Diabetic macular edema: an OCT-based classification

Autonomous Screening for Diabetic Macular Edema Using Deep Learning Processing of Retinal Images

Objective

To develop and validate a deep learning model for diabetic macular edema (DME) detection using color fundus imaging, which is applicable in a diverse, multidevice clinical setting.

Design

Evaluation of diagnostic test or technology.

Subjects

A deep learning model was trained for DME detection using the EyePACS dataset, consisting of 32 049 images from 15 892 patients. The average age was 55.02%, and 51% of the patients were women.

Methods

Data were randomly assigned, by participant, into development (n = 14 246) and validation (n = 1583) sets. Analysis was conducted on the single image, eye, and patient levels. Model performance was evaluated using sensitivity, specificity, and the area under the receiver operating characteristic curve (AUC). Independent validation was further performed on the Indian Diabetic Retinopathy Image Dataset, as well as on new data.

Main Outcome Measures

Sensitivity, specificity, and AUC.

Results

At the image level, a sensitivity of 0.889 (95% confidence interval [CI]: 0.878, 0.900), a specificity of 0.889 (95% CI: 0.877, 0.900), and an AUC of 0.954 (95% CI: 0.949, 0.959) were achieved. At the eye level, a sensitivity of 0.905 (95% CI: 0.890, 0.920), a specificity of 0.902 (95% CI: 0.890, 0.913), and an AUC of 0.964 (95% CI: 0.958, 0.969) were achieved. At the patient level, a sensitivity of 0.900 (95% CI: 0.879, 0.917), a specificity of 0.900 (95% CI: 0.883, 0.911), and an AUC of 0.962 (95% CI: 0.955, 0.968) were achieved.

Conclusions

Diabetic macular edema can be detected from color fundus imaging with high performance on all analysis metrics. Automatic DME detection may simplify screening, leading to more encompassing screening for diabetic patients. Further prospective studies are necessary.

Financial Disclosures

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

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.

Progression of diabetic retinopathy in women with pregestational diabetes during pregnancy and postpartum

BACKGROUND

Diabetic retinopathy (DR) may worsen during pregnancy, but its course in the postpartum remains poorly understood. Understanding the natural history of DR during and after pregnancy can help determine when sight-threatening DR treatment should be administered.

METHODS

A prospective longitudinal cohort study recruited pregnant women with pre-existing type 1 (T1D) or type 2 diabetes from two tertiary Diabetes Antenatal Clinics in Melbourne, Australia. Eye examination results in early pregnancy, late pregnancy, and up to 12-months postpartum were compared to determine DR changes. Two-field fundus photographs and optical coherence tomography scans were used to assess DR severity.

RESULTS

Overall, 105 (61.4%) women had at least two eye examinations during the observation period. Mean age was 33.5 years (range 19-51); 54 women (51.4%) had T1D; 63% had HbA1c <7% in early pregnancy. DR progression rate was 23.8% (95% CI 16.4-32.6). Having T1D (RR 4.96, 95% CI 1.83-13.46), pre-existing DR in either eye (RR 4.54, 95% CI 2.39-8.61), and elevated systolic blood pressure (adjusted RR 2.49, 95% CI 1.10-5.66) were associated with increased risk of progression. Sight-threatening progression was observed in 9.5% of women. Among the 19 eyes with progression during pregnancy, 15 eyes remained stable, three eyes progressed, and only one eye regressed in the postpartum.

CONCLUSIONS

Nearly 1 in 4 women had DR progression from conception through to 12-months postpartum; almost half of these developing sight-threatening disease. DR progression occurring during pregnancy was found to predominantly remain unchanged, or worsen, after delivery, with very few eyes spontaneously improving postpartum.

Visual Outcome after Anti-Vascular Epithelial Growth Factor Therapy Using New Classification of Diabetic Macular Edema by Optical Coherence Tomography

INTRODUCTION

The aim of the study was to examine alterations in visual acuity in patients with diabetic macular edema (DME), classified according to the TCED-HFV optical coherence tomography (OCT) system, following anti-vascular epithelial growth factor (VEGF) therapy.

