Regarding FAZ area, we demonstrated and enlargement of FAZ in each retinal capillary plexus, but it did not reach statistical significance (p > 0,05). We objectified a diminution of VD in the CC, suggesting that DL mainly affects the choroidal microvasculature. Nonetheless, further studies with a larger population are needed.

Correlation analysis between foveal avascular zone and near peripheral retinal hypoperfusion in multiple sclerosis: a wide field optical coherence tomography angiography study.

The identification of non-invasive biomarkers to investigate and monitor retinal structural and vascular changes in multiple sclerosis (MS) represents an interesting source of debate. Until now optical coherence tomography angiography (OCTA) evaluated the foveal avascular zone (FAZ) and areas of retinal non-perfusion only in the macular region in MS patients. It could be interesting to identify possible biomarkers, useful in assessing the ischemic areas also in the near peripheral retina, since FAZ enlargement and the areas of peripheral retinal non-perfusions share common pathogenic processes. In this cross-sectional study, we investigated the correlation between the FAZ area and retinal vessel density (VD) in the near peripheral retina by new wide-field optical coherence tomography angiography (OCTA) in patients affected by relapsing-remitting multiple sclerosis (RR-MS). Moreover, we compared the FAZ area and the VD of superficial and deep capillary plexuses in the fovea region and in the near peripheral retina (6.4 × 6.4 mm) between RR-MS patients and healthy controls by means of a Solix full-range OCTA. Last, we also detected the changes in structural OCT parameters (ganglion cell complex and retinal nerve fiber layer). Thirty-three eyes of 33 RR-MS patients and 35 eyes of 35 healthy controls were enrolled. RR-MS patients showed a lower VD in the superficial capillary plexus and a significant increase in the FAZ area compared with controls. The deep capillary plexus revealed a reduced VD although not statistically significant in patients with respect to controls. In the patients' group, the FAZ area showed significantly negative correlations with VD of superficial capillary plexuses in the foveal and whole region, while the FAZ area did not negatively correlate with the VD of the deep capillary plexus. The significant correlations among OCTA parameters could demonstrate the FAZ area as a possible biomarker for assessing the perfusion status in the near peripheral retina, useful in RR-MS management. These findings could confirm the role of vascular dysfunction in the pathogenetic mechanisms of MS.

MACULAR MICROVASCULATURE IN X-LINKED RETINOSCHISIS: Optical Coherence Tomography and Optical Coherence Tomography Angiography Study.

The study aimed to evaluate the macular microvasculature of X-linked retinoschisis (XLRS) and identify correlations between vascular changes, structural changes, and functional outcome. Genetically confirmed XLRS patients and heathy control subjects underwent complete ophthalmic examination, dilated funduscopic examination, optical coherence tomography, and optical coherence tomography angiography. Schisis distribution, outer plexiform layer discontinuation, photoreceptor layer thickness, and photoreceptor outer segment length were reviewed using optical coherence tomography. Vascular flow density and foveal thickness at foveal and parafoveal area were measured using optical coherence tomography angiography. A total of 17 eyes of 9 XLRS patients and 22 eyes of 11 control subjects were examined from July 2018 to August 2020. Flow density in the deep capillary plexus at foveal and parafoveal area decreased in XLRS patients compared with control subjects (P = 0.014 and 0.001, respectively), whereas foveal avascular zone area and perimeter remarkably increased (P = 0.015 and 0.001, respectively). Although outer and total retinal layers were significantly thicker in XLRS, inner retinal layer was thinner with reduced photoreceptor layer thickness and shortened photoreceptor outer segment length (P < 0.001 and P < 0.001, respectively). Foveal flow loss in deep capillary plexus, foveal avascular zone enlargement, thinner inner retina and photoreceptor layer thickness, and shortened photoreceptor outer segment length correlated with best-corrected visual acuity. X-linked retinoschisis eyes exhibit decreased flow density in the deep capillary plexus and variable foveal avascular zone with enlarged perimeter. Structural deterioration of the photoreceptor best reflects the degenerative changes, whereas microvascular alteration shows considerable correlation with functional outcome in XLRS.

Long-Term Retinal Vascular Changes in Age-Related Macular Degeneration Measured Using Optical Coherence Tomography Angiography.

