Association of pathomorphology, photoreceptor status, and retinal thickness with visual acuity in diabetic retinopathy

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.

Efficacy and Safety of 0.19-mg Fluocinolone Acetonide Implant in Postoperative Cystoid Macular Edema after Pars Plana Vitrectomy: the ILUCYD study

PURPOSE

To assess the efficacy and safety of 0.19-mg fluocinolone acetonide (FAc) intravitreal implant (Iluvien®) in treating chronic postoperative cystoid macular edema (PCME) after pars plana vitrectomy.

DESIGN

Retrospective multicentric case series in clinical settings.

SUBJECTS

Patients with chronic PCME who underwent vitrectomy in tertiary care centers in France. All eyes had a documented good response to the DEX implant prior to FAc implantation.

METHODS

Review of charts and OCT scans of patients treated with a FAc intravitreal implant.

MAIN OUTCOME MEASURES

The primary endpoints were the best-corrected visual acuity (BCVA) and central retinal thickness (CRT). Secondary endpoints were the intraocular pressure (IOP); proportion of patients maintaining a BCVA ≥20/40; need for additional non-study treatment; differences between eyes that underwent a single and multiple surgeries and OCT biomarkers of better BCVA.

RESULTS

Forty-nine eyes of 49 patients with a mean follow-up of 24.5 ± 3.9 months were included. The mean BCVA increased from 0.40 ± 0.26 logMAR at baseline to 0.32 ± 0.24 logMAR at month 24 (M24) (p=0.0035). The mean CRT decreased from 409.37 ± 139.43 μm at baseline to 340 ± 91 μm at M24 (p=0.0001). The mean IOP was 14.0 ± 4 mmHg at baseline and remained stable at 14.03 ± 4.1 mmHg at M24 (p=0.99). During the follow-up, the IOP exceeded 21 mmHg in 9 eyes. The IOP rise was controlled with topical therapy in all eyes except one, which required cyclophotocoagulation. The BCVA was ≥20/40 in 47% of eyes (95% CI: 34%-61%) at baseline and in 58% of eyes at M24 (95% CI: 41%-73%). At M18, the likelihood of achieving a BCVA ≥20/40 was higher in eyes with intact external limiting membrane and ellipsoid zone. Additional dexamethasone implant (DEXi) was injected in 14 eyes (28.57%). The treatment burden of 2.45 ± 1.35 DEXi/year was decreased to 0.57 ± 0.60 DEXi/year after FAc implantation (p=0.001).

CONCLUSION

FAc implant improved the BCVA and reduced the CRT in eyes with chronic PCME after vitrectomy. The IOP rise could be anticipated by the previous response to corticosteroids. FAc implant in eyes with chronic PCME also allowed reducing the treatment burden.

Clinically Labeled Contrastive Learning for OCT Biomarker Classification

This article presents a novel positive and negative set selection strategy for contrastive learning of medical images based on labels that can be extracted from clinical data. In the medical field, there exists a variety of labels for data that serve different purposes at different stages of a diagnostic and treatment process. Clinical labels and biomarker labels are two examples. In general, clinical labels are easier to obtain in larger quantities because they are regularly collected during routine clinical care, while biomarker labels require expert analysis and interpretation to obtain. Within the field of ophthalmology, previous work has shown that clinical values exhibit correlations with biomarker structures that manifest within optical coherence tomography (OCT) scans. We exploit this relationship by using the clinical data as pseudo-labels for our data without biomarker labels in order to choose positive and negative instances for training a backbone network with a supervised contrastive loss. In this way, a backbone network learns a representation space that aligns with the clinical data distribution available. Afterwards, we fine-tune the network trained in this manner with the smaller amount of biomarker labeled data with a cross-entropy loss in order to classify these key indicators of disease directly from OCT scans. We also expand on this concept by proposing a method that uses a linear combination of clinical contrastive losses. We benchmark our methods against state of the art self-supervised methods in a novel setting with biomarkers of varying granularity. We show performance improvements by as much as 5% in total biomarker detection AUROC.

Current Treatments for Diabetic Macular Edema

Diabetic retinopathy is a major retinal disorder and a leading cause of blindness. Diabetic macular edema (DME) is an ocular complication in patients with diabetes, and it can impair vision significantly. DME is a disorder of the neurovascular system, and it causes obstructions of the retinal capillaries, damage of the blood vessels, and hyperpermeability due to the expression and action of vascular endothelial growth factor (VEGF). These changes result in hemorrhages and leakages of the serous components of blood that result in failures of the neurovascular units (NVUs). Persistent edema of the retina around the macula causes damage to the neural cells that constitute the NVUs resulting in diabetic neuropathy of the retina and a reduction in vision quality. The macular edema and NVU disorders can be monitored by optical coherence tomography (OCT). Neuronal cell death and axonal degeneration are irreversible, and their development can result in permanent visual loss. Treating the edema before these changes are detected in the OCT images is necessary for neuroprotection and maintenance of good vision. This review describes the effective treatments for the macular edema that are therefore neuroprotective.

Predictive factors for treatment outcomes with intravitreal anti-vascular endothelial growth factor injections in diabetic macular edema in clinical practice

BACKGROUND

Intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections are the standard of care for diabetic macular edema (DME), a common complication of diabetes. This study aimed to identify factors influencing DME intravitreal anti-VEGF treatment outcomes in real-world practice.

METHODS

This was a multi-center retrospective observational study using medical chart review of participants receiving anti-VEGF injections for DME (N = 248). Demographic and clinical variables were assessed for association with best corrected visual acuity (BCVA) and central macular thickness (CMT) outcomes using regression models.

RESULTS

There was a significant improvement in BCVA (p < 0.001) and CMT (p < 0.001) after 12 months of treatment, although 21% of participants had decreased BCVA, and 41% had a < 10% CMT reduction at 12 months. Higher baseline BCVA (p = 0.022, OR=-0.024, 95% CI=-0.046,-0.004) and longer duration of diabetic retinopathy (p = 0.048, OR=-0.064, 95% CI=-0.129,-0.001) were negative predictors for BCVA response, whereas Aflibercept treatment (p = 0.017, OR = 1.107, 95% CI = 0.220,2.051) compared with other drugs and a positive "early functional response" (p < 0.001, OR=-1.393, 95% CI=-1.946,-0.857) were positive predictors. A higher baseline CMT (p < 0.001, OR = 0.019, 95% CI = 0.012,0.0261) and an "early anatomical response", (p < 0.001, OR=-1.677, 95% CI=-2.456, -0.943) were predictors for greater reduction in CMT. Overall, the variables could predict only 23% of BCVA and 52% of CMT response.

CONCLUSIONS

The study shows a significant proportion of DME patients do not respond to anti-VEGF therapy and identifies several clinical predictors for treatment outcomes.

TRIAL REGISTRATION

The study was approved through the Human Research Ethics Committee, University of Tasmania (approval number H0012902), and the Southern Adelaide Clinical Human Research Ethics Committee (approval number 86 - 067).

Correlation between Choroidal Vascularity Index and Outer Retina in Patients with Diabetic Retinopathy

The choroid supplies blood to the outer retina. We quantified outer retinal and choroidal parameters to understand better the pathogenesis of diabetic retinopathy (DR) and diabetic macular edema (DME). The retrospective cross-sectional single-center study included 210 eyes from 139 diabetic patients and 76 eyes from 52 healthy controls. Spectral-domain optical coherence tomography (OCT) was carried out with a Spectralis HRA + OCT imaging device. The outer retinal layer (ORL), outer nuclear layer (ONL), and choroidal thicknesses were assessed along with the choroidal vascularity index (CVI). The presence of DR, whether with DME or without, was associated with choroidal thinning (p < 0.001). Compared with the controls, patients with DR without DME presented with lower ORL and ONL thickness (p < 0.001), whereas those with DR and DME had higher values of both parameters (p < 0.001). Significant correlations between outer retinal and choroidal parameters were found only in patients with DR without DME (ORL with choroidal thickness: p = 0.003, rho = 0.34; ORL with CVI: p < 0.001, rho = 0.49, ONL with CVI: p < 0.027, rho = 0.25). No correlations between choroidal and outer retinal parameters were observed in the controls and patients with DR and concomitant DME. Aside from diabetic choroidopathy, other pathogenic mechanisms seem to predominate in the latter group.

Ocular delivery of sunitinib-loaded nanoparticles doped in tragacanthic acid hydrogel in treatment of diabetic retinopathy in rats

OBJECTIVE

Diabetic retinopathy (DR) is a common microvascular complication of diabetes mellitus. This study aimed to compare the effect of sunitinib-loaded poly (glycerol sebacate) (PGS)/gelatin nanoparticles doped in an injectable hydrogel with bevacizumab as a standard treatment of DR.

