Association between photoreceptor integrity and visual outcome in diabetic macular edema

Retinal OCT biomarkers associated with reading performance in patients with persistent vs. resolved diabetic macular edema

BACKGROUND

Recent advancements in imaging technologies, particularly structural optical coherence tomography (OCT), have improved the understanding of diabetic macular edema (DME) pathophysiology and provided valuable biomarkers for disease progression and visual outcomes. This prospective study aimed to investigate the association between specific retinal biomarkers identified through OCT imaging and reading performance metrics in patients with previously treated persistent versus resolved DME and good visual acuity.

METHODS

Forty-nine eyes from 35 patients with a history of DME were enrolled. Reading performance was assessed using the Radner reading charts, which include standardized sentences with geometrically progressing print sizes. Structural alterations in the inner and outer retina, as well as the retinal pigment epithelium (RPE), were graded based on OCT images.

RESULTS

Reading performance, measured as maximum reading speed, was associated with specific retinal biomarkers. The disruption of the ellipsoid zone (EZ) in the parafoveal region and the presence of disorganization of the inner retinal layers (DRIL) in the parafovea were correlated with reduced reading speed. These associations were independent of the presence of intraretinal or subretinal fluid.

CONCLUSIONS

Understanding the relationship between retinal biomarkers and reading performance could contribute to a comprehensive evaluation of visual function and quality of life in patients with DME, leading to better management strategies and treatment outcomes.

Ultrastructural imaging biomarkers in diabetic macular edema: A major review

Diabetic macular edema (DME) is a vision-threatening complication of diabetic retinopathy and causes significant morbidity in patients. Anti-vascular endothelial growth factor (VEGF) agents are the mainstay of treatment for DME, with steroid implants being used for the treatment of anti-VEGF resistant eyes. Over the years, several classification systems have been devised to describe the patterns of DME using optical coherence tomography (OCT). With the advent of effective treatments, it has become imperative that imaging cues are not merely used for classifying the disease but also as biomarkers for prognostication of disease activity and treatment response. In this aspect, newer imaging findings such as hyperreflective dots, photoreceptor integrity, and disorganization of retinal inner layers have been characterized in detail by several authors. Macular perfusion analysis using OCT angiography is the latest in the armamentarium for imaging DME. In this narrative review, we have summarized all relevant literature related to the ultrastructural imaging-based biomarkers of DME and their correlation to treatment.

Structural effects of intraretinal cysts on outer retinal layers in eyes with diabetic macular edema

BACKGROUND

Diabetic macular edema (DME) is the main cause of visual loss in individuals with diabetic retinopathy (DR). This study aims to investigate the effects of central macular intraretinal cysts on the underlying outer retinal layer (ORL) in patients with diabetic macular edema (DME).

METHODS

In this retrospective and cross-sectional study, diabetic patients with or without DR were categorized into three groups: without DME (group 1), with DME but without any cyst featuring a plateau in the lower region (group 2), and patients with cyst featuring an inferior cyst plateau (group 3), defined as a flat conformation at its posterior aspect. Variables such as central macular intraretinal cyst height, inferior cyst plateau, and ORL thickness were measured, and ellipsoid zone (EZ) disruption was assessed via Spectral-domain optical coherence tomography (SD-OCT) and compared between groups. Correlations between OCT-measured variables and best-corrected visual acuity (BCVA) were investigated.

RESULTS

A total of 164 eyes were included: 48 in group 1, 47 in group 2 and 69 in group 3. Compared with Groups 1 and 2, Group 3 presented a greater intraretinal cyst height (p < 0.001), a thinner mean ORL beneath the cysts (p < 0.0001) and more frequent EZ disruption (p < 0.0001), which was associated with lower BCVA values. Cyst height, cyst plateau and ORL thickness were significantly correlated with BCVA (p < 0.0001). EZ disruption was associated with the cyst height, the cyst plateau and the underlying ORL thickness. Correlations were observed between cyst height and ORL thickness (r = - 0.32, p < 0.001), between cyst height and cyst plateau (r = 0.60, p < 0.001), and between cyst plateau and ORL thickness (r = - 0.56, p < 0.001). Every increase of 10 μm in plateau width and in cyst height results in reductions of 0.16 μm and 0.29 μm in ORL thickness, respectively, independent of the other parameters. The optimal cutoff point for cyst height that best discriminates plateau formation was determined to be 130.5 μm, with a sensitivity of 89.9% and specificity of 83%.

CONCLUSIONS

In patients with DME, large central intraretinal cysts may assume a flat configuration in their lower region, termed a plateau, and are associated with photoreceptor damage due to compression, which can result in visual impairment. These findings can be understood based on modified Hertz's mechanical contact theory.

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

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

Single-shot OCT and OCT angiography for slab-specific detection of diabetic retinopathy

In this study, we present an optical coherence tomographic angiography (OCTA) prototype using a 500 kHz high-speed swept-source laser. This system can generate a 75-degree field of view with a 10.4 µm lateral resolution with a single acquisition. With this prototype we acquired detailed, wide-field, and plexus-specific images throughout the retina and choroid in eyes with diabetic retinopathy, detecting early retinal neovascularization and locating pathology within specific retinal slabs. Our device could also visualize choroidal flow and identify signs of key biomarkers in diabetic retinopathy.

Pushing Retinal Imaging Forward: Innovations and Their Clinical Meaning - The 2022 Ophthalmologica Lecture

Retinal imaging has greatly expanded our understanding of various pathological conditions. This article presents a summary of the key points covered during the 2022 Ophthalmologica Lecture held at the Euretina Congress in Hamburg. The first part of the article focuses on the use of optical coherence tomography angiography to examine and comprehend the choroid in age-related macular degeneration (AMD). Subsequently, we delve into the discussion of the "postreceptor neuronal loss" theory in AMD, which was studied using en face structural optical coherence tomography (OCT). Following that, we explore pertinent findings obtained through cross-sectional OCT in retinal and optic nerve diseases, such as AMD, diabetic macular edema, pathologic myopia, central serous chorioretinopathy, and Leber's hereditary optic neuropathy.

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.

REal-world treatment outcomes after delayed intRavitreal therapy in center-involving diabetic macular edema - RETORT study

PURPOSE

To compare real-life data on delayed intravitreal treatment of diabetic macular edema (DME) patients to early treatment.

