Baseline choroidal thickness as a predictor for response to anti-vascular endothelial growth factor therapy in diabetic macular edema

The effect of intravitreal anti-VEGF injections on choroidal vascular index in patients with diabetic macular edema

PURPOSE

This study aims to examine and compare the effects of intravitreal bevacizumab injection (IVB) at subfoveal 1500 micron (μm) and submacular 6000 μm in patients with diabetic macular edema (DME).

METHODS

Fifty eyes of 45 patients with DME who completed six doses of IVB were included in the study group, and 50 eyes of 42 patients who had diabetic retinopathy (DR) but did not receive any treatment were included in the control group. Central macular thickness (CMT), central choroidal thickness (CCT), subfoveal and total choroidal area (TCA), and choroidal vascular index (CVI) were calculated and their changes at zero, three and six months were evaluated.

RESULTS

At baseline, CVI was significantly lower in both the subfoveal and total macular areas in the study group (p = 0.004, p = 0.003). In the study group, a significant decrease was observed in CVI between zero and six months in the subfoveal area (p = 0.001). In the submacular area, the decrease in CVI in the study group was significant between zero to three months and zero to six months. There was moderate correlation between measurements of CVI in the subfoveal and total macular areas (r = 0.66, p < 0.001).

CONCLUSION

These findings indicate that intravitreal bevacizumab injection reduces the CVI and the effects of intravitreal anti-VEGF on CVI emerge earlier and more prominently in the submacular 6000 µm area.

[Anatomical and functional outcomes of the "3+PRN" therapeutic protocol in the treatment of diabetic macular edema]

PURPOSE

To evaluate the anatomical and functional results of the "3+PRN" protocol in the treatment of diabetic macular edema (DME), determine the predictive factors for good final visual acuity, and compare it to other protocols.

MATERIALS AND METHODS

We conducted a retrospective, descriptive, comparative, cross-sectional study of patients with DME, which we dubbed HTSM. All patients were treated with three monthly initial intravitreal injections (IVT) of 1.25mg bevacizumab and followed according to the pro re nata (PRN) protocol for a period of 3years. The protocol was based on a monthly monitoring schedule for the first 3months, then increasingly spaced out over time. "On-demand" treatment was indicated with resumption of bevacizumab IVT in the event of worsening of DME.

RESULTS

A total of 52 patients were included. The mean age was 65years. Type 2 was the most frequently observed type of diabetes. The mean duration of the PRN protocol was 6months, and the mean number of injections was 6. The mean visual acuity (VA), initially 1/10, improved to 3/10 by the conclusion of the 3+PRN protocol, with an improvement of more than 5 letters in 77.6% of cases. The mean initial central macular thickness (CMT) was 451.5μm. The final mean EMC decreased to 298.5μm, which corresponds to a reduction of 153μm compared to the initial value. The mean subfoveal choroidal thickness, initially 304.2μm, decreased to a mean of 284.5μm at completion. Comparative analysis of the results before and after the PRN protocol confirmed the existence of a statistically significant correlation between VA and CMT (P<0.05). No correlation was observed between age and visual acuity or between initial and final VA. The analysis of the various tomographic parameters and VA revealed a significantly better visual improvement in the group in whom the external limiting membrane (MLE) and ellipsoid zone (ZE) were intact (P=0.04), as well as in the group in whom serous retinal detachment (SRD) was absent (P<0.001). Posterior vitreous detachment (PVD) was the most frequently observed vitreomacular anomaly. The final VA was similar in the groups with and without PVD (P=0.04).

CONCLUSION

The 3+PRN protocol is effective both functionally and tomographically in the treatment of DME. Various tomographic parameters might influence therapeutic efficacy. However, further in-depth studies are needed to better investigate these parameters.

Wide-Field Optical Coherence Tomography in Patients with Diabetic Macular Edema

Background: The goal of the study was to analyze variations in central, perifoveal, and peripheral retinal thickness (RT) and choroidal thickness (CT) in patients with diabetic macular edema (DME) measured with ultra-wide-field optical coherence tomography (UWF-OCT). Additionally, correlations between RT and CT in the central, perifoveal, and peripheral sectors and the presence of selected systemic factors were evaluated. Methods: A total of 74 consecutive adult diabetic patients with DME and 75 healthy controls were included. Study participants were divided into three groups: DME patients without panretinal photocoagulation (PRP; 84 eyes), DME patients after PRP (56 eyes), and healthy controls (125 eyes). RT and CT were analyzed in three zones: a central circle of 3 mm diameter (central), a ring contained between a centered 9 mm circle and the central 3 mm circle (perifoveal), and a second, more peripheral ring between centered 18 mm and 9 mm circles (peripheral). Additionally, DME subgroups were analyzed according to the correlation of RT and CT with age, axial length, best corrected visual acuity (BCVA), diabetes duration, insulin therapy duration, body mass index (BMI), glycosylated hemoglobin (HbA1c) values, intravitreal injection (IVI) count, and the advancement of retinopathy assessed by the simplified diabetic retinopathy severity scale (DRSS). Results: The increase in RT in the far peripheral sectors in DME patients was not significant. The increases in central and perifoveal RT and lower values of CT in PRP-naive DME patients were strongly associated with poorer BCVA. Patients with DME after PRP presented with BCVA improvements significantly related to the number of IVIs. The amount of DME and RT in peripheral sectors were both independent of systemic factors such as BMI, duration of diabetes, duration of insulin intake, retinopathy severity, and HbA1c levels. Conclusions: Peripheral retinal sectors in DME patients are less affected in terms of increase in their thickness compared to central ones. Functional and morphological associations of DME with UWF-OCT testing refer to central and perifoveal sectors.

Retinal and choroidal changes after anti-VEGF therapy in neovascular-AMD patients: A systematic review and meta-analysis of SD-OCT studies

BACKGROUND

In recent years, the progress made in the field of optical coherence tomography has helped to understand the changes in eye layers in patients with exudative age-related macular degeneration (nAMD). Early diagnosis of nAMD, a leading cause of irreversible vision impairment, is helpful. Therefore, we performed a meta-analysis on OCT measurement alterations before and after anti-VEGF therapy in patients with nAMD and controls.

METHOD

We systematically searched Scopus, PubMed, Cochrane, and Web of Science to find articles that measured choroidal and retinal layer changes after anti-VEGF therapy in nAMD Patients. We chose either a fixed-effects or random-effects model based on the assessed heterogeneity level to perform a meta-analysis. In addition, we conducted meta-regression, subgroup analyses, publication bias, and quality assessment for included studies.

RESULTS

Thirteen studies were included in the meta-analysis, with 733 total participants. Foveal thickness and subfoveal choroidal thickness (CT) decreased significantly in the first 3 years after injections, except for subfoveal CT in the third year after injection. It also showed that CT at 1500 µm temporal and nasal to the fovea did not significantly change.

CONCLUSION

Our results showed anti-VEGF treatment for nAMD patients was associated with a significant reduction in foveal thickness and subfoveal CT in the first 2 years after treatment. Our analysis did not reveal any correlation between changes in foveal thickness and subfoveal CT with best-corrected visual acuity or other factors.

Long-Term Effects of Intravitreal Ranibizumab Compared With Panretinal Photocoagulation on Optical Coherence Tomography Measured Choroidal Thickness and Vascularity

Purpose

Compare choroidal changes in ranibizumab versus panretinal photocoagulation (PRP)-treated eyes with proliferative diabetic retinopathy (PDR).

Methods

DRCR Retina Network Protocol S post hoc analysis evaluated optical coherence tomography change in choroidal thickness (subfoveal and 3mm superior and inferior to the fovea) through five years; choroidal vascularity index (CVI) was assessed at baseline and one year. Mixed linear models for choroidal change included adjustments for the baseline choroidal value and age.

Results

This study included 328 eyes (158 ranibizumab and 170 PRP) from 256 participants (88 ranibizumab and 95 PRP eyes at five years). Mean change in choroidal thickness from baseline to five years at the fovea was -12 µm in ranibizumab versus -8 µm in PRP (difference [95% confidence interval]: -4 [-18 to 10], P = 0.57), superior was -14 µm versus -19 µm (difference: 5 [-8 to 17], P = 0.45) and inferior was -26 µm versus -32 µm [difference: 5 (-9 to 20), P = 0.45]; change at all three points within the ranibizumab group, and the superior and inferior points for PRP, were statistically significant (P < .05). Mean change in CVI at one year was -0.02% in ranibizumab versus -0.95% in PRP (difference: 0.93 [-0.35 to 2.21], P = 0.14).

Conclusions

In patients with PDR, treatment with ranibizumab versus PRP did not result in statistically significant differences in five-year choroidal thickness or one-year CVI change. Both groups had significant decreases in choroidal thickness at five years.

Translational Relevance

Ranibizumab treatment for PDR did not statistically significantly affect choroidal thickness or vascularity differently than PRP.

