One-Year Functional and Morphological Prognosis After Intravitreal Injection Treatments According to Different Morphological Patterns of Diabetic Macular Edema in Real-Life: MARMASIA Study Group Report No.13.

PURPOSE: To evaluate the responses of different optical coherence tomography (OCT) patterns of diabetic macular edema (DME) to intravitreal injection therapy. METHODS: In this retrospective, comparative, and multicenter study, patients who had previously untreated DME, who received intravitreal ranibizumab (IVR) or aflibercept (IVA) and/or steroid treatment with the pro re nata (PRN) treatment regimen after a 3-month loading dose, and had a 12-month follow-up in the MARMASIA Study Group were included. Morphological patterns of DME were divided into four groups based on OCT features diffuse/spongious edema (Group 1), cystoid edema (Group 2), diffuse/spongious edema+subretinal fluid (SRF) (Group 3), and cystoid edema+SRF (Group 4). Changes in central macular thickness (CMT) and best-corrected visual acuity (BCVA) at months 3, 6, and 12, and the number of injections at month 12 were compared between the DME groups. RESULTS: 455 eyes of 299 patients were included in the study. The mean baseline BCVAs [Logarithm of the Minimum Angle of Resolution (logMAR)] in groups 1, 2, 3, and 4 were 0.54 ± 0.24, 0.52 ± 0.25, 0.55 ± 0.23, and 0.57 ± 0.27, respectively. There was no significant difference between the baseline mean BCVAs between the groups (p = .35). The mean BCVAs were significantly improved to 0,47 ± 0,33 in group 1, 0,42 ± 0,33 in group 2, 0,47 ± 0,31 in group 3, and 0,45 ± 0,43 at month 12. There was no significant difference between the groups in terms of BCVA change at month 12 (p = .71). The mean baseline CMTs in groups 1, 2, 3, and 4 were 387,19 ± 128,19, 447,02 ± 132,39, 449,12 ± 109,24, and 544,19 ± 178,61, respectively. At baseline, the mean CMT was significantly higher in Group 4 than in the other groups (p = .000). The mean CMTs were significantly decreased to 325,16 ± 97,55, 334,94 ± 115,99, 324,33 ± 79,20, and 332,08 ± 150,40 in four groups at month 12 respectively (p > .05). The groups had no significant difference in mean CMT at month 12 (p = .835). The change in CMT was significantly higher in Group 4 than in the other groups at month 12 (p = .000). The mean number of intravitreal anti-VEGF injections at month 12 was 4.51 ± 1.57 in Group 1, 4.63 ± 1.54 in Group 2, 4.88 ± 1.38 in Group 3, and 5.07 ± 1.49 in Group 4. The mean number of anti-VEGF injections in Group 1 and Group 2 was significantly lower than in Group 4 (p = 0,014 and p = 0,017). CONCLUSIONS: In real life, there was no significant difference between the DME groups in terms of visual improvement at month 12. However, better anatomical improvement was achieved in Group 4 than in the other DME groups.

Evaluation of thickness of individual macular retinal layers in diabetic eyes from optical coherence tomography.

The effect of diabetes mellitus (DM) on individual retinal layers remains incompletely understood. We evaluated the intra-retinal layer thickness alterations in 71 DM eyes with no diabetic retinopathy (DR), 90 with mild DR, and 63 with moderate DR without macular edema, using spectral-domain optical coherence tomography (SD-OCT) and the Iowa Reference Algorithm for automated retinal layer segmentation. The average thickness of 10 intra-retinal layers was then corrected for ocular magnification using axial length measurements, and pairwise comparisons were made using multivariable linear regression models adjusted for gender and race. In DM no DR eyes, significant thinning was evident in the ganglion cell layer (GCL; p < 0.001), inner nuclear layer (INL; p = 0.001), and retinal pigment epithelium (RPE; p = 0.014) compared to normal eyes. Additionally, mild DR eyes exhibited a thinner inner plexiform layer (IPL; p = 0.008) than DM no DR eyes. Conversely, moderate DR eyes displayed thickening in the INL, outer nuclear layer, IPL, and retinal nerve fiber layer (all p ≤ 0.002), with notably worse vision. These findings highlight distinctive patterns: early diabetic eyes experience thinning in specific retinal layers, while moderate DR eyes exhibit thickening of certain layers and slightly compromised visual acuity, despite the absence of macular edema. Understanding these structural changes is crucial for comprehending diabetic eye complications.