METHODS

In this single-centre, retrospective, interventional, comparative study, DME patients were divided into two groups based on when they received treatment: Group 1 - received treatment within 24 weeks and Group 2 - at or after 24 weeks from the time of treatment advice. Visual acuity and central subfield thickness (CSFT) changes were compared at various time points. Reasons for delaying treatment were noted.

RESULTS

The study included 109 (Group 1-94; Group 2-15) eyes. When treatment was advised, demographic profile, diabetes duration, glucose control and VA between two groups were comparable. At this point, CSFT was higher in Group 1 than in Group 2 (p = 0.036). At injection time, Group 2 had better VA and lower CSFT than Group 1 (p < 0.05). Group 2's VA (53.4 ± 12.67) was significantly lower than Group 1's (57.38 ± 20.01) after 1-year treatment. At 1-year, CSFT decreased in Group 1 and increased in Group 2. Group 1 had mean improvement of + 7.6 letters and Group 2 had a decline of -6.9 letters. Group 2 required more intravitreal anti-VEGF (median - 3; IQR: 2-4), steroid injections (median - 4; IQR: 2-4) and focal laser sessions (median - 4; IQR: 2-4).

CONCLUSION

Late-treated DME eyes needed more injections and focal laser sessions than early treated eyes. Adherence to early treatment of DME in real-life will help prevent long-term vision loss.

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.

Imaging biomarkers and clinical factors associated with the rate of progressive inner and outer retinal thinning in patients with diabetic macular edema

The aim of this study was to assess the relationship of clinical characteristics to the rate of retinal thinning in eyes with diabetic macular edema (DME) treated with anti-vascular endothelial growth factor (VEGF) therapy. We analyzed subjects with a long-term follow-up (≥ 3 years) and evidence of resolved DME after the initiation of anti-VEGF therapy (baseline visit). To measure the long-term rate of retinal thinning during treatment, a second visit (first visit with evidence of resolved DME after 3 years) was also considered. A longitudinal quantitative topographical assessment of the inner and outer retinal thicknesses was provided. Clinical characteristics were associated with the rate of longitudinal retinal thinning. We included 56 eyes (50 patients) in the analysis. A significant longitudinal thinning in the inner and outer retina was detected in all the analyzed regions (p values between 0.027 and < 0.0001). In the multivariable analysis, type of diabetes (type 2 vs. type 1) was associated with increased foveal inner retinal thinning (p = 0.019). A higher number of subfoveal neuroretinal detachment during follow-up (p = 0.006) was associated with faster rates of foveal outer retinal thinning. Type of diabetes (p < 0.0001), higher age (p = 0.033) and cystoid macular edema phenotype (p = 0.040) were associated with increased parafoveal inner retinal thinning. Gender (p = 0.003) and diabetic retinopathy stage (p = 0.013) were associated with faster rates of perifoveal inner retinal thinning, while diabetic retinopathy stage (p = 0.036) was associated with increased perifoveal outer retinal thinning. In conclusion, clinical factors, including DME phenotypes, were associated with the rates of retinal thinning in patients undergoing anti-VEGF treatment.

Optical Coherence Tomography Reflectivity in Foveal Cysts: A Novel Biomarker for Early-Response Prediction of Diabetic Macular Edema Treated with Dexamethasone

This study investigated spectral-domain optical coherence tomography (OCT) biomarkers to predict short-term anatomical improvement for diabetic macular edema (DME) after dexamethasone (DEX) injection in intravitreal anti-vascular endothelial growth factor (anti-VEGF) non-responders. This retrospective comparative study included 31 eyes of 31 patients with DME unresponsive to anti-VEGF, divided into better and lesser responder groups. OCT prior to DEX injection was used to evaluate the morphological features including optical density (ODN) and optical density ratio (ODR) of the outer nuclear layer (ONL) cysts. Correlations between baseline OCT parameters and mean central macular thickness (CMT) changes at 1 month were analyzed. There were no between-group differences in age, sex, number of previous anti-VEGF injections, duration of diabetes, or HbA1c level. However, ODN and ODR values in ONL cysts were lower in the better responder group (p = 0.020 and p < 0.001, respectively). ODN and ODR showed negative correlations with CMT changes (R = −0.546, p = 0.002 and R = −0.436, p = 0.014, respectively). Higher OCT reflectivity in the foveal cystoid space was associated with a lesser decrease in CMT after DEX injection in anti-VEGF non-responders, suggesting the usefulness of this parameter in predicting short-term CMT responses after DEX injection.

Oct biomarkers of treatment-naive diabetic macular edema in patients with non-proliferative and proliferative diabetic retinopathy

PURPOSE

To evaluate and compare the retinal and choroidal spectral-domain optic coherence tomography (SD-OCT) findings of treatment-naïve diabetic macular edema (DME) secondary to non-proliferative and proliferative diabetic retinopathy (NPDR-PDR).

MATERIAL AND METHODS

A hundred and thirty-eight eyes of 138 patients with DME were evaluated. Best-corrected visual acuity was recorded, biomicroscopic anterior and posterior segment examination, SD-OCT imaging, and fundus fluorescein angiography (FFA) were performed. Demographic features, OCT characteristics, FFA, and visual acuity measurements were evaluated and compared between the two groups.

RESULTS

Sixteen eyes were excluded from the study due to the lack of FFA images. Data of 122 eyes were analyzed for the study. Sixty-five eyes with NPDR (Group 1) and 57 eyes with PDR (Group 2) were enrolled in the study. There was no significant difference in central macular thicknesses (CMT) between the two groups. The eyes with DME + PDR showed a higher rate of the diffuse type of macular edema with more para and peri-foveal extension accompanied by larger cysts than the eyes with DME + NPDR. Disorganization of retinal inner layers, disrupted ellipsoid zone, and the epiretinal membrane were more prominent in the eyes with PDR. Also, there were more prominent macular ischemia on FFA and worse initial visual acuity measurements in the eyes with PDR than those with NPDR. Choroidal thickness (CT) was significantly reduced in the PDR group.

CONCLUSION

SD-OCT features of treatment-naïve DME in patients with NPDR and PDR presented some differences. These variations may be related to diabetic retinopathy severity and may provide information about prognosis.

