RETINAL VASCULAR CYSTOID MACULAR EDEMA: Review and New Theory

Artificial intelligence-based assessment of imaging biomarkers in epiretinal membrane surgery

PurposeThis study investigated the applicability of a validated AI-algorithm for analyzing different retinal biomarkers in eyes affected by epiretinal membranes (ERMs) before and after surgery.MethodsA retrospective study included 40 patients surgically treated for ERMs removal between November 2022 and January 2024. Pars plana vitrectomy with ERM/ILM peeling was performed by a single experienced surgeon. A validated AI algorithm was used to analyze OCT scans, focusing on intraretinal fluid (IRF) and subretinal fluid (SRF) volumes, external limiting membrane (ELM) and ellipsoid zone (EZ) interruption percentages and hyper-reflective foci (HRF) counts.ResultsPostoperative best corrected visual acuity (BCVA) significantly improved (p < 0.01), and central macular thickness (CMT) decreased from 483.61 ± 96.32 to 386.82 ± 94.86 µm (p = 0.001). IRF volume reduced from 0.283 ± 0.39 mm3 to 0.142 ± 0.27 mm3 (p = 0.036) particularly in the central 1 mm-circle. SRF, HRF and EZ/ELM interruption percentages exhibited no significant differences (p > 0.05). Significant correlations (p < 0.05) were found between preoperative BCVA and postoperative BCVA (r = 0.45); CMT reduction and postoperative BCVA (r = 0.42), preoperative IRF and Visual Recovery (r = -0.48), ELM and EZ interruption and visual recovery (r = -0.43 and r = -0.47 respectively). Multivariate analysis demonstrated that fluid distribution, especially in the central subfield, correlated with BCVA recovery (R2 = 0.38; p < 0.05; Pillai's Trace = 0.79).ConclusionThe study highlights AI's potential in quantifying OCT biomarkers in ERMs surgery. The findings suggest that improved BCVA is associated with reduced CMT, IRF, and redistribution of IRF towards the periphery. EZ and ELM integrities remain crucial prognostic factors, emphasizing the importance of the preoperative analysis.

Microcystoid Macular Edema in Epiretinal Membrane: Not a Retrograde Maculopathy

PURPOSE

To investigate the incidence, clinical spectrum, and pathophysiology of microcystoid macular edema (MME) in 2 cohorts of patients with epiretinal membrane (ERM) and idiopathic full-thickness macular hole (FTMH).

DESIGN

Single-center, retrospective, interventional, cohort study.

METHODS

Review of clinical charts, structural and en-face optical coherence tomography (OCT), and fluorescein angiography (FA) imaging of ERM and FTMH eyes that underwent surgery with pars plana vitrectomy and internal limiting membrane (ILM) peel, with a minimum follow-up of 6 months. Histopathology analysis of 3 specimens: 2 human retinas and 1 human ILM.

RESULTS

One hundred seventy-two patients with ERM (123) and FTMH (49) were included in the study and followed up a mean of 9.1 ± 4.7 and of 8.2 ± 3.6 months, respectively. Preoperatively, MME was present in 27 of 123 eyes with ERM (21.9%), and in none of 49 eyes with FTMH (P < .001). MME was significantly associated with advanced ERM stages (P < .001). MME was typically located below continuous ERM-ILM adherence areas. FA in 46 ERM eyes showed capillary leakage in 36.4% of eyes without MME or cystoid macular edema (CME), in 39% of eyes with MME, and increased hyperfluorescence in CME. Postoperatively, new-onset MME appeared in 13 of 84 ERM eyes (15.5%) and in 1 FTMH eye (2%, P = .014). MME resolved in 7 of 40 ERM eyes with either preoperative or postoperative MME (17.9%) by 2.8 ± 1.5 months postsurgery. MME showed variable evolution postoperatively. The association between MME and postoperative best corrected visual acuity was significant only in univariate analysis (P = .037). Histopathology analysis showed anatomical continuity between Müller cells and ERM, suggesting a higher risk of iatrogenic damage in ERM eyes during peeling maneuvers.

CONCLUSIONS

Postoperative MME was a frequent finding in ERM and a rare occurrence in FTMH, suggesting that ILM peeling alone may not be sufficient to cause MME. The morphology and clinical characteristics of ERM-related MME are unlikely related to neurodegenerative processes and rather attributable to Müller cell disruption and iatrogenic damage. The characteristics of MME and CME may overlap, blurring the differences between the 2 entities.

Clinical and spectral-domain optical coherence tomography findings and changes in new-onset macular edema after silicone oil tamponade

BACKGROUD

Few investigations have been conducted on the detailed clinical features of CME associated with SiO, from emergence to restoration, especially using OCT images. This study aimed to analyze the clinical and spectral-domain optical coherence tomography (SD-OCT) characteristics and changes in cystoid macular edema (CME) associated with silicone oil (SiO).

METHODS

Retrospective case series. Six cases of newly on-set CME after SiO tamponade were examined. SD-OCT was performed before pars plana vitrectomy, after SiO tamponade, and after SiO removal. Clinical and SD-OCT data was collected.

RESULTS

CME was first noted at 28.83 ± 9.22 days after SiO tamponade. The average foveal thickness was 411 ± 41 μm before oil removal and decreased to 267 ± 69 μm three days after oil removal (P = 0.028). The average visual acuity before and after oil removal were 0.82 ± 0.40 logarithm of the minimum angle of resolution (logMAR) and 0.75 ± 0.45 logMAR, respectively, and the difference was not statistically significant (P = 0.285). SD-OCT revealed that three patients had edema first in the inner nuclear layer (INL), and three had cysts in both INL and outer nuclear layers (ONL) at discovery. Of the six patients, three exhibited cystic changes in the fovea firstly. CME showed rapid recovery following SiO removal, with cysts completely disappearing in four patients (66.7%) within 3 days. However, in two patients (33.3%), the cysts persisted in INL after three days, whereas the cysts in ONL had resolved completely. The ellipsoid zone integrity of the macular region was smoother in patient with better vision.

CONCLUSION

New-onset CME after SiO tamponade may initially affects INL and then ONL. CME shows significant improvement after oil removal, probably initially resolving in ONL, and then followed by INL. SD-OCT enabless monitoring of macular microstructure changes in SiO-treated eyes, and macular cysts' occurrence can indicate the oil removal need.

The spectrum of microcystic macular edema: Pathogenetic insights, clinical entities, and functional prognosis

Microcystic macular edema (MME) is the presence of small cystoid abnormalities localized in the inner nuclear layer of the retina. First identified in the context of multiple sclerosis, successive reports highlighted the presence of microcystic changes in several optic nerve conditions, such as neuromyelitis optica, optic atrophy from several etiologies, medical retinal diseases such as age-related macular degeneration and diabetic retinopathy, and in the postoperative period after epiretinal membrane peeling. Generally, these cysts are not associated with vascular leakage, unlike the more conventional types of macular edema from vascular origin. A number of theories have been proposed to explain these findings: the suspect of neuronal loss as causative finding made the hypothesis of retrograde trans-synaptic degeneration likely, more recently flanked by theories including the presence of vitreomacular traction and Müller cells dysfunction. We gather all the insights regarding the pathogenesis, epidemiology and functional impact of MME.

Future applications of fluorescence lifetime imaging ophthalmoscopy in neuro-ophthalmology, neurology, and neurodegenerative conditions

Fluorescence lifetime imaging ophthalmoscopy (FLIO) has emerged as an innovative advancement in retinal imaging, with the potential to provide in vivo non-invasive insights into the mitochondrial metabolism of the retina. Traditional retinal imaging, such as optical coherence tomography (OCT) and fundus autofluorescence (FAF) intensity imaging, focus solely on structural changes to the retina. In contrast, FLIO provides data that may reflect retinal fluorophore activity, some of which may indicate mitochondrial metabolism. This review builds upon the existing literature to describe the principles of FLIO and established uses in retinal diseases while introducing the potential for FLIO in neurodegenerative conditions.

En face OCT: Breakthroughs in understanding the pathoanatomy of retinal disease and clinical applications

En face optical coherence tomography (OCT) is a practical and informative imaging modality to noninvasively visualize distinct retinal and choroidal layers by providing coronal images using boundary-specific segmentation. Ongoing research with this method is generating breakthroughs in the illustration of new perspectives of retinal disease. The clinical value of en face OCT as an advanced retinal imaging tool is growing steadily and it has unveiled many new insights into the pathoanatomy of retinal disorders. Moreover, this modality can capture various en face OCT biomarkers that correspond to different cell or tissue subtypes, which were previously only identified through histological or electron microscopy methods, underscoring the significance of this technique in providing valuable pathoanatomical information. In this comprehensive review, we will systematically summarize the en face OCT findings across a broad spectrum of retinal diseases, including disorders of the vitreoretinal interface and retinal vascular system (e.g. paracentral acute middle maculopathy or PAMM and diabetic retinopathy), in addition to the en face OCT features of other conditions such as age-related macular degeneration, pachychoroid disease spectrum, myopic degeneration, uveitis and inflammatory disorders, inherited retinal dystrophies, and drug toxicity. We will discuss and highlight the unique clinical and pathoanatomical findings uncovered with en face OCT of each these diseases mentioned above.

