RETINAL MORPHOLOGIC CHANGES AND CONCENTRATIONS OF CYTOKINES IN EYES WITH DIABETIC MACULAR EDEMA

Role of inflammation in diabetic macular edema and neovascular age-related macular degeneration

Diabetic macular edema (DME) and neovascular age-related macular degeneration (nAMD) are multifactorial disorders that affect the macula and cause significant vision loss. Although inflammation and neoangiogenesis are hallmarks of DME and nAMD, respectively, they share some biochemical mediators. While inflammation is a trigger for the processes that lead to the development of DME, in nAMD inflammation seems to be the consequence of retinal pigment epithelium and Bruch membrane alterations. These pathophysiologic differences may be the key issue that justifies the difference in treatment strategies. Vascular endothelial growth factor inhibitors have changed the treatment of both diseases, however, many patients with DME fail to achieve the established therapeutic goals. From a clinical perspective, targeting inflammatory pathways with intravitreal corticosteroids has been proven to be effective in patients with DME. On the contrary, the clinical relevance of addressing inflammation in patients with nAMD has not been proven yet. We explore the role and implication of inflammation in the development of nAMD and DME and its therapeutical relevance.

Multimodal imaging in diabetic retinopathy and macular edema: An update about biomarkers

Diabetic macular edema (DME), defined as retinal thickening near, or involving the fovea caused by fluid accumulation in the retina, can lead to vision impairment and blindness in patients with diabetes. Current knowledge of retina anatomy and function and DME pathophysiology has taken great advantage of the availability of several techniques for visualizing the retina. Combining these techniques in a multimodal imaging approach to DME is recommended to improve diagnosis and to guide treatment decisions. We review the recent literature about the following retinal imaging technologies: optical coherence tomography (OCT), OCT angiography (OCTA), wide-field and ultrawide-field techniques applied to fundus photography, fluorescein angiography, and OCTA. The emphasis will be on characteristic DME features identified by these imaging technologies and their potential or established role as diagnostic, prognostic, or predictive biomarkers. The role of artificial intelligence in the assessment and interpretation of retina images is also discussed.

Immediate response to intravitreal treatment for macular edema due to diabetes and retinal vein occlusion

PURPOSE

To objectively assess the immediate response to intravitreal treatment for macular edema and compare it across different agents.

METHODS

This retrospective, comparative study included patients with macular edema due to diabetic retinopathy (DME) or vein occlusion who were treated with intravitreal injections of either steroids (triamcinolone acetonide or dexamethasone sustained release implant) or anti-vascular endothelial growth factor antibodies (VEGF). The central retinal thickness (CRT) and the best corrected visual acuity (BCVA) were measured 1 day after the injection and compared with immediate pre-injection values.

RESULTS

There were 79 eyes (57 patients) including 51 eyes with DME, 18 with branch retinal vein occlusion edema (BRVO-ME), and 10 eyes with central retinal vein occlusion edema (CRVO-ME). The intravitreal agents were triamcinolone acetonide (TA)(n = 15), dexamethasone sustained release implant (DEX)(n = 22), ranibizumab (n = 19), and bevacizumab (n = 23). Statistically significant improvement in CRT was seen in all injection groups (p < 0.05) while improvement in mean BCVA was significant only in the TA group (p = 0.009). The mean change in CRT was maximum with steroids than with anti-VEGFs; viz. 159.47 µ in TA, 115.45 µ in DEX, 86.10 µ in ranibizumab, and 78.78 µ in bevacizumab group. Least amount of change was noted in the spongy type of macular edema (18.73 µ) while improvement in mean BCVA was statistically significant only in the cystoid group (p = 0.01).

CONCLUSIONS

Comparatively, steroid agents showed better immediate response to therapy than anti-VEGFs. Maximum reduction in central retinal thickness was seen following triamcinolone acetonide injection. Cystoid edema showed better immediate response than spongy retinal thickening.

Clinical and optical coherence tomography biomarkers as prognostic factors in dexamethasone intravitreal implant for diabetic macular edema

PURPOSE

Aim of the study was to evaluate the efficacy of dexamethasone (DEX) 0.7 mg intravitreal implant in patients with diabetic macular edema (DME) and serous retinal detachment (SRD), and to study the prognostic factors on a follow up of 12 months.

METHODS

Forty eyes of twenty- six patients with centre involving DME and SRD, who underwent DEX implant, were enrolled. Best-corrected visual acuity (BCVA), Swept source OCT imaging and intraocular pressure were evaluated. Central macular thickness (CMT), vitreomacular adhesion (VMA), disorganization of retinal inner layers (DRILs), hyperreflective dots (HRD), SRD and ellipsoid zone (EZ) disruption were included in the analysis at baseline and 12 months after implant.

RESULTS

According to our parametric analysis, at 12 months, BVCA improvement from 48.6 ± 23.4 letters to 53.3 ± 24.5 letters was statistically significant (p = 0.04), CMT decreased from 460 ± 99.52 μm to 322.9 ± 117 μm. The presence at baseline of VMA (p = 0.01), EZ disruption (p = 0.03) and DRILs (p = 0.04), were associated with poor BCVA improvement at the end of follow-up.

CONCLUSION

In conclusion, OCT biomarkers can be considered significant prognostic factors for treatment outcome in patients with DME undergoing DEX intravitreal implant.

Exploring the Impact of Glycemic Control on Diabetic Retinopathy: Emerging Models and Prognostic Implications

This review addresses the complexities of type 1 diabetes (T1D) and its associated complications, with a particular focus on diabetic retinopathy (DR). This review outlines the progression from non-proliferative to proliferative diabetic retinopathy and diabetic macular edema, highlighting the role of dysglycemia in the pathogenesis of these conditions. A significant portion of this review is devoted to technological advances in diabetes management, particularly the use of hybrid closed-loop systems (HCLSs) and to the potential of open-source HCLSs, which could be easily adapted to different patients' needs using big data analytics and machine learning. Personalized HCLS algorithms that integrate factors such as patient lifestyle, dietary habits, and hormonal variations are highlighted as critical to reducing the incidence of diabetes-related complications and improving patient outcomes.

Biochemical and microstructural determinants of the development of serous retinal detachment secondary to retinal vein occlusion

Purpose

To study the alteration of cytokine factors in aqueous humor and retinal microstructure in the formation of serous retinal detachment (SRD) secondary to retinal vein occlusion.

Methods

The subjects were 39 patients with RVO, of whom 31 patients had SRD (RVO-SRD). Spectral Domain Optical Coherence Tomography (SD-OCT) was used to measure the completeness of photoreceptor inner segment/outer segment (IS/OS) and the external limiting membrane (ELM) as well as the structure of RVO-SRD, including the height and shape of SRD. The aqueous humor was collected before intravitreal injection of Ranibizumab. The concentrations of VEGF, MCP-1, IL-8, IL-6, b-FGF and TNF-α in the aqueous humor were measured. All patients participated in the 6-month follow-up examinations, which included visual acuity, intraocular pressure, ophthalmologic examination, and SD-OCT. The time of recurrence of RVO-SRD was recorded.

Results

The formation of SRD was associated with the area of congested vein, disrupted IS/OS, ELM layers and high VEGF, MCP-1, IL-8, IL-6 levels. However, the height and shape of SRD were not relevant to any inflammatory factors. Moreover, high levels of MCP-1, IL-8 and IL-6 were found in large areas of congested veins. High levels of MCP-1 and IL-6 were observed in the patients with incomplete IS/OS and ELM. The recurrence of SRD was related to the high MCP-1 level.

Conclusion

High concentrations of cytokine factors in aqueous humor could induce vascular leakage, exacerbate the extent of macular edema, disrupt the structure of ELM and IS/OS, and develop SRD in RVO.

Optical coherence tomography in the management of diabetic macular oedema

Diabetic macular oedema (DMO) is the major cause of visual impairment in people with diabetes. Optical coherence tomography (OCT) is now the most widely used modality to assess presence and severity of DMO. DMO is currently broadly classified based on the involvement to the central 1 mm of the macula into non-centre or centre involved DMO (CI-DMO) and DMO can occur with or without visual acuity (VA) loss. This classification forms the basis of management strategies of DMO. Despite years of research on quantitative and qualitative DMO related features assessed by OCT, these do not fully inform physicians of the prognosis and severity of DMO relative to visual function. Having said that, recent research on novel OCT biomarkers development and re-defined classification of DMO show better correlation with visual function and treatment response. This review summarises the current evidence of the association of OCT biomarkers in DMO management and its potential clinical importance in predicting VA and anatomical treatment response. The review also discusses some future directions in this field, such as the use of artificial intelligence to quantify and monitor OCT biomarkers and retinal fluid and identify phenotypes of DMO, and the need for standardisation and classification of OCT biomarkers to use in future clinical trials and clinical practice settings as prognostic markers and secondary treatment outcome measures in the management of DMO.