METHODS

The medical records of patients with DME receiving anti-VEGF therapy were retrospectively reviewed. Patients were divided into four groups according to the TCED-HFV OCT classification. Patient demographic and clinical characteristics and best-corrected visual acuity (BCVA) before and after treatment were compared among the groups.

RESULTS

The BCVA before treatment was 0.49 ± 0.18, 0.81 ± 0.41, 0.83 ± 0.41, and 0.82 ± 0.49 in the early DME, advanced DME, severe DME, and atrophic maculopathy groups, respectively. The BCVA in the early DME group was therefore significantly lower than that in the other three groups (p = 0.042). After treatment, the BCVA improved to 0.15 ± 0.17, 0.52 ± 0.31, 0.62 ± 0.32, and 0.69 ± 0.47 in the early DME, advanced DME, severe DME, and atrophic maculopathy groups, respectively (p < 0.005). There were some differences among patients in the four groups in terms of the duration of diabetes, percentage of hemoglobin A1c, and duration of hypertension.

CONCLUSION

The TCED-HFV OCT classification of patients with DME is exact and functional and can allow the severity of DME, and its response to anti-VEGF therapy, to be estimated.

Hybrid deep learning models for the screening of Diabetic Macular Edema in optical coherence tomography volumes

Several studies published so far used highly selective image datasets from unclear sources to train computer vision models and that may lead to overestimated results, while those studies conducted in real-life remain scarce. To avoid image selection bias, we stacked convolutional and recurrent neural networks (CNN-RNN) to analyze complete optical coherence tomography (OCT) cubes in a row and predict diabetic macular edema (DME), in a real-world diabetic retinopathy screening program. A retrospective cohort study was carried out. Throughout 4-years, 5314 OCT cubes from 4408 subjects who attended to the diabetic retinopathy (DR) screening program were included. We arranged twenty-two (22) pre-trained CNNs in parallel with a bidirectional RNN layer stacked at the bottom, allowing the model to make a prediction for the whole OCT cube. The staff of retina experts built a ground truth of DME later used to train a set of these CNN-RNN models with different configurations. For each trained CNN-RNN model, we performed threshold tuning to find the optimal cut-off point for binary classification of DME. Finally, the best models were selected according to sensitivity, specificity, and area under the receiver operating characteristics curve (AUROC) with their 95% confidence intervals (95%CI). An ensemble of the best models was also explored. 5188 cubes were non-DME and 126 were DME. Three models achieved an AUROC of 0.94. Among these, sensitivity, and specificity (95%CI) ranged from 84.1-90.5 and 89.7-93.3, respectively, at threshold 1, from 89.7-92.1 and 80-83.1 at threshold 2, and from 80.2-81 and 93.8-97, at threshold 3. The ensemble model improved these results, and lower specificity was observed among subjects with sight-threatening DR. Analysis by age, gender, or grade of DME did not vary the performance of the models. CNN-RNN models showed high diagnostic accuracy for detecting DME in a real-world setting. This engine allowed us to detect extra-foveal DMEs commonly overlooked in other studies, and showed potential for application as the first filter of non-referable patients in an outpatient center within a population-based DR screening program, otherwise ended up in specialized care.

Vitreomacular interface abnormalities in the Ghanaian African

BACKGROUND/OBJECTIVE

Describe vitreomacular interface abnormalities (VMIA) using spectral-domain optical coherence tomography (SD-OCT), and correlations with age-related macular degeneration (AMD) grade in Ghanaian Africans.

SUBJECTS/METHODS

Prospective, cross-sectional study of adults aged ≥50 years recruited in Ghana AMD Study. Participant demographics, medical histories, ophthalmic examination, digital colour fundus photography (CFP) were obtained. High-resolution five-line raster OCT, Macular Cube 512 × 128 scans, and additional line scans in areas of clinical abnormality, were acquired. SD-OCT VMI features classified by International Vitreomacular Traction Study Group system and relationships to AMD grade were evaluated.