Role of Systemic Factors in Improving the Prognosis of Diabetic Retinal Disease and Predicting Response to Diabetic Retinopathy Treatment

Topic

To review clinical evidence on systemic factors that might be relevant to update diabetic retinal disease (DRD) staging systems, including prediction of DRD onset, progression, and response to treatment.

Clinical relevance

Systemic factors may improve new staging systems for DRD to better assess risk of disease worsening and predict response to therapy.

Methods

The Systemic Health Working Group of the Mary Tyler Moore Vision Initiative reviewed systemic factors individually and in multivariate models for prediction of DRD onset or progression (i.e., prognosis) or response to treatments (prediction).

Results

There was consistent evidence for associations of longer diabetes duration, higher glycosylated hemoglobin (HbA1c), and male sex with DRD onset and progression. There is strong trial evidence for the effect of reducing HbA1c and reducing DRD progression. There is strong evidence that higher blood pressure (BP) is a risk factor for DRD incidence and for progression. Pregnancy has been consistently reported to be associated with worsening of DRD but recent studies reflecting modern care standards are lacking. In studies examining multivariate prognostic models of DRD onset, HbA1c and diabetes duration were consistently retained as significant predictors of DRD onset. There was evidence of associations of BP and sex with DRD onset. In multivariate prognostic models examining DRD progression, retinal measures were consistently found to be a significant predictor of DRD with little evidence of any useful marginal increment in prognostic information with the inclusion of systemic risk factor data apart from retinal image data in multivariate models. For predicting the impact of treatment, although there are small studies that quantify prognostic information based on imaging data alone or systemic factors alone, there are currently no large studies that quantify marginal prognostic information within a multivariate model, including both imaging and systemic factors.

Conclusion

With standard imaging techniques and ways of processing images rapidly evolving, an international network of centers is needed to routinely capture systemic health factors simultaneously to retinal images so that gains in prediction increment may be precisely quantified to determine the usefulness of various health factors in the prognosis of DRD and prediction of response to treatment.

Financial Disclosures

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

Subthreshold Photocoagulation, Laser Endpoint Management Based on Optical Coherence Tomography Angiography in Cases of Diabetic Macular Edema Refractory to Anti-VEGF

PURPOSE

This study aimed to determine the changes that occur in the vasculature, as based on optical coherence tomography angiography (OCTA) after non-damaging endpoint management (EpM), using a continuous wave yellow laser. The study was on eyes with diabetic macular edema (DME) that were resistant to anti-vascular endothelial growth factors (anti-VEGFs).

MATERIALS AND METHODS

This was a retrospective analysis of OCTA images of 44 eyes in 44 patients with DME refractory to anti-VEGF. The eyes were treated with a PASCAL Streamline yellow laser (577 nm wavelength, 200 mm spot size). Treatment was administered to the DME area and utilized 10% continuous wave laser energy and 0.50 µm beam diameter spot spacing. Best-corrected visual acuity (BCVA) and enhanced in-depth imaging with optical coherence tomography (EDI-OCT) and fundus autofluorescence (FAF) images were recorded at baseline, and 3 and 6 months posttreatment. Total choroidal area (TCA), luminal area (LA), stromal area (SA), and the choroidal vascularity index (CVI) were calculated using Image J software. The macula was divided into five quadrants in accordance with the mapping system in the Early Treatment Diabetic Retinopathy Study (ETDRS).

RESULTS

All patients (mean age: 58.90 ± 9.55 years) were diagnosed with diabetes mellitus type 2. Mean BCVA at baseline was 0.30 ± 0.11 logarithm of the minimum angle of resolution (logMAR) versus 0.23 ± 0.10 logMAR at 3 months (p = 0.032) and 0.17 ± 0.10 logMAR at 6 months (p = 0.013). The foveal avascular zone area (FAZ) decreased in the deep capillary plexus (DCP) from baseline to 6 months (p = 0.028). Vessel densities (VDs) of the superficial capillary plexus (SCP), DCP, and choriocapillaris decreased significantly in the fovea at 3 and 6 months compared to baseline (p < 0.05 for both follow-up time points). There were significant decreases in SCP and DCP in the superior quadrant at the end of month 6 (p = 0.001 and p = 0.038, respectively). There was a significant decrease in the nasal quadrant of the DCP and choriocapillaris at the end of month 6 (p = 0.024 and p = 0.049, respectively). Although there was a significant decrease in central macular thickness (CMT) (p < 0.001), subfoveal choroidal thickness (SFCT) (p < 0.001), and LA (p = 0.034) at months 3 and 6, there was no significant change in the CVI (p = 0.19). According to the DME recovery rate, 36 eyes (81%) were irradiated once, whereas 8 eyes (19%) were irradiated twice.

CONCLUSIONS

Non-damaging EpM therapy using a continuous wave yellow laser in eyes with DME that are resistant to anti-VEGFs induces significant changes in the SCP, choriocapillaris, and, most commonly, the DCP, which caused a significant decrease in VDs during 6 months of follow-up.

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.

Subfoveal choroidal thickness changes after intravitreal ranibizumab injections in different patterns of diabetic macular edema using a deep learning-based auto-segmentation

PURPOSE

To evaluate the effect of intravitreal injection of ranibizumab (IVR) on subfoveal choroidal thickness (SFCT) and its relationship with central macular thickness (CMT) and best-corrected visual acuity (BCVA) changes in eyes with center-involving DME (CI-DME) using a deep learning-based auto-segmentation.

METHODS

This prospective interventional case series included 68 eyes of 68 patients with CI-DME naive to treatment. Morphological optical coherence tomography (OCT) findings of DME were classified into three patterns of structural change: (i) diffuse retinal thickening (DRT), (ii) cystoid macular edema (CME), and (iii) serous retinal detachment (SRD). All patients underwent 3+prorenata IVR. The treated eyes underwent BCVA evaluation and OCT scanning at baseline and months 1, 3, and 6 after the first injection. Then, the choroid layer was measured using a deep learning-based auto-segmentation.

RESULTS

At baseline, the mean SFCT and CMT for SRD, DRT, and CME groups were 324.68 ± 65.58 μm and 624.37 ± 77.92 μm, 348.91 ± 45.81 μm and 443.5 ± 78.33 μm, 361.4 ± 64.62 μm, and 536.5 ± 66.02 μm, respectively. After anti-VEGF treatment, the SFCT and CMT have decreased by varying degrees. At 3 and 6 months of treatment, there were no significant changes among these groups. There was no correlation between baseline SFCT and the resulting BCVA (P = 0.670, P = 0.584). There was also no correlation between changes in SFCT and BCVA, CMT (P = 0.344, P = 0.336).

CONCLUSION

After treating CI-DME with IVR, SFCT and CMT significantly decreased. However, there were no significant changes among the SRD, DRT, and CME groups.

TRIAL REGISTRATION

Trial registration: ChiCTR, ChiCTR-ROC-17013360. Registered 13 November 2017, http://www.chictr.org.cn/ChiCTR-ROC-17013360 .

OCTA changes following loading phase with intravitreal aflibercept for DME

OBJECTIVE

To quantify changes in optical coherence tomography angiography (OCTA) parameters following intravitreal anti-vascular endothelial growth factor treatment for diabetic macular edema (DME), and to assess associations between pretreatment OCTA parameters and visual outcomes.

DESIGN

Prospective cohort study.

METHODS

Twenty-nine patients with DME received 5 monthly intravitreal injections of aflibercept. OCTA data obtained at baseline and at 6 months were compared using the Wilcoxon signed-rank test. OCTA parameters were foveal avascular zone (FAZ) area, FAZ perimeter, FAZ circularity, vessel density in the superficial vascular plexus (segmented into central, inner, outer, and full Early Treatment of Diabetic Retinopathy Study [ETDRS] map regions. Subanalysis divided patients into treatment responders (reduction of central subfield thickness >50 µm over treatment) and nonresponders. Associations between pretreatment OCTA parameters and visual acuity outcomes were analyzed using multivariable linear and logistic regression.

RESULTS

A total of 29 patients were included: 25 patients (86.2%) had nonproliferative diabetic retinopathy, and 4 patients (13.8%) had proliferative diabetic retinopathy. Vessel density was reduced in the central (p = 0.004) and inner (p = 0.013) ETDRS map regions. This effect was significant only among treatment responders (central p = 0.002; inner p = 0.017). Pretreatment OCT and OCTA parameters were not associated with final visual acuity outcomes.

CONCLUSION

Following intravitreal aflibercept treatment for DME, there was a significant decrease in vessel density of the superficial vascular plexus at the central and inner ETDRS map regions. This was seen only among treatment responders. Observations here are likely to represent the limits of OCTA technology itself, where pretreatment vessel density may have been artifactually overestimated by suspended scattering particles in motion. Pretreatment OCTA parameters did not serve as biomarkers for visual outcome following anti-vascular endothelial growth factor therapy.