METHODS

The shear-sensitive hydrogel was prepared based on tragacanthic acid (TA) cross-linked with sodium acetate. DR was induced in rats by streptozotocin (STZ), and the animals were injected intravitreally a single dose of 20 µL sunitinib solution in three different concentrations (12.5, 25, and 50 µg/mL), sunitinib-loaded nanoparticles in hydrogel (413 μg/mL) and bevacizumab solution (6.25 mg/mL). The efficacy of the treatments was studied by histological and immunohisitological tests, angiogenesis, and optical coherence tomography (OCT). Vascular endothelial growth factor (VEGF) concentration was measured in the retina.

RESULTS

The results revealed that 20 µL of sunitinib with the concentration of 25 µg/mL was effective in DR without any disruption in the retina or any other side effects. This dose was considered the therapeutic dose for nanoparticles. Sunitinib loaded PGS/gelatine nanoparticles that were incorporated in the injectable hydrogel were as effective as bevacizumab in controlling DR. Although sunitinib solution reduced VEGF production and neovascularization in the retina compared to the negative control group, it was not as suitable as the nanoparticles. TA-based hydrogel showed no toxicity on the normal retina, and the angiography and histologic studies confirmed the VEGF results. Conclusions: Sunitinib nanoparticles doped in TA hydrogel may be an appropriate substitution of bevacizumab in the treatment of DR.

Near-Infrared Confocal Reflectance Scanning Laser Ophthalmoscopy (SLO) and Short-Wavelength Autofluorescence Imaging in Cystic Diabetic Macular Edema

Objective

To characterize results of short-wavelength autofluorescent (SW-AF) and near-infrared confocal reflectance scanning laser ophthalmoscopy (NIR-cR SLO) imaging in cystic diabetic macular edema (DME).

Design

Cross-sectional study. Participants: 104 eyes from 52 naïve treatment patients with DME and mild to moderate nonproliferative diabetic retinopathy (NPDR) Methods: complete ocular examination, best-corrected visual acuity (BCVA), and imaging were performed.

Results

In NIR-cR SLO, small/medium and large-sized cysts presented with decreased and increased reflectance, respectively. In SW-AF, increased and decreased autofluorescence, corresponding to medium-/large- and small-sized cysts were noted. Mainly, the lower NIR reflectance was associated with petaloid edema pattern in SW-AF (P=0.011), BCVA (logMAR) (P=0.056), subretinal fluid (P=0.035), and the involved layers of retina by cysts (P < 0.001) in Pearson chi-square test. Fair agreement of 0.31 (P < 0.001) between NIR-cR SLO and late FA leakage was found by the weighted kappa test. In regression analysis, NIR-cR SLO abnormality is highly correlated with outer and inner nuclear layers location of the cystic changes.

Conclusions

The size of cysts and involved layers affect presenting features of SW-AF and NIR reflectance.

Factors predicting the treatment frequency of ranibizumab injections during the second year in diabetic macular edema

PURPOSE

To investigate the predictors of annual treatment frequency in the second year of pro re nata (PRN) intravitreal ranibizumab (IVR) injections for diabetic macular edema (DME).

STUDY DESIGN

A retrospective study.

METHODS

We reviewed 65 eyes of 60 patients with center-involved DME who received PRN IVR injections after 3 monthly loading doses. The central subfield thickness (CST) and qualitative findings were assessed on the spectral domain optical coherence tomography (SD-OCT) images. We then investigated whether the parameters at the baseline or at the 12-month visit were associated with treatment frequency in the second year.

RESULTS

The number of ranibizumab injections decreased from 6 (4-8) during the first year to 2 (0-3) during the second year (P < .001). The injection numbers during the first year (ρ = 0.259, P = .037) but not during the second year (ρ = 0.152, P = .226) were modestly related to the logarithm of the minimum angle of resolution (logMAR) improvement at 24 months. Multivariate analyses revealed that the CST (β = 0.336, P = .005) and hyperreflective walls in the foveal cystoid spaces (β = 0.273, P = .020) at baseline were associated with the number of IVR injections during the second year. The treatment frequency during the second year was also related to the CST (β = 0.266, P = .012), hyperreflective walls (β = 0.394, P = .002), and cumulative doses of ranibizumab injections (β = 0.294, P = .006) at the 12-month visit.

CONCLUSIONS

The cumulative doses of ranibizumab injections, CST, and hyperreflective walls in the foveal cystoid spaces at the 12-month visit are designated predictors of the treatment frequency of ranibizumab injections during the second year in DME.

Characterization of poor visual outcomes of diabetic macular edema: the Fight Retinal Blindness! Project

PURPOSE

To investigate the incidence, characteristics and baseline predictors of poor visual outcomes in eyes with diabetic macular edema (DME) receiving intravitreal therapy in routine clinical practice.

DESIGN

Observational study.

PARTICIPANTS

Treatment-naive eyes starting intravitreal therapy for DME between 2014 and 2018 tracked in the Fight Retinal Blindness! registry. We examined two groups with poor visual outcomes: 1) Those with sustained vision loss of >10 letters from baseline without recovery of visual acuity (VA) or 2) Those with VA<55 letters at 2 years. Respective controls were eyes that did not experience poor visual outcomes.

METHODS

Kaplan-Meier curves analyzed proportion of eyes that experienced poor outcomes. Cox proportional hazards models evaluated potential baseline predictors of poor outcomes.

MAIN OUTCOME MEASURES

The proportion of eyes that experienced poor visual outcomes within 2 years of treatment initiation and its baseline predictors.

RESULTS

The proportion of eyes with sustained VA>10 letter loss was 14% at 2 years while 16% of eyes had VA< 55 letters 2 years after starting intravitreal therapy. Initial treatment with intravitreal corticosteroid was independently associated with higher incidence of >10 letter loss was (Hazard ratio [HR], 3.21; 95% confidence interval [CI], 1.60-6.44; P< 0.01). No improvement in VA 3 months after starting treatment was associated with >10 letter loss (HR, 6.81; 95% CI, 4.11-11.27; P <0.01) and VA<55 letters at 2 years (HR, 4.28; 95% CI, 2.66- 6.89; P <0.01). The other factors related to higher risk of VA<55 letters were older age (HR, 1.02 per year; 95% CI, 1-1.04; P = 0.04) and poor baseline VA (HR, 0.68 per 5 letters; 95% CI, 0.65- 0.72, P <0.001).

CONCLUSION

Fourteen percent of eyes managed with intravitreal therapy in routine clinical care experienced >10 letter loss and 16% had VA<55 letters 2 years after starting treatment for DME. Identification of the incidence and predictors of poor outcomes provides more accurate assessment of the potential benefit from intravitreal therapy.

Correlation Between Retinal Microstructure Detected by Optical Coherence Tomography and Best Corrected Visual Acuity in Diabetic Retinopathy Macular Edema

OBJECTIVE

This study aimed to investigate the correlation between best corrected visual acuity (BCVA) and retinal microstructural parameters detected by optical coherence tomography (OCT) in diabetic retinopathy macular edema (DRME).

METHODS

Thirty-nine patients (64 eyes) with DRME were enrolled in this study. These patients underwent OCT to measure the fracture distance of the external limiting membrane (ELM), junction between the inner and outer segments (IS/OS), central foveal thickness (CFT), and edema layer. The correlation between the above parameters and BCVA was discussed.

RESULTS

CFT and the fracture distances of the ELM and IS/OS layers were negatively correlated with BCVA (p<0.05 for all). There was significant difference in Logarithm of the minimum angle of resolution (LogMAR) BCVA among patients with inner retinal edema, outer retinal edema, and mixed retinal edema (F = 5.57, p = 0.01). The LogMAR BCVA of inner retinal edema was the lowest (p < 0.05), and the LogMAR BCVA of outer retinal edema and mixed retinal edema were comparable (p > 0.05).

CONCLUSION

In eyes with DRME, thin CFT, intact ELM and IS/OS layers, and edema in inner retina is closely correlated with good BCVA.

Relationship Between Final Visual Acuity and Optical Coherence Tomography Findings in Patients with Diabetic Macular Edema Undergoing Anti-VEGF Therapy

Objectives:

To identify the prevalence of findings in optical coherence tomography (OCT) sections before intravitreal anti-VEGF treatment in patients with diabetic macular edema (DME), and to evaluate the relationship between these findings and final visual acuity and number of injections.

Materials and Methods:

This retrospective study included 296 eyes of 191 patients (104 male, 87 female) who started intravitreal ranibizumab treatment after being diagnosed with DME in the retina unit between January 2013 and April 2017 were included the study. Spectral domain OCT findings at the time of presentation such as presence of serous macular detachment (SD), vitreomacular traction (VMT), and epiretinal membrane (ERM) were recorded. In addition, the regularity of the ellipsoid zone (EZ) and inner retinal layers was also studied.