Detecting Visual Field Worsening From Optic Nerve Head and Macular Optical Coherence Tomography Thickness Measurements.

Purpose: Compare the use of optic disc and macular optical coherence tomography measurements to predict glaucomatous visual field (VF) worsening. Methods: Machine learning and statistical models were trained on 924 eyes (924 patients) with circumpapillary retinal nerve fiber layer (cp-RNFL) or ganglion cell inner plexiform layer (GC-IPL) thickness measurements. The probability of 24-2 VF worsening was predicted using both trend-based and event-based progression definitions of VF worsening. Additionally, the cp-RNFL and GC-IPL predictions were combined to produce a combined prediction. A held-out test set of 617 eyes was used to calculate the area under the curve (AUC) to compare cp-RNFL, GC-IPL, and combined predictions. Results: The AUCs for cp-RNFL, GC-IPL, and combined predictions with the statistical and machine learning models were 0.72, 0.69, 0.73, and 0.78, 0.75, 0.81, respectively, when using trend-based analysis as ground truth. The differences in performance between the cp-RNFL, GC-IPL, and combined predictions were not statistically significant. AUCs were highest in glaucoma suspects using cp-RNFL predictions and highest in moderate/advanced glaucoma using GC-IPL predictions. The AUCs for the statistical and machine learning models were 0.63, 0.68, 0.69, and 0.72, 0.69, 0.73, respectively, when using event-based analysis. AUCs decreased with increasing disease severity for all predictions. Conclusions: cp-RNFL and GC-IPL similarly predicted VF worsening overall, but cp-RNFL performed best in early glaucoma stages and GC-IPL in later stages. Combining both did not enhance detection significantly. Translational Relevance: cp-RNFL best predicted trend-based 24-2 VF progression in early-stage disease, while GC-IPL best predicted progression in late-stage disease. Combining both features led to minimal improvement in predicting progression.

Use of a dexamethasone implant to treat macular edema following pars plana vitrectomy and removal of the primary epiretinal membrane.

PURPOSE: The purpose of this study was to evaluate the effectiveness and safety of an intravitreal dexamethasone (DEX) implant for the treatment of macular edema (ME) following pars plana vitrectomy (PPV) and removal of the primary epiretinal membrane (ERM) and to assess the impact of the integrity of the ellipsoid zone (EZ) and disorganization of the retinal inner layer (DRIL) grade on visual and anatomical outcomes. METHODS: Forty-two pseudophakic patients who developed ME following PPV and removal of the primary stage 2-3 ERM were included. Patients were divided into two groups when ME was diagnosed via spectral domain optic coherence tomography (SD-OCT). In the DEX group (n = 22), DEX was implanted for the treatment of ME. In the control group (n = 20), only observation was conducted, without any treatment. The best-corrected visual acuity (BCVA) and macular thickness (MT) of the two groups were compared at baseline and 1, 6, and 12 months after DEX implantation. The effects of OCT parameters such as EZ integrity and DRIL grade were also evaluated in terms of decreases in MT and increases in VA in the treatment of ME with DEX implantation. Intraocular pressure (IOP), number of DEX implantations and adverse effects were also recorded. RESULTS: While a statistically significant increase in the mean BCVA was observed in the DEX group (p < 0.001 at months 1, 6, and 12, respectively), no such increase was detected in the control group (p = 0.169, p = 0.065, and p = 0.058 at months 1, 6 and 12, respectively) compared with the baseline. A statistically significant decrease in the mean MT was observed in the DEX group (p < 0.001 at months 1, 6, and 12); however, no significant difference was observed in the control group (p = 0.081, p = 0.065, and p = 0.054 at months 1, 6 and 12, respectively) compared with the baseline. Significant differences were found between the two groups in terms of the increase in BCVA (p < 0.01) and decrease in MT (p < 0.01) at all visits, with the outcomes being more favorable in the DEX group. A statistically significant relationship was found between the increase in VA and EZ integrity and DRIL grade in both groups. Ten patients (45.4%) received two injections of DEX during the follow-up. An increase in IOP was observed in five patients (22.7%) who were treated with topical antiglaucomatous drops. No significant side effects were observed. CONCLUSION: DEX implantation was found to be effective and safe for the treatment of ME following PPV and primary ERM removal, although some eyes may require repeated injections to achieve visual and anatomical success. Additionally, a relationship was found between EZ integrity, DRIL grade and visual-anatomical outcomes.

Macular structural integrity estimates are associated with Parkinson's disease genetic risk.