Recent Advances in Clinical Applications of Imaging in Retinal Diseases

Many diseases that cause visual impairment, as well as systemic conditions, manifest in the posterior segment of the eye. With the advent of high-speed, high-resolution, reliable, and noninvasive imaging techniques, ophthalmologists are becoming more dependent on ocular imaging for disease diagnosis, classification, and management in clinical practice. There are rapid advances on the indications of multimodal retinal imaging techniques, including the application of ultra-widefield fundus angiography, fundus autofluorescence, optical coherence tomography, as well as optical coherence tomography angiography. This review summarizes and highlights the clinical applications, latest indications, and interpretations of multimodal imaging in age-related macular degeneration, polypoidal choroidal vasculopathy, diabetic macular edema, central serous chorioretinopathy, diabetic retinopathy, retinal vein occlusion, and uveitis.

Persistent diabetic macular edema: Definition, incidence, biomarkers, and treatment methods

Intravitreal antivascular endothelial growth factor (anti-VEGF) treatment has drastically improved the visual and anatomical outcomes in patients with diabetic macular edema (DME); however, success is not always guaranteed, and a proportion of these eyes demonstrate persistent DME (pDME) despite intensive treatment. While standardized criteria to define these treatment-resistant eyes have not yet been established, many studies refer to eyes with no clinical response or an unsatisfactory partial response as having pDME. A patient is considered to have pDME if the retinal thickness improves less than 10-25% after 6 months of treatment. A range of treatment options have been recommended for eyes with pDME, including switching anti-VEGF agents, using corticosteroids and/or antioxidant drugs in adjunct with anti-VEGF therapy, and vitrectomy. In addition, multimodal imaging of DME eyes may be advantageous in predicting the responsiveness to treatment; this is beneficial when initiating alternative therapies. We explore the literature on persistent DME regarding its defining criteria, incidence, the baseline biological markers that may be useful in anticipating the response to treatment, and the available treatment options.

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.

[Choroidal changes in patients with diabetes mellitus]

Diabetic retinopathy (DR) is a microvascular complication of diabetes mellitus (DM) and considered one of the leading causes of vision loss worldwide. The choroid supplies blood to the retina, photoreceptors and the retinal pigment epithelium, it is essential for metabolic exchange in the retina. Many experimental studies have reported that choroidal pathology in diabetic patients may play a role in the development of DR. Choroidal thickness (CT) can be used to assess the vascularization of the choroid. Choroidal vascularity index (CVI) is also used as a marker in assessment of choroidal vascularization. Many studies have been conducted to evaluate choroidal changes in various eye diseases. However, the data on CT in DM patients, especially in those with DR, are conflicting. Thus, the choroidal status in diabetic patients with or without DR remains controversial. In this systematic review we analyze a number of articles dedicated to the relationship between structural changes in the choroid in patients with diabetes mellitus and diabetic retinopathy of different stages, paying particular attention to choroidal thickness and certain other parameters that allow assessment of choroidal changes.

Relationship between ganglion cell complex thickness and vision in age-related macular degeneration treated with aflibercept

PURPOSE

This study aimed to analyze the correlation between ganglion cell complex thickness (GCCT) and vision compared with the choroidal thickness (CT) and central retinal thickness (CRT) in relation to the outcomes of intravitreal aflibercept treatment for choroidal neovascular membranes secondary to age-related macular degeneration (AMD).

METHODS

This was a prospective, observational study. Forty-three eyes of 38 patients with wet AMD received a monthly loading dose of 2 mg aflibercept by intravitreal injection (IVI) during the first 3 months and were then followed at regular monthly intervals for an average of 10 months by a pro re nata regimen. All patients were examined using spectral domain-optic coherence tomography (OCT) and enhanced depth imaging OCT. According to their response to IVI treatment in the third month, patients were divided into 2 groups, both functionally and anatomically.

RESULTS

Three-month GCCT and optic disc retinal nerve fiber layer thickness (ODRNFLT) had the most correlation with the 10-month vision (p  =  0.002, p  =  0.02, respectively). While baseline GCCT was most correlated with the functional response, baseline CRT was most correlated with the anatomical response (p  =  0.01, p  =  0.004, respectively).

CONCLUSIONS

The results suggest that a reduction in 3-month GCCT indicates a good long-term vision outcome, while a reduction in 3-month ODRNFLT shows a poor long-term vision outcome. The literature suggests that this study is the first to demonstrate that baseline GCCT is more strongly correlated with the functional response than it is with CT and CRT. Hence, GCCT has a prognostic value for vision impairment.

Haller Layer Thickness after Intravitreal Aflibercept Injection in Diabetic Macular Edema: 1 Month Change

Purpose: To analyze the changes in subfoveal Haller layer thickness (SFHT), subfoveal choroidal thickness (SFCT), and central macular thickness (CMT) after intravitreal aflibercept injection.Methods: This was a retrospective analysis of 36 diabetic macular edema patients who underwent intravitreal aflibercept injection between December 2016 and June 2021. The SFHT, SFCT, and CMT before and 1 month after the injection were compared using spectral-domain optical coherence tomography.Results: Mean baseline SFHT, SFCT, and CMT were 214.28 ± 80.00 μm, 307.89 ± 96.30 μm, and 525.64 ± 133.24 μm, which were reduced 1 month after the injection to 199.56 ± 75.76 μm, 290.36 ± 94.63 μm, and 409.72 ± 98.45 μm, respectively (<i>p</i> = 0.001, < 0.001, and < 0.001, respectively). There was a significant correlation between baseline SFHT and 1-month post-injection best-corrected visual acuity (BCVA), while thicker subfoveal Haller layers before the injection were associated with better BCVA after the injection (ρ = −0.342; <i>p</i> = 0.041).Conclusions: In diabetic macular edema patients, SFHT, SFCT, and CMT decreased significantly over 1 month after the first intravitreal aflibercept injection. Greater SFHT before the injection was a good short-term predictor of BCVA after injection.

Application of Machine Learning to Ranking Predictors of Anti-VEGF Response

Age-related macular degeneration (AMD) is a heterogeneous disease affecting the macula of individuals and is a cause of irreversible vision loss. Patients with neovascular AMD (nAMD) are candidates for the anti-vascular endothelial growth factor (anti-VEGF) treatment, designed to regress the growth of abnormal blood vessels in the eye. Some patients fail to maintain vision despite treatment. This study aimed to develop a prediction model based on features weighted in order of importance with respect to their impact on visual acuity (VA). Evaluations included an assessment of clinical, lifestyle, and demographic factors from patients that were treated over a period of two years. The methods included mixed-effects and relative importance modelling, and models were tested against model selection criteria, diagnostic and assumption checks, and forecasting errors. The most important predictors of an anti-VEGF response were the baseline VA of the treated eye, the time (in weeks), treatment quantity, and the treated eye. The model also ranked the impact of other variables, such as intra-retinal fluid, haemorrhage, pigment epithelium detachment, treatment drug, baseline VA of the untreated eye, and various lifestyle and demographic factors. The results identified variables that could be targeted for further investigation in support of personalised treatments based on patient data.

Choroidal and Retinal Thicknesses in Type 2 Diabetes Mellitus with Moderate Diabetic Retinopathy Measured by Swept Source OCT

Background: To study choroidal thickness (CT) in type 2 diabetes mellitus (DM2) patients with moderate diabetic retinopathy (DR) and to correlate with changes in retinal thickness (RT) with swept-source OCT (SS-OCT) compared to healthy subjects. Methods: Fifty-four DM2 patients with moderate DR without diabetic macular edema (DME) and 73 age-matched healthy subjects were evaluated using SS-OCT to measure changes in total RT and CT in the nine areas of the Early Treatment Diabetic Retinopathy Study (ETDRS) macular grid. Results: The mean age was 64.06 ± 11.98 years and 60.79 ± 8.62 years in the diabetic and control groups, respectively. Total RT showed statistically significant differences in the temporal inner area, with higher values in the DM2 group (p = 0.010). CT did not show differences between the groups. There was a significant negative correlation between RT and age in all of the outer ETDRS areas and a positive significant correlation in the central area for the DM2 group. There was also a negative significant correlation between CT and age in all of the ETDRS areas except for the inferior inner area. In the DM2 group, a negative correlation was observed between RT and CT in the central area (p = 0.039) and in both horizontal parafoveal areas (temporal inner, p = 0.028; nasal inner, p= 0.003). Conclusion: DM2 patients with moderate DR have no changes with regard to CT. Both CT and RT decreased with age in DM2, showing a negative correlation between these factors in the central and horizontal parafoveal areas of the ETDRS grid.