Central Serous Chorioretinopathy. A Review

Central serous chorioretinopathy (CSC) is a disease characterized by serous detachment of the neuroretina, especially in the posterior pole of the eye. It is often accompanied by serous detachment of the retinal pigment epithelium (RPE) and associated with the leakage of fluid into the subretinal space through the defective RPE. CSC most often affects men of working age. The exact pathophysiology of the disease is not completely known. Based on indocyanine green angiography (ICG), which revealed increased permeability of choroidal vessels, and optical coherence tomography (OCT) showing increased choroidal thickness, choroidal vasculopathy is assumed to be the primary cause of CSC. In most cases, CSC has a good prognosis with spontaneous resorption of the subretinal fluid (SRF) and improvement of visual functions. However, in a small percentage of patients the disease progresses to a chronic or recurrent course, and can lead to irreversible functional and anatomical changes of the retina with a final clinical picture of diffuse retinal pigment epitheliopathy (DRPE). The optimal treatment approach for patients with CSC remains controversial. In recent decades, myriad therapeutic approaches have been used in the treatment of chronic forms of CSC (cCSC); these included for example laser photocoagulation, pharmaceutical treatment, standard photodynamic therapy (PDT) or anti-VEGF. In recent years a less destructive method, specifically PDT in reduced dose regimens, either with a reduced dose of verteporfin or the laser beam energy used, has been preferred in the treatment of cCSC. Comparable efficacy and safety has been demonstrated using reduced-dose or reduced-fluence PDT regimens in patients with cCSC, with an improvement in best-corrected visual acuity and reduction of SRF.

A real-world study for timely assessing the diabetic macular edema refractory to intravitreal anti-VEGF treatment

Background

Early Identifying and characterizing patients with diabetic macular edema (DME) is essential for individualized treatment and outcome optimization. This study aimed to timely investigate optical coherence tomography (OCT) biomarkers of DME refractory to intravitreal anti-vascular endothelial growth factor (VEGF) therapy.

Methods

We retrospective reviewed 72 eyes from 44 treatment-naïve patients who were treated with intravitreal anti-VEGF for DME. OCT scans prior to anti-VEGF were evaluated for serous retinal detachment (SRD), size of outer nuclear layer cystoid changes, diffuse retinal thickening, integrity of the inner segment-outer segment (IS-OS) junction, quantity and location of hyperreflective foci, vitreomacular interface abnormalities, and epiretinal membrane (ERM). The Baseline best-corrected visual acuity (BCVA) and central macular thickness was recorded at baseline and 4 months after treatment with anti-VEGF. The main outcome measure was the correlation between spectral-domain OCT measurements and BCVA response at baseline and after anti-VEGF treatment (mean change from baseline; ≥ 10 Early Treatment Diabetic Retinopathy Study letters in BCVA).

Results

Partially continuous IS-OS layers (partially vs. completely continuous: β, -0.138; Wald chi-square, 16.392; P<0.001) was predictor of better response to anti-VEGF treatment. In contrast, ERM (present vs. absent ERM: β, 0.215; Wald chi-square, 5.921; P=0.015) and vitreomacular traction (vitreomacular traction vs. posterior vitreous detachment: β=0.259; Wald chi-square=5.938; P=0.015) were the predictors of poor response. The improvement of BCVA trended toward the OCT predictive value of central macular thickness reduction; however, this was not significant.

Conclusion

Partially continuous IS-OS layers is predictive of better response to anti-VEGF therapy in DME. Meanwhile, ERM is a significant predictor of poor response.

Efficacy and safety profile of intravitreal dexamethasone implant versus antivascular endothelial growth factor treatment in diabetic macular edema: a systematic review and meta-analysis

To better understand the efficacy of intravitreal dexamethasone implant (Ozurdex) versus antivascular endothelial growth factor (anti-VEGF) treatment in patients with diabetic macular edema (DME). A systematic review and meta-analysis. The study included randomized control trials (RCTs) and non-randomized control trials (Non-RCTs) before December 2021 that compare the efficacy of Ozurdex-related therapyand anti-VEGF therapy. We searched PubMed, Cochrane Library, and EMBASE. The quality of the included studies was assessed carefully. 30 studies were included. Regarding BCVA change, the overall result revealed no significant differences between Ozurdex and anti-VEGF therapies in patients with nonresistant DME, but Ozurdex group had significantly more VA improvement than anti-VEGF therapies in patients with resistant DME (MD 0.12, 95% CI 0.02-0.21). In terms of central retinal thickness (CRT) decrease, there was a significant difference between Ozurdex therapy and anti-VEGF therapy in patients with nonresistant DME (MD 48.10, 95% CI 19.06-77.13) and resistant DME (MD 65.37, 95% CI 3.62-127.13). Overall, Ozurdex therapy resulted in significantly greater VA improvement and CRT decrease than anti-VEGF therapy in resistant DME patients. Ozurdex therapy was not inferior to anti-VEGF therapy in patients with nonresistant DME.

Association between Aqueous Humor Cytokines and Structural Characteristics Based on Optical Coherence Tomography in Patients with Diabetic Macular Edema

Purpose

To investigate the relationship between aqueous humor cytokines and structural characteristics based on optical coherence tomography (OCT) in patients with diabetic macular edema (DME).

Methods

Forty eyes of 28 patients with DME diagnosed in the Affiliated Eye Hospital of Wenzhou Medical University at Hangzhou were included. All patients collected aqueous humor during anti-VEGF treatment, and the IL-6, IL-8, IL-10, VEGF, VCAM-1, ICAM-1, TGF-β1, FGF, and MCP-1 concentrations were detected. OCT examination was performed before anti-VEGF treatment and 1 month after anti-VEGF operation. Central macular thickness (CMT), macular volume (MV), choroidal thickness (CT), and the number of hyperreflective foci (HRF) were obtained for analysis. Each eye was determined whether there is subretinal effusion (SRD), cystoid macular edema (CME), and diffuse retinal thickening (DRT).

Results

The levels of IL-6 and FGF in DME patients with SRD were significantly higher than those without SRD (all P < 0.05). The level of VEGF in DME patients with CME was significantly higher than that in DME patients without CME (P = 0.005); IL-6, TGF-β1, and MCP-1 were significantly higher in DME patients with DRT than that without DRT (all P < 0.05). There was no significant correlation between aqueous humor cytokines and retinal thickness and retinal volume. However, the thinner the CT, the higher the level of aqueous humor cytokines IL-6 (r = -0.313, P = 0.049) and FGF (r = -0.361, P = 0.022). A multivariate linear regression analysis showed that IL-6 was significantly correlated with CT (P = 0.002) and SRD (P = 0.017), FGF was also significantly correlated with CT (P = 0.002) and SRD (P = 0.005), and TGF-β1 was correlated with triglycerides (P = 0.030) and HRF (P = 0.021).

Conclusion

DME patients with significant macular cystoid edema changes may be related to high VEGF concentrations and thin CT; meanwhile, the presence of SRD or a high number of HRF on OCT macular scans in DME patients may indicate high levels of intraocular inflammatory factors. Thus, OCT morphology characteristics to some extent reflect intraocular inflammatory factors and VEGF levels and may guide treatment alternatives.

Optical coherence tomography as retinal imaging biomarker of neuroinflammation/neurodegeneration in systemic disorders in adults and children

The retina and the optic nerve are considered extensions of the central nervous system (CNS) and thus can serve as the window for evaluation of CNS disorders. Spectral domain optical coherence tomography (OCT) allows for detailed evaluation of the retina and the optic nerve. OCT can non-invasively document changes in single retina layer thickness and structure due to neuronal and retinal glial cells (RGC) modifications in systemic and local inflammatory and neurodegenerative diseases. These can include evaluation of retinal nerve fibre layer and ganglion cell complex, hyper-reflective retinal spots (HRS, sign of activated microglial cells in the retina), subfoveal neuroretinal detachment, disorganization of the inner retinal layers (DRIL), thickness and integrity of the outer retinal layers and choroidal thickness. This review paper will report the most recent data on the use of OCT as a non invasive imaging biomarker for evaluation of the most common systemic neuroinflammatory and neurodegenerative/neurocognitive disorders in the adults and in paediatric population. In the adult population the main focus will be on diabetes mellitus, multiple sclerosis, optic neuromyelitis, neuromyelitis optica spectrum disorders, longitudinal extensive transverse myelitis, Alzheimer and Parkinson diseases, Amyotrophic lateral sclerosis, Huntington's disease and schizophrenia. In the paediatric population, demyelinating diseases, lysosomal storage diseases, Nieman Pick type C disease, hypoxic ischaemic encephalopathy, human immunodeficiency virus, leukodystrophies spinocerebellar ataxia will be addressed.

Neuroinflammation and neurodegeneration in diabetic retinopathy

Diabetic retinopathy (DR) is the most common complication of diabetes and has been historically regarded as a microangiopathic disease. Now, the paradigm is shifting toward a more comprehensive view of diabetic retinal disease (DRD) as a tissue-specific neurovascular complication, in which persistently high glycemia causes not only microvascular damage and ischemia but also intraretinal inflammation and neuronal degeneration. Despite the increasing knowledge on the pathogenic pathways involved in DR, currently approved treatments are focused only on its late-stage vasculopathic complications, and a single molecular target, vascular endothelial growth factor (VEGF), has been extensively studied, leading to drug development and approval. In this review, we discuss the state of the art of research on neuroinflammation and neurodegeneration in diabetes, with a focus on pathophysiological studies on human subjects, in vivo imaging biomarkers, and clinical trials on novel therapeutic options.