To determine if age-related macular degeneration (AMD) status affects longitudinal retinal vessel changes. Retrospective, cohort study of 125 eyes (75 patients) with AMD, following retinal vessel density (VD) and foveal avascular zone (FAZ) measurements using optical coherence tomography angiography (OCT-A) over 24 months. FAZ area (<i>P</i> &lt; .001) and perimeter (<i>P</i> &lt; .001) increased over 2 years, with no difference between nonexudative and exudative AMD (<i>P</i> = .134-.976). Eyes with geographic atrophy (GA) showed greater progressive VD loss (<i>P</i> = .023-.038), and greater increase in FAZ area (<i>P</i> = .044) and perimeter (<i>P</i> = .040) compared to eyes without GA. Neither baseline nor 2-year change in vascular parameters were associated with choroidal neovascularization (CNV) or GA incidence in nonexudative AMD, or anti-VEGF injection frequency in exudative AMD (<i>P</i> = .070-.952). AMD eyes with GA undergo more rapid loss of retinal vessel density and FAZ enlargement over 2 years, suggesting a relationship between the retinal vasculature and AMD pathophysiology. <b>[<i>Ophthalmic Surg Lasers Imaging Retina</i> 2022;53:529-536.]</b>.

Changes in retinal and choroidal capillary dynamics in patients with multisystem inflammatory syndrome in children.

PurposeTo evaluate patients with multisystemic inflammatory syndrome in children (MIS-C) associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection using optical coherence tomography angiography (OCTA) during and after resolution of inflammation to investigate the effect of this entity on the retinal and choroidal circulation.MethodsThe study included 38 eyes of 19 patients diagnosed as having MIS-C between March 2021 and June 2021. OCTA measurements of choroidal thickness and vessel density in the radial peripapillary capillary plexus (RPCP), superficial capillary plexus (SCP), and deep capillary plexus (DCP) obtained at time of diagnosis and 60 days later were compared. Correlations between C-reactive protein (CRP) levels at diagnosis and retinochoroidal involvement were investigated.ResultsCompared to post-recovery follow-up examinations, patients with active MIS-C showed foveal avascular zone enlargement (p = 0.031), decreased vessel density in the temporal parafoveal SCP (p = 0.047) and all parafoveal areas of the DCP (p < 0.05 for all), and increased choroidal thickness (p = 0.021). Correlation analysis between CRP levels and OCTA changes during MIS-C revealed significant negative correlations with all parafoveal sectors of the SCP and DCP and a significant positive correlation with CT.ConclusionThere were especially marked effects on the DCP and choroid in MIS-C patients. Our findings also correlate with CRP levels. The use of optical coherence tomography angiography in patients with multisystemic inflammatory syndrome may have potential future implications for detecting ocular microvascular changes that occur before permanent damage develops.Clinical Trial Registration Number and Date: 77/1340; March 1, 2021.

Findings on Optical Coherence Tomography in Malignant Infantile Osteopetrosis.

Malignant infantile osteopetrosis is a rare inherited disorder with neurological complications and a shortened life expectancy. Vision loss is typically attributed to osseous compression of the optic nerves at the level of the optic canal. Fundus imaging is reported, as well as the first optical coherence tomography and optical coherence tomography angiography in this rare condition. Imaging revealed optic nerve pallor, subfoveal ellipsoid zone disruption, and an enlarged foveal avascular zone. These results provide insight regarding other potential mechanisms of vision loss in these patients. [Ophthalmic Surg Lasers Imaging Retina 2022; 53:398-402.].

Assessment of macular findings by OCT angiography in patients without clinical signs of diabetic retinopathy: radiomics features for early screening of diabetic retinopathy

This cross-sectional study aimed to quantitatively analyze the optical coherence tomography angiography (OCTA) images using MATLAB-based software and evaluate the initial changes in macular vascular density and the distortion of the foveal avascular zone (FAZ), before the clinical appearance of diabetic retinopathy. For this purpose, 21 diabetic patients without any clinical features indicating DR, and 21 healthy individuals matched with patients based on their demographic characteristics were included. Macular thickness, macular vascular density, and morphological changes of FAZ were assessed using OCTA. The diagnostic ability of morphological parameters was evaluated by receiver operating curve analysis. The intraclass correlation coefficient (ICCC) index was used to check the consistency of the extracted values. There was no significant difference in age, gender, LogMAR visual acuity, spherical equivalent, and intra-ocular pressure amongst patients and controls. No correlation was found between age and the FAZ area as well as vascular density. The vascular structure of the superficial layer showed FAZ enlargement, reduced vascular density in the macular area, and significant deviations of FAZ shape parameters (convexity and Frequency Domain Irregularity) in patients compared with healthy individuals. Measurements were highly correlated between separate imaging sessions with ICCC of over 0.85 for all parameters. The represented data suggests that radiomics parameters can be applied as both an early screening tool and guidance for better follow-up of diabetic patients who have not had any sign of DR in fundoscopic exams.