BACKGROUND: Optical coherence tomography (OCT) is a non-invasive technique to measure retinal layer thickness, providing insights into retinal ganglion cell integrity. Studies have shown reduced retinal nerve fibre layer (RNFL) and ganglion cell inner plexiform layer (GCIPL) thickness in Parkinson's disease (PD) patients. However, it is unclear if there is a common genetic overlap between the macula and peripapillary estimates with PD and if the genetic risk of PD is associated with changes in ganglion cell integrity estimates in young adults. METHOD: Western Australian young adults underwent OCT imaging. Their pRNFL, GCIPL, and overall retinal thicknesses were recorded, as well as their longitudinal changes between ages 20 and 28. Polygenic risk scores (PRS) were estimated for each participant based on genome-wide summary data from the largest PD genome-wide association study conducted to date. We further evaluated whether PD PRS was associated with changes in thickness at a younger age. To evaluate the overlap between retinal integrity estimates and PD, we annotated and prioritised genes using mBAT-combo and performed colocalisation through the GWAS pairwise method and HyPrColoc. We used a multi-omic approach and single-cell expression data of the retina and brain through a Mendelian randomisation framework to evaluate the most likely causal genes. Genes prioritised were analysed for missense variants that could have a pathogenic effect using AlphaMissense. RESULTS: We found a significant association between the Parkinson's disease polygenic risk score (PD PRS) and changes in retinal thickness in the macula of young adults assessed at 20 and 28 years of age. Gene-based analysis identified 27 genes common to PD and retinal integrity, with a notable region on chromosome 17. Expression analyses highlighted NSF, CRHR1, and KANSL1 as potential causal genes shared between PD and ganglion cell integrity measures. CRHR1 showed consistent results across multiple omics levels. INTERPRETATION: Our findings suggest that retinal measurements, particularly in young adults, could be a potential marker for PD risk, indicating a genetic overlap between retinal structural integrity and PD. The study highlights specific genes and loci, mainly on chromosome 17, as potential shared etiological factors for PD and retinal changes. Our results highlight the importance of further longitudinal studies to validate retinal structural metrics as early indicators of PD predisposition.

Comparative Analysis of Macular and Optic Disc Perfusion Pre and Post Silicone Oil Removal: A Machine Learning Approach.

In the realm of ophthalmic surgeries, silicone oil is often utilized as a tamponade agent for repairing retinal detachments, but it necessitates subsequent removal. This study harnesses the power of machine learning to analyze the macular and optic disc perfusion changes pre and post-silicone oil removal, using Optical Coherence Tomography Angiography (OCTA) data. Building upon the foundational work of prior research, our investigation employs Gaussian Process Regression (GPR) and Long Short-Term Memory (LSTM) networks to create predictive models based on OCTA scans. We conducted a comparative analysis focusing on the flow in the outer retina and vessel density in the deep capillary plexus (superior-hemi and perifovea) to track perfusion changes across different time points. Our findings indicate that while machine learning models predict the flow in the outer retina with reasonable accuracy, predicting the vessel density in the deep capillary plexus (particularly in the superior-hemi and perifovea regions) remains challenging. These results underscore the potential of machine learning to contribute to personalized patient care in ophthalmology, despite the inherent complexities in predicting ocular perfusion changes.

CLINICOPATHOLOGIC CHANGES OF VITREOMACULAR INTERFACE IN IDIOPATHIC EPIRETINAL MEMBRANE WITH DISORGANIZATION OF RETINAL INNER LAYERS.

PURPOSE: To compare the pathological characteristics of the vitreomacular interface of the idiopathic epiretinal membrane with and without disorganization of retinal inner layers (DRIL) and to correlate with clinical data. METHODS: In this clinicopathologic study, the samples of epiretinal membrane and internal limiting membrane were extracted from DRIL(+) (19 eyes) and DRIL(-) (22 eyes) idiopathic epiretinal membrane eyes. Ultrathin series sectioning for transmission electron microscopy was observed and correlated with surgery status and prognosis. RESULTS: All idiopathic epiretinal membrane eyes presented fibrocellular membranes accompanied by vitreous collagen, glial cells, and myofibroblasts, regardless of association with DRIL. A robust signal indicative of Collagen Type VI was observed in eyes DRIL(-), whereas Collagen Type I was discovered in DRIL eyes. Cell debris and microvascular basement membrane were seen on the retinal side of DRIL eyes and a larger cell count on the vitreous side. These have more intraoperative complications and less surgery benefit. CONCLUSION: Although internal limiting membrane peeling seems important, the histopathologic findings underscore the potential for retinal injury in DRIL(+) idiopathic epiretinal membrane eyes. This suggests that further research is needed to investigate individual preoperative assessment and to modify surgical procedures.