Prevalence of Serous Macular Detachment in Recurrent Macular Edema Secondary to Retinal Vein Occlusion

Objectives:

To evaluate the prevalence of serous macular detachment (SMD) accompanying recurrent cystoid macular edema (CME) in patients initially treated for CME secondary to retinal vein occlusion (RVO) with accompanying SMD, and discuss the factors that affect the prevalence.

Materials and Methods:

We retrospectively evaluated the medical records of 71 patients with RVO-associated CME and SMD who achieved complete anatomical resolution after treatment with either a single dexamethasone implant or three loading doses of ranibizumab and developed recurrent CME during follow-up.

Results:

Initial treatment was a single intravitreal dexamethasone implant in 45 patients (63.4%) (Group 1) and three loading doses of intravitreal ranibizumab in 26 patients (36.6%) (Group 2). The mean time to CME recurrence was 4.7±0.8 months (range, 4-7 months) and was similar in both groups (p=0.984). At the time of CME recurrence, SMD was present in 41 patients (57.7%) and absent in 30 patients (42.3%). SMD was present in 27 (60.0%) of the 45 Group 1 patients and 14 (53.8%) of the 26 Group 2 patients (p=0.613). SMD was present in 48.8% of branch RVO and 71.4% of central RVO patients at the time of recurrence (p<0.001).

Conclusion:

SMD accompanied recurrent CME in only 57.7% of patients previously treated for CME and SMD and seems to be more frequent in patients with central RVO. Initial intravitreal treatment choice of either ranibizumab or dexamethasone implant did not affect the prevalence of concurrent SMD in patients with recurrent CME.

Characteristics of macular morphology and microcirculation in diabetic macular edema patients with serous retinal detachment

BACKGROUND

To analyze and compare the characteristics of macular morphology and microcirculation in diabetic macular edema (DME) patients with and without macular serous retinal detachment (SRD).

METHODS

One hundred eyes in 81 patients diagnosed with the DME (the central macular thickness (CMT) of ≥ 300 μm) from March 2020 to November 2020 were selected. According to whether complicated with SRD, patients were divided into DME with SRD (60 eyes) and without SRD (40 eyes) groups. We analyzed the following parameters: CMT, central retinal thickness (CRT), subfoveal choroidal thickness (SFCT), number of hyperreflective foci (HF) in the complete retina, inner retina, outer retina, and subretinal space, the integrity of the ellipsoid zone (EZ) and external limiting membrane (ELM), the presence of disorganization of inner retinal layers (DRIL), foveal avascular zone (FAZ) area, and the vascular flow density of superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris.

RESULTS

(1) Compared to the group without SRD, the group with SRD had a greater CMT (P < 0.05) and a smaller CRT (P < 0.001); (2) The number of the HF in the complete retina, outer retina, and the subretinal space was larger in the group with SRD (P < 0.001); 3.The proportion of the EZ disruption (P < 0.05) and ELM disruption (P < 0.001) were higher in the group with SRD; 4. The SFCT (P < 0.05) and the vascular flow density of choriocapillaris (P < 0.05) were greater in the group with SRD; 5. There were no significant differences in the FAZ area and the vascular flow density of the DCP and SCP (P > 0.05); 6. The presence of the SRD was correlated with the integrity of the ELM, the number of HF in the complete retina, outer retina, and subretinal space (χ2 = 26.930, OR = 0.707, 0.263, 0.995, P < 0.001), as well as the SFCT (OR = 0.992, P < 0.05).

CONCLUSIONS

The results support the hypothesis that the presence of the ELM disruption, the larger number of the HF, and the thickening and hyperperfusion of the choroid may be involved in the pathogenesis of SRD in DME.

Optical Coherence Tomography Biomarkers in Predicting Treatment Outcomes of Diabetic Macular Edema After Dexamethasone Implants

Purpose

To identify optical coherence tomography (OCT) biomarkers that may predict functional and anatomical outcomes in diabetic macular edema (DME) patients treated with intravitreal dexamethasone (DEX) implant.

Materials and Methods

Sixty-four eyes from 50 patients with DME were enrolled. Best-corrected visual acuity (BCVA) and OCT biomarkers including central retinal thickness (CRT), subretinal fluid (SRF), intraretinal cysts (IRC), ellipsoid zone disruption (EZD), disorganization of retinal inner layers (DRIL), hard exudate (HE), hyperreflective foci (HRF), epiretinal membrane (ERM), and vitreomacular interface (VMI) changes were evaluated at baseline and at 3, 6, and 12 months after treatment. Multiple logistic analysis was performed to evaluate each OCT biomarker as a predictive factor for functional and anatomical improvement at the end of treatment.

Results

The presence of SRF at baseline was associated with a favorable outcome, with CRT improving by more than 100 μm after treatment from multivariate logistic regression analysis [odds ratio 6.16 (1.75-21.6)]. In addition, baseline SRF predicted a greater CRT improvement from multiple regression analysis (model R-square 0.11, p = 0.006). The reduction of DRIL, SRF, LONLC, IRC, and EZD were correlated with better CRT improvement (more than 100 μm) (P < 0.05). SRF and EZD recovery can also predict better visual prognosis (P < 0.05).

Conclusion

OCT biomarkers can be used to predict who may benefit the most after DEX treatment. We suggest that the DEX implant should be considered as a first line treatment in DME patients with SRF.

Prediction of anti-VEGF efficacy in diabetic macular oedema using intraocular cytokines and macular optical coherence tomography

PURPOSE

In eyes with diabetic macular oedema (DME), aqueous humour (AH) cytokine levels before and after anti-vascular endothelial growth factor (VEGF) treatment were compared and correlated with optical coherence tomography structural parameters.

METHODS

This prospective study included 56 control patients with cataracts and 83 patients with DME manifesting as diffuse retinal thickening (DRT), cystoid macular oedema and serous retinal detachment (SRD). AH samples were obtained before intravitreal injection of anti-VEGF or cataract surgery. VEGF, interleukin (IL)-6, IL-8, IL-10, interferon-inducible protein 10 (IP-10) and monocyte chemotactic protein 1 (MCP-1) levels were measured by multiplex bead assay. AH cytokine levels, central macular thickness (CMT), number of hyper-reflective foci (HF), continuity of external limiting membrane and ellipsoid zone (EZ) and best-corrected visual acuity were evaluated.

RESULTS

In SRD, IL-6 and MCP-1 levels and HF were increased (all p < 0.05) compared to DRT. At baseline, the number of HF was correlated with VEGF, IL-6, IL-8, IP-10 and MCP-1 (all p < 0.05). Eyes sensitive to anti-VEGF treatment had high baseline levels of VEGF, MCP-1, HF and many EZ disruptions (all p < 0.05). DME patients with normal VEGF levels but with high levels of IL-8, IP-10 and MCP-1 (all p < 0.05) had little change in CMT after anti-VEGF treatment (p = 0.678).

CONCLUSIONS

AH concentrations of some inflammatory cytokines in DME were differentially expressed among the three DME morphologies. HF was associated with VEGF and other inflammatory cytokine levels. Multiple HF at baseline predicted a significant decrease in CMT, and eyes with normal VEGF but increased inflammatory cytokines may be insensitive to anti-VEGF treatment.

Optical coherence tomography and imaging biomarkers as outcome predictors in diabetic macular edema treated with dexamethasone implant

In this retrospective, multicenter study, we determined the predictive value of imaging biomarkers in diabetic macular edema (DME) outcomes following dexamethasone (DEX) implant(s). Sixty-seven eyes of 47 patients' best-corrected visual acuity (BCVA) and central foveal thickness (CFT) on optical coherence tomography (OCT) before and after intravitreal DEX implants were evaluated. Baseline imaging biomarkers were graded using fundus photography and OCT, and the predictive value of biomarkers for significant treatment effects at six months was analyzed. Six months after 2.0 ± 0.8 (mean ± SD) DEX implants, 35 (52%) and 16 (24%) eyes had CFT reduction ≥ 10% from baseline and decreased to < 300 µm, respectively. BCVA improved ≥ 3 lines in 15 (22%) and remained stable in 38 (57%) eyes. At six months, eyes with severe intraretinal cyst (IRC), abundant hyperreflective dots (HRD), and moderate or severe hard exudate had a significantly higher chance of CFT reduction ≥ 10%. Eyes with abundant HRD at baseline and those underwent three DEX implants were more likely to achieve CFT < 300 µm. Eyes with DME and severe IRC, abundant HRD, or moderate-to-severe hard exudate at baseline were more likely to show a significant reduction in CFT six months after DEX implant.

Serum inflammatory marker levels in serous macular detachment secondary to diabetic macular edema

PURPOSE

To evaluate the serum inflammatory marker levels in serous macular detachment (SMD) secondary to diabetic macular edema (DME).

MATERIAL AND METHODS

Patients with DME were divided into two groups according to the presence of SMD. Group 1 consisted of 40 patients with SMD, Group 2 consisted of 40 patients without SMD, and Group 3 consisted of 40 healthy subjects. Neutrophil and mean platelet volume (MPV) were obtained from blood samples. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and the systemic immune inflammation index (SII) were calculated. In Group 1 and 2 sub-group analysis was done according to grade of diabetic retinopathy (DR) and the results were analyzed in these subgroups.