Early Structural and Vascular Changes after Within-24 Hours Vitrectomy for Recent Onset Rhegmatogenous Retinal Detachment Treatment: A Pilot Study Comparing Bisected Macula and Not Bisected Macula.

Background: In this study we aimed at investigating macular perfusion/anatomical changes in eyes with early onset rhegmatogenous retinal detachment (RRD) after prompt surgery within 24 hours, comparing a bisected macula and not bisected macula RRD. Methods: In this prospective observational study, 14 eyes of 14 patients who underwent within-24 hours vitreoretinal surgery for early onset RRD were enrolled. Patients were further divided into two subgroups: the not bisected macula group (NBM group) and the bisected macula group (BM group). At baseline and 3-month follow up, macular architecture and vessel analysis were assessed using optical coherence tomography angiography (OCTA) imaging. In detail, quantitative and qualitative analyses of the macular area were performed to quantify topographical retinal perfusion changes after surgery, calculating the foveal avascular zone (FAZ), vessel density (VD) and vessel length density (VLD) at the superficial capillary plexus (SCP) and deep capillary plexus (DCP). Results: Most cases (43%) were superotemporal RRD. Primary retinal reattachment was obtained in all cases, without recurrences within 3-month follow up. After surgery, a significant FAZ enlargement was observed at both the SCP and DCP level (p < 0.001; p < 0.05), with a significant effect of time noted between the two time points in the NBM and BM subanalysis (F = 3.68; p < 0.017). An excellent functional outcome was maintained for the whole follow-up. On the other hand, after surgery, perfusion parameters did not change significantly apart from the vessel density of the inferior macular sector at the DCP level (p = 0.03). Conclusions: Our findings suggest that the macular perfusion of eyes with RRD is still preserved if the surgery is performed really promptly, thus highlighting the great importance of a correct timing for surgery. OCTA analysis allows for a better understanding of the pathophysiological mechanisms underneath early vascular microarchitecture modifications of the posterior pole in retinal detachment, differentiating the two types of RRD not completely involving the fovea (BM and NBM).

Use of Imaging Technology to Assess the Effect of COVID-19 on Retinal Tissues: A Systematic Review.

PurposeTo evaluate the effect of COVID-19 on retinal tissues by conducting a systematic review and meta-analysis of the current literature.BackgroundThe novel coronavirus disease is not yet well understood. The orbit provides a window into the body's microvasculature, and as such, it is a non-invasive opportunity to analyse the systemic circulation in vivo. By analysing the current literature, we test the hypothesis that non-invasive imaging of the retina could provide insight into the effect of COVID-19 on the retinal microvasculature.MethodsFor this systematic review and meta-analysis, we screened PubMed databases and LitCOVID19 using the search criteria: (OCTA or Optical Coherence Tomography Angiography) AND (COVID-19 or corona or SARS-CoV-2) AND (retina or fundus). Databases were searched on 11 January 2022. The primary study outcomes were studies that utilised OCTA to analyse the retina; secondary outcomes involved studies that involved other imaging modalities such as OCT, fundus photography, and fundus autofluorescence.FindingsThe total number of studies included in this review was 32. Optical coherence tomography angiography scans show reduced central retinal vascular density, a thinner ganglion cell layer, a thicker retinal nerve fibre layer, and an enlarged foveal avascular zone. Optical coherence tomography scans demonstrate a thicker central macular thickness and other changes to the macula, ganglion cell, and inner nuclear layers. Many fundus photographs depicted cotton wool spots, microhaemorrhages, and vascular occlusions. Non-invasive imaging technology has demonstrated that COVID-19 can profoundly affect the retina. Therefore, there is a requirement for long-term follow-up of COVID-19 patients to assess whether the retinal damage caused by COVID-19 is reversible.Supplementary InformationThe online version contains supplementary material available at 10.1007/s40123-022-00509-8.