EN FACE OPTICAL COHERENCE TOMOGRAPHY MORPHOLOGY OF MACULAR PUCKER CORRELATES WITH METAMORPHOPSIA: Possible Role of the Henle Fiber Layer.

PURPOSE: To describe macular pucker contraction patterns with en face optical coherence tomography (OCT), to provide a correlation with metamorphopsia scores, and to discuss the protective role of the Henle fiber layer (HFL) against tangential traction. METHODS: Retrospective, institutional, observational, and consecutive case series. Clinical charts, M-charts scores, and structural and en face OCT imaging of patients diagnosed with macular pucker were reviewed. RESULTS: A 120 eyes of 114 consecutive patients diagnosed with macular pucker were included. En face OCT patterns of macular pucker contraction were foveal in 51 of 120 eyes (42.5%) and extrafoveal in 69 of 120 eyes (57.5%). Foveal macular puckers had regular, a concentric, circle morphology in the HFL (46/51 eyes, 90.2%), whereas extrafoveal membranes had irregular, distorted, circular HFL morphology (62/69 eyes, 89.8%; P < 0.001). Foveal contraction morphology and regular HFL pattern, as well as extrafoveal contraction morphology and an irregular HFL pattern, highly correlated one with another (P < 0.001 in both cases). Foveal macular puckers with regular HFL patterns had significantly less vertical and horizontal M-charts scores as compared with extrafoveal membranes with irregular HFL (P < 0.001 in both cases). Ellipsoid zone and external limiting membrane defects were rare in the parafoveal region (5/120 eyes, 4.2%). Visual acuity did not correlate with metamorphopsia scores (P = 0.903). CONCLUSION: En face OCT imaging identifies macular pucker contraction patterns that correlate with metamorphopsia scores and that can be used alongside the current structural OCT staging system to guide clinicians in the surgical decision-making process.

Spatial Distribution of Hyperreflective Choroidal Foci in the Macula of Normal Eyes.

Purpose: To investigate variations in the spatial distribution of hyperreflective foci in the choroid of the macula in normal eyes. Methods: We included eyes with a normal fundus from patients who had undergone optical coherence tomography angiography, covering a 6-mm × 6-mm area centered on the fovea. The macular area was divided into nine sectors according to the modified Early Treatment of Diabetic Retinopathy Study grid. Hyperreflective choroidal foci (HCF) distribution, choriocapillaris vascular density, and choroidal stromal density were determined on en face images of the choroid in each sector. Results: We included 35 eyes from 35 participants, with a mean age of 52.7 ± 16.8 years. The mean number and area fraction of HCF at the 5-mm macular area were 35.6 ± 7.8 foci/mm2 and 3.0% ± 0.7%, respectively. The number of HCF in the central circle (50.7 ± 20.9 foci/mm2) was greater than that in the inner (35.1 ± 13.0 foci/mm2) or outer rings (35.6 ± 6.5 foci/mm2) (P < 0.001, P < 0.001, respectively). The area fraction of HCF in the central circle (4.84% ± 3.36%) was greater than that in the inner (2.62% ± 1.17%; P < 0.001) or outer rings (3.12% ± 0.67%; P = 0.004). The HCF distribution did not significantly correlate with the choriocapillaris vascular density or choroidal stromal density in each sector. Conclusions: HCF were more densely distributed in the macular center than in the pericentral or peripheral macular areas. Translational Relevance: HCF measurement and spatial distribution could provide additional information for evaluating choroidal stromal characteristics.

Optical coherence tomography characteristics and prognostic predictors of acute macular neuroretinopathy following SARS-CoV-2 infection.