Hyperreflective Foci in Diabetic Macular Edema with Subretinal Fluid: Association with Visual Outcomes after Anti-VEGF Treatment

INTRODUCTION

Objectives of the study were to describe the hyperreflective foci (HRF) on optical coherence tomography angiography in diabetic macular edema (DME) with subretinal fluid (SRF) and explore the association of HRF in the outer retina with photoreceptor integrity and visual outcomes after anti-vascular endothelial growth factor (anti-VEGF) treatment.

METHODS

We retrospectively reviewed 46 eyes (36 patients) with DME treated with anti-VEGF drugs. The following parameters, including best-corrected visual acuity (BCVA), central macular thickness (CMT), the height of SRF, the number of HRF in the superficial capillary plexus, deep capillary plexus, and the outer retina, as well as the integrity of external limiting membrane (ELM) and ellipsoid zone (EZ), were evaluated and compared between the baseline and after 2 monthly injections of anti-VEGF drugs. The relationship between the HRF in the outer retina and the integrity of ELM and EZ, as well as BCVA, was analyzed.

RESULTS

BCVA was significantly improved in DME after anti-VEGF treatment; however, for the subgroup of DME patients with SRF, visual acuity remained unchanged after anti-VEGF treatment (p < 0.05 vs. p = 0.375). The number of HRF (p < 0.05), CMT (p < 0.001), and SRF height (p < 0.001) were significantly reduced, accompanied with partial restoration of ELM and EZ integrity after anti-VEGF injection. The HRF in the outer retina was correlated with the final ELM (p = 0.036) and EZ (p = 0.004) status. The final BCVA was significantly better in eyes with intact ELM (p = 0.002) and EZ at final visit (p < 0.001).

CONCLUSION

The number of HRF in outer retina was negatively associated with the microstructural restoration of ELM and EZ, as well as the visual outcome in DME patients with SRF after anti-VEGF treatment.

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.

Interleaved Optical Coherence Tomography: Clinical and Laboratory Biomarkers in Patients with Diabetic Macular Edema

(1) Background: The global burden of diabetes mellitus (DM) has been estimated to reach 600 million patients worldwide by 2040. Approximately 200 million people will develop diabetic retinopathy within this time frame. Diabetic macular edema (DME) is a severe, vision-threatening complication that can develop at any stage of diabetic retinopathy, and it represents the main cause of vision loss in patients with DM. Its harmful consequences on visual function could be prevented with timely recognition and treatment. (2) Methods: This study assessed the clinical (demographic characteristics, diabetic evolution, and systemic vascular complications); laboratory (glycated hemoglobin, metabolic parameters, capillary oxygen saturation, and renal function); ophthalmologic exam; and spectral-domain optical coherence tomography (SD–OCT) (macular volume, central macular thickness, maximal central thickness, minimal central thickness, foveal thickness, superior inner, inferior inner, nasal inner, temporal inner, inferior outer, superior outer, nasal outer, and temporal outer thicknesses, disruption of the ellipsoid zone, and disruption of the inner retinal layers (DRIL) parameters in three groups of individuals: healthy controls (HC), patients with DME and type 1 DM (T1DM—group A), and patients with DME and type 2 DM (T2DM—group B) to identify novel correlations between them that would open a path to new pathogenetic hypotheses and, implicitly, to the identification of new therapeutic methods, as part of a tailored treatment within the concept of precision medicine. (3) Results: The duration of DM was significantly longer in group A as compared with group B, as were the prevalence of smoking and systemic vascular complications. Capillary oxygen saturation and estimated glomerular filtration rates were significantly lower, and serum creatinine levels were significantly higher in group A as compared to group B. Regarding the OCT findings, DME had a predominantly eccentric pattern, and the right eye was more severely affected in both groups of patients. Significantly higher values were obtained in group B as compared to group A for the following OCT biomarkers: macular volume, central macular thickness, maximal central thickness, minimal central thickness, foveal thickness, superior inner, inferior inner, nasal inner, inferior outer and nasal outer thickness. The disruption of the ellipsoid zone was significantly more prevalent within group A, whereas the overall disruption of the retinal inner layers (DRIL) was identified significantly more frequently in group B. (4) Conclusions: Whereas systemic and laboratory biomarkers were more severely affected in patients with DME and T1DM, the OCT quantitative biomarkers revealed significantly higher values in patients with DME and T2DM.

Idiopathic Epiretinal Membranes: Visual Outcomes and Prognostic Factors

Objectives

To evaluate the associations between anatomical changes and visual outcomes in patients with idiopathic epiretinal membrane (ERM).

Materials and Methods

We performed a prospective study of 130 consecutive idiopathic ERM patients and report their visual outcomes and the factors associated with visual outcome and anatomical changes.

Results

Of 130 eyes of 130 patients, 87 eyes underwent surgery, while the remaining 43 eyes were observed. At 6-month follow-up, the best-corrected visual acuity (BCVA) increased in the whole population. Mean Early Treatment Diabetic Retinopathy Study letter score changed from 51 to 65 in the surgical group and from 67 to 68 in the non-surgical group. The surgical group had improvement in BCVA at all ERM stages and grades of disorganization of the retinal inner layers (DRIL) (p<0.01). In multivariable analysis of the surgical group, factors associated with BCVA of ETDRS 60 letters or more were no or mild DRIL and the absence of ellipsoid zone disruption at baseline (p=0.002 and p=0.034, respectively) and this statistically significant positive correlation was still maintained at 12-month follow-up.

Conclusion

Baseline DRIL grade and presence of ellipsoid zone disruption were the most informative prognostic factors in patients with idiopathic ERMs. Patients with severe DRIL and/or advanced ERMs had improved vision after ERM removal.

Optical coherence tomography patterns of diabetic macular edema and treatment response to bevacizumab: a short-term study

Background:

The purpose of this study was to evaluate the short-term response of intravitreal bevacizumab in diabetic macular edema (DME) and assess the variation in treatment outcomes in different morphology patterns using spectral domain–optical coherence tomography (SD-OCT).

Objective:

To study different morphological patterns of DME based on OCT and compare their treatment response to bevacizumab.

Methods:

Hundred and twelve eyes of 112 patients with DME were included and treated with intravitreal bevacizumab (1.25 mg/0.05 ml monthly for 3 months). The morphological patterns of DME were classified on the basis of OCT into three groups – diffuse retinal thickening (DRT), cystoid macular edema (CME), and serous retinal detachment (SRD) – and changes in central macular thickness (CMT) and best corrected visual acuity (BCVA) after treatment were compared.