Results:

The mean central retinal thickness measured in SD-OCT was 449±81 μm before treatment and 350±96 μm after treatment (p<0.001). SD was detected in 155 eyes (52.4%), ERM in 67 eyes (22.6%), and VMT in 9 eyes (3%). Thirty eyes (10.1%) had disorganization of the retinal inner layers (DRIL) and 54 eyes (18.2%) had EZ deterioration. The presence of ERM, EZ irregularity, and DRIL were associated with significantly lower final visual acuity (p<0.0001), while there was no relationship between pre-treatment SD and final visual acuity (p=0.11). Injection number was higher in eyes with SD and ERM compared to those without, but this difference was statistically significant only in the presence of SD (p=0.01 and p=0.59, respectively). There was no difference in injection number according to EZ irregularity or presence of DRIL.

Conclusion:

The coexistence of SD with DME was associated with increased need for treatment but not with final visual acuity. EZ irregularities, DRIL, and ERM are findings that negatively affect visual acuity.

Macular Thickness Profile and Its Association With Best-Corrected Visual Acuity in Healthy Young Adults

Purpose

To describe the thickness profiles of the full retinal and outer retinal layers (ORL) at the macula in healthy young adults, and associations with best-corrected visual acuity (BCVA).

Methods

In total, 1604 participants (19-30 years) underwent an eye examination that included measurements of their BCVA, axial length, and autorefraction. The retinal thickness at the foveal pit and at the nine Early Treatment of Diabetic Retinopathy Study macular regions (0.5-mm radius around the fovea, and superior, inferior, temporal, and nasal quadrants of the inner and outer rings of the macula) were obtained using spectral-domain optical coherence tomography imaging. A custom program was used to correct for transverse magnification effects because of different axial lengths.

Results

The median full retinal and ORL thicknesses at the central macula were 285 µm and 92 µm. The full retina was thinnest centrally and thickest at the inner macula ring, whereas the ORL was thickest centrally and gradually decreased in thickness with increasing eccentricity. There was no association between axial length and the full retinal or ORL thickness. Increased thicknesses of the full retina at the central macula was associated with better BCVA; however, the effect size was small and not clinically significant.

Conclusions

This article mapped the full retinal and ORL thickness profile in a population-based sample of young healthy adults.

Translational Relevance

Thickness values presented in this article could be used as a normative reference for future studies on young adults and in clinical practice.

Assessment of Inflammation Biomarkers in Diabetic Macular Edema Treated with Intravitreal Dexamethasone Implant

Purpose: To evaluate inflammation biomarkers in diabetic macular edema (DME) treated with intravitreal dexamethasone implant (Ozurdex^®). Methods: This retrospective single-center study investigated 64 eyes of 64 patients with DME who were nonresponsive to prior antivascular endothelial growth factor and treated with intravitreal Ozurdex. The neutrophil/lymphocyte ratio (NLR), monocyte/lymphocyte ratio (MLR), and platelet/lymphocyte ratio were calculated. Visual acuity and optical coherence tomography markers, including hyper-reflective dots and subretinal fluid (SRF), were determined, and central retinal thickness was also evaluated monthly for 3 months. Results: The average age was 64.06 ± 7.81 (48-84) years. The baseline NLR and MLR were significantly higher in patients with better visual outcomes (P = 0.029 and P = 0.048, respectively). Better anatomical outcomes were observed in the presence of SRF (P = 0.027). No significant differences were observed in the rates of the presence of SRF and hyper-reflective points about the better functional outcome (P > 0.05). Conclusions: SRF as an imaging biomarker, and NLR and MLR as blood biomarkers, stand out as markers of inflammation and were found to be associated with better response to Ozurdex implantation in DME.

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.

Optical Coherence Tomography Biomarkers in Bilateral Diabetic Macular Edema Patients with Asymmetric anti-VEGF Response

Background: This study aimed to identify optical coherence tomography (OCT) biomarkers for predicting response to anti-VEGF treatment in diabetic macular edema (DME)Methods: Bilateral DME patients with asymmetric response to a loading dose of anti-VEGF (ranibizumab/aflibercept) treatment were retrospectively studied. The morphologic response criterion was central subfield thickness (CST) ≤300 µm; asymmetric response was defined as ≥10% difference in CST reduction between the eyes. The functional response criterion was an increase in logMAR acuity of ≥3 lines, with an increase below this threshold in the fellow eye considered asymmetric response. Relationships between final morphologic and functional responses to anti-VEGF therapy and baseline values of the following OCT-derived biomarkers were evaluated: DME subtype, CST, vitreoretinal interface anomalies, disorganization of the inner retinal layers (DRIL), external limiting membrane (ELM) disruption, ellipsoid zone (EZ) disruption, and subretinal fluid (SRF).Results: After a loading dose of anti-VEGF, 31 eyes that met both morphologic and functional response criteria were classified as responders (RR) and 27 eyes that did not respond morphologically or functionally based on the defined criteria were classified as resistant (RT). Eyes that showed only functional (n = 5) or morphological response (n = 1) were excluded due to their small number. The presence of SRF or simple epiretinal membrane (ERM) was not associated with any difference in treatment responses (p > .05), while tractional ERM, extensive DRIL (≥500 µm), and ELM and EZ disruptions in the fovea-centered 1000-µm zone were important OCT biomarkers in predicting resistance (p < .001). A multilayer perceptron model ranked predictive power as 100% for ELM disruption, 51.7% for tractional ERM, 25.4% for DRIL, and 24.5% for EZ disruption.Conclusion: Extensive ELM disruption was the strongest OCT biomarker to predict anti-VEGF resistance, followed by tractional ERM. EZ disruption and DRIL had relatively lower predictive value.

Development of a 1-year risk-prediction nomogram for good functional response with anti-VEGF agents in naive diabetic macular oedema

PURPOSE

To develop a risk-prediction nomogram based on baseline variables for good functional response during the 1st year of treatment with anti-VEGF agents in naive diabetic macular oedema (DME).

METHODS

This retrospective study included patients presenting naive-DME treated with anti-VEGF therapy at Dijon University Hospital (France) between 1 February 2012 and 31 March 2015 (derivation cohort). We studied baseline variables that had significant associations with a good functional response to anti-VEGF agents during the 1st year of treatment. We used a program to generate a nomogram based on a binary logistic regression predictive model. Then, this nomogram was tested on data from a separate cohort of naive-DME patients from a multicenter study involving 20 French ophthalmologic centres between January 2014 and June 2015 (validation cohort).

RESULTS

Age, baseline BCVA and ellipsoid zone integrity on spectral-domain optical coherence tomography (SD-OCT) are functional prognostic factors and were used to build a nomogram. The nomogram showed excellent discrimination for good functional responders (area under the curve (AUC) = 0.906, 95% confidence interval (95% CI) = [0.849-0.964], p = 0.004). The discriminative power of this nomogram was tested on the validation cohort data, demonstrating good discrimination of good functional responders (AUC = 0.942, 95% CI = [0.898-0.986], p < 0.001).

CONCLUSION

This nomogram provides a useful estimation of a good functional response in naive-DME patients treated with anti-VEGF agents.

Defining Cystoid Macular Degeneration in Diabetic Macular Edema: An OCT-Based Single-center Study

Objectives:

To describe cystoid macular degeneration (CMD), which has no clear definition in diabetic macular edema (DME), and examine its features in optical coherence tomography (OCT) and fundus fluorescein angiography (FFA).

Materials and Methods:

This study was conducted using OCT images of patients who were followed in Gazi University between November 2011 and March 2015. A total of 259 eyes (187 patients) found to have cystic changes on OCT were included. Macular ischemia, peripheral ischemia, and type of edema were identified on FFA. Vitreomacular interface abnormalities, foveal contour integrity, internal reflectivity of the cysts, and outer retinal layer defects were analyzed from OCT images. The horizontal and vertical diameters of the largest cyst within 1000 μm of the foveal center were measured for the definition of CMD. Cut-offs for these values were determined by receiver operating characteristic curve analysis. Cystoid macular edema (CME) and CMD groups were created and their characteristics were analyzed.

Results:

The horizontal and vertical diameters of the largest cyst were moderately positively correlated with visual acuity (rs=0.349, r=0.419, respectively). Eyes with horizontal diameter of the largest cyst ≥450 μm were classified as CMD; in this group, sensitivity in the prediction of visual acuity ≤20/60 was 58%. Eyes with horizontal diameter of the largest cyst <450 μm were classified as CME; in this group, specificity in the prediction of visual acuity >20/60 was 73%. For the threshold of 300 μm determined for vertical diameter of the largest cyst, sensitivity was 62% and specificity was 69%. The CME and CMD groups were formed according to these cut-off values. Compared to the CME group, the CMD group had greater central subfield thickness and higher prevalence of outer retinal damage, severe disruption of foveal contour, macular ischemia, and diffuse/mixed type edema.