PURPOSE: To analyze the characteristics of optical coherence tomography in acute macular neuroretinopathy (AMN) following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and discuss the prognostic predictors. METHODS: Patients with AMN following SARS-CoV-2 infection were divided into two groups according to the presence or absence of hyperreflective outer nuclear layer (ONL) lesion involving the fovea. RESULTS: The first visit included 14 eyes in the fovea-involved group and 20 eyes in the no fovea-involved group. Ellipsoid zone (EZ) hyporeflection and interdigitation zone (IZ) interruption were detected in all eyes. Other common manifestations were myoid zone (MZ) hyperreflection (76.5%), ONL hyperreflection (73.5%), outer plexiform layer (OPL) thickening (64.7%), and EZ interruption (50%). The follow-up period was 48.4 ± 55.3 days. At the last visit, 12 eyes were in the fovea-involved group and 13 eyes in the no fovea-involved group. IZ interruption was detected in all eyes. Other common manifestations were EZ hyporeflection (92.0%), ONL atrophy (40.0%), OPL thickening (36.0%), OPL linear (32.0%), and MZ hyperreflection (32%). The improvement of visual acuity (VA) was -0.5 ± 0.5 and -0.2 ± 0.4 in the fovea-involved group and the no fovea-involved group, respectively, with a statistically significant difference between them (P = 0.045). Initial VA, initial cotton wool spot, initial ONL cyst, final ONL cyst, and final OPL linear were associated with final VA (P = 0.000, P = 0.029, P = 0.044, P = 0.049, P = 0.049, respectively). CONCLUSIONS: In the early stage of AMN following SARS-CoV-2 infection, IZ interruption and EZ hyporeflection were the most common manifestations, and pathology of IZ was more serious than that of EZ. Subsequently, OPL and ONL atrophied, and ONL atrophied faster. Regardless of whether hyperreflective ONL involved the fovea, VA improved, with a more noticeable improvement found in the fovea-involved group. The presence of initial ONL cyst and initial cotton wool spot, rapid atrophy of OPL, and poorer initial VA indicating poorer VA outcome.

Correlation of glycosylated hemoglobin (HbA1c) with retinal nerve fiber layer (RNFL) thickness and central macular thickness (CMT) in the diabetic population in North India.

PURPOSE: The current study was aimed to find correlation of glycosylated hemoglobin with retinal nerve fiber layer thickness (RNFLT) and central macular thickness (CMT) in the diabetic population in North India. METHODS: This was a cross-sectional observational study of 300 diabetic patients divided equally in two groups with and without retinopathy, and 150 people were included as control. The study was conducted from October 2020 to August 2022. All patients underwent slitlamp fundoscopy with a +78 D lens, and spectral-domain (SD) optical coherence tomography was performed to measure the RNFLT and CMT, and the staging of retinopathy was done as per the ETDRS classification. Along with that, blood investigations were ordered, including fasting (FBS) and post-prandial (PPBS) blood sugar and glycosylated hemoglobin (HbA1c). Quantitative variables were compared using one-way analysis of variance, or Kruskal-Wallis test was applied for inter-group comparison, followed by a Student Newman Keuls Test. RESULTS: The mean age of the patients in the diabetic group with retinopathy was 52.62 ± 9.38 years. The overall male: female ratio was 3:2. The mean FBS in the diabetic group with retinopathy was 146.54 ± 45.40mg/dl; the PPBS and HbA1c in the same were 210.39 ± 63.71mg/dl and 7.85 ± 1.33%, respectively. RNFL thinning was found in all four quadrants in diabetics irrespective of the status of retinopathy (P-value = 0.000) with a significant weak negative (r<0.4) correlation of glycosylated hemoglobin values with RNFLT in the inferior (r value = -0.300, P-value = 0.000) and superior (r value = -0.236, P-value = 0.004) quadrants of right eyes and in inferior (r value = -0.176, p- value = 0.031), superior (r value = -0.222, P value = 0.006), and nasal quadrants (r value = -0.166, p- value = 0.043) of left eyes in diabetics with retinopathy. However, in diabetics without retinopathy, no correlation was found. On correlating HbA1c with CMT, a weak positive (r<0.3) association existed in both eyes in the diabetic group without retinopathy (r = 0.020 and 0.048 for OD and OS, respectively) and diabetics with retinopathy (r = 0.152 and 0.127 for OD and OS, respectively). However, the association was not found to be significant in either of the groups (P-value > 0.05). CONCLUSION: The study concluded that neurodegeneration occurs in diabetic retinopathy as evident with nerve fiber layer thinning, and it is negatively correlated with glycosylated hemoglobin (HbA1c).

OCT angiographic evaluation of changes in macula and optic nerve head vessel density after a water drinking test in glaucomatous and healthy eyes.