Results:

A total of 112 eyes with DME were included and consisted of 40 DRT, 37 CME, and 35 SRD. Treatment with bevacizumab resulted in decrease in central macular thickness and improvement in BCVA in all three groups. The baseline visual acuity and CMT of DRT group was better than that of the other two groups. The treatment outcome was measured in terms of CMT and BCVA. Change in CMT was statistically significant among three groups and was found to be better in DRT group (p < 0.05, 95% confidence interval). However, there was statistically no significant variation between the three groups regarding the change in BCVA (p = 0.169, 95% confidence interval).

Conclusion:

Anatomic and visual improvement can be achieved by bevacizumab in all patterns of DME. However, individual pattern may respond differently. DRT, which appears to be the earliest form of DME, responds better than other types. Thus, the pattern of macular edema shown by OCT may provide an objective guideline in predicting the response of bevacizumab injection in DME.

Long-Term Visual Outcomes and Morphologic Biomarkers of Vision Loss in Eyes With Diabetic Macular Edema Treated With Anti-VEGF Therapy

PURPOSE

To analyze the morphological characteristics and long-term visual outcomes in eyes with diabetic retinopathy (DR) and diabetic macular edema (DME) treated with anti-vascular endothelial growth factor (anti-VEGF) therapy.

DESIGN

Retrospective clinical cohort study.

METHODS

Patients with a long-term follow-up and evidence of resolved DME in at least 1 visit (study visit) after 5 years of follow-up after the initiation of anti-VEGF therapy were included. At the study visit, structural optical coherence tomography (OCT) scans were reviewed for qualitative features reflecting a distress of the neuroretina or retinal pigment epithelium (RPE). A quantitative topographical assessment of the inner and outer retinal thicknesses was also provided.

RESULTS

A total of 61 eyes (50 patients) were included and were divided into 2 subgroups according to visual acuity (VA) at the study visit, yielding a group of 24 eyes with a VA <20/40 ("poor/intermediate vision" group), and 37 eyes with a VA ≥20/40 ("good vision" group). The external limiting membrane (ELM) and RPE bands were more frequently disrupted or absent in the poor/intermediate vision group (P = .003 and P = .019). Similarly, disorganization of retinal inner layers was more prevalent in the poor/intermediate vision group (P = .013). The foveal and parafoveal outer retinal thicknesses were reduced in eyes with poor/intermediate vision (P = .022 and P = .044). Multivariate stepwise linear regression analysis demonstrated that VA was associated with appearances of the RPE and ELM (P < .0001 and P = .048), foveal and parafoveal outer retinal thicknesses (P = .046 and P = .035).

CONCLUSIONS

Modifications in the outer retina and RPE represent OCT biomarkers of long-term visual outcomes in eyes with DME treated with anti-VEGF.

Optical Coherence Tomographic Features and Prognostic Values of Macular Edema in Vogt-Koyanagi-Harada Disease

Purpose: To determine optical coherence tomographic (OCT) features of macular edema (ME) and identify potential prognostic values for ME and visual outcomes in Vogt-Koyanagi-Harada disease (VKH).

Methods: In the retrospective case series, a total of 1,377 VKH patients who were seen in a tertiary uveitis center between September 2011 and January 2018 were reviewed on their demographics, visual acuity, ocular and extraocular manifestations, modes of treatment, and OCT examinations. Of these patients, 79 (5.7%) having ME were included for analysis of OCT features. Four patients were missed without ME resolution, and the remaining 75 patients who either had ME resolved or were followed up for 2 years were included for analysis of disease outcomes.

Results: Of the 115 affected eyes in these 79 patients, 100 (87.0%) had cystoid ME (CME), accounting for the most common OCT feature of VKH-related ME. Disruption of the inner-segment/outer-segment junction (IS/OS) band seen in 33 (28.7%) affected eyes of 24 (30.4%) patients was found as a risk factor for the development of persistent ME [10 of 62 (16.1%) vs. 13 of 13 (100%); P < 0.001] and a poor visual outcome (1.16 ± 0.42 vs. 1.17 ± 0.46 in logMAR unit; P = 0.89). CME patients with a concurrent choroidal neovascular membrane often had a disrupted IS/OS band, thus becoming refractory cases. A 6-month well-controlled intraocular inflammation following standard treatment regimens was found to associate with complete resolution of the refractory edema [4 of 5 (80%) vs. 2 of 13 (15%); P = 0.02].

Conclusions: Intraretinal cystoid changes are most commonly seen in the edematous macula of VKH patients. Disruption of the IS/OS band is a useful risk sign for poor ME and visual outcomes in VKH-related ME, and a long-term well-controlled intraocular inflammation may be critical for the resolution of refractory cases.

Correlation of Photoreceptor Integrity with Retinal Vessel Density and Choriocapillaris in Eyes with Diabetic Retinopathy

PURPOSE

To investigate the correlation of foveal photoreceptor integrity with the vessel density (VD) of the retina and choriocapillaris using swept-source optical coherence tomography (OCT) angiography (OCTA) in eyes with diabetic retinopathy (DR).

METHODS

We retrospectively reviewed subjects having eyes with DR, who underwent OCTA using swept-source OCT (DRI OCT Triton; Topcon). We analyzed the area of the foveal avascular zone (FAZ) and VDs of the superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris. The length of the lateral extent of ellipsoid zone (EZ) disruption, central subfield thickness, and subfoveal choroidal thickness were measured. Furthermore, we analyzed factors that were closely associated with the length of EZ disruption.

RESULTS

A total of 159 eyes with DR and 30 healthy control eyes were included in this study. In all eyes, the lengths of EZ disruption were positively correlated with the FAZ area (P=0.009). However, they were negatively correlated with the parafoveal VD of the SCP (P=0.049), the foveal VD of DCP (P=0.003), and that of the choriocapillaris (P=0.036).

CONCLUSIONS

The size of the FAZ and ischemia at the DCP may play an important role in maintaining foveal photoreceptor integrity in eyes with DR. Considering OCTA artifacts, such as projection and shadowing, future studies are required to reveal the correlation between EZ disruption and the VD of the choriocapillaris.