Progerin mRNA Is Associated with Smoking and Signs of Increased Microvascular Damage in Patients with Diabetic Macular Edema

The premature aging disease Hutchinson-Gilford Syndrome (HGPS) is caused by defined mutations in the LMNA gene, resulting in the activation of a cryptic splice donor site, which leads to a defective truncated prelamin A protein called progerin. Notably, progerin expression has also been detected in non-mutated healthy individuals, and therefore, its involvement in the physiological aging process has been widely discussed. Since diabetes mellitus is associated with premature aging and increased cardiovascular mortality, we aimed to investigate the role of progerin expression in patients with diabetic retinopathy (DR). mRNA expression of progerin was analyzed in blood samples from 140 patients with DR who received anti-vascular endothelial growth factor (VEGF) therapy. Progerin mRNA levels were significantly lower in female compared to male patients (n = 42 vs. n = 98; 0.67 ± 0.19 vs. 0.89 ± 0.51, p = 0.006) and higher in patients with non-proliferative (NP)DR (n = 87 vs. n = 53; 0.9 ± 0.51 vs. 0.71 ± 0.29, p = 0.013) compared to those with proliferative (P)DR. Additionally, a positive correlation was found between progerin mRNA expression and the number of intravitreal anti-VEGF applications (n = 139, r = 0.21, p = 0.015), central macula thickness (CMT), (n = 137, r = 0.18, p = 0.036) and nicotine consumption (n = 105, r = 0.235, p = 0.002). The nuclear localization and significant upregulation of progerin mRNA and protein levels in dermal fibroblasts from HGPS donors emphasize its role in cellular aging mechanisms. Progerin mRNA levels were higher in patients with NPDR. CMT, number of intravitreal anti-VEGF therapy treatments, and cigarette consumption were positively related to progerin mRNA, suggesting an association with disease progression and premature aging.

Radial Peripapillary Capillary Vessel Density as a New Biomarker in Pseudophakic Cystoid Macular Edema

Background/Objectives: Our aim was to investigate the vessel density (VD) of the radial peripapillary capillary (RPC) plexus in eyes with early pseudophakic cystoid macular edema (PCME) and controls using OCT angiography (OCTA). Methods: Patients with PCME and controls underwent structural OCT to assess the retinal nerve fiber layer (RNFL) and central macular thickness (CMT) and 6 × 6 mm2 macular OCTA to record the superficial (SVP), deep (DVP) vascular plexus, and choriocapillaris. A scan area of 4.5 × 4.5 mm2 was centered on the optic disk to analyze the RPC plexus VD. Fluorescein angiography was performed in PCME patients. Results: Data from 30 PCME and 30 control eyes, matched for age, were analyzed. The mean CMT was larger in PCME eyes than in control eyes (450 ± 6.5; 243 ± 3.5 micron, p < 0.001). The mean RNFL thickness was significantly greater in terms of global thickness in the PCME group compared to the control group (103 ± 5.2; 91 ± 2.5 micron, p < 0.001). The PCME group had a statistically significant increase in the VD of the RPC in the whole image, peripapillary region, and inside disk compared to the control group (p < 0.001). There was no difference in SVP (p = 0.660) or DVP (p = 0.480) VD between the two groups. A significant correlation was found between the average RNFL thickness and the VD of the RPC (p < 0.05). Conclusions: Eyes with PCME showed increased VD of the RPC and a correlation between this parameter and RNFL thickness; the VD of the RPC shows potential as a reliable non-invasive biomarker for the early diagnosis of PCME.

Cystoid Macular Edema Following Rhegmatogenous Retinal Detachment Repair Surgery: Incidence, Pathogenesis, Risk Factors and Treatment

Purpose

To review the incidence, risk factors, and treatments for cystoid macular edema (CME) following rhegmatogenous retinal detachment (RRD) repair surgery.

Methods

A comprehensive literature search was conducted across multiple databases. Relevant studies published within the last 20 years were selected and reviewed.

Results

The incidence of CME following RRD repair ranges from 6% to 36%, with higher rates associated with silicone oil tamponade. Key risk factors include recurrent RRD, pre-existing proliferative vitreoretinopathy, older age, and post-RRD cataract surgery. Treatment options primarily focus on anti-inflammatory approaches, with topical NSAIDs and corticosteroids as first-line treatments. For persistent cases, intravitreal corticosteroid injections, particularly dexamethasone implants, have shown potential.

Conclusion

CME remains a significant complication following RRD repair, impacting visual recovery. While various treatment options exist, management of persistent CME remains challenging. Better understanding of the underlying mechanisms of CME is required to develop more effective treatment strategies, particularly for cases resistant to current therapies.

Comparison of intravitreal anti-VEGF agents and oral carbonic anhydrase inhibitors in the treatment of cystoid macular edema secondary to retinitis pigmentosa

Purpose

To compare the efficacy of intravitreal antivascular endothelial growth factor (anti-VEGF) agents with oral carbonic anhydrase inhibitors (CAIs) in treating cystoid macular edema (CME) secondary to retinitis pigmentosa (RP).

Methods

This retrospective study analyzed 98 patients (98 eyes) with RP-CME: 47 (48.0%) received intravitreal anti-VEGF agents (Ranibizumab or Bevacizumab) and 51 (52.0%) were treated with oral CAIs (methazolamide 50 mg/day or acetazolamide 500 mg/day). Medical records were reviewed to assess best-corrected visual acuity (BCVA), central macular thickness (CMT), and intraocular pressure (IOP) at baseline and at 1, 3, 6, and 12 months post-treatment using Generalized Estimation Equations (GEE). Adverse events and risk factors influencing visual prognosis were also evaluated.

Results

Both groups showed significant improvement in BCVA and reduction in CMT at 1 and 3 months post-treatment compared to baseline (all p < 0.001). In the oral CAIs group, these improvements persisted until 6 months. However, by 12 months, neither group exhibited significant improvements in BCVA or CMT compared to baseline (all p > 0.05). Intragroup comparisons revealed that the oral CAIs group had significantly better BCVA and CMT improvements at 3 and 6 months than intravitreal anti-VEGF group (p < 0.001 for BCVA at 3 months, p = 0.003 for BCVA at 6 months; all p < 0.001 for CMT at both 3 and 6 months). No significant differences were found between the two groups in BCVA and CMT at 12 months or in IOP at any time point (all p > 0.05). Subgroup analysis indicated that oral acetazolamide was more effective than methazolamide in reducing CMT and improving BCVA at 3 and 6 months (p = 0.005 for BCVA at 3 months, p = 0.015 for BCVA at 6 months; p = 0.037 for CMT at 3 months, p < 0.001 for CMT at 6 months). There were no significant differences in outcomes between intravitreal Ranibizumab and Bevacizumab (all p > 0.05). Correlation analysis showed that worse BCVA at 12 months was associated with older age (r = 0.202, p = 0.046), higher baseline CMT (r = 0.353, p < 0.001), poorer baseline BCVA (r = 0.579, p < 0.001), but showed no correlation with genotype. Adverse effects from oral CAIs included tingling sensation (3.9%), altered taste (9.8%), and gastrointestinal upset (7.8%). The Ranibizumab group required an average of 3.7 ± 0.8 treatments, and the Bevacizumab group required an average of 3.8 ± 0.5 treatments over the course of 1 year without experiencing severe adverse effects.

Conclusion

Both intravitreal anti-VEGF agents and oral CAIs effectively improved CMT and BCVA in RP-CME patients within the first 3 months of treatment. However, oral CAIs demonstrated superior anatomic and functional improvements at 6 months. Poorer BCVA prognosis was associated with older age, higher baseline CMT, poorer baseline visual acuity. Larger, randomized clinical trials with extended follow-up periods are needed to confirm these findings.

Clinical Efficacy of Tobramycin Dexamethasone+Pranoprofen Eye Drops on Endophthalmitis in Cataract Patients Complicated with Diabetes Mellitus after Intraocular Lens Implantation

BACKGROUND

There is little research on the anti-inflammatory efficacy and safety of tobramycin dexamethasone+pranoprofen eye drops in treating endophthalmitis.

AIM

To appraise the efficacy and safety of tobramycin dexamethasone+propranolofen eye drops in the treatment of endophthalmitis.

METHODS

The degree of corneal edema, foveal thickness, score of anterior chamber (AC) flares, best corrected visual acuity (BCVA), fasting blood glucose, inflammatory indexes of serum and aqueous humor, and adverse reactions were observed every week.

RESULTS

After the intervention with tobramycin dexamethasone+pranoprofen eye drops, corneal edema and foveal thickness reduced, BCVA improved, and the inflammatory markers in serum and aqueous humor decreased. Moreover, the incidence of adverse reactions in the tobramycin dexamethasone+pranoprofen group was lower than that in the control group and the fluorometholone group (P < 0.05).

CONCLUSION

Tobramycin dexamethasone+pranoprofen eye drops can inhibit inflammation better, recover vision faster, and make the incidence of adverse reactions lower in treating cataract patients complicated with DM developing endophthalmitis induced.

Morphologic Features of Regulated vs. Dysregulated Rhegmatogenous Retinal Detachment Using Swept-Source Optical Coherence Tomography

OBJECTIVE

To describe varying morphological features of patients with RRD based on the extent of regulation of the subretinal space by the retinal pigment epithelium (RPE) pump using swept-source optical coherence tomography (SS-OCT).

DESIGN

Prospective clinical cohort study.

METHODS

 Setting: St. Michael's Hospital, Toronto, Canada, from August 2020-August 2023.

PARTICIPANTS

120 consecutive eyes with primary RRD. Cohorts: Subclinical, non-progressive, localized RRD defined as regulated vs. acute, progressive, and extensive defined as dysregulated, assessed with SS-OCT.

MAIN OUTCOME

Morphological features of regulated vs. dysregulated RRDs with SS-OCT.

RESULTS

19.2% (23/120) of RRDs were classified as regulated and 80.8% (97/120) were dysregulated. The mean age of patients with regulated RRDs was 37.1 years (±13.7 SD) vs. 62.6 years (±11.6SD) for patients with dysregulated RRDs (P < .001). The presence of outer retinal corrugations (ORCs) on OCT was observed in 4.3% (1/23) of regulated vs. 81.4% (79/97) of dysregulated RRDs (P < .001). CME was found in 41.6% (5/12) of regulated RRDs compared to 87.3% (83/95) of dysregulated RRDs (P < .001). ORC presence was an independent predictor of having a dysregulated RRD (P = .02, β = 6.6, 95% CI [1.3-33.2]) when controlling for age, sex, baseline VA, lens status, and RD extent. Among patients with regulated RRDs, 25.0% (3/12) were in Stage 2, 0% (0/16) in Stage 3A, 8.3% (1/12) in Stage 3B, 0% (0/16) in Stage 4, and 66.7% (8/12) in Stage 5. In patients with dysregulated RRDs, 14.7% (14/95) were in Stage 2, 15.7% (15/95) were in Stage 3A, 37.9% (36/95) in Stage 3B, 22.1% (21/95) in Stage 4, and 9.5% (9/95) in Stage 5 (P < .001).