Conclusion:

In eyes with DME, CMD can be defined as the largest cyst within 1000 μm of the foveal center having a horizontal diameter of ≥450 μm and vertical diameter ≥300 μm, especially if associated with macular ischemia, outer retinal damage, loss of foveal contour, and diffuse/mixed type edema.

Optical Coherence Tomography Parameters Related to Vision Impairment in Patients with Diabetic Macular Edema: A Quantitative Correlation Analysis

Purpose

To quantitatively explore the correlation between optical coherence tomography (OCT) parameters and vision impairment in patients with diabetic macular edema (DME).

Methods

This study was a retrospective observational case series. One-hundred eyes from 66 patients with DME were retrospectively included. OCT parameters, including central macular thickness (CMT), height of intraretinal cystoid, subretinal fluid and sponge-like retinal swelling, density of hyperreflective foci (HRF), and integrity of the ellipsoidal zone (EZ), were assessed. Correlation analyses and multiple linear regression analysis were performed to quantitatively explore the relationship between best-corrected visual acuity (BCVA) and OCT parameters.

Results

Among all OCT parameters, CMT, height of intraretinal cystoid, height of sponge-like retinal swelling, and density of HRF and EZ integrity were significantly correlated with BCVA (r = −0.550, −0.526, −0.411, −0.277, and −0.501, respectively; P < 0.01). In multiple linear regression analysis, CMT, density of HRF, and EZ integrity fit a significant linear equation (β = 0.482, 0.184, and 0.447, respectively), with the adjusted R square reaching 0.522 (P < 0.001). In eyes without SRF, the height of intraretinal cystoid, density of HRF, and EZ integrity were included in the model and an adjusted R square of 0.605 (P < 0.001) was obtained.

Conclusion

In DME eyes, OCT parameters, including the density of HRF, the EZ integrity together with CMT, or the height of intraretinal cystoid, could explain 52.2% to 60.5% of the variation in BCVA and were weighted approximately 2 : 1 : 2, respectively.

Short-term outcomes of intravitreal dexamethasone in relation to biomarkers in diabetic macular edema

PURPOSE

The purpose of this study was to determine the effects of dexamethasone implant (0.7 mg) on biomarkers such as hyper-reflective dots, external limiting membrane integrity and disorganization of retinal inner layers in treatment-naïve patients, patients who received less than three anti-vascular endothelial growth factor injections and non-responder cases with diabetic macular edema and its effects on edema and visual acuity.

METHODS

This is a prospective study of treatment-naïve patients, patients who received less than three anti-vascular endothelial growth factor injections and non-responder patients with diabetic macular edema, treated with single dexamethasone implant. Pre- and post-injection-based best-corrected visual acuity, central macular thickness, hyper-reflective dots, external limiting membrane integrity and disorganization of retinal inner layers were assessed.

RESULTS

A total of 27 diabetic macular edema eyes, including 9 non-responder eyes, 9 eyes which received less than three anti-vascular endothelial growth factor injections and 9 treatment-naïve eyes, were included in this study. Baseline hyper-reflective dots were 22.22 ± 11.76, 30 ± 7.91 and 19.44 ± 8.82 which reduced to 3.33 ± 1.32, 9 ± 8.35 and 8.78 ± 2.53 four months after implant in treatment-naïve patients, patients who received less than three anti-vascular endothelial growth factor injections and non-responder cases, respectively. Baseline central macular thickness was 589.44 ± 175.37, 537 ± 181.81 and 673.11 ± 138.24 and the central macular thickness after dexamethasone implant was 272.11 ± 39.00, 336.44 ± 132.88 and 524.00 ± 200.39 in treatment-naïve patients, patients who received less than three anti-vascular endothelial growth factor injections and non-responder cases, respectively. External limiting membrane integrity was restored in two patients in each group, whereas two patients with disorganization of retinal inner layers in treatment-naïve group showed reorganization of retinal structures after treatment with dexamethasone implant.

CONCLUSION

Better response to dexamethasone implant in cases with more hyper-reflective dots shows that these hyper-reflective dots can be used as a predictive biomarker. Dexamethasone implant might help in restoring external limiting membrane integrity and resolution of disorganization of retinal inner layers.

Ultra-Widefield Fluorescein Angiography as a Biomarker for Response to Switch in Therapy in Persistent DME

BACKGROUND AND OBJECTIVE

To explore the effect of peripheral ischemia identified on ultra-widefield fluorescein angiography (UWFA) as a biomarker of response to a switch in therapy from bevacizumab to aflibercept in persistent diabetic macular edema (DME).

PATIENTS AND METHODS

Prospective clinical trial of 38 eyes from 38 patients previously treated with bevacizumab and persistent DME. Patients subsequently received aflibercept per protocol and were followed up for 48 weeks. UWFA was obtained for all patients at baseline and 48 weeks. Images were graded and used to calculate an overall ischemic index (II) and macular ischemic index (MII). II was compared with visual and central macular thickness (CMT) outcomes. Paired and independent samples t-tests and Fisher's exact tests were used to assess change and associations.

RESULTS

Patients with an II greater than or equal to 50% at baseline had a poorer baseline visual acuity (VA) (60.1 ± 10.2 vs. 70.7 ± 9.0 letters; P = .005) and a worse MII (6.9 ± 25 vs. 56 ± 52%; P < .001). These patients gained significantly more vision at 48 weeks (8.3 ± 9.3 vs. 2.6 ± 5.9 letters; P = .03). At 48 weeks, there was no significant difference in VA of patients with an II greater or less than 50% (68.4 ± 6.0 vs. 73.3 ± 9.6 letters; P = .16).

CONCLUSIONS

Patients with persistent DME treated with bevacizumab and worse II had poorer baseline VA, potentially due to worse macular ischemia. These patients had greater visual gain with similar final visual outcomes of those without marked peripheral ischemia subsequent to switching to aflibercept. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:771-778.].

Anti-VEGF Treatment of Diabetic Macular Edema: Two-Year Visual Outcomes in Routine Clinical Practice

Purpose

The purpose of this study was to evaluate 2-year visual outcomes in patients with diabetic macular edema (DME) treated with anti-VEGF agents in a routine clinical setting.

Methods

The medical records of patients treated with ranibizumab or aflibercept due to DME at the Eye Hospital, University Medical Centre Ljubljana, Slovenia, between January 2016 and March 2019 were retrospectively reviewed. After applying inclusion and exclusion criteria, 123 patients (123 eyes) were included in the study.

Results

Baseline visual acuity (VA) was 60.9 ± 15.2 letters (median 63; range 7-85). Baseline central retinal subfield thickness (CRT) was 440.7 ± 132.5 μm (median 430; range 114-1000). No significant change in VA over 2 years was found (mean change +2.1 ± 16.8 letters (median 2; range -53-52)). However, there was a significant change in VA in the subgroup with baseline VA <70 letters (mean change +5.7 ± 17.9 letters (median 5; range -52-52)). VA gains of ≥15 letters were achieved in 25 eyes (20.3%). Changes in CRT were significant over 2 years. Patients received 4.5 ± 2.1 (median 5, range 1-9) and 2.6 ± 2.3 (median 2, range 0-8) injections in the first and second years, respectively.

Conclusions

The two-year visual outcomes in this retrospective analysis appear to be comparable to previously reported outcomes in routine clinical practice. Our analysis provides some information about the effectiveness of anti-VEGF treatment in routine clinical practice in Slovenia. More intensive treatment should be implemented in the management of patients in order to achieve better visual outcomes.

Spectral domain optical coherence tomography classification of diabetic macular edema: a new proposal to clinical practice

PURPOSE

To classify the types of diabetic macular edema (DME) and evaluate its morphological features on spectral domain optical coherence tomography (SD-OCT) and determine correlations between visual acuity and OCT findings.

METHODS

We assessed 406 eyes of 309 patients with a diagnosis of DME retrospectively. Three types based on SD-OCT were identified: diffuse macular edema, cystoid macular edema, and cystoid degeneration. Morphological features such as serous macular detachment (SMD), vitreomacular interface abnormalities (VMAI), hard exudates, photoreceptor status, and correlations between visual acuity and those morphological features were also evaluated by SD-OCT.

