Optical Coherence Tomography Angiography Research Articles

Investigating the vascular structure of the conjunctiva in patients using spherical mini-scleral contact lenses utilizing OCT-A imaging

This study aimed to compare the outcomes of Optical Coherence Tomography-Angiography (OCT-A) with the clinical assessments conducted by an experienced ophthalmologist, as well as to analyze the alterations in the conjunctiva of individuals utilizing spherical scleral contact lenses. OCT-A imaging was conducted on 13 patients (mean age: 34.1 years, 10 males) in a prospective study at two time points: at least 8 h post-lens removal and 1-hour post-lens application. The scleral region in the quadrants (superior, inferior, temporal, and nasal) was designated as the region of interest (ROI), located 3 mm from the limbus. This ROI was further divided into two bands: Band 1 (1.5 mm width under the lens) and Band 2 (1.5 mm width outside the lens). The vascular density ratios in the inferior quadrant were significantly reduced after the lens fitting: ROI (0.362 ± 0.074 post-lens vs. 0.452 ± 0.099 pre-lens, adjusted P-value = 0.027) and Band 1 (0.353 ± 0.075 post-lens vs. 0.462 ± 0.095 pre-lens, adjusted P-value = 0.008). In the superior (P-value = 0.026), inferior (P-value < 0.001), and temporal (P-value < 0.001) quadrants, the degree of conjunctival impingement, as scored by an experienced ophthalmologist using slit photographs, was significantly correlated with OCT-A findings. In conclusion, OCT-A identifies microvascular changes undetectable by slit-lamp examination, providing quantitative insights into vascular alterations from scleral lens use and complementing clinical evaluations.

Evaluation of the Efficacy and Safety of Preoperative Intravitreal Triamcinolone Acetonide Combined with Internal Limiting Membrane Peeling for the Treatment of Idiopathic Macular Epiretinal Membrane.

To assess the efficacy and safety of preoperative intravitreal triamcinolone acetonide (IVTA) combined with internal limiting membrane (ILM) peeling for idiopathic epiretinal membrane (IMEM). This was a retrospective study. Thirty-six phakic eyes of 35 patients were included in this study. IVTA was administered to 18 patients (18 eyes, Group IVTA) 7 days before vitrectomy, while the other 17 patients (18 eyes, Group no-IVTA) only underwent vitrectomy and ILM peeling. Patients were followed up for at least 6 months. Data on best-corrected visual acuity (BCVA), intraocular pressure (IOP), central macular thickness (CMT), inner retinal thickness (IRT), vascular parameters (measured by optical coherence tomography angiography, OCTA), mean macular sensitivity (MMS), 63% bivariate contour ellipse area (BCEA) and P1 (measured by macular integrity assessment, MAIA) were collected. There were significant differences in BCVA and IRT between the IVTA group and the no-IVTA group at 6 months after surgery (p = .000 and p = .010). The CMT and MMS of the two groups significantly changed from the preoperative values; however, there were no differences between the 2 groups during the entire study period (p = .242 and p = .849). The changes in vascular parameters, including foveal avascular zone (FAZ) area and vessel densities of superficial and deep capillary plexus (SCP VD and DCP VD), in the two groups were not statistically significant. There were no statistically significant differences in 63% BCEA and P1 either. Macular morphology and macular integrity improved after vitrectomy combined with ILM peeling surgery. Compared with the no-IVTA group, preoperative intravitreal triamcinolone acetonide can improve best corrected visual acuity and accelerate the absorption of intraretinal fluid in terms of a significant reduction in IRT.

Full length title: Stellate Nonhereditary Idiopathic Foveomacular Retinoschisis and Central Anomalous Retinoschisis with mid-PEripheral Traction (CARPET).