Challenges in Diabetic Macular Edema Management: An Expert Consensus Report

Purpose

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

Methods

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

Results

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

Conclusion

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

OCT Biomarkers in Neovascular Age-Related Macular Degeneration: A Narrative Review

Age-related macular degeneration (AMD) is the leading cause of legal blindness in elderly people. Neovascular AMD (nAMD) is responsible for the majority of cases of severe visual loss in eyes with AMD. Optical coherence tomography (OCT) is the most widely used technology for the diagnosis and follow-up of nAMD patients, which is widely used to study and guide the clinical approach, as well as to predict and evaluate treatment response. The aim of this review is to describe and analyze various structural OCT-based biomarkers, which have practical value during both initial assessment and treatment follow-up of nAMD patients. While central retinal thickness has been the most common and one of the first OCT identified biomarkers, today, other qualitative and quantitative biomarkers provide novel insight into disease activity and offer superior prognostic value and better guidance for tailored therapeutic management. The key importance of retinal fluid compartmentalization (intraretinal fluid, subretinal fluid, and subretinal pigment epithelium (RPE) fluid) will be discussed firstly. In the second part, the structural alterations of different retinal layers in various stages of the disease (photoreceptors layer integrity, hyperreflective dots, outer retinal tubulations, subretinal hyperreflective material, and retinal pigment epithelial tears) will be analyzed in detail. The last part of the review will focus on how alterations of the vitreoretinal interface (vitreomacular adhesion and traction) and of the choroid (sub-RPE hyperreflective columns, prechoroidal clefts, choroidal caverns, choroidal thickness and choroidal volume, and choroidal vascular index) interact with nAMD progression. OCT technology is evolving very quickly, and new retinal biomarkers are continuously described. This up-to-date review article provides a comprehensive description on how structural OCT-based biomarkers provide a valuable tool to monitor the progression of the disease and the treatment response in nAMD patients. Thus, in this perspective, clinicians will be able to allocate hospital resources in the best possible way and tailor treatment to the individual patient's needs.

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.

External limiting membrane and ellipsoid zone structural integrity in diabetic macular edema

The external limiting membrane (ELM) and ellipsoid zone (EZ) can be observed exquisitely by SD-OCT. In diabetic macular edema (DME), dysfunction of mitochondria, represented by the EZ in the foveal photoreceptors results in reduced visual acuity (VA). An increase in VEGF was found to correlate with increased severity of DR, increased central subfield thickness (CST), and sequential disruption of ELM and EZ. The mechanism of ELM and EZ restoration after anti-VEGF therapy in DME has been discovered. The ELM restores first followed by EZ restoration. Thus, authors have discovered and established ELM as a novel retinal structural barrier.

Reliability of Subjective Assessment of Spectral-Domain OCT Pathologic Features by Multiple Raters in Retinal Vein Occlusion

Purpose

Design

Participants

Methods

Main Outcome Measures

Results

Conclusions

Indicators of Visual Prognosis in Diabetic Macular Oedema

Diabetic macular oedema (DMO) is an important cause of moderate vision loss in people with diabetes. Advances in imaging technology have shown that a significant proportion of patients with DMO respond sub-optimally to existing treatment options. Identifying associations and predictors of response before treatment is initiated may help in explaining visual prognosis to patients and aid the development of personalized treatment strategies. Imaging features, such as central subfoveal thickness, photoreceptor integrity, disorganization of retinal inner layers, choroidal changes, and macular perfusion, have been reported to be prognostic factors of visual acuity (VA) in DMO. In this review we evaluated each risk factor to understand their relative importance in visual prognostication of DMO eyes post-treatment. Although individually, some of these factors may not be significant predictors, in combination they may form phenotypes that can inform visual prognosis. Stratification based on these phenotypes needs to be developed to progress to personalized medicine for DMO.

Age, Initial Central Retinal Thickness, and OCT Biomarkers Have an Influence on the Outcome of Diabetic Macular Edema Treated With Ranibizumab- Tri-center 12-Month Treat-and-Extend Study

Objective: We report the tri-center 1-year outcomes of a treat-and-extend (T&E) regimen in four-week intervals with ranibizumab for diabetic macular edema (DME).

Methods: In this retrospective study, all eyes received 3 monthly loading injections of 0.5 mg ranibizumab, followed by a T&E regimen for DME. Regression models were used to evaluate the associating factors for visual and anatomical outcomes.

Results: Ninety one eyes from 64 patients were enrolled. Mean LogMAR best-corrected visual acuity (BCVA) improved from 0.58 at baseline to 0.36 at month 12 and mean central retinal thickness (CRT) decreased from 411 μm at baseline to 290 μm at month 12. Younger age and eyes having thinner baseline CRT, with ellipsoid zone disruption (EZD), and without epiretinal membrane (ERM) were associated with better final CRT. Moreover, eyes with thicker baseline CRT tend to receive more injections. Among the parameters, only having ERM or EZD was associated with significant BCVA recovery.

Conclusions: A T&E regimen with ranibizumab by 4-week intervals is effective in improving BCVA and reducing CRT with efficacy notable starting from the third month. Clinical parameters including age, initial CRT, and presence of ERM or EZD significantly influenced therapeutic outcomes. Moreover, the presence of ERM should not preclude DME patients from receiving anti-VEGF therapy. Future studies with larger cohorts are warranted.

OPTICAL COHERENCE TOMOGRAPHY FEATURES OF CHOROIDAL NEOVASCULARIZATION AND THEIR CORRELATION WITH AGE, GENDER, AND UNDERLYING DISEASE

PURPOSE

To investigate the influence of age, gender, and underlying disease on the optical coherence tomography (OCT) features of choroidal neovascularization (CNV) secondary to inflammation, myopia (mCNV), and age-related macular degeneration (AMD-CNV).

METHODS

Demographic and clinical data of eyes with treatment-naive inflammatory CNV, mCNV, and Type 2 AMD-CNV were collected. Optical coherence tomography images were reviewed to determine the presence of pitchfork sign, pigment epithelial detachment, subretinal fluid (SRF), intraretinal cysts, subretinal hyperreflective material, atrophy, and outer retinal disruption graded 1 to 4. The influence of demographics and underlying etiology on OCT signs was investigated.