OUTCOMES

VMIA prevalence, posterior vitreous detachment (PVD), vitreomacular adhesions (VMA), vitreomacular traction (VMT), epiretinal membranes (ERM), correlations with AMD grade.

RESULTS

The full Ghana AMD cohort included 718 participants; 624 participants (1248 eyes) aged ≥50 years (range = 50-101, mean = 68.8), 68.9% female were included in this analysis. CFP with OCT scans were available for 776 eyes (397 participants); 707 (91.1%) had gradable CFP and OCT scans for both AMD and VMI grading forming the dataset for this report. PVD was absent in 504 (71.3%); partial and complete PVD occurred in 16.7% and 12.0% respectively. PVD did not increase with age (p = 0.720). VMIA without traction and macular holes were observed in 12.2% of eyes; 87.8% had no abnormalities. VMIA was not significantly correlated with AMD grade (p = 0.819).

CONCLUSIONS

This provides the first assessment of VMIA in Ghanaian Africans. VMIA are common in Africans; PVD may be less common than in Caucasians. There was no significant association of AMD grade with VMIA.

Predicting visual outcomes following anti-vascular endothelial growth factor treatment for diabetic macular edema

PURPOSE

To assess the utility of pre-defined imaging biomarkers on optical coherence tomography (OCT) and OCT angiography (OCTA) in patients with diabetic macular edema (DME) following anti-vascular endothelial growth factor (anti-VEGF) therapy in determining visual and anatomical outcomes.

METHODS

In this prospective, non-randomized, and interventional study, 17 patients with treatment-naive DME were included. OCT biomarkers [size/reflectivity of cysts, disorganization of retinal inner layers, integrity of ellipsoid zone or external limiting membrane, subfoveal serous retinal detachment, hyper-reflective foci (HRF)] and OCTA [vascular density (VD), foveal avascular zone (FAZ), and total micro-aneurysms in superficial capillary plexus and deep capillary plexus (DCP)] were analyzed at baseline and after three monthly intravitreal anti-VEGF injections. Response was defined as a decrease of 10% or more in central macular thickness from the baseline after three injections.

RESULTS

13/17 (76.47%) patients were categorized as responders to anti-VEGF therapy. Non-responders had significantly greater hyper-reflectivity of cysts (P = 0.015), larger cystic spaces (P = 0.023), and an increased number of HRF (P = 0.04) at baseline. On OCTA, non-responders showed larger FAZ in DCP (1.35 ± 0.21 versus 1.14 ± 0.28 mm2) (P = 0.042) and lower VD (61.17 ± 0.45 versus 62.73 ± 3.32) in DCP at baseline. At 3 months, the VD increased in responders (63.10 ± 3.42) compared to a decrease in non-responders (60.82 ± 1.13) (P = 0.032).

CONCLUSIONS

Non-responders show a higher number of micro-aneurysms, larger FAZ, and lower VD in the DCP on OCTA and higher cyst hyper-reflectivity and HRF and larger cystic spaces on OCT imaging.

Multivendor fully automatic uncertainty management approaches for the intuitive representation of DME fluid accumulations in OCT images

Diabetes represents one of the main causes of blindness in developed countries, caused by fluid accumulations in the retinal layers. The clinical literature defines the different types of diabetic macular edema (DME) as cystoid macular edema (CME), diffuse retinal thickening (DRT), and serous retinal detachment (SRD), each with its own clinical relevance. These fluid accumulations do not present defined borders that facilitate segmentational approaches (specially the DRT type, usually not taken into account by the state of the art for this reason) so a diffuse paradigm is used for its detection and visualization. In this paper, we propose three novel approaches for the representation and characterization of these types of DME. A baseline proposal, using a convolutional neural network as backbone, another based on transfer learning from a general domain, and a third approach exploiting information of regions without a defined label. Overall, our baseline proposal obtained an AUC of 0.9583 ± 0.0093, the approach pretrained with a general-domain dataset an AUC of 0.9603 ± 0.0087, and the approach pretrained in the domain taking advantage of uncertainty, an AUC of 0.9619 ± 0.0073.