RESULTS

The most common type of DME was cystoid edema (68.5%). No statistically significant difference was found between groups in sex (P = 0.40), type of diabetes (P = 0.50), or diabetic retinopathy (P = 0.78). However, the duration of symptoms and BCVA was significantly lower in the group with cystoid degeneration compared with the group with cystoid edema (P < 0.001) and the group with diffuse macular edema (P < 0.001). In the group with cystoid degeneration compared with the groups with cystoid and diffuse edema, the central fovea and central subfield were significantly thicker (both (P < 0.001), the subfoveal choroid was significantly thinner (P = 0.049), rate of serous macular detachment was significantly lower (P < 0.001), and the rate of outer retinal damage was significantly higher (P < 0.001).

CONCLUSIONS

Cystoid macular degeneration, which is consistent with poor functional and morphological outcomes, should be differentiated from cystoid macular edema. Serous macular detachment, which is mostly seen in eyes with early stages of DME, should be evaluated as an accompanying morphological finding rather than a type of DME.

AFLIBERCEPT FOR PERSISTENT DIABETIC MACULAR EDEMA: Forty-Eight-Week Outcomes

PURPOSE

To evaluate functional and anatomical outcomes after a switch from intravitreal bevacizumab to aflibercept in patients with persistent diabetic macular edema.

METHODS

Prospective, single-arm, open-label clinical trial of patients with persistent diabetic macular edema, despite previous treatment with bevacizumab. Five loading doses of intravitreal aflibercept were administered every 4 weeks with subsequent injections administered every 8 weeks. Patients were reviewed every 4 weeks, and best-corrected visual acuity and central macular thickness were recorded. Primary outcome measures included change in central macular thickness and best-corrected visual acuity at week 48 compared with baseline. Paired t-tests were used to assess change between baseline and follow-up visits.

RESULTS

At baseline, 43 eyes from 43 patients were recruited with a median (interquartile range) of 12 (7-24) previous intravitreal anti-vascular endothelial growth factor injections over a period of 18 (8-34) months. Mean ± SD central macular thickness reduced by 59 ± 114 μm (P = 0.002), and best-corrected visual acuity improved by 3.9 ± 7.0 letters (P = 0.001) after 48 weeks in the 41 patients who completed the trial. Best-corrected visual acuity improvements were more marked in patients who gained ≥5 letters after the first injection (8.9 ± 5.7 vs. 1.8 ± 6.5 letter gain at 48 weeks, P = 0.002), a difference which remained significant after regression analysis with baseline best-corrected visual acuity . Vision gains and central macular thickness reduction were similar in 9 fellow eyes eligible for inclusion being concurrently treated for diabetic macular edema with bevacizumab.

CONCLUSION

Intravitreal aflibercept was effective in improving anatomical and visual outcomes among patients with an incomplete response to intravitreal bevacizumab with 48 weeks of follow-up. Patients with a good early response subsequent to switching had a better improvement in vision at 48 weeks.

Hyperreflective Foci in the Outer Retinal Layers as a Predictor of the Functional Efficacy of Ranibizumab for Diabetic Macular Edema

Anti-VEGF drugs are as the first-line therapies for diabetic macular edema (DME). In this study, we investigated the association between hyperreflective foci in the outer retinal layers and functional efficacy in DME patients who received intravitreal ranibizumab (IVR) injections. We retrospectively reviewed 77 eyes of 71 patients with DME treated with pro re nata IVR injections for at least 12 months. We evaluated how baseline hyperreflective foci in the outer retinal layers on spectral domain optical coherence tomography images were associated with an improvement in logarithm of the minimum angle of resolution visual acuity (logMAR VA) at 12 months. Forty-three eyes with hyperreflective foci in the outer retinal layers had greater VA improvement than 34 eyes without such foci at 12 months. Multivariate analyses demonstrated that both logMAR VA and hyperreflective foci in the outer retinal layers at baseline were associated with VA improvement. Structural analyses revealed that the central subfield thickness was decreased and that the ellipsoid zone of photoreceptors was improved more significantly in eyes with hyperreflective foci in the outer layers than eyes without such lesions. Baseline hyperreflective foci in the outer retinal layers predict the functional efficacy of IVR injections for DME.

The Relationship Between Macular Cyst Formation and Ischemia in Diabetic Macular Edema

Objectives:

To evaluate the relationship between cyst characteristics and macular and peripheral ischemia in diabetic macular edema (DME).

Materials and Methods:

We retrospectively reviewed eyes with DME and included those with clinically significant macular edema as defined by ETDRS (Early Treatment Diabetic Retinopathy Study) and cystoid spaces in optical coherence tomography scans in this study. Central subfield thickness (CSFT), horizontal and vertical diameters of the largest cyst, cyst area, and the remaining retinal thickness outside the cyst were determined. The presence and number of hyperreflective foci in the cyst wall and the internal reflectivity of the cyst were analyzed. Outer retinal damage was graded. Fluorescein angiography was used to determine the areas of macular and peripheral ischemia, which were graded as mild or severe. Correlations between macular and peripheral ischemia and cyst-related measurements and structural changes in the retina were evaluated.

Results:

This retrospective study included 250 eyes of 186 patients with DME. Mean CSFT was significantly greater in eyes with macular ischemia (510.4±144.7 μm) compared to eyes without macular ischemia (452.1±114.6 μm) (p=0.001). Horizontal and vertical diameter of the largest cyst increased with the presence and severity of macular ischemia (p=0.045 and p=0.016, respectively). Remaining retinal thickness increased with the presence and severity of peripheral ischemia (p=0.009). There was a statistically significant relationship between the number of the hyperreflective foci in the cyst wall and internal reflectivity of the cyst (p=0.007). Patients with greater CSFT had a 1.04-times higher odds of having macular ischemia and 0.25-times higher odds of having outer retinal damage.

Conclusion:

The likelihood of macular ischemia increases with larger cyst diameter, CSFT, and extent of outer retinal damage. Thickness of the noncystic area is increased in the presence of peripheral ischemia.

Multifocal electroretinogram in diabetic macular edema and its correlation with different optical coherence tomography features

PURPOSE

To evaluate multifocal electroretinogram (mfERG) parameters in eyes with diabetic macular edema (DME) and its correlation with vision and optical coherence tomography (OCT) features.

METHODS

Fifty-four eyes of 27 subjects with DME due to nonproliferative diabetic retinopathy were evaluated. MfERG responses were measured in three concentric rings. Macular thickness was measured by OCT in each segment of the three concentric rings, and mfERG rings were superimposed on the macular thickness map. The correlation between macular thickness in specific points of the thickness map and changes of the mfERG parameters in the corresponding points of the mfERG field map was evaluated and the relationship between the OCT and mfERG changes and changes of best-corrected visual acuity (BCVA) was investigated. The central foveal B-scans of SD-OCT were used to evaluate any correlation between the external limiting membrane (ELM) status, ellipsoid zone (EZ) status, presence of cysts or disorganization of retinal inner layers (DRIL), and mfERG parameters at the central corresponding area.

RESULTS

The mean of BCVA was 0.5 ± 0.3 in logMAR, and the central macular thickness was 392.6 ± 123.4 microns. The central ring P1 and N2 amplitudes had a significant correlation with BCVA in univariate and multivariate analyses (P = 0.001 for both, r = - 0.346 and r = - 0.646, respectively). There was a significant correlation between retinal thickness and the N1 amplitude in the central ring (P = 0.02, r = - 0.343). Outer retinal layer disruption (ELM and EZ) correlated with prolonged P1 implicit time at the corresponding location (P = 0.005, r = 0.068). The presence of the DRIL was associated with reduced P1 and N2 amplitudes (P = 0.037, r = - 0.284 and P = 0.019, r = - 0.562, respectively). A significant correlation was also found between the presence of cysts and a lower central P1 amplitude (P = 0.033, r = - 0.376).

CONCLUSION

In diabetic patients, discrete changes of some parameters in the central ring of the mfERG field map (e.g., P1 and N2 amplitudes) have a significant correlation with both structural OCT abnormalities in the corresponding points of the thickness map (like DRIL, intraretinal cyst and ELM/EZ disruption) and BCVA. Predictive models such as those described in this report may make it possible to identify the relationship between specific anatomical and functional characteristics in diabetic retinopathy.

Disorganization of Inner Retina and Outer Retinal Morphology in Diabetic Macular Edema

Importance

In diabetic macular edema (DME), identification of baseline markers on spectral-domain optical coherence tomography (SD-OCT) and their association with severity of diabetic retinopathy (DR) might aid in disease management and the design of future trials.

Objective

To examine associations between DR severity, retinal morphology on SD-OCT, and visual acuity in participants with DME.

Design, Setting, and Participants

This cross-sectional observational case series was conducted at a single tertiary care referral center. Demographics, visual acuity, SD-OCT, and color fundus photographs of 80 individuals with DME (102 eyes) seen between December 28, 2013, and April 30, 2014, were analyzed between May 1 and July 31, 2016.