RESULTS

The neutrophils, MPV, NLR, and SII levels were significantly higher in Group 1 (p = 0.000, p = 0.004, p = 0.000, p = 0.001, respectively). In subgroup analysis; the neutrophils, NLR, and SII levels were significantly higher in patients with proliferative DR (p = 0.044, p = 0.046, p = 0.046, respectively) and the SII levels were significantly higher in patients with severe nonproliferative DR in Group 1 (p = 0.039). The mean CMT values were 548.8 ± 138.3 µm in Group 1 and 420.1 ± 112.7 µm in Group 2. The CMT values were significantly higher in Group 1 (p: 0.000). However, there was no significant correlation between the CMT values and the systemic inflamatuar markers levels (p>0.05) in both of the groups.

CONCLUSIONS

NLR and SII levels were significantly higher in DME with SMD, especially in advanced cases. Elevated serum inflammatory markers might be associated with a higher incidence of SMD.

Changes in aqueous and vitreous inflammatory cytokine levels in diabetic macular oedema: a systematic review and meta-analysis

Diabetic macular oedema (DME) is considered a chronic inflammatory disease associated with aberrations in many intraocular cytokines. Studies assessing the role of these cytokines as biomarkers in the diagnosis and management of DME have demonstrated inconsistent findings. We quantitatively summarized data related to 116 candidate aqueous and vitreous inflammatory cytokines as biomarkers in DME. A systematic search without year limitation was performed up to 19 October 2020. Studies were included if they provided data on aqueous or vitreous cytokine concentrations in patients with DME. Effect sizes were generated as standardized mean differences (SMDs) of cytokine concentrations between patients with DME and controls. Data were extracted from 128 studies that included 4163 study eyes with DME and 1281 control eyes. Concentrations (standard mean difference, 95% confidence interval and p-value) of aqueous IL-6 (1.28, 0.57-2.00, p = 0.004), IL-8 (1.06, 0.74-1.39, p < 0.00001), MCP-1 (1.36, 0.57-2.16, p = 0.0008) and VEGF (1.31, 1.01-1.62, p < 0.00001) and vitreous VEGF (2.27, 1.55-2.99, p < 0.00001) were significantly higher in patients with DME (n = 4163) compared to healthy controls (n = 1281). No differences, failed sensitivity analyses or insufficient data were found between patients with DME and healthy controls for the concentrations of the remaining cytokines. This analysis implicates multiple cytokine biomarker candidates other than VEGF in DME and clarifies previously reported inconsistent associations. As the therapeutic options for DME expand to include multiple agents with multiple targets, it will be critical to manage the treatment burden with tailored therapy that optimizes outcomes and minimizes treatment burden. Intraocular cytokines have the promise of providing a robust individualized assessment of disease status and response to therapy. We have identified key candidate cytokines that may serve as biomarkers in individualized treatment algorithms.

Update on Current and Future Management for Diabetic Maculopathy

Diabetic macular edema (DME) remains the major cause of preventable blindness in the working-age population in developed countries, and screening programs are extremely important in the management of this complication of diabetic retinopathy. The introduction of modern imaging modalities and technological advances have facilitated both the early detection and the follow-up of patients with DME, particularly optical coherence tomography angiography and artificial intelligence. Intravitreal therapy is the gold standard treatment for DME, but not all patients respond equally to this therapy, and sometimes it is not easy to apply treatment protocols correctly; for these reasons, clinical practice results may differ from those of clinical trials in terms of vision gain. One approach has been to implement new treatment regimens, such as treat and extend, and new molecules and therapeutic targets are constantly being developed. The main goal of this review paper is to describe the current treatment options and management strategies for DME in Europe and to provide a brief oversight of the novel therapeutic options on the horizon.

Factors Associated With the Presence of Foveal Bulge in Eyes With Resolved Diabetic Macular Edema

Purpose: To evaluate factors associated with the presence of foveal bulge (FB) in resolved diabetic macular edema (DME) eyes.

Methods: A total of 165 eyes with complete integrity of ellipsoid zone (EZ) at the fovea and resolved DME were divided into two groups according to the presence of FB at 6 months after intravitreal injection of ranibizumab treatment. Best-corrected visual acuity (BCVA), central foveal thickness (CFT), outer nuclear layer (ONL) thickness, height of serous retinal detachment (SRD) and non-SRD, and inner segment (IS) and outer segment (OS) lengths of the two groups were measured and compared at baseline and each follow-up. The correlations between the presence of FB and pre- and post-treatment factors were determined by logistic regression analysis.

Results: At baseline, BCVA was significantly better, and CFT and incidence and height of SRD were significantly lower in the FB (+) group (all P < 0.05). At 6 months, FB was present in 65 (39.39%) eyes. Post-treatment BCVA was significantly better and OS length was significantly longer in the FB (+) group at 6 months (all P < 0.05). Multivariate analysis identified younger age, better BCVA, and lower CFT before treatment as significant predictors of the existence of FB at 6 months (all P < 0.05). At 6 months, better BCVA and longer OS length were significantly correlated with the existence of FB (all P < 0.05).

Conclusions: Factors associated with the presence of FB after the resolution of DME include younger age, better baseline BCVA and lower baseline CFT, and better post-treatment BCVA and longer post-treatment OS length.

The role of inflammation and neurodegeneration in diabetic macular edema

The pathogenesis of diabetic macular edema (DME) is complex. Persistently high blood glucose activates multiple cellular pathways and induces inflammation, oxidation stress, and vascular dysfunction. Retinal ganglion cells, macroglial and microglial cells, endothelial cells, pericytes, and retinal pigment epithelium cells are involved. Neurodegeneration, characterized by dysfunction or apoptotic loss of retinal neurons, occurs early and independently from the vascular alterations. Despite the increasing knowledge on the pathways involved in DME, only limited therapeutic strategies are available. Besides antiangiogenic drugs and intravitreal corticosteroids, alternative therapeutic options tackling inflammation, oxidative stress, and neurodegeneration have been considered, but none of them has been currently approved.

Behavior of hyperreflective spots noted on optical coherence tomography following intravitreal therapy in diabetic macular edema: A systematic review and meta-analysis

Purpose:

Hyperreflective spots (HRS) are considered as spectral domain optical coherence tomography biomarkers in predicting response to intravitreal therapy (IVT) in diabetic macular edema (DME). We aimed to determine if there was a quantitative reduction in HRS following IVT in DME, if the response to antivascular endothelial growth factor (anti-VEGF) drugs was different from steroids, and if HRS-response was associated with improvement in visual acuity (VA) or reduction in central macular thickness (CMT).

Methods:

PubMed/MEDLINE, Scopus, ProQuest, CINAHL, Wiley online, and Web of Science were searched (between January 1, 2011 and July 1, 2020). Publication bias and heterogeneity were assessed. Meta-analysis was done using the random-effects model.

Results:

Totally, 1168 eyes from 19 studies were eligible for inclusion. IVT was associated with a reduction in quantitative HRS (z = -6.3, P < 0.0001). Studies, however, showed heterogeneity (I² = 93.2%). There was no difference between anti-VEGF and steroid therapies (P = 0.23). The evidence on predicting VA and CMT outcomes were limited by the number of analyzable studies, owing to the wide variation in individual study designs, and lack of randomized controlled trials.

Conclusion:

We could conclude that there is a definite reduction in quantitative HRS following either form of IVT. We highlight the lacunae in the existing literature on HRS in DME and propose goals for future studies to harness the advantage of this promising biomarker.

Aqueous humor analyses of diabetic macular edema patients with subretinal fluid

We identified treatment-naïve diabetic macular edema (DME) patients with or without subretinal fluid (SRF). We compared their baseline characteristics: aqueous concentrations of interleukin (IL)-1β, IL-2, IL-6, IL-8, IL-10, and IL-17, as well as tumor necrosis factor-α, vascular endothelial growth factor (VEGF), and placental growth factor (PlGF). We also compared fundus and optical coherence tomography (OCT) findings, and responsiveness to anti-VEGF treatments. Of 67 DME patients, 18 (26.87%) had SRF. Compared to the no SRF group, the SRF group had significantly higher levels of IL-6, IL-8, VEGF, and PlGF in aqueous humor. After grouping according to diabetic retinopathy stage, non-proliferative diabetic retinopathy (NPDR) patients with SRF had higher aqueous levels of IL-6 and IL-8, compared to NPDR patients without SRF. Moreover, proliferative diabetic retinopathy (PDR) patients with SRF had higher aqueous levels of VEGF and PlGF, compared to PDR patients without SRF. Fundus and OCT analyses revealed that the SRF group had a greater proportion of patients with succinate or patch-shaped hard exudates involving the macula, and greater central subfield thickness (CST) at baseline. After 6 months of anti-VEGF treatments, the SRF group showed better responsiveness in terms of CST; however, visual acuity was not correlated with responsiveness. Considering higher aqueous levels of VEGFs and pro-inflammatory cytokines, SRF could be a biomarker related to diabetic retinopathy activity. DME patients with SRF showed better anatomical responsiveness to anti-VEGF treatments, but did not show better functional improvement on short-term evaluation compared to those of DME patients without SRF.

Temporal variation of optical coherence tomography biomarkers as predictors of anti-VEGF treatment outcomes in diabetic macular edema

PURPOSE

To report a longitudinal analysis of specific optical coherence tomography (OCT) features in eyes with diabetic macular edema (DME) treated with anti-VEGF.