Dynamics of Retinal Vessel Loss After Acute Optic Neuritis in Patients With Relapsing Multiple Sclerosis

Background and ObjectivesRarefication of the retinal vasculature as measured by optical coherence tomography angiography (OCT-A) is a novel finding in patients with multiple sclerosis (MS). This study aimed to analyze longitudinal dynamics of the retinal vasculature following an acute inflammatory relapse including acute optic neuritis (ON) and to search for associations with alterations of the retinal architecture and visual function.MethodsThis prospective longitudinal cohort study included patients with relapsing-remitting MS or clinically isolated syndrome having an acute ON (n = 20) or a non-ON relapse (n = 33). Patients underwent examinations at baseline and after 7, 14, 28, 90, and 180 days with OCT, OCT-A, and assessment of the high- (HCVA) and low-contrast visual acuity (LCVA).ResultsRetinal vessel loss of the superficial vascular complex (SVC) evolves early after ON and reaches a plateau between 90 and 180 days (relative vessel loss 15% ± 8% [mean ± SD]). In addition, an 18% ± 18% intraindividual increase of the foveal avascular zone (FAZ) is evident within 180 days after acute ON. Both SVC thinning and FAZ enlargement were associated with worse HCVA and LCVA. Rarefication of the SVC evolved simultaneously to thinning of the common ganglion cell and inner plexiform layer (GCIP) after ON. No alterations of the deep vascular complex were seen in eyes with ON, and no alterations of the retinal vasculature were recognized in patients having acute non-ON relapses.DiscussionRarefication of the SVC and growing of the FAZ evolve rapidly after ON and are linked to persistent visual disability. ON-related SVC thinning might be closely linked to GCIP atrophy and might occur due to an altered local metabolic activity within inner retinal layers.

Radiation optic neuropathy diagnosis in nasopharyngeal carcinoma patients with radiation encephalopathy.

To develop a suitable radiation optic neuropathy (RON) diagnostic model based on optical coherence tomography angiography (OCTA) and to reveal the correlation between endocrine and OCTA indexes in nasopharyngeal carcinoma (NPC) patients with radiation encephalopathy (RE). This retrospective cross-sectional study included seventy-seven male NPC patients with RE following radiotherapy (41 non-RON and 36 RON). Endocrine and OCTA indexes were collected. The macular and peripapillary vessel density (VD) were automatically analyzed using AngioVue 2.0 of the RTVue XR Avanti device. The OCTA indexes were included in the multivariable binary logistic regression model between non-RON and RON. For all RE patients, a multiple linear regression was performed between each of the OCTA indexes and the endocrine indexes. Compared to non-RON, enlarged foveal avascular zone (FAZ) area, reduced superficial vascular plexus (SVP) VD and radial peripapillary capillary plexus density, reduced full retinal thickness, ganglion cell complex thickness and peripapillary retinal nerve fiber layer thickness were observed in RON. Foveal VD in the SVP was included in the RON diagnostic model. Free triiodothyronine (FT3) showed a significantly negative correlation with the FAZ area but showed a significantly positive correlation with foveal VD in the SVP and deep vascular plexus, peripapillary VD and thickness and parafoveal and perifoveal thickness. OCTA may be useful for diagnosing RON in male NPC patients with RE following radiotherapy. Reduced FT3 and foveal VD in SVP may be sensitive in screening RON in these patients.

Quantitative analysis of early retinal vascular changes in type 2 diabetic patients without clinical retinopathy by optical coherence tomography angiography.

To investigate the quantitative differences in optical coherence tomography angiography (OCTA) data between type 2 diabetes patients without clinically detectable diabetic retinopathy (DR) and healthy subjects. Thirty-nine patients with type 2 diabetes without DR and 41 age- and sex-matched healthy controls were recruited. The vessel density and foveal avascular zone (FAZ) area in the superficial capillary plexus and deep capillary plexus were measured using Nidek RS-3000 Advance® and compared between patient cohorts. Foveal vessel density (%) and FAZ (%) were also calculated. A significant decrease in vessel density has been observed in the deep capillary plexus of the patients compared to healthy individuals (5.58 ± 0.98 mm2 versus 6.15 ± 0.89 mm2, p < 0.001). However, there were no significant differences in other parameters between cohorts (p > 0.05 in all parameters). Despite the decrease of deep capillary plexus density in the macular region, there was no significant change observed in foveal vessel density (p:0.44). It has also been observed that the duration of diabetes mellitus correlates with vessel density decrease in deep capillary plexus (R:-0.52; p < 0.001). In both groups, all parameters in deep capillary plexus were significantly higher than superficial capillary plexus (p < 0.001 for all parameters). OCTA can identify quantitative changes in DCP before the manifestation of clinically apparent retinopathy. DCP-VD reduction may be an earlier finding than FAZ enlargement. Despite the reduction of VD, FVD could be preserved for a certain period of time in DM patients.