Optical Coherence Tomography Classification Systems for Diabetic Macular Edema and Their Associations With Visual Outcome and Treatment Responses - An Updated Review

ABSTRACT

Optical coherence tomography (OCT) is an invaluable imaging tool in detecting and assessing diabetic macular edema (DME). Over the past decade, there have been different proposed OCT-based classification systems for DME. In this review, we present an update of spectral-domain OCT (SDOCT)-based DME classifications over the past 5 years. In addition, we attempt to summarize the proposed OCT qualitative and quantitative parameters from different classification systems in relation to disease severity, risk of progression, and treatment outcome. Although some OCT-based measurements were found to have prognostic value on visual outcome, there has been a lack of consensus or guidelines on which parameters can be reliably used to predict treatment outcomes. We also summarize recent literatures on the prognostic value of these parameters including quantitative measures such as macular thickness or volume, central subfield thickness or foveal thickness, and qualitative features such as the morphology of the vitreoretinal interface, disorganization of retinal inner layers, ellipsoid zone disruption integrity, and hyperreflec-tive foci. In addition, we discuss that a framework to assess the validity of biomarkers for treatment outcome is essentially important in assessing the prognosis before deciding on treatment in DME. Finally, we echo with other experts on the demand for updating the current diabetic retinal disease classification.

Choroidal Structural Changes of Posterior Subtenon Triamcinolone Acetonide Injection in Eyes with Refractory Diabetic Macular Edema

Purpose

To access the choroidal structural changes of posterior subtenon triamcinolone acetonide (PSTA) injection in eyes with refractory diabetic macular edema (DME).

Methods

Patients with refractory DME were enrolled and followed for 4 weeks after switching to PSTA injection. All patients underwent spectral-domain optical coherence tomography with enhanced depth imaging, and the choroidal images were binarized into the luminal area and total choroidal area. Subfoveal choroidal thickness (SFCT) and choroidal vascularity index (CVI) were evaluated before and after switching treatments.

Results

After switching to PSTA treatment, the final best-corrected visual acuity and central subfield thickness in eyes with refractory DME were significantly improved compared to the baseline values (P=0.002 and P < 0.001, respectively). Both the SFCT and CVI decreased during the follow-up period, and significant decreases were observed at 4-week follow-up (P < 0.001 and P=0.012, respectively). The linear regression analysis showed a significant correlation between the baseline SFCT and the final visual outcomes (P=0.047).

Conclusions

The alterations of SFCT and CVI in this study suggest that the choroidal vasculature is involved in the pathogenesis of refractory DME and could be affected by PSTA treatment. SFCT rather than CVI may be a prognostic biomarker for eyes with refractory DME.

Baseline Subfoveal Choroidal Thickness as a Predictor for Response to Short-Term Intravitreal Bevacizumab Injections in Diabetic Macular Edema

Purpose

This article aims to evaluate how the subfoveal choroidal thickness (SFCT) and best-corrected visual acuity (BCVA) respond to the intravitreal injection of bevacizumab and to assess the correlation between these changes. It will also assess the use of the baseline SFCT as a predictor for BCVA changes in eyes of treatment-naive, diabetic macular edema (DME) patients.

Methods

This retrospective, consecutive case series comprised 59 eyes of 39 treatment-naive DME patients. Complete slit-lamp assessment, swept-source optical coherence tomography (SS-OCT) scans to measure SFCT and BCVA values were performed at two stages: baseline and one month after the third monthly injection of intravitreal bevacizumab.

Results

Patients’ ages ranged from 46.3 to 76.4 years (mean: 62.6 ± 2.3). The mean SFCT was 318 ± 82 μm at baseline, which decreased after 3 months to 300 ± 66 μm (P-value = 0.021). There was an improvement in the mean of the logMAR best-corrected visual acuity (BCVA) from 0.7 (decimal equivalent: 0.2) to 0.5 (decimal equivalent: 0.3) (P-value = 0.019). There was no association between SFCT changes and BCVA changes (P-value = 0.180). Wilcoxon signed-rank test disclosed that a better BCVA improvement was related to a greater subfoveal choroidal thickness at baseline P-value <0.00.

Conclusion

Eyes with a higher baseline subfoveal choroidal thickness (SFCT) attained greater BCVA improvement than eyes with a lower baseline SFCT. In addition to this, changes to SFCT do not appear to correlate with BCVA changes. These findings do not support using OCT SFCT changes as a prognostic factor for changes to BCVA after intravitreal bevacizumab treatment in evaluating treatment-naive DME eyes.

Choroidal Blood Flow After Intravitreal Ranibizumab in Vitrectomized and Non-Vitrectomized Eyes with Diabetic Macular Edema

Aim

Diabetic retinopathy staging system and progression predictors are soon to be considered insufficient for ophthalmologic practice. Given the growing evidence of the role of choroidal dysfunction, our purpose was to assess choroidal vascular changes with intravitreal ranibizumab (RBZ) treatment in diabetic macular edema (DME).

Methods

This was a prospective longitudinal cohort study. The study included DME eyes, grouped in vitrectomized (group 1) and non-vitrectomized (group 2) eyes, submitted to RBZ in a pro re nata regimen, with 24 weeks of follow-up. Main outcome measures such as central subfield foveal thickness (CFT), choroidal thickness (CT), and choroidal vascular index (CVI) were obtained from structural OCT, and choriocapillaris flow density (CCD) was obtained from OCT angiography and analyzed before and after treatment.

Results

Thirty-one patients were included, 10 eyes in group 1 and 24 eyes in group 2. The mean number of injections was 5.18 (range 2–6). Globally, there was an improvement in BCVA (+4.3 ETDRS letters, p=0.004) and CFT (−84.6 µm, p<0.001) with no changes in CT, CVI, or CCD (p>0.05). When considering only group 2, there was a significant decrease in CT (p=0.033) and a significant increase in CCD (p=0.010) 6 months after treatment, with no differences in CVI (p=0.111). Baseline CVI was correlated with visual acuity at week 24 both globally (r=0.406, p=0.029) and in group 2 (r=0.604, p=0.004).

Conclusion

In non-vitrectomized eyes, choriocapillaris blood flow improves with RBZ. Baseline CVI may correlate with visual function after RBZ. ClinicalTrials.gov NCT04387604.

[Diabetic Macular Edema]

Diabetic macular edema (DME) is a chronic retinal disease, which requires intensive clinical monitoring. Within the last ten years the intravitreal anti-VEGF (vascular endothelial growth factor) therapy has become the standard of care to improve and stabilize vision in patients with centre involving DME. Long-acting intravitreal corticosteroids can achieve similar visual results with fewer injection rates. Because of steroid-induced side effects (progression of cataract, glaucoma) these drugs are regarded as second-line medication. Since the introduction of anti-VEGF-medication the focal laser photocoagulation is no longer considered as first-line therapy for DME. However, a focal laser treatment can sometimes be a possible alternative in specific situations. In patients with proliferative diabetic retinopathy and DME, the intravitreal anti-VEGF therapy is approved for both conditions. In ischemic maculopathy the functional outcome is restricted. For the indication of anti-VEGF-treatment for DME with accompanying central ischemia not only visual acuity and optical coherence tomography parameters should be considered, the amount of ischemia seen on fluorescein angiography should also be taken into account. In tractional macular edema due to epiretinal membranes and vitreomacular adhesions a pars-plana vitrectomy with membrane peeling is indicated.

Diabetisches Makulaödem

Das diabetische Makulaödem (DMÖ) ist für den Großteil der Visusminderungen bei Diabetikern verantwortlich. Eine Reduktion der Sehschärfe durch ein DMÖ kann schon im milden nicht-proliferativen Stadium der diabetischen Retinopathien (DR) auftreten 1. Der chronische Verlauf der diabetischen Makulopathie erfordert ein intensives klinisches Monitoring über einen langen Zeitraum. Dieser Beitrag gibt einen Überblick über das diagnostische und therapeutische Management beim Vorliegen eines DMÖ.

Effect of calcium dobesilate on retrobulbar blood flow and choroidal thickness in patients with non-proliferative diabetic retinopathy

INTRODUCTION

Diabetic retinopathy is one of the most common causes of blindness in work-aging adults and develops in one third of diabetic patients. Calcium dobesilate (CaD) treatment have protective effects on blood retinal barrier (BRB) and anti-oxidant as well as anti-inflammatory properties.

OBJECTIVES

To assess effects of CaD administration on retrobulbar blood flow and choroidal thickness in patients with diabetic retinopathy.

METHODS

In this quasi-experimental study, diabetic patients with diabetic retinopathy (DR) were recruited from Shahid Motahari and Poostchi ophthalmology clinic affiliated to Shiraz University of Medical Sciences. Patients were treated with CaD, 1 gr per day for seven days. Before and after CaD administration, retrobulbar blood flow and subfoveal choroidal thickness were assessed. Retrobulbar blood flow were evaluated by measuring peak systolic velocity (PSV), end diastolic velocity (EDV) and resistive index (RI) of ophthalmic artery (OA), central retinal artery (CRA) and short ciliary artery (SCA).