To report the clinical and multimodal imaging (MMI) findings and long-term follow-up of stellate nonhereditary idiopathic foveomacular retinoschisis (SNIFR) contiguous with midperipheral retinoschisis (MPRS) and to describe a severe SNIFR variant termed CARPET (Central Anomalous Retinoschisis with mid-PEripheral Traction). Retrospective case series. Eleven patients (15 eyes) with SNIFR contiguous with MPRS in at least one eye at baseline or final follow-up. MMI features, including cross-sectional and en face macular and peripheral spectral-domain optical coherence tomography (OCT) and OCT angiography, were reviewed in all cases at baseline and at the final follow-up visit. Various courses (including progression, regression, or stability) of MPRS or SNIFR over time were evaluated. MPRS exhibited centripetal progression to SNIFR in 5 eyes of 3 patients with follow up of 67, 60, and 27 months, respectively, with maintenance of excellent visual acuity (range: 20/25-20/20) in 4 of these 5 eyes. In 2 eyes of 2 patients (including 1 eye with initial centripetal progression of MPRS to SNIFR), MPRS contiguous with SNIFR spontaneously resolved with long-term follow-up (77 and 48 months, respectively). SNIFR contiguous with MPRS partially regressed after 48 months in one patient, and was stable after 54 months in another. A distinctive midperipheral microvasculopathy, associated with MPRS that was contiguous with SNIFR, was identified in 7 eyes of 4 patients. Finally, 3 eyes of 3 patients exhibited additional unique features, including central neurosensory detachment and outer lamellar macular hole, which were associated with significant midperipheral traction, representing a severe variant subtype of SNIFR that we refer to as CARPET. Two of these 3 eyes progressed with short-term follow-up of 6 and 2 months, respectively, while the schisis resolved and vision improved after pars plana vitrectomy in the third case. MPRS can progress to SNIFR over multiple years of follow-up. SNIFR with MPRS can also spontaneously resolve or remain stable. MPRS can additionally be complicated by a midperipheral inner retinal microvasculopathy. Finally, CARPET may represent a unique and severe variant form of SNIFR driven by midperipheral vitreoretinal traction and associated with significant vision loss.

Imaging and classification of central serous chorioretinopathy-What do I really need?

Multimodal imaging plays akey role in the diagnostics and classification of central serous chorioretinopathy (CSC). In this article the most important imaging modalities in CSC, such as optical coherence tomography (OCT), fluorescein angiography, indocyanine green angiography and OCT angiography are presented and their significance explained. Based on these imaging findings, CSC subtypes and possible classification attempts are presented.

Retinal Vascular Parameters Changes (by Optical Coherence Tomography Angiography) in Early Rheumatoid Arthritis: A Hospital-Based Study

ABSTRACT Purpose To evaluate the retinal vascular changes related to early Rheumatoid Arthritis (RA) and to correlate these changes with disease activity. Methods 108 eyes of 54 early RA patients and 66 eyes of 33 age and sex-matched healthy participants underwent Optical Coherence Tomography Angiography (OCTA) examination to evaluate superficial (SCP), deep retinal capillary plexus (DCP), and radial peripapillary capillaries (RPC), we collected Values of the vessel density (VD) of SCP and DCP, central foveal thickness (CFT), foveal avascular zone (FAZ) along with a full rheumatological examination and disease activity score by (DAS28). Results RPC values were significantly lower among RA patients in all subfields apart from the temporal one. There was a significant difference between RA patients and healthy controls in foveal and all perifoveal measurements, except the nasal perifoveal region. Also, the FAZ value was significantly higher in RA patients. We performed Spearman’s correlation between OCTA and RA disease parameters and detected a negative correlation between the duration of disease-related symptoms and RPC and parafoveal measurements and between DAS-28 and foveal measurements. A significant positive correlation between anti-CCP titer and FAZ measurements was detected among RA patients. Conclusion OCTA can detect early retinal microcirculation affection in RA patients in the form of a reduction in the vascular density in most of the subfields of the peripapillary area as well as the fovea, perifoveal, and parafoveal areas. The results of the current study can provide new insight into the applications of OCTA as a diagnostic tool in RA patients’ assessment and follow-up.

Imaging in Pachychoroid Disease.