CONCLUSIONS

There are significant morphologic differences between regulated and dysregulated RRDs using SS-OCT. ORCs are present in almost all dysregulated cases but in a minority of regulated cases and they are an independent predictor of RPE-photoreceptor regulation status. Demographic and clinical features differentiate regulated and dysregulated RRD and understanding these differences has significant implications for optimal management and postoperative outcomes.

Changes in vessel density patterns assessed with OCTA in patients with diabetic macular edema treated with anti-VEGF therapy

AIMS

To determine the presence of sectoral changes in vessel density (VD) patterns induced by vascular endothelial growth factor inhibitors (anti-VEGF) in patients with diabetic macular edema (DME) using optical coherence tomography angiography (OCTA).

METHODS

Prospective, interventional study. A total of 43 patients (63 eyes) were initially enrolled in the study. We performed swept source (SS) OCT and sectorial OCTA measurement to determine parafoveal VD at baseline and after six months of anti-VEGF treatment. In the locations with statistically significant differences in VD between baseline and month 6, we performed univariate and multivariate analyses to determine which, if any, of the baseline variables were associated with the observed changes.

RESULTS

A total of 34 patients (48 eyes) were included in the final analysis. Mean VD decreased from baseline to month 6 (from 45.2 (± 3.5) to 44.6 (± 3.2) % in the SCP and from 50 (± 3.3) to 49 (± 3.9) % in the DCP). The only significant changes in VD were observed in the nasal sector of the deep capillary plexus, with a decrease of 2.9% (p = 0.001). On univariate and multivariate analyses, the only variable significantly associated with changes in VD in the nasal sector after 6 months of treatment was baseline VD in the same sector.

CONCLUSIONS

Anti-VEGF therapy has a small impact on VD values over time. These variations observed after treatment seems to be related to changes over areas of vascular anomalies and displaced vessels adjacent to cystic areas, with no significant changes over ischemic areas. No correlation was observed between this trend and other clinical baseline features.

Microvascular changes in eyes with non-proliferative diabetic retinopathy with or without macular microaneurysms: an OCT-angiography study

PURPOSE

To evaluate different quantitative non-invasive retinal biomarkers of microvascular impairment and neurodegeneration in patients affected by mild and moderate non proliferative diabetic retinopathy (NPDR) with or without macular microaneurysms (MAs).

METHODS

A cross-sectional case-control study. Ninety-seven eyes with NPDR, 49 with no central MAs and 48 with central MAs, underwent color fundus photography and optical coherence tomography (OCT)/OCT-angiography (OCT-A). Thickness of central macula, retinal nerve fiber layer (NFL), ganglion cell layer (GCL+) and NFL + GCL + was evaluated on OCT. FAZ metrics (ImageJ), perfusion and vessel density (PD/VD), and fractal dimension (FD) (MATLAB) were evaluated on 3 × 3 OCT-A slabs of both superficial and deep capillary plexuses (SCP/DCP). All evaluations were performed on the full image and after subdivision in 4 quadrants.

RESULTS

In the MA group, 77 MAs were detected (45.5% in the DCP). The MA group showed: increased FAZ area and perimeter in the SCP (p < 0.01) and DCP (p = 0.02), and reduced circularity index in the SCP (p = 0.03); reduced VD in the SCP (p < 0.01) and reduced PD, VD (p < 0.01) and FD (p = 0.02) in the DCP; decreased VD and FD in the SCP (p = 0.02 and p = 0.05), and in VD and FD in the DCP in the inferior quadrant (p = 0.04 and p = 0.03); a decrease in VD in the SCP in the nasal quadrant (p = 0.05). No differences have been detected in OCT parameters.

CONCLUSIONS

Our results suggest that the presence of central MAs in patients with NPDR may correlate with more pronounced macular microvascular impairment, particularly during the mild and moderate stages of the disease.

The Role of Immune Cells and Signaling Pathways in Diabetic Eye Disease: A Comprehensive Review

Diabetic eye disease (DED) encompasses a range of ocular complications arising from diabetes mellitus, including diabetic retinopathy, diabetic macular edema, diabetic keratopathy, diabetic cataract, and glaucoma. These conditions are leading causes of visual impairments and blindness, especially among working-age adults. Despite advancements in our understanding of DED, its underlying pathophysiological mechanisms remain incompletely understood. Chronic hyperglycemia, oxidative stress, inflammation, and neurodegeneration play central roles in the development and progression of DED, with immune-mediated processes increasingly recognized as key contributors. This review provides a comprehensive examination of the complex interactions between immune cells, inflammatory mediators, and signaling pathways implicated in the pathogenesis of DED. By delving in current research, this review aims to identify potential therapeutic targets, suggesting directions of research for future studies to address the immunopathological aspects of DED.

Oral Intake of Hydrogen Water Improves Retinal Blood Flow Dysregulation in Response to Flicker Stimulation and Systemic Hyperoxia in Diabetic Mice

Purpose

To examine the effects of hydrogen water on retinal blood flow (RBF) dysregulation in diabetes, we evaluated changes in RBF in response to flicker stimulation and systemic hyperoxia in diabetic mice.

Methods

Twelve type 2 diabetic mice were divided into a group that received non-hydrogen water (n = 6, control group) and the other that received hydrogen-rich water (0.6-0.8 mM) (n = 6, HRW group) from six weeks of age. Body weight, blood glucose, intraocular pressure, and blood pressure were evaluated from eight to 14 weeks of age. RBF was measured in the vascular area of the optic disc as mean blur rate using laser speckle flowgraphy in the resting state and response to flicker stimulation and hyperoxia. We evaluated glial activation and oxidative stress based on immunofluorescence expression.

Results

At 14 weeks, blood glucose level was significantly lower in the HRW group, though still elevated. RBF changes improved significantly in the HRW group compared with the control group from eight weeks of age and persisted throughout the study. Immunofluorescent expression of glial fibrillary acidic protein, particularly in the outer plexiform layer, was significantly decreased in the HRW group. Among oxidative stress markers, 3-nitrotyrosine was significantly suppressed in the HRW group.

Conclusions

Hydrogen-rich water intake significantly improved RBF dysregulation in diabetic mice. Hydrogen may improve impaired neurovascular coupling function in diabetic mice by suppressing gliosis and oxidative stress in the retina.

Translational Relevance

This study highlights the potential of oral intake of hydrogen-rich water to mitigate retinal dysfunction in diabetic mice.

Association between choroidal thickness and diabetic macular edema: a meta-analysis

AIMS

To evaluate the association between subfoveal choroidal thickness (SFCT) and diabetic macular edema (DME).

DESIGN

A systematic review and meta-analysis.

METHODS

A retrospective or prospective study comparing SFCT in diabetic retinopathy (DR) patients with and without DME was included. The data were collected from published studies retrieved from PubMed, Web of Science, Embase, Ovid Medline, and Cochrane Library. The final search was conducted on July 2, 2023. Heterogeneity was assessed using I2 statistics, and a random-effects model was used for the meta analysis. This study calculated the weighted mean difference (WMD) and 95% confidence interval (CI) for SFCT.

RESULTS

A total of 26 relevant studies were identified, involving a combined sample size of 3201 eyes (1302 DR-DME eyes and 1899 DR-no DME eyes). The results showed no significance between DR-DME and DR-no DME (WMD = - 3.57 μm; 95% CI -26.54 to 19.41 μm; P = 0.76). Sub-analysis based on nonproliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR) subgroups showed that the SFCT of NPDR-DME was significantly thinner than that of NPDR-no DME eyes (WMD = - 19.80 μm; 95% CI - 34.55 to - 5.04 μm; P = 0.009), while there was no significance in SFCT between PDR-DME and PDR-no DME (WMD = - 26.45 μm; 95% CI - 104.00 to 51.11 μm; P = 0.50).

CONCLUSION

The SFCT was thinner in NPDR-DME eyes compared to NPDR-no DME eyes. Thinning SFCT might cause retinal hypoxia, and play an important role in DME occurrence. Additionally, this study highlights the importance of considering DR grades and treatment history when evaluating SFCT between DME and no DME.

Retinal Vein Occlusion-Background Knowledge and Foreground Knowledge Prospects-A Review

Thrombosis of retinal veins is one of the most common retinal vascular diseases that may lead to vascular blindness. The latest epidemiological data leave no illusions that the burden on the healthcare system, as impacted by patients with this diagnosis, will increase worldwide. This obliges scientists to search for new therapeutic and diagnostic options. In the 21st century, there has been tremendous progress in retinal imaging techniques, which has facilitated a better understanding of the mechanisms related to the development of retinal vein occlusion (RVO) and its complications, and consequently has enabled the introduction of new treatment methods. Moreover, artificial intelligence (AI) is likely to assist in selecting the best treatment option for patients in the near future. The aim of this comprehensive review is to re-evaluate the old but still relevant data on the RVO and confront them with new studies. The paper will provide a detailed overview of diagnosis, current treatment, prevention, and future therapeutic possibilities regarding RVO, as well as clarifying the mechanism of macular edema in this disease entity.

Global research trends and future directions in diabetic macular edema research: A bibliometric and visualized analysis

BACKGROUND

Diabetic Macular Edema (DME) significantly impairs vision in diabetics, with varied patient responses to current treatments like anti-vascular endothelial growth factor (VEGF) therapy underscoring the necessity for continued research into more effective strategies. This study aims to evaluate global research trends and identify emerging frontiers in DME to guide future research and clinical management.

METHODS

A qualitative and quantitative analysis of publications related to diabetic macular edema retrieved from the Web of Science Core Collection (WoSCC) between its inception and September 4, 2023, was conducted. Microsoft Excel, CiteSpace, VOSviewer, Bibliometrix Package, and Tableau were used for the bibliometric analysis and visualization. This encompasses an examination of the overall distribution of annual output, major countries, regions, institutions, authors, core journals, co-cited references, and keyword analyses.