METHODS

A total of 133 eyes of 103 consecutive patients with center-involving DME were included in the study. The eyes were treated between August 2008 and April 2019 with three monthly intravitreal anti-VEGF injections, either with or without prompt or deferred laser, followed by pro re nata (PRN) re-treatment. The following OCT biomarkers were evaluated: subfoveal neuroretinal detachment (SND) (defined as present (SND+) or absent (SND-)), hyperreflective retinal foci (HRF) number (defined as: absent/few(HRF-) or moderate/many (HRF+)), external limiting membrane (ELM) integrity, central macular thickness (CMT), and central retinal thickness (CRT). Changes in SND status and in the number of HRF were evaluated at each DME recurrence throughout the follow-up(FU) period. Mutual correlation among OCT biomarkers and their relationship with visual and anatomic outcomes were assessed both at baseline and over the FU period.

RESULTS

The mean FU was 71.2 months (SD 28.4; min. 12-max. 111). At baseline, the prevalence of SRD+ was 27.8% and a high number of HRF were detected in 41.4% of the eyes. A significant reduction in the number of HRF, CMT, CRT, and in the prevalence of SND was recorded in the post-loading phase (p-value <0.0001). In DME recurrences, the presence of SND+ and HRF+ was significantly more frequent in eyes with baseline SND+ and HRF+ compared to eyes presenting baseline SND- and HRF- (p-value <0.0001). No role of SND (p-value: 0.926) and HRF (p-value: 0.281) as baseline predictors of visual and anatomic outcomes was demonstrated, while a worse visual outcome was significantly correlated with a higher incidence of relapsing SND+ (p-value <0.0001) and HRF+ (p-value <0.0028) throughout the FU period.

CONCLUSION

In this study, SND and HRF were frequently present in DME recurrences with the same pattern exhibited at baseline, suggesting that these OCT biomarkers may characterize a specific pattern of DME that repeats over time. Moreover, the results suggested that the persistence and recurrence of SND and HRF may account for a decrease in visual function more than the baseline prevalence of these biomarkers. Further studies are required to confirm these findings.

Challenges in Diabetic Macular Edema Management: An Expert Consensus Report

Purpose

This paper aimed to present daily-practice recommendations for the management of diabetic macular edema (DME) patients based on available scientific evidence and the clinical experience of the consensus panel.

Methods

A group of Spanish retina experts agreed to discuss different aspects related with the clinical management of DME patients.

Results

Panel was mainly focused on therapeutic objectives in DME management; definition terms; and role of biomarkers as prognostic and predictive factors to intravitreal treatment response. The panel recommends to start DME treatment as soon as possible in those eyes with a visual acuity less than 20/25 (always according to the retina unit capacity). Naïve patient was defined, in a strict manner, as a patient who, up to that moment, had never received any treatment. A refractory DME patient may be defined as the one who did not achieve a complete resolution of the disease, regardless of the treatment administered. Different optical coherence tomography biomarkers, such as disorganization of the retinal inner layers, hyperreflective dots, and cysts, have been identified as prognostic factors.

Conclusion

This document has sought to lay down a set of recommendations and to identify key issues that may be useful for the daily management of DME patients.

Evaluation of retinal inflammatory biomarkers after intravitreal steroid implant and Ranibizumab injection in diabetic macular edema

PURPOSE

To compare the efficacy of intravitreal (IV) ranibizumab (IVR) injection with IV dexamethasone implant (IVDEX) in treatment naive diabetic macular edema (DME) patients with inflammatory component.

MATERIALS AND METHODS

Treatment naive DME eyes with subfoveal neurosensorial detachment (SND) and hyperreflective spots (HRS) were treated either three loading doses of IVR (18 eyes) or one dose of IVDEX (19 eyes). Central macular thickness (CMT), height of SND, the number of HRSs scattered on the individual retinal layers and photoreceptor integrity were assessed using spectral domain- optical coherence tomography scans over 3-months follow-up.

RESULTS

The mean change in best-corrected visual acuity (BCVA) was -0.11 ± 0.08 logMAR in IVDEX group and -0.04 ± 0.06 logMAR in IVR group at 1-month (p = 0.011). IVDEX group showed statistically significant more increase in BCVA compared to those receiving IVR injections at 2-months (p = 0.004) and 3-months (p = 0.017) visits. Compared to baseline, the number of total HRSs and the number of HRSs at each individual inner retinal layer significantly decreased in both groups at all follow-up visits. However, IVDEX group showed more decrease in the total number of HRSs at 2- and 3-months (p < 0.001 at 2-months, and p = 0.006 at 3-months) and in the mean number of HRSs located at inner nuclear layer-outer plexiform layer level (p = 0.016 at 1-month, p < 0.001 at 2-months, and p < 0.001 at 3-months). After treatment, the number of HRSs on the outer nuclear layer showed some non-significant increase in both groups.

CONCLUSION

HRSs tended to migrate from inner retina to the outer retina in DME eyes by treatment. Dexamethasone seemed to be more effective option in such cases with inflammatory component.

The Vitreous Ecosystem in Diabetic Retinopathy: Insight into the Patho-Mechanisms of Disease

Diabetic retinopathy is one of the leading causes of blindness in the world with the incidence of disease ever-increasing worldwide. The vitreous humor represents an extensive and complex interactive arena for cytokines in the diabetic eye. In recent decades, there has been significant progress in understanding this environment and its implications in disease pathophysiology. In this review, we investigate the vitreous ecosystem in diabetic retinopathy at the molecular level. Areas of concentration include: the current level of knowledge of growth factors, cytokine and chemokine mediators, and lipid-derived metabolites in the vitreous. We discuss the molecular patho-mechanisms of diabetic retinopathy based upon current vitreous research.

Comparison of the effects of aflibercept and dexamethasone in central retinal vein occlusion with serous retinal detachment

Clinical relevance: Previous studies have shown the efficacy of aflibercept and dexamethasone in central retinal vein occlusion. However, the efficacy of these two drugs in central retinal vein occlusion accompanied by serous macular detachment has not been investigated and compared. This results in a search for more precise data to evaluate the effects of two drugs in real-world studies.Background: The aim of this study is to compare the efficacy of intravitreal aflibercept and dexamethasone implantation injections in central retinal vein occlusion accompanied by serous retinal detachment.Methods: Sixty-eight eyes of 68 patients with treatment-naive macular oedema post-central retinal vein occlusion were enrolled in the retrospectively designed study. All of the patients had serous retinal detachment at baseline. The patients received three intravitreal aflibercept injections with an interval of four weeks and followed by pro re nata treatment protocol (intravitreal aflibercept group, n = 37) or a single dose dexamethasone implantation injection (dexamethasone implantation group, n = 31). Best-corrected visual acuity, central retinal thickness and the height of serous retinal detachment parameters were compared at baseline, and in the first, second, third and sixth months.Results: The groups were similar in terms of baseline characteristics (p > 0.05 for all). The visual gain was greater in the intravitreal aflibercept group (p = 0.013). While the intravitreal aflibercept group had a significant central retinal thickness decrease in the first and sixth months (p = 0.011 and p = 0.001, respectively), this superiority was not observed during the entire follow-up period (p = 0.212). There was no difference in serous retinal detachment resolution between the groups (p = 0.403). Two patients in the intravitreal aflibercept group (5.4%) and five patients in the dexamethasone implantation group (16.1%) had serous retinal detachment at the final visit (p = 0.158).Conclusion: Both intravitreal aflibercept and dexamethasone implantation injections seemed to be effective in the treatment of central retinal vein occlusion with serous retinal detachment. Intravitreal aflibercept treatment yielded better results in terms of visual gain and showed a faster anatomical response.

Early treatment with dexamethasone intravitreal implants in diabetic macular edema: Naïve versus refractory patients

PURPOSE

To assess the efficacy and safety of dexamethasone 0.7 mg implants (DEX-I) in patients with diabetic macular edema (DME) either naïve to therapy or refractory to anti-VEGF treatment, in a single-center, real-world setting.

METHODS

Patients diagnosed with DME and treated with DEX-I were retrospectively enrolled in the study and split in two groups: naïve (Group 1, n = 64) and refractory (Group 2, n = 64) to treatment. Patients were evaluated at baseline, at 1 month, and every 3 months after each DEX-I implant. Main outcome measures were change in best-corrected visual acuity (BCVA) and central macular thickness (CMT) from baseline to follow-up visits.

RESULTS

Significant improvements in BCVA were observed in treatment-naïve patients at 6 months following the first and second DEX-I injection (p = 0.0023 and p = 0.0063, respectively), with significant reductions in mean CMT at 6 months after all DEX implants. In treatment-refractory patients, mean CMT was significantly reduced from baseline to 6 months (p < 0.05) after all DEX-I injections, although no changes were observed in BCVA.

CONCLUSIONS

DEX-I improved visual acuity and macular edema mostly in treatment-naïve patients, suggesting DEX-I may be a viable first-line treatment option in DME.

The prognostic role of optical coherence tomography in diabetic macular edema patients undergoing early dexamethasone implant shift

PURPOSE

To determine the prognostic characteristics of optical coherence tomography (OCT) parameters by evaluating diabetic macular edema (DME) patients with early dexamethasone (DEX) shift after three doses of intravitreal ranibizumab (RNB) injection.