RESULTS

In this study, 26 DR patients with a mean age of 56.15 ± 8.93 years and mean diabetes mellitus duration of 15.04 ± 7.64 years were enrolled. Subfoveal choroidal thickness was significantly increased from 316.08 ± 61.69 to 327.81 ± 58.03 after CaD treatment (P value < 0.001). PSV of CRA and EDV of all arteries were significantly increased after CaD administration. In addition, RI of all arteries was significantly reduced after CaD treatment (P < 0.001).

CONCLUSION

CaD treatment may improve the ophthalmic blood flow and increase the subfoveal choroidal thickness in DR patients. These results may be suggestive of protective effects of CaD on endothelium function as well as microvascular circulation.

Diabetic retinopathy and diabetic macular oedema pathways and management: UK Consensus Working Group

The management of diabetic retinopathy (DR) has evolved considerably over the past decade, with the availability of new technologies (diagnostic and therapeutic). As such, the existing Royal College of Ophthalmologists DR Guidelines (2013) are outdated, and to the best of our knowledge are not under revision at present. Furthermore, there are no other UK guidelines covering all available treatments, and there seems to be significant variation around the UK in the management of diabetic macular oedema (DMO). This manuscript provides a summary of reviews the pathogenesis of DR and DMO, including role of vascular endothelial growth factor (VEGF) and non-VEGF cytokines, clinical grading/classification of DMO vis a vis current terminology (of centre-involving [CI-DMO], or non-centre involving [nCI-DMO], systemic risks and their management). The excellent UK DR Screening (DRS) service has continued to evolve and remains world-leading. However, challenges remain, as there are significant variations in equipment used, and reproducible standards of DMO screening nationally. The interphase between DRS and the hospital eye service can only be strengthened with further improvements. The role of modern technology including optical coherence tomography (OCT) and wide-field imaging, and working practices including virtual clinics and their potential in increasing clinic capacity and improving patient experiences and outcomes are discussed. Similarly, potential roles of home monitoring in diabetic eyes in the future are explored. The role of pharmacological (intravitreal injections [IVT] of anti-VEGFs and steroids) and laser therapies are summarised. Generally, IVT anti-VEGF are offered as first line pharmacologic therapy. As requirements of diabetic patients in particular patient groups may vary, including pregnant women, children, and persons with learning difficulties, it is important that DR management is personalised in such particular patient groups. First choice therapy needs to be individualised in these cases and may be intravitreal steroids rather than the standard choice of anti-VEGF agents. Some of these, but not all, are discussed in this document.

CHANGES IN SUBFOVEAL CHOROIDAL THICKNESS AFTER INTRAVITREAL DEXAMETHASONE IMPLANT THERAPY FOR DIABETIC MACULAR EDEMA

PURPOSE

To investigate changes in subfoveal choroidal thickness (SFCT) and their relationship with best-corrected visual acuity and optical coherence tomography parameters after intravitreal dexamethasone implant injection for diabetic macular edema.

METHODS

Eighty-one eyes treated with dexamethasone implant injection for diabetic macular edema were evaluated for best-corrected visual acuity, central macular thickness, SFCT, and optical coherence tomography parameters at baseline and Weeks 7 and 14.

RESULTS

The mean baseline SFCT significantly decreased at Weeks 7 (P < 0.001) and 14 (P < 0.001). At Week 7, each 1-µm reduction in central macular thickness and five Early Treatment Diabetic Retinopathy Study letters (-0.1 logarithm of the minimal angle of resolution) improvement were associated with SFCT reductions of 0.09 (P = 0.002) and 3.91 (P = 0.044) µm, respectively. At Week 14, each 1-µm reduction in central macular thickness was associated with a 0.14-µm reduction in SFCT (P < 0.001). Eyes with good functional and anatomical responses exhibited significantly greater SFCT reductions. Subretinal fluid resulted in greater SFCT changes (P = 0.039) and better best-corrected visual acuity (P = 0.033) at Week 7. A continuous ellipsoid zone/interdigitation zone layer was associated with a smaller mean SFCT at Week 7 (P = 0.002) and better best-corrected visual acuity at Weeks 7 and 14 (both, P < 0.001).

CONCLUSION

Changes in SFCT after dexamethasone implant injection therapy for diabetic macular edema may predict anatomical and functional outcomes and correlate with optical coherence tomography features that are known as predictors of treatment response.

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.

Role of Oral Antioxidant Supplementation in the Current Management of Diabetic Retinopathy

Oxidative stress has been postulated as an underlying pathophysiologic mechanism of diabetic retinopathy (DR), the main cause of avoidable blindness in working-aged people. This review addressed the current daily clinical practice of DR and the role of antioxidants in this practice. A systematic review of the studies on antioxidant supplementation in DR patients was presented. Fifteen studies accomplished the inclusion criteria. The analysis of these studies concluded that antioxidant supplementation has a IIB level of recommendation in adult Type 1 and Type 2 diabetes mellitus subjects without retinopathy or mild-to-moderate nonproliferative DR without diabetic macular oedema as a complementary therapy together with standard medical care.

Predictors for 2-Year Functional and Morphological Outcomes of a Treat-and-Extend Regimen with Ranibizumab in Patients with Diabetic Macular Edema

PURPOSE

The purpose of the study was to investigate longer term functional and morphological outcomes and their predictors in diabetic macular edema (DME) following a treat-and-extend regimen (TER) without loading dose under ranibizumab.

METHODS

Patient data were reviewed and analyzed retrospectively over a period of 24 months after initiation of TER. Best-corrected visual acuity (BCVA), treatment frequency, and quantitative and qualitative spectral-domain optical coherence tomography parameters were assessed.

RESULTS

118 eyes of 87 patients were included. A mean of 9.74 ± 2.13 injections in the first and 7.63 ± 2.29 in the second year were applied. There were significant gains of BCVA and reductions in central retinal thickness from baseline to 12 and 24 months (all p < 0.001). Percentage of eyes with an intact inner segment/outer segment (IS/OS) junction increased from 15.3% at baseline to 42.1% at 24 months (p < 0.001). An intact IS/OS junction at baseline increased the probability of having a dry retina after 12 months by 79.3% (p = 0.017) and after 24 months by 88.1% (p = 0.040). Less IS/OS disruption at baseline predicted longer maximum recurrence-free treatment intervals at 2 years (r = -0.345, p < 0.001) and better BCVA at 1 year (r = -0.347, p < 0.001). Baseline bigger intraretinal cysts were associated with more IS/OS disruption at 24 months (r = 0.305, p = 0.007). Younger age and lower BCVA at baseline were predictive for a higher BCVA gain at 24 months (p = 0.046, p < 0.001).

CONCLUSION

Ranibizumab applied in a TER without loading dose in DME significantly improves visual acuity and retinal anatomical structure throughout 2 years. The evaluated predictors might help guide routine clinical treatment in DME.

Factors Affecting a Short-Term Response to Anti-VEGF Therapy in Diabetic Macular Edema

Diabetic macular edema (DME) is a common cause of visual impairment in patients with diabetes. Although intravitreal anti-vascular endothelial growth factor (VEGF) injections were efficacious in clinical trials, several patients exhibited a poor response. This study aimed to compare clinical features between patients who were susceptible to intravitreal anti-VEGF injections for DME and those who were not. A single-center, retrospective study of 102 such patients was conducted (123 eyes; mean ± standard deviation age, 63.4 ± 10.8 years; 57.8% males). Systemic and ocular data, assessed at baseline and after a month, were compared between good (>20% decrease in central macular thickness (CMT)) and poor (≤20% decrease in CMT) responders using the Mann-Whitney U test/Fisher's exact test. Eighty-one eyes (65.9%) were good responders. The glycosylated hemoglobin level was higher (p = 0.011) in poor (7.5% ± 0.94%) than in good (7.04% ± 1.19%) responders. The foveal avascular zone was larger (p = 0.0003) in poor (0.67 ± 0.33 μm²) than in good (0.47 ± 0.23 μm²) responders. The number of microaneurysms in the pericapillary network was higher (p = 0.0007) in poor (2.7 ± 2.2) than in good (1.4 ± 2.0) responders. Baseline glycemic control and macular ischemia may be associated with the short-term response to intravitreal anti-VEGF injections.

Choroidal Vascularity Index as a Biomarker for Visual Response to Antivascular Endothelial Growth Factor Treatment in Diabetic Macular Edema

PURPOSE

To investigate the choroidal vascularity index (CVI) as a prognostic factor for the visual efficacy of antivascular endothelial growth factor (VEGF) treatment in diabetic macular edema (DME).