The term pachychoroid was proposed as a term indicating an abnormal increase in choroidal thickness. Eyes presenting with pachychoroid changes often exhibit dilation of the large choroidal vessels, compressing the overlying choriocapillaris and Sattler's layer. Pachychoroid spectrum diseases may present pathological findings such as pigment epitheliopathy, choroidal neovascularization (CNV), submacular serous detachment, and distinct choroidal and scleral alterations. Recent advancements in imaging modalities such as widefield indocyanine green angiography (WF-ICGA), optical coherence tomography angiography (OCTA), and enhanced depth imaging optical coherence tomography (OCT) have significantly improved our understanding of these conditions. WF-ICGA revealed venous outflow congestion in the peripheral retina as one of the characteristics of pachychoroid diseases. Scleral thickness measurements using ultrasound biomicroscopy and anterior segment OCT indicate that a thicker anterior sclera may contribute to choroidal congestion and disease pathogenesis. OCTA has emerged as a superior tool for identifying CNV and understanding the disease etiology, offering better sensitivity and specificity compared to traditional methods. These imaging advancements provide valuable insights into the structural and functional changes associated with pachychoroid diseases, potentially guiding future diagnostic and therapeutic strategies. The aim of the present review is to define the morphological characteristics of the pachychoroid spectrum of diseases, which share similar choroidal findings.

Correction of Non-Uniform Rotational Distortion in the Proximally Controlled Endoscopic OCTA.

Endoscopic Optical Coherence Tomography (OCT) can provide high-resolution cross-sectional images for internal organ tissues. Combining the endoscopic imaging with Optical Coherence Tomography Angiography (OCTA), information of blood vessels in superficial lumen tissues is expected to be acquired. However, in endoscopic OCT systems using proximal scanning probes, performance of OCTA encounters significant challenges due to non-uniform rotational distortion (NURD) caused by the non-constant rotation of the distal imaging unit. In this study, we proposed a registration method for endoscopic OCTA imaging in a proximally controlled OCT System. Global registration and A-line registration were employed to correct the distortion caused by mechanical friction between the catheter sheath and torque coil. Experimental performances in both microfluidic channel and rat rectum show significant correction of NURD. Our study achieved the first implementation of endoscopic OCTA under a spiral B-scan rotation scheme in a proximally controlled OCT system, facilitating clear visualization of blood flow.

Walking More Than 10,000 Steps Per Day May be Associated with Increased Optic Disc Vessel Density in Patients With Primary Open Angle Glaucoma.

The study aimed to investigate the relationship between average daily steps (ADS) and optic disc angioflow vessel density (VD) in patients with primary open angle glaucoma (POAG). This is a cross-sectional study. Forty-one POAG patients (74 eyes) were recruited from Wenzhou Glaucoma Progression Study (WGPS) who were divided into two groups based on international physical activity guidelines: 21 subjects (38 eyes) in the ADS>10,000 group and 20 patients (36 eyes) in the ADS≤10,000 group. ADS was monitored using a waist-worn accelerometer (ActiGraph wGT3x-BT) worn on the waist for seven consecutive days, while optic disc VD was assessed by the optical coherence tomography angiography. Papillary VD was significantly denser in the ADS>10,000 group (ADS:12782±2925) compared to the ADS≤10,000 group (ADS:7418±1543) for both whole image-all VD (WIAVD) and whole image-capillary VD (WICVD) (P=0.026, 0.032, respectively). Univariate analysis indicates that WIAVD was more denser in ADS>10,000 vs ADS≤10,000 (P=0.013) and that WICVD was more denser in ADS>10,000 vs ADS≤10,000 (P=0.019). Furthermore, every 1μm thicker in retinal nerve fiber layer (RNFL) thickness was associated with a 0.24 denser in WIAVD (P<0.0001) and a 0.23 denser in WICVD (P<0.0001). Each 1-dB improvement in mean deviation (MD) was linked to a 0.75 increase in WIAVD (P<0.0001) and a 0.83 increase in WICVD (P<0.0001). Additionally, a 1mmHg increase in intraocular pressure was associated with a 0.5 decrease in WIAVD (P<0.009) in univariate analysis and a 0.31 decrease in multivariate analysis (P<0.012). Multivariate analysis revealed that patients with ADS>10,000 had 1.75 higher WIAVD and 1.64 higher WICVD compared to those with ADS≤10,000 after adjusting for other risk factors. POAG patients with ADS>10,000 exhibited higher papillary VD compared to those with ADS≤10,000, implying that increasing daily steps, particularly exceeding 10,000 steps, may potentially enhance ocular blood flow.