METHODS

Fifty-four eyes of 34 patients who had DEX implant after three doses of RNB were included in this retrospective study. Early DEX shift includes patients who received direct DEX implant replacement after three doses of RNB load. Baseline OCT values and factors affecting best corrected visual acuity (BCVA) and central macular thickness (CMT) response were analyzed with logistic regression analyses.

RESULTS

The presence of subretinal fluid and hyperreflective spot (HRS) >20 were found to be a negative predictive factor for anatomical response. (p = 0.009, p = 0.001, respectively) Low initial BCVA creates a positive effect on visual gain.( p = 0.041) Giant outer nuclear layer cysts, completely disrupted inner segment-outer segment and HRS > 20 have a negative effect on visual gain. (p = 0.025, p = 0.043, p = 0.023, respectively) According to the receiver operating characteristic analysis, the subretinal fluid volume threshold at which >20% reduction in CMT occurs was determined to be 0.85 mm³. (sensitivity 70%, specificity 84% area under the curve 0.817, p = 0.021).

CONCLUSION

The presence of high number of HRS and high subretinal fluid volume at the baseline negatively affect prognosis even in patient groups with early DEX shift.

Increased expression of Protein S in eyes with diabetic retinopathy and diabetic macular edema

Protein S (PS) is a multifunctional glycoprotein that ameliorates the detrimental effects of diabetes mellitus (DM). The aim of this study was to evaluate the distribution of PS in diabetic retinopathy (DR) and diabetic macular edema (DME). This was a study of 50 eyes with DM (37 with DME, 6 with proliferative DR, and 7 with no DR) and 19 eyes without DM. The level of PS was measured by enzyme immunoassay and was compared between eyes with or without DM, with or without DME, and with severe DME (≥ 350 μm) or mild DME (< 350 μm). We also performed immunohistopathologic evaluations of post-mortem eyes and the cystoid lesions excised during surgery. The aqueous free PS was significantly higher with DM (7.9 ± 1.2 ng/ml, P < 0.01) than without DM (6.1 ± 0.7). The aqueous free PS was significantly elevated with DME (8.2 ± 1.2, P < 0.05) compared to proliferative DR (7.0 ± 1.0) and no DR (7.0 ± 0.7). Eyes with severe DME had significantly higher aqueous free PS than mild DME (8.5 ± 1.3 vs. 7.7 ± 1.0, P < 0.05). Immunohistochemistry showed PS in the outer plexiform layer of the retina and cystoid lesion. The higher expression of PS with DR and DME suggests that PS is involved in their pathogenesis.

DETECTION OF MORPHOLOGIC PATTERNS OF DIABETIC MACULAR EDEMA USING A DEEP LEARNING APPROACH BASED ON OPTICAL COHERENCE TOMOGRAPHY IMAGES

PURPOSE

To develop a deep learning (DL) model to detect morphologic patterns of diabetic macular edema (DME) based on optical coherence tomography (OCT) images.

METHODS

In the training set, 12,365 OCT images were extracted from a public data set and an ophthalmic center. A total of 656 OCT images were extracted from another ophthalmic center for external validation. The presence or absence of three OCT patterns of DME, including diffused retinal thickening, cystoid macular edema, and serous retinal detachment, was labeled with 1 or 0, respectively. A DL model was trained to detect three OCT patterns of DME. The occlusion test was applied for the visualization of the DL model.

RESULTS

Applying 5-fold cross-validation method in internal validation, the area under the receiver operating characteristic curve for the detection of three OCT patterns (i.e., diffused retinal thickening, cystoid macular edema, and serous retinal detachment) was 0.971, 0.974, and 0.994, respectively, with an accuracy of 93.0%, 95.1%, and 98.8%, respectively, a sensitivity of 93.5%, 94.5%, and 96.7%, respectively, and a specificity of 92.3%, 95.6%, and 99.3%, respectively. In external validation, the area under the receiver operating characteristic curve was 0.970, 0.997, and 0.997, respectively, with an accuracy of 90.2%, 95.4%, and 95.9%, respectively, a sensitivity of 80.1%, 93.4%, and 94.9%, respectively, and a specificity of 97.6%, 97.2%, and 96.5%, respectively. The occlusion test showed that the DL model could successfully identify the pathologic regions most critical for detection.

CONCLUSION

Our DL model demonstrated high accuracy and transparency in the detection of OCT patterns of DME. These results emphasized the potential of artificial intelligence in assisting clinical decision-making processes in patients with DME.

Incidence of Paradoxical Neurosensory Detachment in Diabetic Eyes Undergoing Hemodialysis for End-Stage Renal Disease

Introduction

Ocular fluid dynamics are known to improve during hemodialysis, and the improvement of uremia after dialysis may lead to osmotic pressure changes in the retina, which eventually affect retinal edema. Recent studies using optical coherence tomography (OCT) to assess the effect of hemodialysis on macular thickness have shown variable results with a majority of them finding a decrease in retinal thickness. Paradoxical neurosensory retinal detachment (NSD) may be defined as the accumulation of subretinal fluid under the macula in patients who are on continuous HD. The purpose of the study was to find out the incidence of paradoxical neurosensory detachment in diabetic eyes undergoing hemodialysis (HD) and its management.

Methods

This was a cross-sectional, prospective study involving end-stage renal disease (ESRD) patients secondary to diabetes. This study evaluated the changes in macular thickness in diabetic retinopathy patients with and without diabetic macular edema (DME) by spectral-domain optical coherence tomography (SD-OCT) 60 minutes before and after HD for ESRD.

Results

Sixty-three eyes (36 patients) were included, with a mean age of 58.2±9.8 years. Seven eyes had paradoxical NSD at presentation with an incidence of 11.11%. Eyes with DME (Group A) showed a significant reduction in central macular thickness (CMT) by 28±2μm post HD, compared to eyes without DME (Group B) where CMT decreased by 15±2μm (p=0.003). Massive subretinal fluid accumulation (paradoxical NSD) with mean CMT 675.57±69.41μm recovered to 250.71±46.79μm at the final follow-up. Five eyes underwent an intravitreal dexamethasone implant (DEX-I, Ozurdex; Allergan, Dublin, Ireland) to achieve the resolution of SRF, whereas two eyes improved spontaneously by nine months.

Conclusion

Hemodialysis results in a decrease of macular thickness in diabetic eyes with or without DME. Paradoxical neurosensory detachment can develop in eyes of patients undergoing HD chronically. Intravitreal dexamethasone implant (DEX-I, Ozurdex; Allergan, Dublin, Ireland) results in early amelioration of such a complication.

OCT Hyperreflective Retinal Foci in Diabetic Retinopathy: A Semi-Automatic Detection Comparative Study

Optical coherence tomography (OCT) allows us to identify, into retinal layers, new morphological entities, which can be considered clinical biomarkers of retinal diseases. According to the literature, solitary, small (<30 µm), medium level hyperreflective (similar to retinal fiber layer) retinal foci (HRF) may represent aggregates of activated microglial cells and an in vivo biomarker of retinal inflammation. The identification and quantification of this imaging biomarker allows for estimating the level and possibly the amount of intraretinal inflammation in major degenerative retinal disorders, whose inflammatory component has already been demonstrated (diabetic retinopathy, age-related macular degeneration, radiation retinopathy). Currently, diabetic retinopathy (DR) probably represents the best clinical model to apply this analysis in the definition of this clinical biomarker. However, the main limitation to the clinical use of HRF is related to the technical difficulty of counting them: a time-consuming methodology, which also needs trained examiners. To contribute to solve this limitation, we developed and validated a new method for the semi-automatic detection of HRF in OCT scans. OCT scans of patients affected by DR, were analyzed. HRF were manually counted in High Resolution spectral domain OCT images. Then, the same OCT scans underwent semi-automatic HRF counting, using an ImageJ software with four different settings profiles. Statistical analysis showed an excellent intraclass correlation coefficient (ICC) between the manual count and each of the four semi-automated methods. The use of the second setting profile allows to obtain at the Bland–Altman graph a bias of −0.2 foci and a limit of agreement of ±16.3 foci. This validation approach opens the way not only to the reliable and daily clinical applicable quantification of HRF, but also to a better knowledge of the inflammatory component—including its progression and regression changes—of diabetic retinopathy.

Malfunction of outer retinal barrier and choroid in the occurrence and progression of diabetic macular edema

Diabetic macular edema (DME) is the most common cause of vision loss in diabetic retinopathy, affecting 1 in 15 patients with diabetes mellitus (DM). The disruption of the inner blood-retina barrier (BRB) has been largely investigated and attributed the primary role in the pathogenesis and progression in DME, but there is increasing evidence regarding the role of outer BRB, separating the RPE from the underlying choriocapillaris, in the occurrence and evolution of DME. The development of novel imaging technologies has led to major improvement in the field of in vivo structural analysis of the macula allowing us to delve deeper into the pathogenesis of DME and expanding our vision regarding this condition. In this review we gathered the results of studies that investigated specific outer BRB optical coherence tomography parameters in patients with DM with the aim to outline the current status of its role in the pathogenesis and progression of DME and identify new research pathways contributing to the advancement of knowledge in the understanding of this condition.