METHODS

We retrospectively reviewed 92 DME eyes receiving anti-VEGF treatment, which were stratified as responders (≥5 letters gained) and nonresponders (<5 letters gained or lost). Baseline systematic features and optical coherence tomography features, including the CVI, adjusted ellipsoid zone (EZ) reflectivity, subretinal fluid (SRF), and disorganization of the retinal inner layers (DRIL), were evaluated between the two groups.

RESULTS

The baseline CVI was significantly lower in nonresponders than in responders (0.66 ± 0.05, 0.69 ± 0.05, and 0.72 ± 0.05, p = 0.014). After adjusting for other factors, the baseline CVI, DRIL, SRF, and adjusted EZ reflectivity were significantly associated with visual outcomes (CVI: odds ratio (OR) = 0.17, p = 0.006; adjusted EZ reflectivity: OR = 0.56, p = 0.007; DRIL: OR = 6.71, p = 0.001; and SRF: OR = 0.29, p = 0.008).

CONCLUSION

DME patients with a higher CVI, higher adjusted EZ reflectivity, the presence of SRF, and the absence of DRIL at baseline were more likely to gain >5 letters in visual acuity after anti-VEGF treatment. CVI may serve as a novel biomarker for visual response to anti-VEGF treatment in DME.

Automatic prediction of treatment outcomes in patients with diabetic macular edema using ensemble machine learning

Background

This study aimed to predict the treatment outcomes in patients with diabetic macular edema (DME) after 3 monthly anti-vascular endothelial growth factor (VEGF) injections using machine learning (ML) based on pretreatment optical coherence tomography (OCT) images and clinical variables.

Methods

An ensemble ML system consisting of four deep learning (DL) models and five classical machine learning (CML) models was developed to predict the posttreatment central foveal thickness (CFT) and the best-corrected visual acuity (BCVA). A total of 363 OCT images and 7,587 clinical data records from 363 eyes were included in the training set (304 eyes) and external validation set (59 eyes). The DL models were trained using the OCT images, and the CML models were trained using the OCT images features and clinical variables. The predictive posttreatment CFT and BCVA values were compared with true outcomes obtained from the medical records.

Results

For CFT prediction, the mean absolute error (MAE), root mean square error (RMSE), and R² of the best-performing model in the training set was 66.59, 93.73, and 0.71, respectively, with an area under receiver operating characteristic curve (AUC) of 0.90 for distinguishing the eyes with good anatomical response. The MAE, RMSE, and R² was 68.08, 97.63, and 0.74, respectively, with an AUC of 0.94 in the external validation set. For BCVA prediction, the MAE, RMSE, and R² of the best-performing model in the training set was 0.19, 0.29, and 0.60, respectively, with an AUC of 0.80 for distinguishing eyes with a good functional response. The external validation achieved a MAE, RMSE, and R² of 0.13, 0.20, and 0.68, respectively, with an AUC of 0.81.

Conclusions

Our ensemble ML system accurately predicted posttreatment CFT and BCVA after anti-VEGF injections in DME patients, and can be used to prospectively assess the efficacy of anti-VEGF therapy in DME patients.

[Morphometric study of the choroid in pregnant women with disorders of carbohydrate metabolism]

In recent years, much attention is being paid to studying the state of the choroid in various eye pathologies, but changes in the choroid of pregnant women with disorders of glucose metabolism remain unexplored.

PURPOSE

To study choroidal thickness in pregnant women with disorders of carbohydrate metabolism in the III trimester.

MATERIAL AND METHODS

The study included 376 pregnant women in the third trimester of pregnancy: 49 of them had type 1 diabetes (T1D), 248 had gestational diabetes (GD), and 79 were healthy pregnant women who comprised the control group. Three subgroups were distinguished among patients with GD, depending on the timing of the development of GD in the I (160 patients), II (56 patients), or III (32 patients) trimesters. Optical coherence tomography was performed to measure choroidal thickness in the foveal region.

RESULTS

In patients with GD, no significant differences in average indexes of choroidal thickness in subgroups with different timing of diabetes development were observed, however, the pregnant women of the GD subgroup with beginning of its development in the first trimester had the smallest indexes of average choroidal thickness. In pregnant women with GD who received insulin, choroidal thickness was lower than in patients who did not receive it, although statistical significance of that was not established. In patients with T1D and diabetic retinopathy (DR), choroidal thickness was significantly lower compared to patients with T1D without DR, GD and control groups. Obtained data indicates the presence of changes in the choroid and development of diabetic choroidopathy in pregnant women with T1D and DR.

CONCLUSION

The study of choroidal changes in pregnant women with disorders of carbohydrate metabolism can help identify criteria for manifestation of diabetic microangiopathy, choroidopathy, and predict the progression of DR.

Novel imaging biomarkers in diabetic retinopathy and diabetic macular edema

Diabetic retinopathy is one of the major microvascular complications of diabetes mellitus. The most common causes of vision loss in diabetic retinopathy are diabetic macular edema and proliferative diabetic retinopathy. Recent developments in ocular imaging have played a significant role in early diagnosis and management of these complications. Color fundus photography is an imaging modality, which is helpful for screening patients with diabetic eye disease and monitoring its progression as well as response to treatment. Fundus fluorescein angiography (FFA) is a dye-based invasive test to detect subtle neovascularization, look for areas of capillary non-perfusion, diagnose macular ischemia, and differentiate between focal and diffuse capillary bed leak in cases of macular edema. Recent advances in retinal imaging like the introduction of spectral-domain and swept source-based optical coherence tomography (OCT), fundus autofluorescence (FAF), OCT angiography, and ultrawide field imaging and FFA have helped clinicians in the detection of certain biomarkers that can identify disease at an early stage and predict response to treatment in diabetic macular edema. This article will summarize the role of different imaging biomarkers in characterizing diabetic retinopathy and their potential contribution in its management.

Choroidal Thickness in Diabetes and Diabetic Retinopathy: A Swept Source OCT Study

Purpose

Previous studies on the association between choroidal thickness (CT) and severity of diabetic retinopathy (DR) gave conflicting results. The aim of this study was to evaluate the CT changes in diabetic patients and associated factors in a large sample of Chinese patients with diabetes.

Methods

Type 2 diabetes mellitus patients without history of ocular treatment were recruited from the community health system in Guangzhou, China. The swept source OCT instrument was used to obtain high-definition retina and choroid images. The diabetic retinopathy (DR) status was graded based on the guidelines of the United Kingdom National Diabetic Eye Screening Programme. Univariate and multivariate linear regression analyses was used to explore the association of CT with DR severity, diabetic macular edema (DME), hemoglobin A1c, and vision function.

Results

A total of 1347 patients were included in the final analysis. After adjusting for other factors, the patients with stage R3 DR had significantly thinner CT (β = –29.1 µm, 95% CI –53.8 to –4.4, P = 0.021) in comparison in those with R0. After adjusting for other factors, the CTs were thicker than those in R0 patients with difference of 15.6 µm (95% CI 4.3-26.9, P = 0.007) for outer nasal sector, 15.7 µm (95% CI 3.8-25.5, P = 0.008) for outer inferior, and 12.2 µm (95% CI 0.4-24.0, P = 0.042) for inner inferior sector. The presence of DME and hemoglobin A1c levels did not significantly affect average CT. Higher average CT was significantly associated with better best corrected visual acuity, with a –0.02 LogMAR unit per 100 µm increase in average CT (95% CI –0.03 to –0.01, P < 0.001).

Conclusions

CT increased in the early stage of DR, and further decreased with DR progression. DME was not significantly associated with CT. These findings provide more clues to suggest that choroid alterations play a role in the pathogenesis of DR.

Impact of sub-foveal choroidal thickness on clinical features and long-term clinical outcomes in polypoidal choroidal vasculopathy

PURPOSE

To study the clinical features and long-term clinical outcomes in polypoidal choroidal vasculopathy (PCV) in eyes with different sub-foveal choroidal thickness (SFCT).

METHODS

In this retrospective, observational comparative study, treatment-naïve eyes diagnosed with PCV using the 'EVEREST-2' study criteria were included. The eyes were divided into three groups of thin, medium and thick choroids, based on the SFCT data of total study eyes. Demographic, clinical, imaging features and treatment outcomes between the 3 groups were compared.

RESULTS

Sixty-three eyes in 63 patients were included. Right eye was involved in 39 (61%) cases and left eye in 24 (39%) cases. Mean age was 68.3 ± 6.82 years (range 54-85 years). Mean SFCT was 274 µm (median = 269 µm), and one standard deviation was 79.2 µm. Totally, 11, 43 and 9 eyes were included in the thin, medium and thick choroid groups, respectively. The mean SFCT was 161 ± 24.1 µm, 275 ± 39.6 µm and 412 ± 26.2 µm in the thin, medium and thick choroid groups, respectively. There was no statistically significant difference in the clinical and imaging features and treatment outcomes between eyes with thin, medium and thick SFCT.