Main Outcomes and Measures

Features captured on SD-OCT and thickness metrics. On SD-OCT we graded type and shape of DME, shape and presence of septae within the intraretinal cystoid abnormalities, presence of hyperreflective dots and foci, integrity of the external limiting membrane and ellipsoid zone, presence and extent of disorganization of the inner retinal layers (DRIL), and the status of the vitreomacular interface and epiretinal membrane. We measured retinal thickness at the fovea and at the site of maximum pathology, choroidal thickness at the fovea, and 1000 μm temporal and nasal to the fovea. Color photographs were graded to derive a DR severity stage.

Results

The mean (SD) age was 63 (11) years, and 30 participants (37.5%) were women. The odds of having DRIL were greater in eyes with disrupted external limiting membrane (odds ratio [OR], 4.4; 95% CI, 1.6-12.0; P = .003), disrupted ellipsoid zone (OR, 2.7; 95% CI, 1.0-7.2; P = .03), presence of epiretinal membrane (OR, 2.8; 95% CI, 1.0-7.4; P = .03), and increase in retinal thickness at the fovea (OR, 1.6; 95% CI, 1.1-2.2; P < .001). Occurrence of DRIL was more likely in eyes with proliferative DR (OR, 7.3; 95% CI, 1.7-31.4; P = .007). Mean visual acuity decreased by approximately 4.7 letters for each 100-μm increase in the average global DRIL (95% CI, -7.9 to 1.4; P = .006).

Conclusions and Relevance

An association was found between DRIL and disruption of the outer retina and increasing DR severity. Further longitudinal studies seem warranted to determine whether DRIL is a clinically relevant noninvasive morphological marker in eyes with DME.

Predictor of Early Remission of Diabetic Macular Edema under As-Needed Intravitreal Ranibizumab

The early remission of diabetic macular edema (DME) often occurs in eyes treated with anti-vascular endothelial growth factor (VEGF) treatment. We retrospectively reviewed and characterized eyes with early remission of DME at six months in 80 eyes under pro re nata (PRN) intravitreal ranibizumab (IVR) injections. The number of eyes without center-involved DME gradually increased and 14 and 20 eyes achieved remission of DME at 3 or 6 months, respectively, under the PRN regimen following three monthly loading doses. In particular, eyes with early remission at 6 months had smaller CSF thickness than those without the remission before and after the treatment except at the 1-month visit (P < 0.05); however, the changes in CSF thickness did not differ between them. VA and its changes were not different between eyes with and without remission. Multivariate analysis revealed that smaller CSF thickness at baseline predicted the early remission of DME under PRN IVR injections (odds ratio, 0.989; 95% confidence interval, 0.982–0.997; P = 0.008). These data elucidate the clinical characteristics of early remission of DME under PRN IVR injections and suggest that smaller CSF thickness at baseline is a novel predictor of early remission under PRN IVR injections for DME.

Macular thickness amplitude changes when switching from discontinuous to continuous therapy for diabetic macular oedema

OBJECTIVE

To investigate if the mean central retinal thickness (CRT) amplitude, measured between visits, is consistently decreased when switching from discontinuous to continuous therapy for diabetic macular oedema (DME) following fluocinolone acetonide (FAc) administration.

METHODS AND ANALYSIS

In this retrospective cohort study, all patients with DME treated with FAc at a single centre were included. The primary outcome was CRT amplitude changes measured at each visit prior to and after FAc administration. Secondary outcomes included average number of DME treatments before and after FAc injection, visual acuity and intraocular pressure changes.

RESULTS

Nineteen eyes were included. The mean (SD) follow-up after FAc was 399 (222) days. The mean (SD) CRT amplitude before FAc was 194.6 (114.90) µm, and following FAc administration, the amplitude decreased to 70.8 (94.23) µm (95% CI -189.5 to -58.1; p≤0.001). After FAc, the number of treatments required per month significantly decreased from an average of 1 treatment every 2.7 months to every 6 months (p=0.009).

CONCLUSION

In patients with DME, the CRT amplitude values and number of treatments significantly decrease following FAc administration while maintaining vision. Further studies are needed to evaluate the significance of these interesting findings.

Granular lesions of short-wavelength and near-infrared autofluorescence in diabetic macular oedema

OBJECTIVES

To document and characterise hyper- and hypo-reflective lesions, which we describe as 'granular' on short-wavelength autofluorescence (SW-AF) and near-infrared (NIR)-AF images in diabetic macular oedema (DMO).

METHODS

Consecutive 103 eyes of 78 patients suffering from centre-involving DMO were reviewed retrospectively. Mosaics of hyper- and hypo-fluorescent dots on both SW-AF and NIR-AF signals were delineated and defined as granular lesions in the macula. We evaluated the association of such lesions with the logarithm of the minimum angle of resolution visual acuity (logMAR VA) and spectral-domain optical coherence tomography (SD-OCT) images.

RESULTS

Diffuse mosaics of hyper- and hypo-fluorescent dots were delineated in 36 and 45 eyes on SW-AF and NIR-AF images, respectively, and both AF images defined granular lesions in 33 eyes. These lesions were delineated in both the fovea and extrafoveal areas on NIR-AF images but were limited to the parafoveal and perifoveal subfields on SW-AF images. There was a significant difference in logMAR VA between eyes with and without granular lesions (0.358 ± 0.269 vs. 0.185 ± 0.234; P = 0.001). Granular lesions were associated with the mosaic pattern on NIR-AF images (P < 0.001) but not with other parameters on SW-AF and NIR-AF images. The retinal thickness in the central subfield was greater in eyes with granular lesions (538.0 ± 163.6 μm vs. 448.8 ± 120.2 μm; P = 0.003). Granular lesions were associated with ELM disruption and hyper-reflective foci in the outer retinal layers (P = 0.004 and P = 0.037, respectively).

CONCLUSIONS

Granular lesions defined on both SW-AF and NIR-AF images were related to retinal oedema with photoreceptor damage and concomitant VA reduction in DMO.

Association between Visual Acuity and Retinal Layer Metrics in Diabetics with and without Macular Edema

Purpose

Diabetes is known to cause alterations in retinal microvasculature and tissue that progressively lead to visual impairment. Optical coherence tomography (OCT) is useful for assessment of total retinal thickening due to diabetic macular edema (DME). In the current study, we determined associations between visual acuity (VA) and retinal layer thickness, reflectance, and interface disruption derived from enface OCT images in subjects with and without DME.

Materials and Methods

Best corrected VA was measured and high-density OCT volume scans were acquired in 149 diabetic subjects. A previously established image segmentation method identified retinal layer interfaces and locations of visually indiscernible (disrupted) interfaces. Enface thickness maps and reflectance images of the nerve fiber layer (NFL), combined ganglion cell and inner plexiform layer (GCLIPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), photoreceptor outer segment layer (OSL), and retinal pigment epithelium (RPE) were generated in the central macular subfield. The associations among VA and retinal layer metrics were determined by multivariate linear regressions after adjusting for covariates (age, sex, race, HbA1c, diabetes type, and duration) and correcting for multiple comparisons.

Results

In DME subjects, increased GCLIPL and OPL thickness and decreased OSL thickness were associated with reduced VA. Furthermore, increased NFL reflectance and decreased OSL reflectance were associated with reduced VA. Additionally, increased areas of INL and ONL interface disruptions were associated with reduced VA. In subjects without DME, increased INL thickness was associated with reduced VA, whereas in subjects without DME but with previous antivascular endothelium growth factor treatment, thickening of OPL was associated with reduced VA.

Conclusions

Alterations in retinal layer thickness and reflectance metrics derived from enface OCT images were associated with reduced VA with and without presence of DME, suggestive of their potential for monitoring development, progression, and treatment of DME.

EVALUATION OF MACULAR ISCHEMIA IN EYES WITH BRANCH RETINAL VEIN OCCLUSION: An Optical Coherence Tomography Angiography Study

PURPOSE

To quantitatively assess macular morphology and perfusion status using optical coherence tomography, and optical coherence tomography angiography in eyes with branch retinal vein occlusion when macular edema has completely resolved, and to investigate the impact on visual function.

METHODS

Thirty consecutive eyes with branch retinal vein occlusion-macular edema that resolved after treatment with intravitreal ranibizumab injections were included. Macular sensitivity was measured by microperimetry; defect length of foveal ellipsoid zone band was measured using optical coherence tomography; foveal avascular zone and parafoveal nonperfusion areas (NPA) were measured by optical coherence tomography angiography.