Isorhamnetin Ameliorates Dry Eye Disease via CFTR Activation in Mice

Dry eye disease is one of the most common diseases, with increasing prevalence in many countries, but treatment options are limited. Cystic fibrosis transmembrane conductance regulator (CFTR) is a major ion channel that facilitates fluid secretion in ocular surface epithelium and is a potential target of therapeutic agent for the treatment of dry eye disease. In this study, we performed a cell-based, high-throughput screening for the identification of novel natural products that activate CFTR and restore the aqueous deficiency in dry eye. Screening of 1000 natural products revealed isorhamnetin, a flavonol aglycone, as a novel CFTR activator. Electrophysiological studies showed that isorhamnetin significantly increased CFTR chloride current, both wild type and ∆F508-CFTR. Isorhamnetin did not alter intracellular cAMP levels and the activity of other ion channels, including ANO1, ENaC, and hERG. Notably, application of isorhamnetin on mouse ocular surface induced CFTR activation and increased tear volume. In addition, isorhamnetin significantly reduced ocular surface damage and expression of interleukin (IL)-1β, IL-8, and tumor necrosis factor (TNF)-α in an experimental mouse model of dry eye. These data suggest that isorhamnetin may be used to treat dry eye disease.

En face image-based classification of diabetic macular edema using swept source optical coherence tomography

This retrospective study was performed to classify diabetic macular edema (DME) based on the localization and area of the fluid and to investigate the relationship of the classification with visual acuity (VA). The fluid was visualized using en face optical coherence tomography (OCT) images constructed using swept-source OCT. A total of 128 eyes with DME were included. The retina was segmented into: Segment 1, mainly comprising the inner nuclear layer and outer plexiform layer, including Henle’s fiber layer; and Segment 2, mainly comprising the outer nuclear layer. DME was classified as: foveal cystoid space at Segment 1 and no fluid at Segment 2 (n = 24), parafoveal cystoid space at Segment 1 and no fluid at Segment 2 (n = 25), parafoveal cystoid space at Segment 1 and diffuse fluid at Segment 2 (n = 16), diffuse fluid at both segments (n = 37), and diffuse fluid at both segments with subretinal fluid (n = 26). Eyes with diffuse fluid at Segment 2 showed significantly poorer VA, higher ellipsoid zone disruption rates, and greater central subfield thickness than did those without fluid at Segment 2 (P < 0.001 for all). These results indicate the importance of the localization and area of the fluid for VA in DME.

Intravitreal ranibizumab and dexamethasone implant injections as primary treatment of diabetic macular edema: simultaneously double protocol

PURPOSE

To assess the 12-month efficacy and safety of simultaneously administered intravitreal dexamethasone implant (DEX implant) and ranibizumab (simultaneous double protocol) injections in comparison with ranibizumab monotherapy as the first-line treatment of diabetic macular oedema (DMO).

METHODS

Prospective, consecutive, clinical interventional study. Patients were randomized into two groups: 24 naive DMO patients (34 eyes) who received simultaneous double-protocol therapy and 22 DMO patients (34 eyes) who received ranibizumab monotherapy were included. Monthly ranibizumab (0.5 mg) was administered for the first 6 months and later on, an as-needed treatment basis. DEX implant injection was performed at any time during the loading dose of the three consecutive monthly injections of ranibizumab, and with as-needed reinjections of ranibizumab from 6th month onwards. Change in visual acuity was the primary efficacy endpoint. Secondary efficacy endpoints were a gain of ≥15 letters and a change in the central foveal thickness.

RESULTS

Mean BCVA increased from baseline to month 12 in the simultaneously double-protocol therapy group compared with the ranibizumab monotherapy group (21.6 versus 9.6 letters [P < 0.001]). The corresponding proportions of eyes gaining ≥15 letters were 60% versus 29.4% (P < 0.0001). Moreover, the mean reductions in the central foveal thickness were 413 versus 282 µm (P = 0.001). At 12 month, the simultaneous double-protocol therapy decreased a significant number of foveal cysts and subfoveal neuroretinal detachment compared with those by ranibizumab monotherapy.

CONCLUSIONS

The simultaneous addition of DEX implant at any time during the three monthly loading doses of ranibizumab in patients with DMO significantly improved the visual outcomes and revealed superior anatomic outcomes than those with the ranibizumab monotherapy.

A Real-World Study of Dexamethasone Implant in Treatment-Naïve Patients with Diabetic Macular Edema: Efficacy and Correlation Between Inflammatory Biomarkers and Treatment Outcome

Purpose

There has been an increasing clinical interest in specific retinal parameters as non-invasive biomarkers of retinal inflammation in diabetic macular edema (DME) that have been shown to have prognostic value, such as hyperreflective retinal fields (HRFs) and subfoveal neuroretinal detachment (SND).

Methods

We conducted a prospective, non-comparative study of treatment-naïve patients with DME to evaluate the efficacy of a Pro Re Nata (PRN) regimen of intravitreal dexamethasone implant 0.7 mg (DexI, Ozurdex™). After administration, patients underwent subsequent injections according to PRN criteria in case of edema relapse, but not earlier than 4 months after the previous treatment. Patients were evaluated at baseline, within 15 days of injection, and every month thereafter. During all visits, best-corrected visual acuity (BCVA) was recorded; central retinal thickness (CRT), type of edema, presence of SND, and presence and number of HRFs were evaluated using swept-source optical coherence tomography (SS-OCT) 3D. Treatment outcome was defined as changes in BCVA, CRT, SND and HRFs at 12 (T12) and 24 (T24) months compared with baseline (T0).

Results

The study enrolled 24 eyes of 18 patients. The mean duration of follow-up was 18±6.6 months; for all eyes, T12 data were available, while follow-up reached T24 for 12 eyes. BCVA improved significantly and CRT decreased significantly during treatment; the edema was no longer detectable in 13/24 eyes at T12 and 8/12 eyes at T24. No patient presented SND at T12 and T24, and the mean number of HRFs decreased significantly during treatment. Results with CRT and HRFs correlated with BCVA at 12 and 24 months. No significant adverse events were observed.

Conclusion

In patients with DME, the intravitreal dexamethasone implant was effective and safe in improving both functional and tomographic parameters. This result is consistent with improvement in biomarkers of inflammation.

In vivo intraocular biomarkers: Changes of aqueous humor cytokines and chemokines in patients affected by uveal melanoma

Inflammatory, angiogenic, and immune processes have been associated with uveal melanoma (UM). The aim of the present study was to evaluate the presence of some specific aqueous humor (AH) soluble biomarkers in eyes affected by UM. Thirty-five eyes affected by primary UM and 35 control eyes, scheduled for cataract surgery, underwent full ophthalmic examination and AH sampling at time of surgery (brachytherapy or cataract surgery, respectively). AH samples were analyzed by means of ELISA, to detect the concentration of selected cytokines, chemokines, and growth factors. Compared with the control group, higher levels of IL-6 (P = .049), IL-8 (P = .006), RANTES (P = .008), EGF (P = .032), bFGF (P = .016), MIF (P = .007), and MCP (P = .020) were detected in eyes with UM. VEGF concentration between the two groups was statistically borderline (P = .058). Comparison between clinical characteristics and cytokine concentrations showed a positive correlation between tumor thickness and IL-8 (P = .032), and degree of serous retinal detachment and IL-6 (P = .021). UM is characterized by the presence of retinal neuroinflammatory, angiogenic, and immune biomarkers in AH. The proteomic analysis of AH could characterize UM microenvironment, allowing to better understand its pathophysiology.

Hyperreflective foci in diabetic macular edema with serous retinal detachment: association with dyslipidemia

AIMS

Hyperreflective foci (HF), detected in the retina of diabetic patients, suggest the presence of microglial activation and migration, while controversies still remain for the origin of HF to be precursors of hard exudates. We investigated the presence of HF and their association with dyslipidemia in serous retinal detachment (SRD)-type diabetic macular edema (DME).

METHODS

Forty-two eyes in 42 patients with diabetic retinopathy (DR) and 22 eyes in 22 patients with branch retinal vascular occlusion (BRVO) showing macular edema were included in this study. The medical records and OCT findings were retrospectively reviewed in patients with SRD-type DME and compared with those with BRVO. The mean number of HF, the mean choroidal thickness, and lipid profiles were analyzed and compared between groups.

RESULTS

The mean number of HF was significantly higher in DR group compared to BRVO group. Significant correlation of HF was noted with triglycerides (r = 0.523, P = 0.002). Triglycerides were significantly associated with HF by linear regression (β = 0.012, 95% CI 0.001-0.024, P = 0.034) and remained significantly associated by multiple linear regression (β = 0.014, 95% CI 0.003-0.025, P = 0.014).

CONCLUSIONS

HF on OCT of DME patients could be indicative of activated microglia. HF are associated with dyslipidemia, especially high triglycerides, suggesting inflammatory reaction from dyslipidemia in diabetic retina.

Baseline SD-OCT characteristics of diabetic macular oedema patterns can predict morphological features and timing of recurrence in patients treated with dexamethasone intravitreal implants

AIMS

To evaluate the timing and spectral-domain optical coherence tomography (SD-OCT) features of diabetic macular oedema (DME) recurrence according to baseline OCT patterns in patients treated with dexamethasone implant (DEX-I).