RESULTS

Overall, 5624 publications were analyzed, indicating an increasing trend in DME research. The United States was identified as the leading country in DME research, with the highest h-index of 135 and 91,841 citations. Francesco Bandello emerged as the most prolific author with 97 publications. Neil M. Bressler has the highest h-index and highest total citation count of 46 and 9692, respectively. The journals "Retina - the Journal of Retinal and Vitreous Diseases" and "Ophthalmology" were highlighted as the most prominent in this field. "Retina" leads with 354 publications, a citation count of 11,872, and an h-index of 59. Meanwhile, "Ophthalmology" stands out with the highest overall citation count of 31,558 and the highest h-index of 90. The primary research focal points in diabetic macular edema included "prevalence and risk factors," "pathological mechanisms," "imaging modalities," "treatment strategies," and "clinical trials." Emerging research areas encompassed "deep learning and artificial intelligence," "novel treatment modalities," and "biomarkers."

CONCLUSION

Our bibliometric analysis delineates the leading role of the United States in DME research. We identified current research hotspots, including epidemiological studies, pathophysiological mechanisms, imaging advancements, and treatment innovations. Emerging trends, such as the integration of artificial intelligence and novel therapeutic approaches, highlight future directions. These insights underscore the importance of collaborative and interdisciplinary approaches in advancing DME research and clinical management.

Migraine eye: correlation between migraine and the retina

Background

Activation of the trigeminal vascular system in migraine releases vasoactive neurotransmitters, causing abnormal vasoconstriction, which may affect the ocular system, leading to retinal damage. The purpose of our study was to determine whether there are differences in each retinal layer between migraine patients and healthy subjects.

Methods

A case-control study recruited 38 migraine patients and 38 age- and sex-matched controls. Optical coherence tomography was used to measure the thickness of the peripapillary and macular retinal nerve fiber layer (pRNFL and mRNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), and inner nuclear layer (INL).

Results

The mean ages of the migraine patients and controls were 36.29 ± 9.45 and 36.45 ± 9.27 years, respectively. Thirty-four patients (89.48%) in both groups were female. The mean disability score was 19.63 ± 20.44 (indicating severe disability). The superior-outer INL of migraine patients were thicker than controls. Thickness of the GCL at temporal-outer sector and mRNFL at the superior-outer sector of the headache-side eyes was reduced. However, the INL of the headache-side-eye showed negative correlation with the disability score. This is the first study having found thinning of the GCL and mRNFL of the headache-side eyes. The INL was also thickened in migraines but showed negative correlation with the disability score.

Conclusions

Increased INL thickness in migraine patients may result from inflammation. The more severe cases with a high disability score might suffered progressive retinal neuronal loss, resulting in thinner INL than less severe cases.

Risk Factors Associated with Cystoid Macular Edema among Patients Undergoing Primary Repair of Rhegmatogenous Retinal Detachment

PURPOSE

To investigate predictors of the development and resolution of cystoid macular edema (CME) after rhegmatogenous retinal detachment (RRD) repair.

DESIGN

Retrospective cross sectional study.

SUBJECTS

Patients who underwent primary repair of uncomplicated RRD.

METHODS

Demographics, ophthalmic history, visual acuity, RRD features, time to development/resolution of CME, OCT characteristics of CME/epiretinal membrane (ERM), type of surgery, and treatments were collected. Logistic regressions were used to identify predictors of CME development and resolution.

MAIN OUTCOME MEASURES

Predictors of CME development and resolution.

RESULTS

A total of 708 eyes were included, of which 55 (7.8%) developed CME. Factors associated with an increased risk of CME development included total number of retinal detachment surgeries (odds ratio [OR] 1.66 [1.24-2.23], P < 0.001), prior intraocular surgery (OR 4.43 [1.19-16.51], P = 0.03), and presence of ERM after surgery (OR 4.49 [2.30-8.74], P < 0.001). Patients undergoing pars plana vitrectomy (PPV) were more likely to develop CME compared with patients undergoing scleral buckling (SB; OR 3.09 [1.18-8.10], P = 0.02). A longer average time to CME detection was associated with lower CME resolution (OR 0.94 [0.89-0.998], P = 0.04). In patients who developed an ERM postsurgically, those who developed CME after ERM had a lower rate of resolution compared with those who developed CME before ERM (P = 0.03).

CONCLUSIONS

Cystoid macular edema may be more likely to develop in patients undergoing PPV than SB, those who underwent more surgeries for RRD repair, those who had prior intraocular surgery, or those who developed an ERM after RRD repair. Resolution of CME may be affected by the time to detection of CME and ERM development.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Protective Effect of Pemafibrate Treatment against Diabetic Retinopathy in Spontaneously Diabetic Torii Fatty Rats

Diabetic retinopathy (DR) can cause visual impairment and blindness, and the increasing global prevalence of diabetes underscores the need for effective therapies to prevent and treat DR. Therefore, this study aimed to evaluate the protective effect of pemafibrate treatment against DR, using a Spontaneously Diabetic Torii (SDT) fatty rat model of obese type 2 diabetes. SDT fatty rats were fed either a diet supplemented with pemafibrate (0.3 mg/kg/day) for 16 weeks, starting at 8 weeks of age (Pf SDT fatty: study group), or normal chow (SDT fatty: controls). Normal chow was provided to Sprague-Dawley (SD) rats (SD: normal controls). Electroretinography (ERG) was performed at 8 and 24 weeks of age to evaluate the retinal neural function. After sacrifice, retinal thickness, number of retinal folds, and choroidal thickness were evaluated, and immunostaining was performed for aquaporin-4 (AQP4). No significant differences were noted in food consumption, body weight, or blood glucose level after pemafibrate administration. Triglyceride levels were reduced, and high-density lipoprotein cholesterol levels were increased. Extension of oscillatory potential (OP)1 and OP3 waves on ERG was suppressed in the Pf SDT fatty group. Retinal thickness at 1,500 microns from the optic disc improved in the Pf SDT fatty group. No significant improvements were noted in choroidal thickness or number of retinal folds. Quantitative analyses showed that AQP4-positive regions in the retinas were significantly larger in the Pf SDT fatty group than in the SDT fatty group. The findings suggest that pemafibrate treatment can exert protective effects against DR.

Diabetic Retinopathy Leading to Blindness- A Review

Diabetic retinopathy (DR) is the most common microvascular complication of diabetes that damages the retina, leading to blindness. People with type 1 diabetes are at greater risk of developing DR than people with type 2 diabetes. Diabetic retinopathy may be divided into two primary categories: Proliferative diabetic retinopathy (PDR) and non-proliferative diabetic retinopathy (NPDR). There are multiple risk factors for the onset and progression of diabetic retinopathy, such as hypertension, obesity, smoking, duration of diabetes, and genetics. Numerous investigations have evaluated the levels of a wide range of inflammatory chemokines within DR patients' serum, vitreous, and aqueous fluids. In diabetic retinopathy, the vitreous fluid exhibited rises in angiogenic factors like platelet-derived growth factor (PDGF) or vascular endothelial growth factor (VEGF) or declines in antiangiogenic factors like pigment epithelium-derived factor (PEDF). For prevention of diabetic retinopathy, more physical activity as well as less sedentary behavior were linked to a reduced likelihood of DR. Supplementing with nutraceuticals containing vitamins (B1, B2, B6, B12, C, D, E, and l-methyl folate) and mineral (zinc) can help decrease or avoid an outbreak of DR. Only laser photocoagulation and Anti-vascular endothelial growth factor (Anti-VEGF) injections are advised as favorable therapies in severe retinopathy. When it comes to treating DR's VEGF levels, inflammation, oxidative stress, apoptosis, and angiogenesis, Traditional Chinese medicine (TCM) has an excellent future.

Alterations of outer retinal reflectivity in diabetic patients without clinically detectable retinopathy

PURPOSE

This study aimed to investigate alterations of outer retinal reflectivity on spectral-domain optical coherence tomography (OCT) in diabetic patients without clinically detectable retinopathy (NDR).

METHODS

In this retrospective study, 64 NDR patients and 71 controls were included. Relative reflectivity (RR) of the ellipsoid zone (EZ), photoreceptor outer segment (OS) and inner segment (IS), and outer nuclear layer (ONL) at the foveola and at 500 μm, 1000 μm, and 2000 μm nasal (N), temporal (T), superior (S), and inferior (I) to the foveola was measured by cross-line OCT and ImageJ. Retinal vessel densities (VD) in fovea, parafovea, and perifovea areas were detected by OCT angiography (OCTA).

RESULTS

EZ RR in most retinal locations was significantly lower in NDR eyes compared to controls (all P < 0.05), except the foveola. Compared with controls, NDR eyes also displayed lower RR at N2000, T2000, S1000, and I1000 of OS, at S500 and I500 of IS, and at I500 of ONL (all P < 0.05). Negative correlations could be observed between retinal RR and diabetes duration, HbA1c, and best-corrected visual acuity (BCVA) (r =  - 0.303 to - 0.452). Compared to controls, EZ, OS, and IS RR of the NDR eyes showed lower correlation coefficients with whole image SCP and DCP VD of parafovea and perifovea regions.

CONCLUSION

Outer retinal reflectivity, along with the coefficients between retinal reflectivity and VD, is reduced in NDR patients and is correlated with diabetes duration, HbA1c, and BCVA. The reduction of outer retinal reflectivity may be a potential biomarker of early retinal alterations in diabetic patients.

[Multimodal topographically oriented approach to the study of full-thickness macular holes]

PURPOSE

This article studies the relationship between structural changes according to the findings of optical coherence tomography (OCT) and OCT angiography (OCTA), microperimetry (MP), multifocal electroretinography (mfERG) parameters in topographically corresponding areas of the macular region in idiopathic full-thickness macular holes (FTMH).

MATERIAL AND METHODS

OCT, OCTA, MP and mfERG were performed in 14 eyes with FTMH stages I-IV according to Gass. In 13 points at a distance of 0-2.5°, 2.5-5.0°, and 5.0-10.0° from the fixation point, the light sensitivity (LS), amplitude and latency of the P1 component were compared with the size of the hole, the area of cystic changes (CC) at the level of the inner nuclear layer (INL) and the outer plexiform layer and Henle fiber layer complex (OPL+HFL), vessel density in the superficial and deep capillary plexus (SCP and DCP).