Optical Coherence Tomography Angiography Flow Signal in Non-Treatment-Naïve Patients with Neovascular Age-Related Macular Degeneration Treated with Faricimab

Background and Objectives: Age-related macular degeneration (AMD) remains a leading cause of legal blindness. Anti-Vascular Endothelial Growth Factor (VEGF) agents are the first-line treatment for neovascular AMD (nAMD). The choroid plays a key role in AMD and is affected by the anti-VEGF treatment. Faricimab, a bispecific antibody additionally targeting angiopoietin 2 (Ang2), was recently approved for nAMD treatment. This study investigates the effect of Faricimab on choroidal flow signal. Materials and Methods: Optical coherence tomography angiography images of 29 nAMD eyes were examined retrospectively. Patients had received treatment with other anti-VEGF agents before Faricimab application. The flow signal in the choroid was measured before, after one and after a series of ≥2 Faricimab injections. Results: The flow signal decreased significantly (p = 0.026) at the choriocapillaris (CC) level after ≥2 injections. The flow signal did not show a significant change in Haller’s layer but increased slightly in Sattler’s layer (p = 0.034). Conclusions: In conclusion, our results show that the flow signal, especially at the CC level, changed during treatment. Despite the known influence of anti-VEGF treatment on the choroid, auxiliary inhibition of Ang2 might enhance this effect. Due to the retrospective nature, moderate sample size and non-treatment, naïve patients, care must be taken while interpreting our observations. Prospective studies with larger sample sizes and treatment-naïve patients will be needed.

Comparison of retinal and choroidal vascular changes via optical coherence tomography angiography between pseudoexfoliative glaucoma and pseudoexfoliation syndrome and control group.

This study aims to evaluate the differences in retinal and choroidal vasculature using optical coherence tomography angiography (OCTA) in patients with pseudoexfoliative glaucoma (PEX-G) and patients with pseudoexfoliation syndrome without glaucoma (PEX-S) and the control group. In this cross-sectional study, 25 patients with PEX-G, 27 PEX-S cases, and 25 patients as the control group (C) were evaluated. All patients and the control group underwent macular and optic nerve head (ONH) OCTA, performed using the Optovue device. The foveal and parafoveal vascular density (VD) in superficial capillary plexus (SCP) and deep capillary plexus (DCP), foveal avascular zone (FAZ) area, outer retina flow area, choriocapillaris flow area, peripapillary VD, and retinal nerve fiber layer (RNFL) thickness in the macula and peripapillary region were assessed. 77 eyes of 77 patients were included. The mean foveal SCP VD in the control group was 9.62 % and 8.92 % higher than in the PEX-S and PEX-G groups; the median foveal DCP VD had 11.3 % and 13.2 % higher values in the controls. The PEX-S and PEX-G groups showed no differences regarding the macular microvasculature. The intradisc VD and the peripapillary VD were 7.5 % and 17.9 % lower in the PEX-G group compared to the controls. Besides, the peripapillary VD was significantly correlated with the RNFL thickness (R2:0.789, p:<0.0001). In patients with PEX, regardless of glaucoma, the retinal VD showed deficiencies compared to the controls. Also, the peripapillary VD was strongly correlated with the RNFL thickness. These findings mean that retinal vascular changes might precede the development of glaucoma in PEX syndrome and can even be its cause.

Association between retinal morphological characteristics and visual function in myopic traction maculopathy.

To quantify retinal morphological characteristics in patients with myopic traction maculopathy (MTM), including myopic foveoschisis (MF), using optical coherence tomography angiography (OCTA) and investigate the correlation of MTM with visual function. This cross-sectional study included 19 eyes with myopic foveoschisis (MF) and foveal detachment (FD), 37 eyes with MF without FD, and 24 myopic eyes as control. OCTA was used to assess macular vessel density (VD) in the superficial capillary plexus (SCP), deep capillary plexus (DCP), foveal avascular zone (FAZ) area, FAZ perimeter, acircularity index, retinal thickness, and retinal volume. Microperimetry was performed to evaluate macular sensitivity (MS) covering the central 20°, 10°, 2° field centered at fovea. Correlations between macular microcirculation parameters, best-corrected visual acuity (BCVA), and MS were determined. Compared to myopic controls, decreased macular parafoveal SCP VD, DCP VD, and the area VD in a 300 µm wide annulus surrounding the FAZ (FD-300), were found in the group of MF patients with FD, with (p = 0.007, 0.002, 0.005) respectively, and in the group of MF patients without FD, with (p = 0.01, 0.049, 0.009), respectively. In the MF without FD group, parafoveal SCP VD significantly correlated with BCVA, 2°MS, 10°MS, and 20°MS (p = 0.018, 0.002, 0.001, 0.029), FD-300 area density, retinal thickness, and retinal volume was significantly correlated with BCVA (p = 0.024, 0.015, 0.045). In the MF with FD group, DCP VD was significantly associated with 10° and 20° MS (p = 0.048, 0.014), as were retinal thickness and volume (all p < 0.05); however, FD-300 area density correlated significantly with BCVA (p = 0.014). Macular perfusion is closely associated with functional alterations in MTM. Macular VD could serve as a valuable biomarker for monitoring MTM progression and optimizing medical and surgical decisions.