PURPOSE: To evaluate the effects of a water drinking test (WDT) on the intraocular pressure (IOP) and vascular density of the optic nerve head and macula in healthy individuals and those with primary open glaucoma using optical coherence tomography angiography. METHODS: In this prospective comparative study, 30 healthy patients and 44 POAG subjects were divided into two groups. The study's outcome measures were the IOP and vessel density of the optic nerve and macular area. After ingesting 1000 ml of water in 5 min, the effect of the WDT on the IOP and the vascular density of the macular area and optic nerve head were measured at baseline and then 20, 40, and 60 min later at intervals of 20 min. RESULTS: The initial IOP in the healthy and glaucomatous eye groups was comparable (15.94 ± 2.6 and 16.87 ± 4.21 mmHg, respectively, P = 0.506). The IOP of both groups peaked at 40' measurements. POAG eyes had significantly higher IOP elevation (4.34 ± 0.30 vs. 2.24 ± 0.30 mmHg, P < 0.001). The glaucomatous eyes had lower radial peripapillary capillary (RPC) and whole macular superficial capillary plexus (SCP) densities at baseline (48.55 ± 5.99 vs. 51.33 ± 3.75) and (48.92 ± 3.41 vs. 45.29 ± 5.29), respectively (P < 0.001). After the WDT, the change in vessel density between groups in the RPC, whole superficial, and deep capillary plexuses was insignificant (SCP and DCP of 0.66 and 0.70, respectively, P = 0.16). CONCLUSION: The WDT caused a significant IOP jump in both glaucomatous and healthy eyes, but generally, the alterations in the glaucomatous eyes were more pronounced. The changes in vascular density in the macula and optic nerve head were similar between the groups.

Modeling Human Macular Cone Photoreceptor Spatial Distribution.

Purpose: The purpose of this study was to investigate the spatial distribution of human cone photoreceptors and examine cone density differences between the retinal meridians and quadrants. Method: Using adaptive optics scanning laser ophthalmoscopy, the maculae were imaged in 17 eyes of 11 subjects with normal chorioretinal health aged 54 to 72 years. We measured cone density at 325 points within the central 10 degrees radius of the retina. Cone density spatial distributions along the primary retinal meridians and in four macular quadrants (superior-nasal, superior-temporal, inferior-temporal, and inferior-nasal) were analytically modeled using the polynomial function to assess the meridional and quadrantal difference. Results: The mean and 95% confidence interval for the prediction of cone density along the primary retinal meridians was modeled with a 7-degree one-variable polynomial (R2 = 0.9761, root mean squared error [RMSE] = 0.0585). In the 4 retinal quadrants, cone density distribution was described by a 2-variable polynomial with X degree 3 and Y degree 4 (R² = 0.9834, RMSE = 0.0377). The models suggest no statistically significant difference between medians and between quadrants. However, cone density difference at corresponding spatial locations in different areas can be up to 25.6%. The superior-nasal region has more areas with high cone density, followed by quadrants of inferior-nasal, inferior-temporal, and superior-temporal. Conclusions: Analytical modeling provides comprehensive knowledge of cone distribution across the entire macula. Although modeling analysis suggests no statistically significant difference between medians and between quadrants, the remarkable cone density discrepancies in certain regions should be accounted for in applications requiring sensitive detection of cone variation.

Effect of brimonidine on vascular density and imagej-derived flow index of optic nerve head and macula in primary open angle glaucoma.

PURPOSE: To study the effect of brimonidine on vascular density and flow index of optic nerve head (ONH) and macula in primary open angle glaucoma (POAG) using optical coherence tomography angiography (OCTA). METHODS: Twenty-three brimonidine-naïve POAG patients were started on brimonidine. They underwent OCTA ONH and macula before commencing brimonidine and one month thereafter. Systemic arterial blood pressure (SABP) and intraocular pressure (IOP) were measured at each visit to calculate mean ocular perfusion pressure (MOPP). The OCT angiograms were analyzed using ImageJ software to calculate ONH and macular flow indices. RESULTS: Thirty-seven eyes (23 patients) with a mean age of 56.7 ± 12.49 years were included of whom 60.8% were males. Brimonidine was associated with an increase in the superficial flow index (SFI) (P-value = 0.02) and optic nerve head flow index (ONHFI) (P-value = 0.01). Also, superficial vascular density (SVD) for whole image, superior-hemi and fovea increased (P-value = 0.03, 0.02, 0.03 respectively). ONH inferior-hemi vascular density decreased (P-value = 0.01) despite an increase in inferior quadrant retinal nerve fiber layer thickness (RNFLT) (P-value = 0.03). There was no statistically significant correlation between flow indices and MOPP at baseline and follow-up. A moderate negative correlation was found between SVD and DVD at the fovea and MOPP at baseline and follow-up (P-value = 0.03, 0.05) (P-value = 0.02, 0.01) respectively. CONCLUSIONS: Brimonidine was associated with an increase in SFI, ONHFI and SVD indicating improved GCC and RNFL perfusion in POAG. Despite the increase in inferior quadrant RNFLT, the concomitant decrease in inferior-hemi ONHVD precluded a conclusion of hemodynamically-mediated improvement of RNFLT.