RESULTS

LS and P1 component amplitude were significantly reduced at a distance of up to 5.0° from the fixation point. LS correlates with the apical and basal diameter of the hole (R> -0.53), the area of CC in the INL (R> -0.62) and the OPL+HFL complex (R> -0.55), the density of vessels in the SCP at a distance of up to 2.5° from the fixation point (R>0.51) and in the DCP at a distance of up to 5° from the fixation point (R>0.49). The P1 amplitude correlates with the basal diameter of the hole (R= -0.38), the area of CC in the INL and the OPL+HFL complex (R> -0.33) and vessel density in the SCP (R=0.37) at a distance of up to 2.5° from the fixation point, as well as vessel density in the DCP at a distance of up to 5° from the fixation point (R=0.47). Vessel density in the DCP is significantly lower in the presence of CC in the retina (p<0.001).

CONCLUSION

In FTMH, there is a relationship between bioelectrical activity and LS, and structural disorders, capillary perfusion in different layers of the retina. A multimodal topographically oriented approach allows studying the relationship between structural and functional parameters in individual points of the retina and can be used in monitoring of FTMH after surgical treatment.

Myopic macular schisis: Insights into distinct morphological subtypes and novel biomechanical hypothesis

PURPOSE

To analyze the features of myopic macular schisis (MMS) in different retinal layers and to explore the role of Müller cells in the pathophysiology of such condition.

METHODS

Spectral-domain optical coherence tomography (SD-OCT) images of myopic eyes with staphyloma and macular schisis were reviewed. The morphological features of MMS were analyzed and correlated with their geographical location in the parafoveal and perifoveal region. A biomechanical model was adopted to explain MMS morphological differences. The effect of the different schisis subtypes with best corrected visual acuity (BCVA) was also explored.

RESULTS

A total of 36 eyes from 26 patients were included in this study. MMS was classified into inner, middle and outer retinal subtypes. The prevalence of middle retinal schisis was significantly lower in the parafovea, within a central 3 mm-diameter circle (p < 0.001) centered at the fovea . The prevalence of inner retinal schisis was significantly higher outside the central 3-mm diameter circle, in the perifoveal region (p < 0.001). No significant differences were noted in the prevalence of outer retinal schisis for these two locations (p = 0.475). The presence of middle retinal schisis within the central 3-mm diameter circle showed a weak association with lower BCVA (p = 0.058). The presence of outer retinal schisis within the central 3-mm diameter circle was significantly related with lower BCVA (p = 0.024).

CONCLUSION

Three major forms of MMS are distinguished: inner, middle and outer retinal schisis. This classification may have clinical importance as only the outer grade of schisis was associated with vision loss.

Imaging Histology Correlations of Intraretinal Fluid in Neovascular Age-Related Macular Degeneration

Purpose

Fluid presence and dynamism is central to the diagnosis and management of neovascular age-related macular degeneration. On optical coherence tomography (OCT), some hyporeflective spaces arise through vascular permeability (exudation) and others arise through degeneration (transudation). Herein we determined whether the histological appearance of fluid manifested this heterogeneity.

Methods

Two eyes of a White woman in her 90s with anti-vascular endothelial growth factor treated bilateral type 3 neovascularization secondary to age-related macular degeneration were osmicated, prepared for submicrometer epoxy resin sections, and correlated to eye-tracked spectral domain OCT. Examples of intraretinal tissue fluid were sought among similarly prepared donor eyes with fibrovascular scars, in a web-based age-related macular degeneration histopathology resource. Fluid stain intensity was quantified in reference to Bruch's membrane and the empty glass slide.

Results

Exudative fluid by OCT was slightly reflective and dynamically responded to anti-vascular endothelial growth factor. On histology, this fluid stained moderately, possessed a smooth and homogenous texture, and contained blood cells and fibrin. Nonexudative fluid in degenerative cysts and in outer retinal tubulation was minimally reflective on OCT and did not respond to anti-vascular endothelial growth factor. By histology, this fluid stained lightly, possessed a finely granular texture, and contained mainly tissue debris. Quantification supported the qualitative impressions of fluid stain density. Cells containing retinal pigment epithelium organelles localized to both fluid types.

Conclusions

High-resolution histology of osmicated tissue can distinguish between exudative and nonexudative fluid, some of which is transudative.

Translational Relevance

OCT and histological features of different fluid types can inform clinical decision-making and assist in the interpretation of newly available automated fluid detection algorithms.

Relationships of Macular Functional Impairment With Structural and Vascular Changes According to Glaucoma Severity

Purpose

To determine the pointwise relationships of central visual field (VF) defects with macular ganglion cell loss and macular vessel density (VD) loss during various stages of glaucoma.

Methods

Eyes with primary open-angle glaucoma (POAG) were subjected to optical coherence tomography (OCT) and OCT angiography (OCTA) to evaluate macular ganglion cell layer (GCL) thickness and macular VD in the superficial and deep vascular complexes (SVC and DVC). OCT, OCTA, and VF locations were matched after correcting for retinal ganglion cell (RGC) displacement. Pointwise correlations of GCL thickness and VDs of the SVC and DVC with central VF sensitivity (VFS) were evaluated by Pearson's correlation analysis and compared in eyes with early and advanced POAG by Meng's test.

Results

Of the 100 eyes, 52 and 48 were classified as early and advanced POAG. Macular VD showed overall better correlation with central VFS than GCL thickness in both the early and advanced groups. SVC density showed the strongest correlation with central VFS in all groups (R = 0.327 in early group, R = 0.325 in advanced group, all P < 0.001). Although DVC density showed better correlation with VFS (R = 0.311) than GCL thickness (R = 0.212) in the early group (P < 0.001), the correlation was comparable in the advanced group (R = 0.199 and 0.176, respectively, P = 0.254).

Conclusions

After adjustment for RGC displacement, macular SVC density was better correlated with central VFS than macular GCL thickness in both early and advanced POAG. Macular DVC density showed better correlation with VFS than GCL thickness in early but not in advanced POAG, indicating that DVC loss may be involved in early central VF loss.

Clinically relevant factors associated with a binary outcome of diabetic macular ischaemia: an OCTA study

AIMS

We investigated the demographic, ocular, diabetes-related and systemic factors associated with a binary outcome of diabetic macular ischaemia (DMI) as assessed by optical coherence tomography angiography (OCTA) evaluation of non-perfusion at the level of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in a cohort of patients with diabetes mellitus (DM).

MATERIALS AND METHODS

617 patients with DM were recruited from July 2015 to December 2020 at the Chinese University of Hong Kong Eye Centre. Image quality assessment (gradable or ungradable for assessing DMI) and DMI evaluation (presence or absence of DMI) were assessed at the level of the SCP and DCP by OCTA.

RESULTS

1107 eyes from 593 subjects were included in the final analysis. 560 (50.59%) eyes had DMI at the level of SCP, and 647 (58.45%) eyes had DMI at the level of DCP. Among eyes without diabetic retinopathy (DR), DMI was observed in 19.40% and 24.13% of eyes at SCP and DCP, respectively. In the multivariable logistic regression models, older age, poorer visual acuity, thinner ganglion cell-inner plexiform layer thickness, worsened DR severity, higher haemoglobin A1c level, lower estimated glomerular filtration rate and higher low-density lipoprotein cholesterol level were associated with SCP-DMI. In addition to the aforementioned factors, presence of diabetic macular oedema and shorter axial length were associated with DCP-DMI.

CONCLUSION

We reported a series of associated factors of SCP-DMI and DCP-DMI. The binary outcome of DMI might promote a simplified OCTA-based DMI evaluation before subsequent quantitative analysis for assessing DMI extent and fulfil the urge for an updating diabetic retinal disease staging to be implemented with OCTA.

Imaging ocular water inflow in the mouse with deuterium oxide MRI

Abnormal intraocular fluid flow or clearance is involved with a variety of eye diseases such as glaucoma and diabetic retinopathy, but measurement of water exchange dynamics in the vitreous and aqueous remain challenging. 2H MRI can be used to image deuterium oxide (D₂O) as a tracer, but the signal-to-noise ratio for deuterium is low due to its low concentration, which has hampered its application to imaging the eye. To overcome this challenge, we investigated the feasibility of direct D2O MRI to measure water dynamics in the mouse eye. The balanced steady-state free precession (bSSFP) sequence provided substantially higher signal-to-noise ratio for imaging D2O in fluid compared to standard gradient echo and spin echo sequences. bSSFP allowed dynamic imaging of intraocular water inflow in the mouse with 41 s temporal resolution. The inflow rate in the vitreous was found to be faster than in the aqueous. These studies demonstrate the feasibility of in vivo imaging of water inflow dynamics into the both the vitreous and aqueous in mice, which could be useful in studies of abnormal fluid exchange in rodent models of eye disease.

Morphological changes of foveal cysts as a predictor for visual response to anti-vascular endothelial growth factor treatments in diabetic macular edema : Degenerative cyst in DME

PURPOSE

To investigate morphological changes of intraretinal cyst in association with visual acuity following treatment for diabetic macular edema.

METHODS

This retrospective study enrolled 105 eyes from 105 treatment naïve patients with diabetic macular edema following anti-vascular endothelial growth factor injections. Best-corrected visual acuity (BCVA) and optical coherence tomography (OCT) data were obtained at baseline, 1, 3, 6, and 12 months. The width and height of the largest intraretinal cyst (IRC) at all different visits were measured and were correlated to final visual acuity by receiver operating characteristic curve. The exudative feature was defined by the presence of hard exudates. Multivariate logistic regression was used to select the independent predictor for visual outcomes.