Topographic correlation of microperimetry with foveal microstructure characteristics in idiopathic epiretinal membrane patients with an ectopic inner foveal layer

PurposeTo identify foveal structure-function topographic association and relationship in patients with idiopathic epiretinal membrane (ERM) related to ectopic inner foveal layer (EIFL).MethodsThis was a cross-sectional, observational study that involved 40 individuals with idiopathic ERM: 22 without EIFL (Group 1) and 18 with EIFL (Group 2). Quantitative foveal light sensitivity was measured using microperimetry, and foveal microstructure was assessed using spectral-domain optical coherence tomography (SD-OCT) and optical coherence tomography angiography (OCTA). Multiple indices of microvascular parameters of OCTA images were further processed using the AngioTool software. LASSO regression and quantile regression analyses were performed to identify the spatial distribution correlation between foveal light sensitivity and foveal microstructure parameters.ResultsGroup 2 exhibited reduced light sensitivity across all parameters of microperimetry compared to Group 1 (P < 0.001). Additionally, the central foveal thickness, the percentage of ellipsoid zone disruption, and the foveal avascular zone area were significantly lower in Group 1 than in Group 2 (all P < 0.005). Compared to Group 1, the vessel density (VD) and perfusion density of the foveal region was significantly increased in Group 2 (P < 0.001). In contrast, Group 2 showed significantly decreased VD in the parafoveal region compared with Group 1 (P < 0.05). Significant differences in OCTA parameters including ‘total number of junctions’, ‘junction density’, ‘total vessel length’, ‘average vessel length’, ‘total number of end points’ were observed between Group 1 and Group 2 (all P < 0.01). The foveal light sensitivity was significantly positively correlated with VD in the parafoveal region and negatively correlated with EIFL alteration, best-corrected visual acuity and ellipsoid zone disruption [Log(λ) = − 0.18303, λ = 0.6561].ConclusionsThe presence of EIFL and decreased VD in the parafoveal region, factors that collectively elevate the risk of disease progression, are significantly and independently correlated with reduced microperimetric retinal sensitivity in patients with idiopathic ERM.

Multimodal Imaging Characteristics and Correlation to Outcomes in Patients with CRAO Presenting to a Large Academic Center

PurposeTo characterize a large modern cohort of patients with central retinal artery occlusion (CRAO) by describing presenting features and outcomes relating to manually segmented optical coherence tomography (OCT) features, angiographic reperfusion, and visual recovery. DesignRetrospective clinical cohort study. MethodsPatients with CRAO (ICD-10: H34.1) initially presenting to a tertiary referral center between January 2017 and December 2021 were included. Demographics, eye exam findings, fundus photographs, OCT, and fluorescein angiography (FA) were analyzed. Main outcome measures included total and inner retinal thickness on macular OCT, reperfusion, visual outcomes, and development of neovascularization. Results145 eyes of 144 patients with mean age at of 69.4±13.6 years were included. The mean time to presentation was 1.6±4.2 days, with 19% examined within 4.5 hours and 26% within 6 hours of vision loss. 19% had cilioretinal artery (CLRA) sparing. Mean initial visual acuity (VA) was 1.68±1.10 LogMAR (CLRA sparing) compared to 2.53±0.58 LogMAR (non-CLRA sparing), P<0.001. 32% had elevated inflammatory makers. Out of 47 eyes with final fluorescein angiography, one-third showed some reperfusion. Final vision was 1.40±1.16 LogMAR (CLRA sparing) compared to 2.46±0.81 (non-CLRA sparing), P<0.001. A third of patients improved in VA in both groups, 27% of patients gained more than 2 lines of vision in the CLRA sparing group and 36% in the non-CLRA sparing group. 17% improved to better than 20/200 in CLRA-sparing and 4% in non-CLRA sparing. 11% developed neovascularization all in non-CLRA sparing. In a multiple linear regression, VA at presentation was associated with regaining vision of 2 lines or more (OR=2.603, P=0.007). OCT showed progressive thinning over time, reaching lowest measurements at 6 months, and stabilizing thereafter. ConclusionsIn this modern cohort of acute CRAO patients, presentation to a tertiary facility within 12 hours of symptoms was seen in almost half of the patients. Final visual acuity improved in almost a third of the patients, however, vision better than the legal blindness limit was rare (∼5%). Interestingly, a third of patients had some mild elevation of systemic inflammatory markers. Better visual acuity at presentation was associated with visual gain, while baseline OCT values had poor correlation with final outcome.