Optical coherence tomography angiography in thyroid associated ophthalmopathy: a systematic review.

PURPOSE: To evaluate the evidence for alterations of blood flow, vascular and perfusion densities in the choroid, macula, peripapillary region, and the area surrounding the optic nerve head (ONH) in patients with thyroid-associated ophthalmopathy (TAO) based on changes of OCTA parameters. METHODS: A systematic review of Pubmed, Google Scholar, Scopus, WOS, Cochrane, and Embase databases, including quality assessment of published studies, investigating the alterations of OCTA parameters in TAO patients was conducted. The outcomes of interest comprised changes of perfusion and vascular densities in radial peripapillary capillary (RPC), ONH, superficial and deep retinal layers (SRL and DRL), choriocapillaris (CC) flow, and the extent of the foveal avascular zone (FAZ). RESULTS: From the total of 1253 articles obtained from the databases, the pool of papers was narrowed down to studies published until March 20th, 2024. Lastly, 42 studies were taken into consideration which contained the data regarding the alterations of OCTA parameters including choriocapillary vascular flow, vascular and perfusion densities of retinal microvasculature, SRL, and DRL, changes in macular all grid sessions, changes of foveal, perifoveal and parafoveal densities, macular whole image vessel density (m-wiVD) and FAZ, in addition to alterations of ONH and RPC whole image vessel densities (onh-wiVD and rpc-wiVD) among TAO patients. The correlation of these parameters with visual field-associated parameters, such as Best-corrected visual acuity (BCVA), Visual field mean defect (VF-MD), axial length (AL), P100 amplitude, and latency, was also evaluated among TAO patients. CONCLUSION: The application of OCTA has proven helpful in distinguishing active and inactive TAO patients, as well as differentiation of patients with or without DON, indicating the potential promising role of some OCTA measures for early detection of TAO with high sensitivity and specificity in addition to preventing the irreversible outcomes of TAO. OCTA assessments have also been applied to evaluate the effectiveness of TAO treatment approaches, including systemic corticosteroid therapy and surgical decompression.

CLINICALLY RELEVANT POSTERIOR VITREOUS DETACHMENT STAGING USING CIRCUMPAPILLARY AND MACULAR VOLUME OPTICAL COHERENCE TOMOGRAPHY.

PURPOSE: This study was designed to investigate retinal nerve fiber layer circumpapillary optical coherence tomography to determine posterior vitreous detachment (PVD) status and to develop a clinically relevant PVD grading scale based on retinal nerve fiber layer circumpapillary optical coherence tomography to determine the incidence of PVD by age and association with vitreomacular traction disorders. METHODS: Ophthalmic images and medical records of patients with retinal diseases were retrospectively analyzed by three masked graders using retinal nerve fiber layer circumpapillary optical coherence tomography and macular optical coherence tomography. Based on PVD status, eyes were categorized into five newly defined PVD stages. RESULTS: Among 2002 eyes, PVD stages were as follows: A) 25 (1.25%); B) 725 (36.21%); C-) 248 (12.39%); C+) 151 (7.54%); D) 851 (42.51%); X) 2 (0.1%). Posterior vitreous detachment was correlated with advanced age (P < 0.0001). Limited separation or partial separation between lamella within the posterior vitreous cortex (Stage B) was noted early (68% of eyes <18 years). Overall, 34% of eyes >70 years did not exhibit complete PVD. Of 75 eyes with tractional vitreoretinal disorders, 64 (85.3%) were Stage C-/C+, identifying Stage C as the high-risk "complication" stage. CONCLUSION: Imaging analyses using retinal nerve fiber layer circumpapillary optical coherence tomography and macular optical coherence tomography scans in conjunction allow rapid assessment of the PVD stage. These techniques can assist clinicians and surgeons in counseling patients and planning surgical approaches. Observations confirmed the progression of PVD through predictable stages and the progression of PVD with age.

Analysis of macular thickness and peripapillary retinal nerve fiber layer thickness in various ABO and Rh blood groups.