RESULTS

Intraretinal cyst width but not the cyst height after treatment at 1 month independently predicted final visual loss of ten letters or more (multivariate P = 0.009). The optimal cutoff value was 196 um with a sensitivity of 0.889 and a specificity of 0.656. Eyes with large IRC width using this cutoff were consistently larger than those with small IRC width through 12 months (P = 0.008, Mann-Whitney U test). Small IRC width < 196 um at 1 month was more likely to coexist with exudative feature (P = 0.011, Fisher's exact test). Among baseline factors, large IRC width predicted IRC width ≥ 196 um at 1 month (multivariate P < 0.001).

CONCLUSION

Cyst morphology following intravitreal injection predicts visual outcomes. Eyes with IRC width ≥ 196 um after treatment at 1 month tends to be more degenerative, and less likely to coexist with exudative feature.

Subretinal Pseudocysts: A Comprehensive Analysis of this Novel OCT Finding

INTRODUCTION

In current clinical practice, several optical coherence tomography (OCT) biomarkers have been proposed for the assessment of severity and prognosis of different retinal diseases. Subretinal pseudocysts are subretinal cystoid spaces with hyperreflective borders and only a few single cases have been reported thus far. The aim of the study was to characterize and investigate this novel OCT finding, exploring its clinical outcome.

METHODS

Patients were evaluated retrospectively across different centers. The inclusion criterion was the presence of subretinal cystoid space on OCT scans, regardless of concurrent retinal diseases. Baseline examination was set as the first time the subretinal pseudocyst was identified by OCT. Medical and ophthalmological histories were collected at baseline. OCT and OCT-angiography were performed at baseline and at each follow-up examination.

RESULTS

Twenty-eight eyes were included in the study and 31 subretinal pseudocysts were characterized. Out of 28 eyes, 16 were diagnosed with neovascular age-related macular degeneration (AMD), 7 with central serous chorioretinopathy, 4 with diabetic retinopathy, and 1 with angioid streaks. Subretinal and intraretinal fluid were present in 25 and 13 eyes, respectively. Mean distance of the subretinal pseudocyst from the fovea was 686 µm. The diameter of the pseudocyst was positively associated with the height of the subretinal fluid (r = 0.46; p = 0.018) and central macular thickness (r = 0.612; p = 0.001). At follow-up, subretinal pseudocysts disappeared in most of the reimaged eyes (16 out of 17). Of these, two patients presented retinal atrophy at baseline examination and eight patients (47%) developed retinal atrophy at follow-up. Conversely, seven eyes (41%) did not develop retinal atrophy.

CONCLUSION

Subretinal pseudocysts are precarious OCT findings, usually disclosed in a context of subretinal fluid, and are probably transient alterations within the photoreceptor outer segments and retinal pigment epithelium (RPE) layer. Despite their nature, subretinal pseudocysts have been associated with photoreceptor loss and incomplete RPE definition.

Assessment of Parafoveal Diabetic Macular Ischemia on Optical Coherence Tomography Angiography Images to Predict Diabetic Retinal Disease Progression and Visual Acuity Deterioration

Importance

The presence of diabetic macular ischemia (DMI) on optical coherence tomography angiography (OCTA) images predicts diabetic retinal disease progression and visual acuity (VA) deterioration, suggesting an OCTA-based DMI evaluation can further enhance diabetic retinopathy (DR) management.

Objective

To investigate whether an automated binary DMI algorithm using OCTA images provides prognostic value on DR progression, diabetic macular edema (DME) development, and VA deterioration in a cohort of patients with diabetes.

Design, Setting, and Participants

In this cohort study, DMI assessment of superficial capillary plexus and deep capillary plexus OCTA images was performed by a previously developed deep learning algorithm. The presence of DMI was defined as images exhibiting disruption of fovea avascular zone with or without additional areas of capillary loss, while absence of DMI was defined as images presented with intact fovea avascular zone outline and normal distribution of vasculature. Patients with diabetes were recruited starting in July 2015 and were followed up for at least 4 years. Cox proportional hazards models were used to evaluate the association of the presence of DMI with DR progression, DME development, and VA deterioration. Analysis took place between June and December 2022.

Main Outcomes and Measures

DR progression, DME development, and VA deterioration.

Results

A total of 321 eyes from 178 patients were included for analysis (85 [47.75%] female; mean [SD] age, 63.39 [11.04] years). Over a median (IQR) follow-up of 50.41 (48.16-56.48) months, 105 eyes (32.71%) had DR progression, 33 eyes (10.28%) developed DME, and 68 eyes (21.18%) had VA deterioration. Presence of superficial capillary plexus-DMI (hazard ratio [HR], 2.69; 95% CI, 1.64-4.43; P < .001) and deep capillary plexus-DMI (HR, 3.21; 95% CI, 1.94-5.30; P < .001) at baseline were significantly associated with DR progression, whereas presence of deep capillary plexus-DMI was also associated with DME development (HR, 4.60; 95% CI, 1.15-8.20; P = .003) and VA deterioration (HR, 2.12; 95% CI, 1.01-5.22; P = .04) after adjusting for age, duration of diabetes, fasting glucose, glycated hemoglobin, mean arterial blood pressure, DR severity, ganglion cell-inner plexiform layer thickness, axial length, and smoking at baseline.

Conclusions and Relevance

In this study, the presence of DMI on OCTA images demonstrates prognostic value for DR progression, DME development, and VA deterioration.

Dengue Virus Infection of Human Retinal Müller Glial Cells

Retinopathy is a recently recognized complication of dengue, affecting up to 10% of hospitalized patients. Research on the pathogenesis has focused largely on effects of dengue virus (DENV) at the blood-retinal barrier. Involvement of retinal Müller glial cells has received little attention, although this cell population contributes to the pathology of other intraocular infections. The goal of our work was to establish the susceptibility of Müller cells to infection with DENV and to identify characteristics of the cellular antiviral, inflammatory, and immunomodulatory responses to DENV infection in vitro. Primary human Müller cell isolates and the MIO-M1 human Müller cell line were infected with the laboratory-adapted Mon601 strain and DENV serotype 1 and 2 field isolates, and cell-DENV interactions were investigated by immunolabelling and quantitative real-time polymerase chain reaction. Müller cells were susceptible to DENV infection, but experiments involving primary cell isolates indicated inter-individual variation. Viral infection induced an inflammatory response (including tumour necrosis factor-α, interleukin [IL]-1β, and IL-6) and an immunomodulatory response (including programmed death-ligand [PD-L]1 and PD-L2). The type I interferon response was muted in the Müller cell line compared to primary cell isolates. The highest infectivity and cell responses were observed in the laboratory-adapted strain, and overall, infectivity and cell responses were stronger in DENV2 strains. This work demonstrates that Müller cells mount an antiviral and immune response to DENV infection, and that this response varies across cell isolates and DENV strain. The research provides a direction for future efforts to understand the role of human retinal Müller glial cells in dengue retinopathy.

Central and peripheral changes in the retina and choroid in patients with diabetes mellitus without clinical diabetic retinopathy assessed by ultra-wide-field optical coherence tomography angiography

Background

To explore the central and peripheral retinal and choroidal changes in diabetic patients without clinical diabetic retinopathy (DM-NoDR) using ultra-wide-field swept-source optical coherence tomography angiography (UWF-SS-OCTA).

Methods

67 DM-NoDR eyes and 32 age-matched healthy eyes were recruited. Retinal and choroidal parameters, including qualitative retinal microangiopathy, vessel flow (VFD) and linear density (VLD), thickness, and volume, were measured in the central and peripheral areas of the 24 × 20 mm² UWF-SS-OCTA images.

Results

DM-NoDR eyes had significantly more nonperfusion area and capillary tortuosity than controls in the central and peripheral areas (p < 0.05). The presence of central capillary tortuosity was associated with higher levels of serum creatinine (OR 1.049, 95%CI 1.001-1.098; p = 0.044) and blood urea nitrogen (OR 1.775, 95%CI 1.051-2.998; p = 0.032) in DM-NoDR eyes. For DM-NoDR eyes versus controls, VFD in the 300-μm annulus around the foveal avascular zone, superficial capillary plexus (SCP), and full retina, and SCP-VLD significantly decreased, while VFD in the deep capillary plexus (DCP), retinal thickness, and retinal volume increased (p < 0.05). Analysis in the central and peripheral areas recapitulated all these findings, except for decreased peripheral thickness and volume and no difference in peripheral DCP-VFD. In DM-NoDR eyes, choriocapillaris-VFD, choroidal thickness, and choroidal volume increased in the central area, while VFD in the large and medium choroidal vessel layer decreased in the whole image (p < 0.05).

Conclusion

Retinal and choroidal changes already existed in the central and/or peripheral areas of DM-NoDR eyes. UWF-SS-OCTA, enabling the visualization of the peripheral fundus area, is a promising image technique for the early detection of fundus changes in DM-NoDR patients.

Quantitative Parameters Relevant for Diabetic Macular Edema Evaluation by Optical Coherence Tomography Angiography

Diabetic macular edema (DME) is one of the main ocular complications of diabetes mellitus (DM) that can lead to important vision loss in diabetic patients. In clinical practice, there are cases of DME with unsatisfying treatment responses, despite adequate therapeutic management. Diabetic macular ischemia (DMI) is one of the causes suggested to be associated with the persistence of fluid accumulation. Optical coherence tomography angiography (OCTA) is a non-invasive imaging modality, able to give in-depth information about retinal vascularization in a 3-dimensional manner. The OCTA devices currently available can provide various OCTA metrics that quantitatively assess the retinal microvasculature. In this paper, we reviewed the results of multiple studies that investigated the changes in OCTA metrics in the setting of DME and their possible contribution to the diagnosis, therapeutic management, follow-up and prognosis of patients with DME. We analyzed and compared relevant studies that investigated OCTA parameters related to changes in macular perfusion in the setting of DME and we evaluated the correlations between DME and several quantitative parameters, such as vessel density (VD), perfusion density (PD), foveal avascular zone (FAZ)-related parameters, as well as complexity indices of retinal vasculature. The results of our research showed that OCTA metrics, evaluated especially at the level of the deep vascular plexus (DVP), are useful instruments that can contribute to the assessment of patients with DME.