RESULTS

The logarithm of minimum angle of resolution visual acuity was significantly associated with the defect length of the foveal ellipsoid zone band (P = 0.005), the parafoveal NPA in the superficial capillary plexus (P = 0.007), and the parafoveal NPA in the deep capillary plexus (P = 0.006). Macular sensitivity correlated with parafoveal thickness on the affected side (P = 0.034), the defect length of the foveal ellipsoid zone band (P = 0.048), parafoveal NPA in the superficial capillary plexus (P = 0.008), and parafoveal NPA in the deep capillary plexus (P = 0.012). Multivariate analysis where the only significant parameters in the univariate analyses were used as the independent variables showed that parafoveal NPA was most significantly associated with the logarithm of minimum angle of resolution visual acuity (β = 0.500, P = 0.005) and macular sensitivity (β = -0.480, P = 0.007).

CONCLUSION

In eyes with branch retinal vein occlusion-macular edema resolved by intravitreal ranibizumab treatments, visual function was strongly associated with parafoveal NPA size.

Foveal threshold and photoreceptor integrity for prediction of visual acuity after intravitreal aflibercept on age-related macular degeneration

Purpose

To determine whether baseline foveal threshold and photoreceptor integrity can predict best-corrected visual acuity (BCVA) at 12 months after intravitreal aflibercept (IVA) therapy in eyes with neovascular age-related macular degeneration (AMD).

Patients and methods

We evaluated 25 eyes of 25 patients with treatment-naïve neovascular AMD who received IVA once a month for 3 months, followed by once every 2 months for 8 months. BCVA, integrity of the external limiting membrane (ELM) or the ellipsoid zone (EZ) of the photoreceptors, and retinal sensitivity were determined before (baseline) and at 6 and 12 months after initial IVA. The average threshold foveal sensitivity and mean deviation within the central 10° were determined by Humphrey central 10-2 perimetry. Correlations between BCVA at 12 months and integrity of the ELM or EZ, foveal threshold, and mean deviation at each visit were determined.

Results

At 12 months, BCVA improved significantly from 0.20±0.23 to 0.10±0.22 logMAR (logarithm of the minimum angle of resolution) units, and foveal threshold and mean deviation improved significantly from 29.0±5.1 and -3.38±3.10 dB to 32.6±3.2 and -1.64±2.10 dB, respectively (P=0.0009 and P=0.0021). At baseline, both foveal threshold and integrity of the ELM were significantly correlated with BCVA at 12 months (P=0.0428 and P=0.0275).

Conclusion

These results indicate that both integrity of the ELM and foveal threshold at baseline can predict BCVA after treatment for neovascular AMD. There is a possibility that these parameters can predict the efficacy of IVA in each case.

Association between characteristics of foveal cystoid spaces and short-term responsiveness to ranibizumab for diabetic macular edema

PURPOSE

To investigate the association between the characteristics of foveal cystoid spaces and short-term responsiveness to ranibizumab treatment for diabetic macular edema (DME) at 3 months from the initial injection.

METHODS

We retrospectively reviewed 66 eyes of 61 patients with center-involved DME who received three consecutive ranibizumab injections and following as-needed administrations. We evaluated the relationship between visual improvement at 3 months and the preoperative optical coherence tomography (OCT) parameters including hyperreflective foci, heterogeneous OCT reflectivity, mean levels of OCT reflectivity and height of foveal cystoid spaces.

RESULTS

Twenty-three eyes without preoperative hyperreflective foci in the foveal cystoid spaces had significantly greater improvement in the logarithm of the minimum angle of resolution visual acuity (logMAR VA) at 3 months than 43 eyes with foci (P = 0.006). That was similar to the greater reduction in CSF thickness in eyes without lesions after treatment at the same time point (P < 0.001). VA improvement at 3 months was not associated with the height (R = 0.215, P = 0.083) or the reflectivity levels (R = -0.079, P = 0.538) of foveal cystoid spaces. There were no differences in VA changes between eyes with and without heterogeneous reflectivity in foveal cystoid spaces (P = 0.297). Multivariate analyses showed that logMAR VA and the absence of hyperreflective foci in foveal cystoid spaces were associated with VA improvement at 3 months.

CONCLUSION

Hyperreflective foci in foveal cystoid spaces at baseline predict poorer short-term responsiveness to ranibizumab injections for DME.

INTEGRITY OF OUTER RETINAL LAYERS AFTER RESOLUTION OF CENTRAL INVOLVED DIABETIC MACULAR EDEMA

PURPOSE

To evaluate the integrity of outer retina layers after resolution of central involved diabetic macular edema (DME) and to demonstrate the effect of various baseline factors for the final vision and final external limiting membrane (ELM) integrity.

METHODS

Fifty-nine eyes of 48 patients with resolved DME were included. Several optical coherence tomography parameters including central subfield thickness, maximum foveal thickness, foveal center point thickness, and the extent of the ellipsoidal (ISe) layer and ELM damage were assessed at the time of DME and after resolution of DME. Eyes having laser scars near the fovea were excluded. Final visual acuity was classified as good (Snellen≥20/40, logarithm of the minimum angle of resolution ≤0.3) or impaired (Snellen <20/40, logarithm of the minimum angle of resolution >0.3) for the logistic regression analysis. Zero Inflated Poison Regression model was used to find the best predictors for post-treatment ELM damage.

RESULTS

External limiting membrane and inner segment ellipsoidal band layers were disrupted in 16 eyes (27.2%) and 21 eyes (35.5%) at the final visit, respectively. Baseline ELM damage (p=0.001), baseline impaired vision (p= 0.013), and the most recent glycosylated hemoglobin level (p=0.018) were the best set of parameters for having impaired final visual acuity. Baseline vision, severity of diabetic retinopathy, absence of intravitreal injection, central subfield thickness, and history of extrafoveal macular laser (not within 1 mm of fovea) (p<0.001, for all parameters) were independent predictors for the final ELM damage.

CONCLUSION

Outer retinal layers may be damaged even after complete resolution of DME, where inner segment ellipsoidal band layer damage appeared to be more common than ELM damage. Poorly controlled diabetic patients with damaged ELM and worse vision at the time of DME were more likely to have ELM damage and subsequent impaired vision after complete resolution of DME.

Association of Vascular Versus Avascular Subretinal Hyperreflective Material With Aflibercept Response in Age-related Macular Degeneration

PURPOSE

To investigate flow signal within subretinal hyperreflective material (SHRM) using optical coherence tomography angiography (OCTA) and its association with aflibercept treatment responses in treatment-naïve neovascular age-related macular degeneration (nAMD).

DESIGN

Prospective consecutive interventional case series.

METHODS

Forty-four eyes of 44 patients with treatment-naïve nAMD manifesting SHRM on OCT were studied. All patients underwent OCTA and received 3 monthly aflibercept injections. The intrinsic flow signals within SHRM were quantitatively analyzed using OCTA, and eyes were classified into the vascular and avascular SHRM groups.

RESULTS

Of 44 eyes, 21 (47.7%) and 23 (52.3%) showed vascular SHRM and avascular SHRM, respectively. Compared with eyes with avascular SHRM, eyes with vascular SHRM showed higher rates of external limiting membrane (ELM) disruption owing to SHRM (P = .015), classic choroidal neovascularization (CNV) (85.7% vs 26.1%, P = .87 × 10^-4), and intraretinal fluid (P = .008) at baseline. After 3 aflibercept injections, 38 eyes (86.4%) showed dry macula despite persistent SHRM in 24 eyes (54.5%). Compared with the eyes with resolved SHRM, those with persistent SHRM showed higher rate of vascular SHRM (75.0% vs 15.0%, P = .86 × 10^-4), classic CNV (P = .032), absence of polypoidal lesion (P = .020), ELM disruption owing to SHRM (P = .042), and intraretinal fluid (P = .008). Dry macula after loading injections was significantly associated with SHRM resolution (P = .025).

CONCLUSIONS

In nAMD, SHRM can be categorized as vascular and avascular by quantitative OCTA analysis. Vascular SHRM persisted after treatment and was associated with failure to achieve dry macula, suggesting that vascular SHRM is predictive of lower response to anti-VEGF therapy.

Relation between macular morphology and treatment frequency during twelve months with ranibizumab for diabetic macular edema

Purpose

To investigate whether baseline optical coherence tomography (OCT) parameters can predict the treatment frequency of intravitreal ranibizumab (IVR) injections during the first year in patients with diabetic macular edema (DME) treated with pro re nata (PRN) IVR injections.

Methods

We retrospectively reviewed 68 eyes of 63 patients with center-involved DME who received IVR injections for 12 months or longer according to three monthly IVR injections followed by the PRN dosing. We measured the mean retinal thicknesses in the individual subfields of the Early Treatment Diabetic Retinopathy Study grid and evaluated the qualitative and quantitative parameters on OCT sectional images. We investigated the relationship between these OCT parameters at baseline and the number of IVR injections during the 12-month follow-up.