PURPOSE: To determine the association between ABO and Rh blood groups with retinal structural indices including macular thickness and peripapillary retinal nerve fiber layer (RNFL) thickness. METHODS: This cross-sectional study was conducted using convenience sampling in a tertiary referral eye hospital in Tehran, Iran. Study participants were referred to the hospital laboratory to test their blood group. Ocular examinations were performed including measurement of visual acuity, auto-refraction, subjective refraction, and slit-lamp biomicroscopy. Retinal imaging was carried out using Spectral-domain OCT under dilated papillary conditions. RESULTS: Three hundred and twenty-eight individuals were recruited in this study. Of these, 219 (60.7%) were female and the mean age of the participants was 63.29 ± 5.57 years (range: 56 to 83 years). According to the multiple linear regression model, the global peripapillary RNFL thickness [coefficient: -3.05 (95% CI: -5.30 to -0.74); P = 0.010] and peripapillary RNFL thickness in the superior [coefficient: -4.65 (95% CI: -8.40 to -0.89), P < 0.001] and inferior [coefficient: -4.00 (95% CI: -7.81 to -0.19); P = 0.040] quadrants were significantly thinner in individuals with blood type B compared to those with other ABO blood groups. The average [coefficient: 12.69 (95% CI: 4.12-21.64); P = 0.004) and central [coefficient: 16.21 (95%: 6.44-25.97); P = 0.001) macular thicknesses were significantly thicker in AB group compared to other blood groups. The average macular thickness was significantly thinner in Rh + compared to the Rh- group [coefficient: -8.33 (95% CI: -15.4 to -1.25); P = 0.021]. CONCLUSION: Retinal structural indices may be related to blood groups implying a genetic linkage. Considering the lack of consistency among various studies, larger trials are needed to explore the effect of ABO and Rh grouping on peripapillary RNFL and macular thicknesses.

Correlation in retinal thickness and macular retina plus choroidal microcirculation in pediatric myopia.

To analyze the relationship in retinal thickness, macula retina and choroidal microcirculation in pediatric patients with myopia. Pediatric patients with high myopia (high myopia group, n = 30, 60 eyes) and pediatric patients with low to moderate myopia (low myopia group, n = 30, 60 eyes) admitted to our hospital from January 2021 to January 2022 were randomly selected as the study subjects. Retinal thickness, the blood density of retina, and the blood density of the choroid were collected in each area of the macula by taking optical coherence tomography (OCT) and OCT angiography (OCTA). Pearson correlation analysis was conducted to compare the results from the 2 groups. Outer retinal thickness showed a weak positive correlation with Superficial vascular complex flow density (SVD) and deep vascular complex flow density (DVD) (P < .05), but no significant correlation with choroidal capillary density (P > .05); inner retinal thickness showed a weak positive correlation with SVD and DVD (P < .05), but no significant correlation with choroidal capillary density (P > .05). In pediatric patients with myopia, there is a positive correlation between the blood flow density of macular retina and retinal thickness, and the retinal thickness will become thinner with increasing myopia.

Spatially resolved imaging of human macular capillaries using adaptive optics-enhanced optical coherence tomography angiography.

Documenting the organization of the retinal capillaries is of importance to understand the visual consequences of vascular diseases which may differentially affect the microvascular layers. Here we detailed the spatial organization of the macular capillaries in ten healthy human subjects using a prototypic adaptive optics-enhanced optical coherence tomography angiography (AO-OCTA) system. Within the central 6° × 6°, the radial peripapillary capillaries and the superficial, intermediate and deep vascular plexuses (SVP, IVP and DVP, respectively) were consistently resolved. In 8 out of the 10 eyes, the capillary segments composing the perifoveal arcade (PFA) were perfused only by the SVP, while drainage of the PFA showed more variability, comprising a case in which the PFA was drained by the DVP. Around the center, a distinct central avascular zone could be documented for each layer in 7 of the 10 cases; in three eyes, the IVP and SVP merged tangentially around the center. In all eyes, the foveal avascular zone was larger in the DVP than in the SVP and IVP. In one eye with incomplete separation of the inner foveal layers, there was continuity of both the SVP and the IVP; a central avascular zone was only present in the DVP. The diversity of perfusion and drainage patterns supported a connectivity scheme combining parallel and serial organizations, the latter being the most commonly observed in perifoveal vessels. Our results thus help to further characterize the diversity of organization patterns of the macular capillaries and to robustly analyze the IVP, which will help to characterize early stages of microvascular diseases.