Clinical utility of ultra-widefield fluorescein angiography and optical coherence tomography angiography for retinal vein occlusions

Retinal vein occlusions (RVOs) are the second most common retinal vascular disease after diabetic retinopathy, and are a significant cause of visual impairment, especially in the elderly population. RVOs result in visual loss due to macular ischemia, cystoid macular edema (CME), and complications related to neovascularization. Vascular assessment in RVOs traditionally relies on standard fluorescein angiography (FA) for assessment of macular and retinal ischemia, which aids in prognostication and guides intervention. Standard FA has significant limitations-it is time-consuming, requires invasive dye administration, allows for limited assessment of the peripheral retina, and is usually evaluated semi-qualitatively, by ophthalmologists with tertiary expertise. More recently, the introduction of ultra-widefield FA (UWF FA) and optical coherence tomography angiography (OCTA) into clinical practice has changed the tools available for vascular evaluation in RVOs. UWF FA allows for evaluation of peripheral retinal perfusion, and OCTA is non-invasive, rapidly-acquired, and provides more information on capillary perfusion. Both modalities can be used to provide more quantitative parameters related to retinal perfusion. In this article, we review the clinical utility and impact of UWF FA and OCTA in the evaluation and management of patients with RVOs.

Pathways of Fluid Leakage in Age-Related Macular Degeneration

Age related macular degeneration is the most common cause of blindness in the western world and the development of intravitreal pharmacotherapies for the treatment of the neovascular complications of this disorder is considered a revolution in the care of this devastating disease. Anti-vascular endothelial growth factor (VEGF) agents such as ranibizumab and aflibercept can prevent blindness by reducing or resolving fluid in AMD and therefore the detection of these biomarkers (e.g. intraretinal and subretinal fluid) with high resolution, depth resolved tools such as optical coherence tomography (OCT) is a critical process in the successful management of this condition. However, there is growing evidence to indicate that fluid is not always the result of neovascular pathways and therefore the obligatory administration of anti-VEGF therapy in response to the observation of fluid on OCT may be flawed. Non-neovascular mechanisms of fluid leakage (e.g. retinal pigment epithelium pump impairment) should also be considered and in these circumstances anti-VEGF injection should be deferred. This editorial will review the neovascular and non-neovascular pathways of fluid leakage in AMD and will provide more informed guidance for the overall evaluation and management of exudation in AMD, including an observe and extend regimen in the context of non-neovascular fluid.

LONG-TERM MICROVASCULAR REMODELING AND CYSTIC CHANGES AFTER RETINAL DETACHMENT TREATED WITH SILICON OIL TAMPONADE

PURPOSE

To determine the long-term microvascular alterations associated with macular cystic changes after retinal detachment surgery with silicone oil tamponade.

METHODS

The results of two optical coherence tomography angiographies performed at 11 months and 38 months after silicone removal were retrospectively analyzed for 30 eyes. The data were compared between both measurements and between eyes with macular cysts (MC+) and without macular cysts (MC-). Two patterns of cysts were identified and compared: cysts exclusively involving the inner nuclear layer (INLc) and cysts present in all retinal layers.

RESULTS

At both end points, 20 eyes (67%) presented with macular cysts, 12 of them (40%) had INLc. At the first end point, vascular density of superficial capillary plexus was higher and superficial foveal avascular zone was smaller in MC+ eyes than in MC- eyes (P = 0.04 and P = 0.017, respectively). At the second end point, vascular density of superficial capillary plexus significantly decreased in MC+ eyes as compared with the first end point (P < 0.001) and superficial foveal avascular zone enlarged (P < 0.001). Macular central thickness decreased between follow-ups only in eyes with INLc (P < 0.01). The final best-corrected visual acuity was better in eyes with INLc than in eyes with cysts present in all retinal layers (P < 0.01). There was no difference between the final best-corrected visual acuity in eyes with INLc and MC- eyes.

CONCLUSION

Macular cysts are a common finding long after silicon removal. Vascular remodeling seems characterized by an initial increase of the vascular density of superficial capillary plexus in eyes with cysts, which is followed by its progressive decrease. The INLc is the most common pattern of cysts. They are associated with a progressive decrease of the central macular thickness without visual impairment.

The effect of retinal perfusion on the bioelectric activity of the retina in full-thickness macular holes

BACKGROUND: Information on retinal capillary perfusion in idiopathic full-thickness macular hole (FTMH) is limited, and there are no data on the possible effect of blood supply to individual areas and layers of the retina on their functional activity. AIM: To study the relationship between vascular perfusion in the superficial and deep capillary plexuses (SCP and DCP) and the bioelectrical activity of the retina in full-thickness macular hole. MATERIALS AND METHODS: Multifocal electroretinography (mfERG), optical coherence tomography (OCT), and OCT-angiography (OCTA) were performed in 18 eyes with FTMH and 10 intact eyes. In the projection of individual hexagons of the mfERG pattern, parameters of bioelectrical activity were compared with structural changes (hole, cystic changes), capillary density in the SCP and DCP. RESULTS: In the FTMH group, the density of capillaries in the superficial capillary plexuses correlated with P1 implicit time in the R2 ring hexagons (R = 0.23, p 0.05), in the hole zone and intraretinal cystic changes (R = 0.21 and R = 0.22, p 0.05), P1 amplitude in the hole zone (R = 0.24, p 0.05). In deep capillary plexuses, the capillary density correlated with N1 implicit time at the fixation point and the hole zone (R = 0.57 and R = 0.19, p 0.05), P1 implicit time at the hole zone (R = 0.2, p 0.05), P1 amplitude in the hexagons of the R2 and R3 rings (R = 0.46 and R = 0.44, p 0.05), more pronounced in the hole zone and cystic changes (R = 0.54 and R = 0.29, p 0.05). CONCLUSIONS: There is a correlation between capillary perfusion in different layers of the retina and its bioelectrical activity in FTMH. A decrease in perfusion in the deep capillary plexus of the macula with a chronic macular hole may be a predictor of a low functional prognosis in the outcome of surgical treatment of FTMH.

Photoreceptor function and structure in retinal degenerations caused by biallelic BEST1 mutations

The only approved retinal gene therapy is for biallelic RPE65 mutations which cause a recessive retinopathy with a primary molecular defect located at the retinal pigment epithelium (RPE). For a distinct recessive RPE disease caused by biallelic BEST1 mutations, a pre-clinical proof-of-concept for gene therapy has been demonstrated in canine eyes. The current study was undertaken to consider potential outcome measures for a BEST1 clinical trial in patients demonstrating a classic autosomal recessive bestrophinopathy (ARB) phenotype. Spatial distribution of retinal structure showed a wide expanse of abnormalities including large intraretinal cysts, shallow serous retinal detachments, abnormalities of inner and outer segments, and an unusual prominence of the external limiting membrane. Surrounding the central macula extending from 7 to 30 deg eccentricity, outer nuclear layer was thicker than expected from a cone only retina and implied survival of many rod photoreceptors. Co-localized however, were large losses of rod sensitivity despite preserved cone sensitivities. The dissociation of rod function from rod structure observed, supports a large treatment potential in the paramacular region for biallelic bestrophinopathies.

Focal Photocoagulation as an Adjunctive Therapy to Reduce the Burden of Intravitreal Injections in Macula Edema Patients, the LyoMAC2 Study

AIM

To assess the efficacy of focal photocoagulation of capillary macroaneurysms (CMA) to reduce the burden of intravitreal injections (IVI) in patients with macular edema (ME).

MATERIALS AND METHODS

Retrospective multicenter study in patients with diabetic ME or ME secondary to retinal vein occlusion (ME-RVO). CMA associated with ME were selectively photocoagulated. Patients were followed for one year after photocoagulation.

RESULTS

93 eyes of 76 patients were included in this study. At 6 months after the laser (n = 93), there was a significant decrease in mean macular thickness (from 354 µm to 314 µm, p < 0.001) and in mean IVI number (from 2.52 to 1.52 at 6 months, p < 0.001). The mean BCVA remained stable (0.32 and 0.31 logMAR at baseline and 6 months, p = 0.95). At 12 months (n = 81/93), there was a significant decrease in mean macular thickness (from 354 µm to 314 µm, p < 0.001) and in mean IVI number (from 4.44 to 2.95 at 12 months, p < 0.001), while the mean BCVA remained stable (0.32 and 0.30 logMAR at baseline and 12 months, p = 0.16).

CONCLUSION

Focal laser photocoagulation of CMA seems to be effective and safe for reducing the burden of IVI in patients with ME. Their screening during the follow-up should be considered closely.

Mechanisms of macular edema

Macular edema is the pathological accumulation of fluid in the central retina. It is a complication of many retinal diseases, including diabetic retinopathy, retinal vascular occlusions and uveitis, among others. Macular edema causes decreased visual acuity and, when chronic or refractory, can cause severe and permanent visual impairment and blindness. In most instances, it develops due to dysregulation of the blood-retinal barrier which permits infiltration of the retinal tissue by proteins and other solutes that are normally retained in the blood. The increase in osmotic pressure in the tissue drives fluid accumulation. Current treatments include vascular endothelial growth factor blockers, corticosteroids, and non-steroidal anti-inflammatory drugs. These treatments target vasoactive and inflammatory mediators that cause disruption to the blood-retinal barrier. In this review, a clinical overview of macular edema is provided, mechanisms of disease are discussed, highlighting processes targeted by current treatments, and areas of opportunity for future research are identified.

Optical coherence tomography angiography metrics in different stages of diabetic macular edema

Background

To investigate the optical coherence tomography angiography (OCTA) characteristics of diabetic macular edema (DME) at different stages.

Methods

This study was a cross-sectional study. Patients diagnosed with DME were recruited. DME was classified into early, advanced, and severe DME. The vessel density (VD) in the superficial vascular plexus (SVP), deep vascular plexus (DVP) and foveal avascular zone (FAZ) parameters, including FAZ area, FAZ perimeter, acircularity index and foveal VD in a 300-μm-wide region around the FAZ (FD-300), were calculated by the AngioVue software. A multivariate generalized estimating equation was used to evaluate the associations between visual acuity and OCTA metrics.