RESULTS

One hundred and eighty-five eyes from 179 patients were enrolled. The mean [SD] age was 36 [±14.4], 62 [±18], and 77 [±8] for the inflammatory CNV, mCNV, and AMD-CNV, respectively (P < 0.001). Multiple linear regression showed that the presence of pitchfork sign was negatively associated with age (P < 0.0001), regardless of underlying disease. By contrast, the SRF, pigment epithelial detachment, intraretinal cysts, and the outer retinal disruption were all positively influenced by age, regardless of gender and underlying disease (all P < 0.01). Logistic regression showed that none of the OCT signs increased the likelihood for diagnosis of inflammatory CNV. By contrast, the absence of SRF was suggestive for mCNVs, and the presence of pigment epithelial detachment and SRF was suggestive for AMD-CNVs.

CONCLUSION

The age of the patient had a significant effect on the OCT appearance of the CNV, particularly the presence of a pitchfork sign, regardless of the underlying etiology. The absence of SRF was suggestive for a diagnosis of mCNVs. The presence of SRF and pigment epithelial detachment was suggestive for AMD-CNVs.

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.

External limiting membrane: retinal structural barrier in diabetic macular edema

Advances in spectral-domain optical coherence tomography (SD-OCT) technology have enhanced the understanding of external limiting membrane (ELM) and ellipsoid zone (EZ) in diabetic macular edema. An increase in VEGF has been demonstrated to be associated with sequential ELM and EZ disruption on SD-OCT. An intact ELM is a prerequisite for an intact EZ in DME. Anti-VEGF therapy leads to restoration of barrier effect of ELM. The ELM restores first followed by EZ restoration.

COMBINED VITRECTOMY WITH INTRAVITREAL DEXAMETHASONE IMPLANT FOR REFRACTORY MACULAR EDEMA SECONDARY TO DIABETIC RETINOPATHY, RETINAL VEIN OCCLUSION, AND NONINFECTIOUS POSTERIOR UVEITIS

PURPOSE

To compare the efficacy of intraoperative intravitreal dexamethasone implant for macular edema secondary to diabetic retinopathy (DME), retinal vein occlusion (RVO), and noninfectious posterior uveitis.

METHODS

A retrospective review of 62 patients (29 men and 33 women; mean age 51.19 ± 14.41 years; 65 eyes) was performed. Best-corrected visual acuity (in logarithm of the minimal angle of resolution), central foveal thickness, intraocular pressure, and postoperative edema-free period were postoperatively assessed up to 1 year. The preoperative and postoperative numbers of other intravitreal injections needed were compared.

RESULTS

Best-corrected visual acuity gradually improved in the DME group (from 0.87 to 0.51) but failed to improve from Month 3 onward in the RVO and uveitis groups. Central foveal thickness decreased in all groups, especially in the DME group (from 550.93 to 338.10 μm). Edema-free period was longest in the DME group (19.34 ± 15.12 months), followed by the uveitis (12.91 ± 7.85 months) and RVO (8.50 ± 8.76 months) groups. Subjects in the uveitis group used more intraocular pressure-lowering agents (1.00 ± 1.27) than those in the DME (0.13 ± 0.49) and RVO (0.36 ± 0.79) groups. Increased intraocular pressure events were most frequent in postoperative Week 1, especially in the uveitis group.

CONCLUSION

Vitrectomy combined with intravitreal dexamethasone implant for DME, RVO, and noninfectious posterior uveitis had a favorable clinical outcome.

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.

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.

Interdigitation and Ellipsoid Zones Disruption Correlate with Visual Outcomes among Treatment-Naive Patients with Diabetic Macular Edema

INTRODUCTION

We have recently shown that defects in interdigitation and ellipsoid zones (IZ and EZ) can predict response to anti-VEGF therapy in a small group of treatment-naive diabetic macular edema (DME) patients. The aim of the current study is to further evaluate this association in a larger study group of patients over a longer follow-up time.

METHODS

Thirty eyes of 30 treatment-naive DME patients were analyzed in this retrospective study. The integrity of foveal IZ and EZ was evaluated using optical coherence tomography at the diagnosis of DME and following anti-VEGF injections. The defect size was correlated with best-corrected visual acuity (BCVA) and central macular thickness (CMT).

RESULTS

The mean patients' age at baseline was 63.0 ± 10.0 years. Patients underwent 3.9 ± 2.9 anti-VEGF injections for a mean of 9.1 ± 4.8 months. Following treatment, the mean Snellen visual acuity (VA) improved from 20/52 to 20/44 (p = 0.05), CMT decreased from 432.5 ± 141.4 μm to 375.2 ± 121.4 µm (p = 0.05) and IZ/EZ defect size decreased from 259.83 ± 375.94 µm to 65.34 ± 143.97 µm (p = 0.001). In patients with no IZ/EZ defects at baseline, the mean Snellen VA was better when compared to those with IZ/EZ defects (20/36 vs. 20/70, p = 0.031). The number of eyes with IZ/EZ defects decreased from 17 (57%) at baseline to 6 (20%) at end of follow-up (p < 0.01). BCVA gain correlated with IZ/EZ defect size reduction (r = 0.41, p = 0.02) but not with improvement in CMT (r = 0.28, p = 0.121).

CONCLUSIONS

IZ/EZ defect size correlated not only with baseline BCVA but also predicted the change in BCVA after anti-VEGF treatment. Possible future automatic measurement of IZ/EZ defect size might prove helpful for the evaluation of treatment response.

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.

Intraocular pressure might play a role in the surgical management of patients with epiretinal membrane

PURPOSE

To investigate the prognostic factors and visual outcomes for patients with epiretinal membrane after pars plana vitrectomy and possible interactions between multiple factors.

METHODS

A retrospective chart review of adult patients with epiretinal membrane treated with pars plana vitrectomy performed by a single surgeon between February 1, 2015, and January 31, 2017 was conducted. The surgical procedures included standard 25-gauge vitrectomy with peeling of the epiretinal membrane and internal limiting membrane (ILM). Factors including age, sex, vision, intraocular pressure (IOP), lens status, and baseline optical coherence tomography angiography were analyzed to determine any association with visual outcomes. IOP and lens status were evaluated at every visit point and were used for analysis.

RESULTS

Visual changes after pars plana vitrectomy in patients with epiretinal membrane were significantly associated with time, lens status, baseline ellipsoid zone integrity, baseline vision, baseline parafoveal vessel density of superficial capillary plexus (SPVD), and IOP. Further investigation using Johnson-Neyman analysis revealed that vision improved over time, especially in pseudophakic eyes. High IOP at baseline or during follow-up was identified as a significant factor associated with limited visual improvement.