Improved analysis with spectral-domain optical coherence tomography angiography for evaluating vascular damage in exfoliation syndrome

Improved analysis with spectral-domain optical coherence tomography angiography for evaluating vascular damage in exfoliation syndrome

Changes in optic nerve head microvasculature following disc hemorrhage absorption in glaucomatous eyes

This study investigated the changes in optic nerve head (ONH) microvasculature, circumpapillary retinal nerve fiber layer (cpRNFL) thickness, and visual field (VF) sensitivity following the absorption of optic disc hemorrhage (DH). Intradisc vessel density (dVD) was calculated using a 3 × 3 mm optic disc scan in 60 eyes of 60 patients with primary open angle glaucoma and DH who had undergone two or more swept-source optical coherence tomography angiography exams. Clinical parameters at the time of DH occurrence and after absorption, as well as those between the subgroups based on DH recurrence and location, were compared. Linear regression analysis was performed to identify factors associated with changes in cpRNFL thickness in the DH-affected quadrant. Mean dVD, cpRNFL thickness, and VF sensitivity significantly decreased after DH absorption (all P < 0.05). The reduction in dVD was more pronounced in eyes with recurrent DH compared to those with a single episode (P = 0.032). Eyes with DH occurring within or at the margin of the disc cup showed a greater dVD reduction than those with DH occurring outside the disc cup (P = 0.049). The reduction in cpRNFL thickness in the DH-affected quadrant correlated with dVD reduction in the same quadrant (β = 0.370, P = 0.013) and DH recurrence (β = -2.617, P = 0.033). This finding suggests that DH pathogenesis may be associated with changes in optic disc vasculature, contributing to glaucomatous progression.

Optic Disc Microvasculature Reduction and Visual Field Progression in Primary Open-Angle Glaucoma.

To investigate the relationship between optic disc vessel density (ODVD) reduction and visual field (VF) progression in primary open-angle glaucoma (POAG) patients. Retrospective case series. A total of 187 POAG eyes underwent ≥ 5 consecutive VF, spectral-domain optical coherence tomography, and swept-source OCT angiography imaging sessions during ≥ 3 years of follow-up. ODVD reduction was defined as a statistically significant negative slope (P < 0.05) of ODVD, calculated as the ratio of pixels occupied by vessels within the temporal optic disc area for any global, superior, or inferior sectors. The association between VF progression and rate of ODVD change was assessed by logistic regression and multivariable longitudinal linear mixed-effects models versus time. During 3.67 ± 0.38 years of follow-up on the 187 eyes, 90 (48.1%) and 56 (29.9%) showed ODVD reduction and VF progression, respectively. A higher proportion of eyes with ODVD reduction had VF progression than did those without ODVD reduction (51/90 eyes [56.7%] vs. 5/97 eyes [5.2%]; P < 0.001). VF progression was associated with a faster rate of global ODVD change (odds ratio (OR), 5.10; P = 0.002) as well as a faster rate of global retinal nerve fiber layer (RNFL) thinning (OR, 39.6; P = 0.008) in the multivariable model. Optic disc microvasculature reduction was associated with VF progression even after adjusting for possible influencing factors including RNFL thinning in POAG. This suggests that deep ONH circulation has a role in the pathogenesis of glaucoma.