METHODS

This is a retrospective observational study (72 eyes/65 patients). Best-corrected visual acuity, timing of DME recurrence, and SD-OCT pattern [intraretinal cysts (IRC), IRC plus subretinal fluid (mixed), external limiting membrane (ELM), ellipsoid (IS/OS) layer integrity] were assessed at baseline and monthly until first DME recurrence.

RESULTS

Forty-two (58.3%) and 30 (41.6%) DME eyes had an IRC and mixed DME pattern at baseline, respectively. Twenty-four out of thirty mixed eyes (80%) relapsed without subretinal fluid. At baseline, mixed eyes showed similar changes in ELM and IS/OS (60 and 76.6% of eyes, respectively) versus IRC eyes (42.8 and 80.9% of eyes). After DME recurrence, more mixed eyes at baseline showed ELM and IS/OS changes (63.3 and 86.6%) than IRC eyes (50 and 76.2%). 33.3% of mixed eyes had DME recurrence at ≥ 6 months from first DEX-I implant versus 19% of IRC eyes.

CONCLUSIONS

Mixed DME eyes were treated with DEX-I relapse later and more frequently without subretinal fluid than IRC eyes. SD-OCT characteristics of different DME patterns at baseline can predict morphological features and timing of DME recurrence.

The Application of Structural Retinal Biomarkers to Evaluate the Effect of Intravitreal Ranibizumab and Dexamethasone Intravitreal Implant on Treatment of Diabetic Macular Edema

Background: The aim of this study was to compare the therapeutic effect of intravitreal treatment with ranibizumab and dexamethasone using specific swept-source optical coherence tomography retinal biomarkers in patients with diabetic macular edema (DME). Methods: 156 treatment-naïve patients with DME were divided in two groups: 75 patients received 3 monthly intravitreal injections of ranibizumab 0.5 mg (Lucentis^®) (Group 1) and 81 patients received an intravitreal implant of dexamethasone 0.7 mg (Ozurdex^®) (Group 2). Patients were evaluated at baseline (V1), at three months post-treatment in Group 1, and at two months post-treatment in Group 2 (V2). Best-corrected visual acuity (BCVA) and swept source-OCT were recorded at each interval. Changes between V1 and V2 were analyzed using the Wilcoxon test and differences between the two groups of treatment were assessed using the Mann–Whitney test. Multiple regression analysis was performed to evaluate the possible OCT biomarker (CRT, ICR, CT, SND, HRS) as predictive factors for final visual acuity improvement. Results: In both groups, BCVA improved (p-value < 0.0001), and a significant reduction in central retinal thickness, intra-retinal cysts, red dots, hyper-reflective spots (HRS), and serous detachment of neuro-epithelium (SDN) was observed. A superiority of dexamethasone over ranibizumab in reducing the SDN height (p-value = 0.03) and HRS (p-value = 0.01) was documented. Conclusions: Ranibizumab and dexamethasone are effective in the treatment of DME, as demonstrated by functional improvement and morphological biomarker change. DME associated with SDN and HRS represents a specific inflammatory pattern for which dexamethasone appears to be more effective.

Aqueous humour cytokine changes during a loading phase of intravitreal ranibizumab or dexamethasone implant in diabetic macular oedema

PURPOSE

To determine the effect of intravitreal ranibizumab and a dexamethasone implant on aqueous humour cytokine, protein and enzyme levels and to correlate findings to morphologic and functional changes.

METHODS

In a prospective, randomized, controlled, double-blind study, patients with clinically significant diabetic macular oedema (CSME) were randomly allocated to receive either monthly intravitreal injections of ranibizumab (Lucentis, Novartis Pharma) or a single dexamethasone implant (Ozurdex, Pharm-Allergan) at baseline (BL). Aqueous humour samples were collected at BL and weeks 2, 8 and 20.

RESULTS

The study included 18 eyes of 18 patients. In the dexamethasone implant group, soluble intercellular adhesion molecule 1 (sICAM-1) (weeks 2 and 8), CXCL9/monokine induced by gamma interferon (MIG) (weeks 2 and 8), soluble vascular cell adhesion protein 1 (sVCAM-1) (weeks 2 and 8) and monocyte chemo-attractant protein 1 (MCP-1) (week 2) levels were significantly decreased compared with baseline. In the ranibizumab group, placental growth factor (PIGF) (week 2) and vascular endothelial growth factor (VEGF) (week 2 and 8) levels were significantly decreased compared with baseline. No significant changes in central retinal thickness (CRT) or Early Treatment Diabetic Retinopathy Study (ETDRS) best corrected visual acuity (BCVA) were observed in the Ozurdex group at any time-points. ETDRS scores significantly increased at week 20 (84.88 ± 8.88 letters) compared with baseline (74.78 ± 14.85 letters), and the CRT decreased significantly at week 4 (381.00 ± 114.64 μm) compared with baseline (440 ± 144 μm) in the Lucentis group.

CONCLUSION

The dexamethasone implant affected the aqueous cytokines and proteins MCP-1, sICAM-1, sVCAM-1 and MIG, whereas ranibizumab treatments reduced VEGF and PIGF levels. Morphological changes may diverge from cytokine changes. Results may indicate a rationale for a combination therapy for CSME using both agents, the dexamethasone implant and repeatedly administered ranibizumab injections.

Choroidal Thickness After Dexamethasone Implant or Aflibercept in Patients with Diabetic Macular Edema Persistent to Ranibizumab

Purpose: This study aims to compare subfoveal choroidal thicknesses (SFCTs) after intravitreal dexamethasone (IVD) or intravitreal aflibercept (IVA) treatment in patients with persistent diabetic macular edema (DME) unresponsive to intravitreal ranibizumab (IVR). Methods: The study consisted of patients with DME unresponsive to IVR treatment in which 37 were administered 1 dose IVD (group A) and 34 patients who were administered 3 doses of IVA (group B), as well as 35 healthy individuals (group C). Detailed ophthalmological examination and optical coherence tomography parameters of group A and group B, including central retinal thickness and SFCT, were retrospectively evaluated before and after treatment. Results from preinjection, and 1, 2, and 3 months after injection were analyzed. Results of group A and group B were compared within themselves and also compared with group C. Results: SFCT measurements were compared within group A and group B (1 = preinjection; 2 = 1 month postinjection; 3 = 2 months postinjection; 4 = 3 months postinjection). There was significant thinning in SFCT between 1-2, 1-3, 1-4, 2-3, 2-4, and 3-4 time intervals within both group A and group B (both P < 0.001). Comparison of SFCT measurements showed preinjection, 1-, and 2-month values of group A were significantly thicker than those of group C (P < 0.001), whereas there was no significant difference between 3-month values (P = 0.09). Preinjection, 1-, and 2-month values of group B were significantly thicker than those of group C (P < 0.001), whereas there was no significant difference between 3-month values (P = 0.06). Conclusions: Three month follow-up showed thinning in SFCT measurements in patients with persistent DME unresponsive to IVR who were applied IVD or IVA treatment.

Diabetic macular edema with neuroretinal detachment: OCT and OCT-angiography biomarkers of treatment response to anti-VEGF and steroids

PURPOSE

To assess and compare early changes in neuroinflammatory and vascular parameters in diabetic macular edema (DME) with subfoveal neuroretinal detachment (SND) after treatment with intravitreal dexamethasone (DEX-I) and ranibizumab (IVR).

METHODS

Thirty-three eyes (33 patients) with treatment naïve DME with SND were retrospectively evaluated at baseline and 2 months after DEX-I (15 eyes) and 1 month after 3 monthly IVR injections (18 eyes). Inclusion criteria were: complete eye examination, good quality OCT and OCT-A images. OCT parameters included: central macular thickness (CMT); number of hyper-reflective retinal spots (HRS) in inner, outer (IR, OR) and full retina; choroidal thickness (CT), extent of disorganization of inner retinal layers (DRIL), outer retina integrity (OR). On OCT-A: foveal avascular zone (FAZ) parameters in the superficial capillary plexus (SCP); cysts area and perfusion density (PD) in SCP and deep capillary plexus (DCP) and flow voids (FV) in choriocapillaris. FAZ was analyzed using ImageJ, perfusion parameters and FV using MATLAB.

RESULTS

BCVA increased equally after both treatments (13.0 ± 10.0 ETDRS letters, p < 0.0001). There was a similar decrease (p < 0.05) in: height of SND, cysts area at SCP, central and mean CT, increase in FAZ perimeter and OR integrity, after both treatments. A greater decrease in DEX-I versus IVR group was found in: CMT (- 38.7% vs. - 22.2%, p = 0.012), HRS number in IR (- 29.2% vs. - 14.0%, p = 0.05) and full retina (- 24.7% vs. - 8.0%, p = 0.03), DRIL extension (- 62.0% vs. - 24%, p = 0.008), cysts area at DCP (- 68.7% vs. - 26.1%, p = 0.03), FAZ-CI (- 19.1% vs. - 8.3%, p = 0.02), PD at DCP (- 27.5%  vs. + 4.9%, p = 0.02). FV did not change.

CONCLUSIONS

More pronounced changes in specific inflammatory parameters in the inner retina are documented after steroid versus anti-VEGF treatment. These include reduction in HRS number, DRIL extension, CMT, cysts area at DCP. These data may help in further study of noninvasive imaging biomarkers for better evaluation of treatment response.