CONCLUSION

Our study showed that vision improved over time after vitrectomy for patients with epiretinal membrane. The surgical outcomes are more stable in pseudophakic eyes, and vision improved after cataract extraction in phakic eyes. IOP should be managed and monitored closely to optimize surgical and visual outcomes in patients.

Persistent or Recurrent Diabetic Macular Edema After Fluocinolone Acetonide 0.19 mg Implant: Risk Factors and Management

PURPOSE

To investigate baseline characteristics of patients undergoing additional antivascular endothelial growth factor (VEGF) injections for residual or recurrent diabetic macular edema (DME) in the first year after 0.19-mg fluocinolone acetonide (FAc) implant.

DESIGN

Prospective cohort study.

METHODS

Ninety-four eyes of 66 patients received an FAc implant. Eyes with persistent or recurrent DME were managed with pro re nata anti-VEGF agents. Demographic data and medical history were collected at baseline. Best-corrected visual acuity and central macular thickness were measured every 2 months. The 3 outcomes explored were 1) the risk factors for administration of additional anti-VEGF agents, 2) the interval from FAc to first anti-VEGF injection; and 3) the number of anti-VEGF doses required to maintain regression of DME.

RESULTS

Eighteen eyes (19.1%) of 13 patients received 1.3 ± 0.6 anti-VEGF injections. These eyes had significantly thicker central macular thickness at baseline and over the entire follow-up period (P < .001); best-corrected visual acuity was similar at every time point to eyes that were not receiving extra DME treatments. Eyes without preexistent panretinal photocoagulation (PRP) had a higher risk to undergo supplemental treatments (hazard ratio 1.5 [95% confidence interval 1.1-2.5, P = .03). The interval between FAc implant and the first anti-VEGF had a significant linear positive relationship with the number of dexamethasone implants before FAc implant (P = .002, R² = 0.47). No association was found between baseline factors and the number of injections given.

CONCLUSION

Anti-VEGF agents are efficient treatment to maintain visual acuity in residual/recurrent DME after FAc. Patients with higher baseline central macular thickness and with no previous central macular thickness are more likely to require additional treatments to control DME.

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.

[Specific biomarkers of response to antiangiogenic therapy]

Age-related macular degeneration (AMD) and diabetic macular edema (DME) are the main causes of blindness in the elderly and loss of central vision in patients with diabetic retinopathy, respectively. Anti-VEGF therapy is currently the gold standard for treatment of such patients; it has proved its effectiveness in both randomized clinical trials and clinical practice. However, it should be taken into account that the extent of therapeutic response varies depending on individual characteristics of patients, including the presence of biomarkers that predict the therapeutic response. Numerous studies have discovered a variety of biomarkers for patients with DME and AMD, but their reliability differs and not all of them are eligible for predicting the effectiveness of the treatment. Compared to full clinical examination, biomarkers can offer shorter clinical study duration and lower costs. Most of the specific biomarkers for predicting the response to antiangiogenic therapy are identified using optical coherence tomography. The purpose of this article is to provide contemporary data on the diagnosis and treatment of patients depending on the presence of specific biomarkers.

Automated Quantification of Photoreceptor alteration in macular disease using Optical Coherence Tomography and Deep Learning

Diabetic macular edema (DME) and retina vein occlusion (RVO) are macular diseases in which central photoreceptors are affected due to pathological accumulation of fluid. Optical coherence tomography allows to visually assess and evaluate photoreceptor integrity, whose alteration has been observed as an important biomarker of both diseases. However, the manual quantification of this layered structure is challenging, tedious and time-consuming. In this paper we introduce a deep learning approach for automatically segmenting and characterising photoreceptor alteration. The photoreceptor layer is segmented using an ensemble of four different convolutional neural networks. En-face representations of the layer thickness are produced to characterize the photoreceptors. The pixel-wise standard deviation of the score maps produced by the individual models is also taken to indicate areas of photoreceptor abnormality or ambiguous results. Experimental results showed that our ensemble is able to produce results in pair with a human expert, outperforming each of its constitutive models. No statistically significant differences were observed between mean thickness estimates obtained from automated and manually generated annotations. Therefore, our model is able to reliable quantify photoreceptors, which can be used to improve prognosis and managment of macular diseases.

DEXAMETHASONE IMPLANT FOR DIABETIC MACULAR EDEMA IN NAIVE COMPARED WITH REFRACTORY EYES: The International Retina Group Real-Life 24-Month Multicenter Study. The IRGREL-DEX Study

PURPOSE

To investigate efficacy and safety of repeated dexamethasone (DEX) implants over 24 months, in diabetic macular edema (DME) eyes that were treatment naive compared with eyes refractory to anti-vascular endothelial growth factor treatment, in a real-life environment.

METHODS

This multicenter international retrospective study assessed best-corrected visual acuity and central subfield thickness (CST) of naive and refractory eyes to anti-vascular endothelial growth factor injections treated with dexamethasone implants. Safety data (intraocular pressure rise and cataract surgery) were recorded.

RESULTS

A total of 130 eyes from 125 patients were included. Baseline best-corrected visual acuity and CST were similar for naive (n = 71) and refractory eyes (n = 59). Both groups improved significantly in vision after 24 months (P < 0.001). However, naive eyes gained statistically significantly more vision than refractory eyes (+11.3 ± 10.0 vs. 7.3 ± 2.7 letters, P = 0.01) and were more likely to gain ≥10 letters (OR 3.31, 95% CI 1.19-9.24, P = 0.02). At 6, 12, and 24 months, CST was significantly decreased compared with baseline in both naive and refractory eyes; however, CST was higher in refractory eyes than in naive eyes (CST 279 ± 61 vs. 313 ± 125 μm, P = 0.10).

CONCLUSION

Over a follow-up of 24 months, vision improved in diabetic macular edema eyes after treatment with dexamethasone implants, both in eyes that were treatment naive and eyes refractory to anti-vascular endothelial growth factor treatment; however, improvement was greater in naive eyes.

En face slab optical coherence tomography imaging successfully monitors progressive degenerative changes in the innermost layer of the diabetic retina

OBJECTIVE

To evaluate the usefulness of en face slab optical coherence tomography (OCT) imaging for monitoring diabetic retinal neurodegeneration with supporting animal experimental data.