Standardization of Optical Coherence Tomography Angiography Nomenclature in Retinal Vascular Diseases: Consensus-based Recommendations.

To develop a consensus nomenclature for Optical Coherence Tomography Angiography (OCTA) findings in retinal vascular diseases (RVD). Expert consensus using standardized online surveys with modified Likert scale. RVD imaging experts, OCT biomedical engineers and the members of the International Retinal Imaging Society (IntRIS) METHODS: A PubMed literature review identified quantitative and qualitative terms forming the basis for a consensus-building process using a modified Delphi method. Agreement levels were categorized as "Accepted" (median ≥ 6), "Considerable Consensus" (median 6-7, IQR ≤ 3), "Strong Consensus" (median ≥ 8, IQR ≤ 2), and "Refined Strong Consensus" (median ≥ 8, IQR ≤ 2, with ≥ 70% responses in the 8-10 range). A multidisciplinary expert panel refined the terminology through three survey rounds, leading to a final survey conducted by IntRIS members. Consensus on OCTA nomenclature in RVD RESULTS: The literature review identified 58 relevant papers, yielding 51 quantitative and 108 qualitative terms. A series of three surveys was used to refine the nomenclature framework for describing OCTA findings. The selected framework includes a generic term ("OCTA signal"), adjective terms ("presence/absence", "decreased/increased", "normal/abnormal"), and descriptive/etiologic terms ("of unknown cause", "due to blockage", "due to non-perfusion"). In the final survey among 44 IntRIS members, the framework achieved strong consensus for overall acceptance (median: 8.0, IQR: 7.0-9.0). The term "OCTA signal" met refined strong consensus criteria (median: 8.0, IQR: 8.0-9.0, with ≥ 70% of responses in the 8-10 range). Adjective terms, including "absence/presence" and "increased/decreased," were also rated with strong consensus (median: 8.0, IQR: 7.0-9.0). Similarly, descriptive/etiologic terms achieved strong consensus (median: 8.0, IQR: 7.0-9.0). Adoption of the framework for clinical practice and scientific reporting was rated with strong consensus (clinical: median 8.0, IQR: 7.0-9.0; scientific: median 9.0, IQR: 8.5-10.0). This study establishes a strong consensus framework for reporting OCTA findings in RVD for clinical and scientific contexts.

Assessment of clinical outcomes and prognostic factors following membrane peeling in idiopathic epiretinal membrane using EIFL staging system: an optical coherence tomography angiography analysis

BackgroundTo evaluate the associations between anatomical changes and visual outcomes after membrane peeling in eyes with different stages of idiopathic epiretinal membrane (iERM) using optical coherence tomography angiography (OCTA).MethodsAll iERM eyes were graded into four stages based on the presence of ectopic inner foveal layers (EIFL) and underwent 23-gauge vitrectomy combined with ERM and internal limiting membrane (ILM) peeling, while their fellow eyes were treated as the control group. OCTA was used to measure retinal thickness(RT), foveal avascular zone (FAZ)-related parameters and superficial and deep capillary plexus (SCP and DCP) layers using 6 × 6 mm scans before, 1 month and 3 months after surgery. In addition, best corrected visual acuity (BCVA), metamorphopsia and macular features were assessed.ResultsForty-six subjects were included in this study. In comparison to the preoperative data, visual acuity and metamorphopsia improvement was statistically significant in four stages(P < 0.05) and the higher stage (3 and 4) achieved more pronounced improvements (P = 0.002). For higher stage, RT reduced with an increase in stage(P < 0.001), superficial and deep foveal vessel density (SFVD and DFVD) and parafoveal vessel density (PRVD) in SCP declined remarkably, FAZ area was enlarged obviously, FAZ perimeter (PERIM), foveal vessel density (FD) and PRVD in DCP increased significantly after surgery (P < 0.05). Similar to high-stage patients, those with stage 2 iERMs demonstrated a decreasing trend in central macular thickness (CMT), paraRT (parafoveal thickness), SFVD, and DFVD(P < 0.05). Nevertheless, no notable alterations were observed in other indicators. Distinct from other groups, only CMT and FD increased slightly in stage 1 iERMs (P < 0.05). Post-LogMAR BCVA and LogMAR BCVA-d (pre-LogMAR BCVA –3-month post-LogMAR BCVA) were positively correlated with preoperative stages, CMT, pre-LogMAR BCVA, SFVD, and vascular tortuosity(P < 0.05). but negatively correlated with FAZ area and DFVD (P < 0.05). Preoperative and postoperative metamorphopsia had a certain positive correlation with preoperative CMT (P < 0.05).ConclusionsAccording to OCTA analysis, different EIFL stages of iERMs showed significantly functional and anatomic differences before and after membrane peeling. Low-stage patients have better post-op visual function, while high-stage patients benefit more from surgery. It also demonstrated EIFL staging system contribute doctors to manage iERMs.