CONCLUSION

Eyes with PCV can have a choroid of varying thicknesses. Clinical, imaging and treatment responses were similar between the three sub-foveal choroidal thickness groups in this study. In future, more studies are required to evaluate the role of the choroidal thickness and its relationship to treatment in PCV.

Bradykinin 1 Receptor Antagonist BI1026706 Does Not Reduce Central Retinal Thickness in Center-Involved Diabetic Macular Edema

Purpose

The bradykinin 1 receptor may be important in inflammatory retinal vascular leakage in diabetic macular edema. BI 1026706 is an antagonist of bradykinin 1 receptor that has demonstrated efficacy in preclinical studies. Boehringer Ingelheim trial 1320.22 (NCT02732951) was a randomized, double-blind, placebo-controlled study. The pharmacodynamics, safety, and tolerability of oral BI 1026706 for 12 weeks were evaluated in patients with type 1 or type 2 diabetes mellitus and mild visual impairment owing to center-involved diabetic macular edema.

Methods

Patients (n = 105) were randomized to receive either oral BI 1026706 100 mg twice daily (morning and evening) or placebo for 12 weeks. The primary end point of the study was week 12 change from baseline in central subfield foveal thickness (CSFT) by spectral domain optical coherence tomography. Additional end points included absolute CSFT values, safety, and pharmacokinetics.

Results

After 12 weeks of treatment, there was no meaningful change from baseline in the adjusted mean CSFT in either treatment group (BI 1026706, 10.3 µm; placebo, –6.2 µm; adjusted mean treatment difference, 16.5 µm [95% confidence interval, –16.2 to 49.1]). There were also no differences in best-corrected visual acuity outcomes between treatment groups. Most reported adverse events were of mild or moderate intensity, and were balanced between treatment groups.

Conclusions

BI 1026706 was not superior to placebo in CSFT week-12 change from baseline. Therefore, BI 1026706 does not reduce CSFT, a morphologic sign of diabetic macular edema.

Translational Relevance

Kinin-kallikrein inhibition effects may not be apparent over 12 weeks for bradykinin 1 receptor inhibition alone.

Comparison of the Effect of Ranibizumab and Aflibercept on Changes in Macular Choroidal Thickness in Patients Treated for Diabetic Macular Edema

Purpose

The aim of this study was to assess the effect of intravitreal injections (IVI) of ranibizumab and aflibercept on the choroidal thickness (CT) in patients with treatment-naive diabetic macular edema (DME) before and after monthly IVI. Patients and Methods. Prospective monocenter study. Inclusion criteria were treatment-naive DME eyes without concomitant panretinal photocoagulation, associated with a decrease in best-corrected visual acuity ≤75 letters on the Early Treatment Diabetic Retinopathy Study (ETDRS) scale. DME was defined by a central retinal thickness ≥300 μm on swept-source OCT (Triton DRI OCT, Topcon Corporation, Itabashi, Japan). Patients received 5 IVI of ranibizumab or aflibercept. The primary endpoint was the change in the central subfield CT (CSCT) between inclusion (M0) and 1 month after the fifth IVI (M5). The secondary endpoint was the CT changes between M0 and M5 in other locations of the macular ETDRS grid.

Results

Twenty-four eyes of 24 patients with a mean age of 61.1 years were included. Eleven and 13 patients were, respectively, treated with ranibizumab and aflibercept, and 86.4% had type 2 diabetes. The overall CSCT decreased significantly by −12 μm between M0 and M5 (231.7 μm at M0 and 219.7 μm at M5) (p=0.03). It decreased by −15.2 μm (p=0.02) in the aflibercept group (206.9 μm at M0 and 191.7 μm at M5) and by −7.3 μm (p=0.4) in the ranibizumab group (267.5 μm at M0 and 260.2 μm at M5). The CSCT decreased by −4.9 μm in noninjected contralateral eyes (242.3 μm at M0 and 237.4 μm at M5). CT changes between M0 and M5 in the superior, temporal, inferior, and nasal macular inner ring were significant in the aflibercept group but not in the ranibizumab and control groups.

Conclusion

In DME patients, the CSCT decreases after 5 IVI of anti-VEGF, especially after aflibercept treatment.

Macular microvascular changes after intravitreal bevacizumab injection in diabetic macular edema

OBJECTIVE

To evaluate the changes in retinal capillary plexus and the choriocapillaris after a single intravitreal injection of bevacizumab in eyes with diabetic macular edema using optical coherence tomography angiography (OCTA).

DESIGN

Prospective interventional case series.

PARTICIPANTS

Patients having diabetes with centre-involving diabetic macular edema.

METHODS

In this prospective interventional case series, eyes with centre-involving diabetic macular edema were enrolled. Vascular density (VD), vascular diameter index (VDI), vascular length density (VLD), foveal avascular zone (FAZ) area, and foveal density (FD)-300 were measured using en face OCTA images before and 1 month after administration of intravitreal bevacizumab. VD and VDI measurements were performed in the superficial capillary plexus (SCP) and deep retinal capillary plexus (DCP) and in the choriocapillaris. Additionally, capillary nonperfusion area (CNPA) was detected automatically based on vessel distance map in 4 concentric rings around the foveal centre. The segmentation error was manually corrected, and the measurements were performed by 2 expert graders.

RESULTS

Twenty-three eyes of 19 patients with a mean age of 62.76 ± 6.88 years were included. There were no significant changes in the FAZ area, FD-300, or in the VD of the foveal and parafoveal SCP and DCP. Also, VLD and VDI of the SCP and DCP remained unchanged. The change in the CNPA was not statistically significant. The VD of choriocapillaris increased significantly after injections (p = 0.005).

CONCLUSIONS

FAZ area and VD of the retinal capillary plexus remained stable in the short-term period after intravitreal bevacizumab. In addition, the choriocapillaris blood flow improved after bevacizumab injection.

Profile of non-responder and late responder patients treated for diabetic macular edema: systemic and ocular factors

Diabetic macular edema (DME) treatment represents a challenge for the ophthalmologists, and several aspects of real treatment expectancy are still being discussed and not yet fully elucidated. A univocal definition of responsiveness to treatment has not been reached. How the clinicians can evaluate the therapeutic success? The evaluation of systemic and ocular factors should help in this complex management. The age influences the long-term outcomes, and the role of glycemic control is confounded by contrasting correlations between hemoglobin glycated A1c and DME. Long-term treatment success is influenced by baseline best-corrected visual acuity (BCVA), central macular thickness (CMT) and early BCVA response. Also baseline diabetic retinopathy severity scale score is useful to evaluate the chances of improvement before and during treatments. The time-switching was influenced by early BCVA response, however considering a delayed response in a percentage of patients. Several structural optical coherence tomography (OCT) findings could predict long-term success, as the presence of serous retinal detachment, hyperreflective retinal spots, the disruption of external limiting membrane and ellipsoid zone, the disorganization of inner retinal layers and continued increase in CMT were considered predictors of poor response to treatment. Foveal avascular zone enlargement, high number of microaneurysms (Mas), lower vessel density (VD) in deep capillary plexus and lower parafoveal VD in superficial capillary plexus were considered as OCT angiography biomarkers of poor responsiveness. The aim of this review is to report the factors that could influence the response to treatment of DME patients.

Changes in choroidal structure following intravitreal aflibercept therapy for retinal vein occlusion

AIMS

To examine the choroidal change accompanying retinal vein occlusion (RVO) in detail, we measured changes in choroidal structure after intravitreal aflibercept (IVA) injections for RVO using binarisation of enhanced depth imaging optical coherence tomographic (EDI-OCT) images and assessed associations with clinical outcome.

METHODS

Retrospective, observational case series. Forty treatment-naïve patients (10 central, 18 major branch and 12 macular branch RVO) were examined by EDI-OCT before and 1, 3 and 6 months after IVA injections. EDI-OCT images were binarised using ImageJ. Subfoveal cross-sectional areas of the luminal, stromal and total choroid over a 1500 µm span were measured and the stromal area to total choroidal area (S/C) ratio was calculated.

RESULTS

Compared to normal contralateral eyes, afflicted eyes at baseline exhibited significantly greater stromal area (p<0.001), total choroidal area (p=0.001) and S/C ratio (p<0.001), but no difference in luminal area (p=0.083). The stromal area, S/C ratio and total choroidal area were significantly reduced in afflicted eyes at 1, 3 and 6 months after IVA (all p<0.006). Baseline S/C ratio was significantly correlated with baseline visual acuity (VA), baseline central retinal thickness (CRT) and VA and CRT improvement at 1, 3 and 6 months post-treatment even after adjusting for the axial length, age and sex (all p<0.012).

CONCLUSION

RVO induces substantial oedema of the choroidal stromal area that is detectable by binarisation of EDI-OCT images. This stromal oedema likely stems from high intraocular vascular endothelial growth factor levels. Changes in choroidal structure may be used to assess severity and prognosis of RVO.