Results

Three loading doses were administered to 10 eyes; four to seven annualized IVR injections were administered to 34 eyes. The number of eyes that received IVR injections decreased gradually until month 6 and was almost constant from months 7 to 11. No relationships were seen between the treatment frequency and baseline systemic factors and the ophthalmic examination findings. Univariate analyses showed that the number of IVR injections during the first year was associated with the mean retinal thickness in the individual subfields and the transverse length of the disrupted external limiting membrane (ELM) and ellipsoid zone of the photoreceptors. Multivariate analysis showed a significant association with the thickness in the inferior subfield alone. The treatment frequency during the 12-month follow-up was not correlated with improved visual acuity but was associated with the decrease in the central subfield thickness and disrupted ELM.

Conclusion

The retinal thickness in the inferior subfield predicts the treatment frequency during the first year in eyes with DME treated with PRN IVR injections.

Thickness of the retinal photoreceptor outer segment layer in healthy volunteers and in patients with diabetes mellitus without retinopathy, diabetic retinopathy, or diabetic macular edema

Purpose

The purpose of this study was to investigate whether the severity of diabetic disease in the retina is paralleled by changes in the photoreceptor layer.

Methods

This cross-sectional study included healthy volunteers (30 volunteers, 60 eyes) and patients with diabetes (48 patients, 96 eyes). Each patient underwent a single session of spectral domain optical coherence tomography (OCT) in which each retina was imaged twice. On each OCT image, the thickness of the PROS layer was measured at the foveal center and at points 750 μm temporal to and nasal to the center. For statistical analyses, OCT images were assigned to one of the following groups: healthy, diabetes without retinopathy (DM), diabetic retinopathy (DR), or diabetic retinopathy with macular edema (DME).

Results

The mean PROS thickness at the foveal center in the first and second-obtained OCT images was as follows: healthy, 38.5 μm and 38.6 μm; DM, 38.2 μm and 38.2 μm; DR, 35.6 μm and 36.1 μm; DME, 32.6 μm and 32.6 μm. In the first and second-obtained images, significant differences were found between the healthy group and DR and DME (p < 0.05 for all), between the DM group and the DME (p < 0.05 for all), and between the DR group and the DME group (p < 0.05 for all). No significant differences between groups were found at the nasal and temporal locations.

Conclusion

The PROS layer at the foveal center was thinner in patients who had diabetic retinopathy or diabetic macular edema than both the healthy volunteers and diabetic patients without retinopathy.

Restoration of foveal photoreceptors after intravitreal ranibizumab injections for diabetic macular edema

Anti-vascular endothelial growth factor drugs are the first-line treatment for diabetic macular edema (DME), although the mechanism of the visual acuity (VA) improvement remains largely unknown. The association between photoreceptor damage and visual impairment encouraged us to retrospectively investigate the changes in the foveal photoreceptors in the external limiting membrane (ELM) and ellipsoid zone (EZ) on spectral-domain optical coherence tomography (SD-OCT) images in 62 eyes with DME treated with intravitreal ranibizumab (IVR) injections. The transverse lengths of the disrupted EZ and ELM were shortened significantly (P < 0.001 and P = 0.044, respectively) at 12 months. The qualitative investigation also showed restoration of the EZ and ELM lines on SD-OCT images. The EZ at 12 months lengthened in 34 of 38 eyes with discontinuous EZ and was preserved in 16 of 21 eyes with complete EZ at baseline. VA improvement was positively correlated with shortening of the disrupted EZ at 12 months (ρ = 0.463, P < 0.001), whereas the decrease in central subfield thickness was associated with neither VA improvement nor changes in EZ status (ρ = 0.215, P = 0.093 and (ρ = 0.209, P = 0.103, respectively). These data suggested that photoreceptor restoration contributes to VA improvement after pro re nata treatment with IVR injections for DME independent of resolved retinal thickening.

VISUAL AND MORPHOLOGIC OUTCOMES OF INTRAVITREAL RANIBIZUMAB FOR DIABETIC MACULAR EDEMA BASED ON OPTICAL COHERENCE TOMOGRAPHY PATTERNS

PURPOSE

To evaluate the visual and morphologic outcomes of intravitreal ranibizumab (IVR) in eyes with diabetic macular edema (DME) based on the morphologic pattern on optical coherence tomography.

METHODS

A prospective and consecutive series of 55 eyes with DME was classified according to OCT features: diffuse retinal thickening (DRT), cystoid macular edema (CME), and serous retinal detachment (SRD). Patients received three consecutive monthly injections of IVR and as needed thereafter. The primary outcome was the number of treatments undertaken by DME type over 12 months. Best-corrected visual acuity, retinal thickness, and microstructural changes were also evaluated.

RESULTS

The eyes were classified as DRT (n = 23), CME (16), or SRD (16). The mean number of injections over 12 months was significantly different among the groups: DRT (3.69), CME (5.33), and SRD (5.09; P = 0.028). Best-corrected visual acuity of SRD (20/60) was significantly worse than that of the other types (DRT = 20/38; CME = 20/43; P = 0.015) after 12 months.

CONCLUSION

Vision gains and retinal anatomy improvement were maintained in all three types during the first year of IVR administration. Especially, DRT maintained a good response to ranibizumab in a fewer number of injections. Disruption of the photoreceptor integrity at the baseline was correlated with poorer visual outcome and occurred more frequently in SRD.

Spectral Domain Optical Coherence Tomography Features and Classification Systems for Diabetic Macular Edema: A Review

Spectral domain optical coherence tomography (SD-OCT) is fast becoming the current standard of care for the detection and assessment of diabetic macular edema. With the application of SD-OCT for imaging of retinal microstructure and measurement of retinal thickness, new information regarding disease characteristics has been gathered, which was unrecognized previously. Retinal thickness measurements on SD-OCT have also been used for deciding the management and monitoring of the disease. Since its development, OCT has enhanced the understanding of retinal anatomical changes in diabetic retinopathy. Several authors have used SD-OCT to classify diabetic macular edema with the purpose of correlating the pathophysiology with disease severity. The classification systems have helped monitor the treatment efficacy and provide prognostic information on the treatment outcome. The following review article summarizes these classifications.

Relationship between Functional and Structural Changes in Diabetic Vessels in Optical Coherence Tomography Angiography

The decorrelation signals in optical coherence tomography angiography (OCTA) are derived from the flow of erythrocytes and concomitantly delineate the retinal vasculature. We compared the structural and functional characteristics of vascular lesions visualized in fluorescein angiography (FA), OCTA, and en-face OCT images in 53 eyes (28 patients) with diabetic retinopathy (DR). The foveal avascular zone (FAZ) areas in OCTA images in the superficial layer almost corresponded to those in FA images. The FAZ areas in the en-face OCT images in the superficial layer were smaller than those in the FA images and correlated with each other, which agreed with the finding that en-face OCT images often delineated the vascular structure in the nonperfused areas in FA images. Microaneurysms appeared as fusiform, saccular, or coiled capillaries in OCTA images and ringed, round, or oval hyperreflective lesions in en-face OCT images. OCTA and en-face OCT images detected 41.0 ± 16.1% and 40.1 ± 18.6%, respectively, of microaneurysms in FA images, although both depicted only 13.9 ± 16.4%. The number of microaneurysms in FA images was correlated with that in OCTA and en-face OCT images. Comparisons of these modalities showed the associations and dissociations between blood flow and vascular structures, which improves the understanding of the pathogenesis of DR.

Predicting outcomes to anti-vascular endothelial growth factor (VEGF) therapy in diabetic macular oedema: a review of the literature

Diabetic macular oedema affects visual acuity to a varying degree. The current treatment of choice is intravitreal anti-vascular endothelial growth factor (VEGF) that has proven both its anatomical and visual efficacy in several large randomised clinical trials (RCTs). Although most patients respond well to anti-VEGF agents, some, however, show a moderate or even poor response. There is no clear consensus as to how to manage these patients, or define them. In addition, identifying early in the course of treatment which patients will respond and which patients will not is paramount to any personalised treatment regimen. Most large RCTs such as RESTORE and Protocol I have attempted post hoc analyses to identify demographic, clinical, optical coherence tomography (OCT) and fluorescein angiography findings that might predict patient response. Although some factors were found to be predictive, the lack of uniformity between the different RCTs means that no consensus exists as to which of these factors can be reliably used. This review looks at the large diabetic macular oedema RCTs such as RESTORE, Protocol I, READ-2 and BOLT in an attempt to identify common prognostic indicators between the various studies. We also attempted to look at several other OCT parameters such as the inner segment-outer segment (IS-OS) layer, the external limiting membrane layer, and choroidal thickness to help determine whether they can truly predict visual outcomes in patients being treated with anti-VEGF therapy. Finally, we provide a simplified summary about which factors might be relevant in clinical practice to help guide physicians in treatment decisions.