ABCA4 Deep Intronic Variants Contributed to Nearly Half of Unsolved Stargardt Cases With a Milder Phenotype.

The purpose of this study was to investigate the contribution and natural progression of ABCA4 deep intronic variants (DIVs) among a Chinese Stargardt disease (STGD) cohort. For unsolved STGD probands, DIVs in ABCA4 were detected by next-generation sequencing, and splicing effects were evaluated by in silico tools and validated through minigene experiments. Comprehensive ocular examinations, especially fundus changes, were carried out and analyzed. These and long-term follow-up data were compared with data of patients carrying biallelic coding variants of ABCA4. Seven DIVs in ABCA4 were identified in 18 of 40 (45.0%) unsolved STGD probands, involving 2 novel and 5 known variants. Four DIVs were confirmed to effect splicing through minigene assay. The c.161-395G>A was the most prevalent DIV allele (30.6%, 11/36). In the early 5-year duration, localized maculopathy was predominant, accounting for 51.9% (14/27) of fundus recordings. Expanded macular lesion within the vascular arch, with or without flecks, was observed in 75.0% (12/16) of recordings beyond the 5-year duration, whereas generalized retinal dystrophy was rarely observed. Compared with those in the non-DIV group, the patients in the DIV group manifested milder fundus change at all disease stages (P < 0.05). Follow-up visits utilizing wide-field fundus autofluorescence (FAF) further validated the slower development of lesions. Optical coherence tomography angiography (OCTA) documented a gradual reduction in perfusion in each layer's capillaries and high-reflective deposits below the sub-RPE layer. DIVs contribute to nearly half of STGD cases with missing heritability, totally occupying 7.8% of all STGD families. Based on optimized grading criteria, patients with DIV alleles manifested localized macular lesions with slow progress. The amount of residual correctly spliced mRNA might play a role, suggesting that adding or enhancing normal ABCA4 expression might be a potential approach of intervention.

Comparisons of oscillatory potentials and 30 Hz flicker electroretinograms for discriminating eyes with diabetic retinopathy from normal eyes.

To compare the amplitudes and implicit times of the oscillatory (OPs) of the full-field electroretinograms (ERGs) to those of the 30 Hz flicker ERGs in differentiating eyes with diabetic retinopathy (DR) from normal eyes. Single-center observational study. Full-field ERGs were recorded in 55 patients with Type 2 diabetes mellitus (DM) and 20 normal control subjects. The amplitudes and implicit times of the OPs and of the 30 Hz flicker ERGs were measured. Optical coherence tomography angiography (OCTA) was used to record 3×3 mm enface images of the retina from which the vascular density (VD) of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were obtained. The receiver operating characteristic (ROC) curves were used to determine the ability of each ERG parameter to discriminate diseased eyes from normal eyes. The significance of the correlations between each ERG parameter and the VD of the SCP and DCP was determined. The area under the ROC curves (AUCs) was significantly larger for the implicit times than for the amplitudes of each ERG component (P<0.005). There were no significant differences in the AUCs between the OPs and 30 Hz flicker ERGs in differentiating eyes with DM or DR from normal eyes. The implicit time of the 30 Hz flicker ERG had the highest significant correlation coefficient with the VD of the DCP (r = - 0.31, P <0.001). The OPs and 30 Hz flicker ERGs have equal ability in differentiating eyes with DR from normal eyes but with better ability for the implicit times than the amplitudes. The implicit time of the 30 Hz flicker ERG is the most sensitive parameter that is correlated with the reduction of VD among the full-field ERG components.