RESEARCH DESIGN AND METHODS

We retrospectively examined 72 diabetic eyes over 3 years using Cirrus-HD OCT. Two-dimensional en face slab OCT images of the innermost retina were reconstructed and graded according to the ratio of dark area to total area, and relative red, green, and blue color area ratios were calculated and used as indexes for each en face slab OCT image. Values from en face OCT images were used for statistical analyses. To obtain insight into the pathogenesis of diabetic retinal neurodegeneration, we used the InsPr-Cre;Pdk1^flox/flox diabetic mouse model.

RESULTS

Both OCT grade and relative red color area ratio significantly increased with the advancing stage of diabetic retinopathy (p=0.018 and 0.006, respectively). After a mean follow-up period of 4.6 years, the trend was unchanged in the analyses of 42 untreated eyes (p<0.001 and 0.001, respectively). Visual acuity showed a weak but significant negative correlation with the red color ratio on en face slab OCT images, but central retinal thickness did not exhibit a clinically meaningful correlation with values obtained from en face slab OCT images. Immunohistochemical analyses of InsPr-Cre;Pdk1^flox/flox diabetic mice demonstrated the loss of ganglion axon bundles and thinning of laminin without apparent retinal vascular change at the age of 20 weeks.

CONCLUSIONS

En face slab OCT imaging would be a novel useful modality for the assessment of diabetic retinal neurodegeneration as it could detect subtle optical changes occurring in the innermost retina in diabetic eyes. Our animal experimental data suggest that dark areas observed on en face slab OCT images might be the impairment of the extracellular matrix as well as neurons.

Contrast sensitivity is associated with outer-retina thickness in early-stage diabetic retinopathy

PURPOSE

To determine the relationship between contrast sensitivity (CS) and outer-retina thickness (ORT) in diabetics who have minimal or no diabetic retinopathy (DR).

METHODS

Twenty non-diabetic control subjects and 40 type-2 diabetic subjects participated (20 had no clinically apparent DR [NDR] and 20 had mild non-proliferative DR [NPDR]). No subject had a history of treatment for macular oedema. Letter CS, microperimetry (MP) sensitivity and visual acuity (VA) were measured. Letter CS and MP measurements were performed over the central 6° of the visual field. Spectral domain optical coherence tomography (SD-OCT) images were obtained at corresponding locations, outer-retina thickness was quantified, and structure-function relationships were evaluated.

RESULTS

Analysis of variance indicated significant letter CS differences among the groups (p < 0.001). Letter CS was reduced significantly for the mild NPDR group (p < 0.001; 33% reduction), but not the NDR group (p = 0.08). There were no significant differences in MP sensitivity or ORT among the groups (both p > 0.10). Nevertheless, Hoeffding's D tests indicated significant associations between ORT and letter CS (p < 0.001) and between ORT and MP sensitivity for the mild NPDR group (p = 0.01). VA was not significantly associated with ORT for either diabetic group (both p > 0.49).

CONCLUSIONS

Outer-retina thickness is associated with letter CS and MP sensitivity, but not VA, in mild NPDR. This finding highlights the usefulness of simple letter CS measures and suggests neural dysfunction can occur in the absence of marked structural abnormalities in early-stage DR.

Optical Coherence Tomography Biomarkers of the Outer Blood-Retina Barrier in Patients with Diabetic Macular Oedema

BACKGROUND

Numerous studies confirmed the main role of the inner blood-retinal barrier in the development of Diabetic Macular Oedema (DMO). Lately, the focus of research shifted towards the external retinal barrier with potential involvement in the pathogenesis of DMO.

OBJECTIVE

We aim to identify the OCT changes of the external blood-retinal barrier in patients with DMO and to define them as biomarkers with predictive value. Materials and method. We set up retrospectively 3 groups of patients diagnosed with nonproliferative diabetic retinopathy (NPDR) and DMO, proliferative diabetic retinopathy (PDR) and DMO, and controls. We compared the RPE thickness in every quadrant between groups and performed correlations between best-corrected visual acuity (BCVA) and the thickness of the retinal layers. The Social Science Statistics platform was used for statistical tests.

RESULTS

The NPDR-DMO group consisted of 18 eyes, the PDR-DMO group consisted of 19 eyes, and the control group included 36 eyes. In the PDR-DMO group, RPE thickness was decreased in almost all quadrants (p < 0.001); in the NPDR-DMO group, only the central minimum and central maximum values of the RPE thickness were significantly different from the control group. We did not find any strong correlation between BCVA and the thickness of the retinal layers.

CONCLUSION

The thickness of the RPE layer is an OCT biomarker able to predict the functioning of the outer BRB. Eyes with PDR-DMO exhibited decreased thickness of the RPE layer in almost all quadrants, highlighting the degenerative changes occurring in a hypoxic environment. The thickness of a specific layer could not be identified as a biomarker to correlate significantly with BCVA, most likely because we did not analyze specific morphologic features, such as continuity and reflectivity. The analysis of the RPE thickness could clarify the unexplained decrease of BCVA and predict early the evolution of DR.

Diabetic Macular Edema: State of Art and Intraocular Pharmacological Approaches

Diabetic macular edema (DME) is the main cause of vision loss in diabetic retinopathy (DR). Although it is one of the main complications of diabetes, the pathogenesis of DME is not completely understood. The hyperglycemic state promotes the activation of multiple interlinked pathways leading to DME. Different classifications have been proposed: based on clinical features, on pathogenesis or on diagnostic tests (optical coherence tomography - OCT and fluorescin angiography - FA). The multimodal imaging allows a better analysis of the morphological features of the DME. Indeed, new inflammatory biomarkers have been identified on OCT. Also, several studies are evaluating the role of the morphological features, identified on multimodal imaging, to find new prognostic factors. Over the past decade, great progresses have been made in the management of DME. Therapeutic alternatives include intraocular injection of anti-vascular endothelial grow factor agents (anti-VEGF) and steroid molecules, focal/grid laser photocoagulation and vitreo-retinal surgery. This review is focused on the description and analysis of the current intravitreal therapeutic pharmacological strategies. Current guidelines recommend anti-VEGF as first line therapy in DME. Corticosteroids are becoming increasingly relevant blocking the inflammatory cascade and indirectly reducing VEGF synthesis.