Results

Ninety-two eyes from 74 patients with DME were included in this study. Compared to early (P = 0.006) and advanced DME (P = 0.003), the acircularity index was higher in severe DME. Both whole and parafoveal VD in the DVP decreased in eyes with severe DME compared to early DME (P = 0.018, P = 0.005, respectively) and advanced DME (P = 0.035, P = 0.012, respectively). In the multivariate generalized estimating equation, DME severity, FAZ area and foveal thickness were positively associated with worse visual acuity (P = 0.001, P = 0.007 and P = 0.001, respectively).

Conclusion

Compared to early and advanced DME, severe DME showed increased irregularity in the FAZ and more extensive vessel damage in the DVP. Greater severity level of DME, larger FAZ area, and increased foveal thickness could be risk factors for poor visual acuity.

Trial registration The protocol was published in the Chinese Clinical Trial Registry (ChiCTR2000033082).

Effect of intravitreal dexamethasone implant in treatment-naive and previously-treated patients with diabetic macular edema

PURPOSE

To document the effects of intravitreal dexamethasone implant on retinal microvasculature in patients with diabetic retinopathy complicated by center-involving macular edema.

METHODS

35 eyes of 35 patients affected by retinopathy due to type 2 diabetes (15 treatment-naïve and 20 previously treated) were included in this retrospective study with a follow-up of 4 months. Foveal avascular zone (FAZ) area and superficial capillary plexus (SCP) and deep capillary plexus (DCP) densities in the foveal and parafoveal areas were measured by optical coherence tomography angiography (OCTA) at baseline and 2 and 4 months post-injection. Intraocular pressure, morphological and functional parameters were evaluated.

RESULTS

a significant difference was found in both groups at 2 months after injection in terms of functional (BCVA, p < 0.05) and morphological (CMT, p < 0.05) parameters. During follow-up, FAZ area, SCP, and DCP in the foveal and parafoveal areas did not change significantly.

CONCLUSIONS

intravitreal dexamethasone implant is effective in the treatment of diabetic center-involving macular edema and was associated with significant improvements in BCVA and CMT at 2 months after injection. After a single dexamethasone implant injection, FAZ area and retinal vascular density does not show significant variations in both naive and non-naive DME patients subgroups.

Optical coherence tomography angiography analysis of microvascular abnormalities and vessel density in treatment-naïve eyes with diabetic macular edema

Background

The aim of this study was to evaluate the structural retinal vascular integrity using optical coherence tomography angiography (OCTA) in treatment-naïve eyes with diabetic macular edema (DME) and to compare it with findings in diabetic eyes without DME.

Methods

In this prospective study, 70 eyes with diabetic retinopathy were included (37 eyes with DME and 33 eyes without DME). The medical records, including swept-source optical coherence tomography and 9 × 9 mm swept-source OCTA images were reviewed and compared between DME and non-DME groups. Microaneurysms, intraretinal microvascular abnormalities (IRMA), areas of capillary non perfusion, foveal avascular zone (FAZ), and capillary vascular density (CVD) were analyzed in the superficial capillary plexus (SCP) and the deep capillary plexus (DCP).

Results

Compared to the non-DME eyes, DME eyes had more microaneurysms in the SCP and the DCP (p = 0,039 and p = 0,024 respectively), more IRMA in the SCP (p = 0,005), larger areas of capillary non perfusion in the SCP and the DCP (p = 0,026 and p = 0,02 respectively) and larger FAZ in both plexuses (p = 0,048 in the SCP and p = 0,012 in the DCP). The CVD in the DCP was lower in DME eyes compared to non-DME eyes (p = 0,007). The severity of DME was significantly correlated to the number of microaneurysms and to the FAZ surface. Central macular thickness was significantly correlated with the number of microaneurysms in the DCP, the surface of capillary non perfusion areas and the FAZ area in both plexuses.

Conclusions

OCTA with a 9 × 9 mm field of view showed that the retinal vascular integrity regarding the number of microaneurysms, the number of IRMA, the surface of capillary non perfusion areas, the FAZ area and the CVD, was significantly more impaired in DME eyes compared to diabetic eyes without DME. The DCP seemed to be more affected in diabetic eyes with and without DME than the SCP.

Diabetic Macular Edema: Current Understanding, Molecular Mechanisms and Therapeutic Implications

Diabetic retinopathy (DR), with increasing incidence, is the major cause of vision loss and blindness worldwide in working-age adults. Diabetic macular edema (DME) remains the main cause of vision impairment in diabetic patients, with its pathogenesis still not completely elucidated. Vascular endothelial growth factor (VEGF) plays a pivotal role in the pathogenesis of DR and DME. Currently, intravitreal injection of anti-VEGF agents remains as the first-line therapy in DME treatment due to the superior anatomic and functional outcomes. However, some patients do not respond satisfactorily to anti-VEGF injections. More than 30% patients still exist with persistent DME even after regular intravitreal injection for at least 4 injections within 24 weeks, suggesting other pathogenic factors, beyond VEGF, might contribute to the pathogenesis of DME. Recent advances showed nearly all the retinal cells are involved in DR and DME, including breakdown of blood-retinal barrier (BRB), drainage dysfunction of Müller glia and retinal pigment epithelium (RPE), involvement of inflammation, oxidative stress, and neurodegeneration, all complicating the pathogenesis of DME. The profound understanding of the changes in proteomics and metabolomics helps improve the elucidation of the pathogenesis of DR and DME and leads to the identification of novel targets, biomarkers and potential therapeutic strategies for DME treatment. The present review aimed to summarize the current understanding of DME, the involved molecular mechanisms, and the changes in proteomics and metabolomics, thus to propose the potential therapeutic recommendations for personalized treatment of DME.

Increased Macrophage-like Cell Density in Retinal Vein Occlusion as Characterized by en Face Optical Coherence Tomography

Objectives: to quantitatively analyze macrophage-like cells (MLCs) at the vitreoretinal interface in retinal vein occlusion (RVO) using swept-source optical coherence tomography angiography (SS-OCTA) and en face optical coherence tomography (OCT). Methods: The study included 72 RVO patients, with 43 acute patients and 29 chronic patients. For a normal control, 64 fellow eyes were included. MLCs were visualized in a 5 μm en face OCT slab above the vitreoretinal interface centered on the fovea. After semi-automatic binarization and quantification, we evaluated the MLC count and density among groups. We also investigated the MLC density and distribution relative to retinal edema. Results: Morphological changes and congregation of MLCs appeared in RVO eyes. The MLC density of both the acute and chronic groups was significantly higher than that of the control eyes (p < 0.001). In the acute group, the MLC density of the edematous region was lower than both the non-edematous region (p < 0.001) and the whole image (p < 0.01). The MLC density in acute eyes was negatively correlated to central fovea thickness (CFT) (r = −0.352, p < 0.05). The MLC density in chronic eyes was positively correlated to CFT and mean retina thickness (MRT) (r = 0.406, p < 0.05; r = 0.412, p < 0.05, respectively). Conclusions: SS-OCTA is a viable and simple method for the characterization of MLCs at the vitreoretinal interface. A significant increase in the MLC density in both acute and chronic eyes implicates the activation and recruitment of MLCs in RVO and that the MLC density and distribution can be affected by retinal edema.

Correlation between the Outcome of Vitrectomy for Proliferative Diabetic Retinopathy and Erythrocyte Hematocrit Level and Platelet Function

We investigate-d whether biomarkers such as red blood cell hematocrit (Hct), platelet count (PLT), mean platelet volume (MPV), and platelet distribution width (PDW) are useful prognostic indicators of postoperative macular edema (ME) after vitrectomy for proliferative diabetic retinopathy (PDR). A total of 42 eyes of 42 patients with PDR who underwent vitrectomy between January 2018 and May 2020 were analyzed retrospectively. We divided them into two groups according to whether treatment was required for postoperative ME and compared the relationship between Hct, PLT, MPV, and PDW and the onset of postoperative ME. The group that received postoperative treatment (group T) comprised 11 eyes of 11 patients, and the group that did not (group N) comprised 31 eyes of 31 patients. The age (years) was 52.0 ± 3.1 in group T and 60.0 ± 11.6 in group N. When appropriate statistical analysis was performed for comparison between groups, significant differences were found in age (p = 0.05), insulin use (p = 0.03), preoperative intraocular pressure (p = 0.05), diastolic blood pressure (p = 0.03), and Hct (p = 0.04). Multivariate logistic regression analysis was performed, and a significant difference was found in Hct (p = 0.02). These results suggest that Hct might be useful as a predictor of ME after PDR surgery.

Development and Application of an Intelligent Diagnosis System for Retinal Vein Occlusion Based on Deep Learning

This study is aimed at developing an intelligent algorithm based on deep learning and discussing its application for the classification and diagnosis of retinal vein occlusions (RVO) using fundus images. A total of 501 fundus images of healthy eyes and patients with RVO were used for model training and testing to investigate an intelligent diagnosis system. The images were first classified into four categories by fundus disease specialists: (i) healthy fundus (group 0), (ii) branch RVO (BRVO) (group 1), (iii) central RVO (CRVO) (group 2), and (iv) macular branch RVO (MBRVO) (group 3), before being diagnosed using the ResNet18 network model. Intelligent diagnoses were compared with clinical diagnoses. The specificity of the intelligent diagnosis system under each attention mechanism was 100% in group 0 and also revealed a high sensitivity of over 95%, F1 score of over 97%, and an accuracy of over 97% in this group. For the other three groups, the specificities of diagnosis ranged from 0.45 to 0.91 with different attention mechanisms, in which the ResNet18+coordinate attention (CA) model had the highest specificities of 0.91, 0.88, and 0.83 for groups 1, 2, and 3, respectively. It also provided a high accuracy of over 94% with a coordinate attention mechanism in all four groups. The intelligent diagnosis and classifier system developed herein based on deep learning can determine the presence of RVO and classify disease according to the site of occlusion. This proposed system is expected to provide a new tool for RVO diagnosis and screening and will help solve the current challenges due to the shortage of medical resources.