Anatomical and functional responses in eyes with diabetic macular edema treated with "1 + PRN" ranibizumab: one-year outcomes in population of mainland China

BACKGROUND

To evaluate the anatomical and functional responses in eyes with diabetic macular edema (DME) treated with ranibizumab under "1 + pro re nata (PRN)" regimen.

METHODS

This prospective interventional case series included 69 eyes of 69 patients with DME treated with intravitreal injections of 0.5 mg ranibizumab followed by repeated injections as needed. Best-corrected visual acuity (BCVA), central foveal thickness (CFT), subfoveal choroidal thickness (SFCT), and predictive factors for final visual outcomes were assessed.

RESULTS

Logarithm of minimal angle of resolution (logMAR) BCVA improved from 0.64 ± 0.23 at baseline to 0.56 ± 0.27, 0.53 ± 0.26, 0.47 ± 0.25, 0.44 ± 0.32, 0.47 ± 0.26 and 0.46 ± 0.26 at time-point of months 1, 2, 3, 6, 9, and 12, respectively (P < 0.05 for any follow-up time-point except month 1). CFT decreased from 478.23 ± 172.31 μm at baseline to 349.74 ± 82.21 μm, 313.52 ± 69.62 μm, 292.59 ± 61.07 μm, 284.67 ± 69.85 μm, 268.33 ± 43.03 μm, and 270.39 ± 49.27 μm at above time-points, respectively (P < 0.05). The number of injections was 6.83 times over 12 months' follow-up under "1 + PRN" regimen. Multivariate analysis showed that the factors including age, BCVA at baseline, disruption of ellipsoid zone, posterior vitreous detachment (PVD), and vitreomacular traction (VMT) were correlated with the final BCVA.

CONCLUSIONS

Intravitreal injections of ranibizumab under "1 + PRN" regimen is a not only effective but also safe way to improve visual acuity of DME patients. And older age, lower baseline BCVA, VMT, and disruption of ellipsoid zone are predictors for final poor BCVA while PVD is a positive predictive factor for good final BCVA.

TRIAL REGISTRATION

The trial was registered retrospectively in ClinicalTrials.gov on 2 June 2019 (NCT03973138).

Choroidal Changes of Long-Term Type 1 Diabetic Patients without Retinopathy

The aim of the study is to assess choroidal thickness (CT) and choroidal volume (CV) in 90 type 1 diabetes mellitus (DM1) patients with no diabetic retinopathy (DR) and 60 control eyes using spectral domain optical coherence tomography (SD-OCT) and swept source (SS)-OCT in the areas of the Early Treatment Diabetic Retinopathy Study (ETDRS). Mean ages were 42.93 ± 13.62 and 41.52 ± 13.05 years in the diabetic and control groups, respectively. Significant differences were obtained between both groups with Spectralis SD-OCT in all ETDRS areas and in the total CV, excluding the temporal perifoveal one. With Triton SS-OCT, statistically significant differences were obtained in the subfoveal CT and in the vertical areas. CT showed the same tendency with both OCTs, with greater CT and CV in the DM1 group than the mean values of the control group. To assess the influence of DM1 evolution in the CT modifications, DM1 patients were divided into Group 1, with less than 24 years of diagnosis, and Group 2, with ≥24 years of DM1 evolution. Using both OCTs, seven of the nine ETDRS areas and the CV had lower values in Group 2. CT and CV measured by OCT were higher in DM1 without DR. There is a choroidal thinning related to disease evolution in DM1. In patients with DM evolution greater than 24 years, the CT is statistically lower than in patients with less evolution of the disease.

Relationship between diabetic macular edema and choroidal layer thickness

Purpose

To investigate the relationship between diabetic macular edema (DME) and the choroidal layer thickness in diabetic patients.

Methods

This is a retrospective observation study. Three hundred eighteen eyes of 159 diabetes mellitus (DM) patients and age-matched 100 eyes of 79 healthy controls were enrolled. DME was defined as over 300 μm in the central retinal subfield of the Early Treatment Diabetic Retinopathy Study (ETDRS) grid sector. The central choroidal thickness (CCT), as well as inner and outer layers were determined based on enhanced depth imaging (EDI)–OCT. Diabetic patients with/without systemic diabetic treatments (DT) at the start of this study was defined as DT+ and DT–, respectively. The number of eyes examined was 62 and 256 eyes in DME+and DME–groups, respectively. DM patients were further subdivided into 4 groups with/without DME and DT; DME+DT+(35 eyes), DME–DT+(159 eyes), DME+DT–(27 eyes), and DME–DT–group (97 eyes). Multiple comparisons on CCT layers including control and each DM group were statistically examined.

Results

The total CCT layer was 254±83, 283±88, and 251±70 μm in the control, DME+, and DME–group, respectively. A total CCT layer in DME+was significantly thicker than the DME–group (P < 0.05). The outer CCT layer was 195±75, 222±83, and 193±63 μm in the control, DME+, and DME–group, respectively. The outer CCT layer in DME+ was significantly thicker than the DME–group (P < 0.05). In the subdivided groups, the total CCT layers in the control, DME+DT+, DME–DT+, DME+DT–and DME–DT–groups were 254±83, 274±88, 247±66, 290±84 and 258±75 μm, respectively. The outer CCT layers in each group were 195±75, 214±83, 189±58, 228±77, and 201±70 μm, respectively. Total CCT and the outer layer in DME+DT–was significantly thicker than the DME–DT+group (each P < 0.05). In contrast, there was no significant difference in inner layer between the groups.

Conclusions

The total and outer CCT layers of diabetic eyes were significantly thickened in the DME+DT–as compared with the DME–DT+group, suggesting that CCT may be related to the pathology of DME.

Optical Coherence Tomography (Angiography) Biomarkers in the Assessment and Monitoring of Diabetic Macular Edema

Retinopathy is one of the most severe diabetes-related complications, and macular edema is the major cause of central vision loss in patients with diabetes mellitus. Significant progress has been made in recent years in optical coherence tomography and angiography technology. At the same time, various parameters have been attributed the role of biomarkers creating the frame for new monitoring and treatment strategies and offering new insights into the pathogenesis of diabetic retinopathy and diabetic macular edema. In this review, we gathered the results of studies that investigated various specific OCT (angiography) parameters in diabetic macular edema, such as central subfoveal thickness (CST), cube average thickness (CAT), cube volume (CV), choroidal thickness (CT), retinal nerve fiber layer (RNFL), retinal thickness at the fovea (RTF), subfoveal choroidal thickness (SFCT), central macular thickness (CMT), choroidal vascularity index (CVI), total macular volume (TMV), central choroid thickness (CCT), photoreceptor outer segment (PROS), perfused capillary density (PCD), foveal avascular zone (FAZ), subfoveal neuroretinal detachment (SND), hyperreflective foci (HF), disorganization of the inner retinal layers (DRIL), ellipsoid zone (EZ), inner segment/outer segment (IS/OS) junctions, vascular density (VD), deep capillary plexus (DCP), and superficial capillary plexus (SCP), in order to provide a synthesis of biomarkers that are currently used for the early diagnosis, assessment, monitoring, and outlining of prognosis.

Evaluating diurnal changes in choroidal sublayer perfusion using optical coherence tomography angiography

PURPOSE

To investigate diurnal changes of choroidal sublayer perfusion in normal eyes and to identify influencing factors using optical coherence tomography angiography (OCTA).

METHODS

A prospective study was conducted on healthy volunteers, each of whom underwent repeated measurements of subfoveal choroidal thickness (SFCT) via enhanced depth imaging (EDI) optical coherence tomography (OCT) as well as perfusion of choroidal vascular sublayers using OCTA at 7 a.m., 12 p.m., 4 p.m. and 8 p.m. Possible interactions between diurnal variations and other factors, such as mean arterial pressure (MAP), gender and age, were evaluated.

RESULTS

A total of 22 eyes from 22 participants were analysed. Mean age of participants was 56 years. A significant pattern of diurnal variation was observed for SFCT (p < 0.001) as well as perfusion of Sattler's layer (SLP; p = 0.009) and Haller's layer (HLP; p = 0.003). SFCT demonstrated a linear decrease, being thicker in the morning (348 μm) and thinner in the evening (310 μm). Both, SLP and HLP showed a quadratic relation to time of day, increasing from morning (64% and 76%) to afternoon (66% and 77%), before decreasing again in the evening (64% and 76%). HLP changes were significantly associated with fluctuations of MAP (B = 0.0007; CI 0.0001-0.0014; p = 0.047). No significant differences with regard to gender were detectable. However, older participants (≥60 years) had fewer diurnal changes (p = 0.042).

CONCLUSION

Optical coherence tomography angiography-based analysis of choroidal sublayer perfusion demonstrated significant diurnal variations. Therefore, it is important to account for time of day, when comparing longitudinal OCTA data.