Prevalence of diabetic retinopathy in women with pregestational diabetes during pregnancy and the postpartum

BACKGROUND

Diabetic retinopathy (DR) may be affected by pregnancy. The majority of prevalence data regarding DR in pregnancy predate the advent of contemporary guidelines for diabetes management during pregnancy. This study reports DR prevalence and associated risk factors in women with pregestational diabetes during pregnancy and the postpartum in Australia.

METHODS

A total of 172 pregnant women with type 1 (T1DM) or type 2 diabetes diagnosed pre-pregnancy were prospectively recruited from two obstetrics hospitals in Melbourne (November 2017-March 2020). Eye examinations were scheduled in each trimester, at 3-, 6-, and 12-months postpartum. DR severity was graded from two-field fundus photographs by an independent grader utilising the Airlie House Classification. Sight-threatening DR (STDR) was defined as the presence of diabetic macular oedema or proliferative DR.

RESULTS

Overall, 146 (84.9%) women had at least one eye examination during pregnancy. The mean age was 33.8 years (range 19-51), median diabetes duration was 7.0 years (IQR 3.0-17.0), 71 women (48.6%) had T1DM. DR and STDR prevalence during pregnancy per 100 eyes was 24.3 (95% CI 19.7-29.6) and 9.0 (95% CI 6.1-12.9); while prevalence in the postpartum was 22.2 (95% CI 16.5-29.3) and 10.0 (95% CI 5.4-17.9), respectively. T1DM, longer diabetes duration, higher HbA1c in early pregnancy, and pre-existing nephropathy were significant risk factors.

CONCLUSIONS

The prevalence of DR in pregnant women was similar to the non-pregnant diabetic population in Australia. One in nine participants had STDR during pregnancy and the postpartum, highlighting the need to optimise DR management guidelines in pregnancy given the significant risk of vision loss.

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.

Factors associated with diabetic macular edema in patients with proliferative diabetic retinopathy

PURPOSE

To identify factors associated with diabetic macular edema (DME) and to characterize the types of DME present in eyes with proliferative diabetic retinopathy (PDR).

METHODS

Observational, retrospective case series of PDR patients reviewed for demographic information, general medical history, ophthalmologic history, optical coherence tomography (OCT), and fluorescein angiogram image characteristics. DME and vitreomacular interface (VMI) status were determined using OCT images. DME was defined as center-involving DME (CI-DME) and noncenter-involving DME (NCI-DME). VMI was defined as vitreomacular adhesion (VMA), vitreomacular traction (VMT), or macular posterior vitreous detachment (PVD).

RESULTS

A total of 293 eyes of 210 screened patients with PDR were included. Of the eyes, 194/293 (66.2%) had DME, and 99/293 (33.8%) had no DME; in univariable analysis, there were no significant differences in VMI status (p = 0.4) or epiretinal membrane (ERM, p = 0.1) between them. Of 194 eyes with DME, 90/194 (46.4%) had CI-DME, and 104/194 (53.6%) had NCI-DME. In univariable analysis, CI-DME eyes were significantly more likely than NCI-DME eyes to have a PVD (p = 0.029) and ERM (p < 0.001). In multivariable analysis, the presence of younger age (p = 0.028) and presence of ERM (p = 0.001) were significantly more likely to be observed in eyes with CI-DME.

CONCLUSION

In this exploratory study focused on diabetic patients with PDR, we determined that VMI status did not have a significant association with DME in general, but VMI status, younger age, and presence of ERM may be associated with CI-DME.

Imaging diabetic retinal disease: clinical imaging requirements

Diabetic retinopathy (DR) is a sight-threatening complication of diabetes mellitus (DM) and it contributes substantially to the burden of disease globally. During the last decades, the development of multiple imaging modalities to evaluate DR, combined with emerging treatment possibilities, has led to the implementation of large-scale screening programmes resulting in improved prevention of vision loss. However, not all patients are able to participate in such programmes and not all are at equal risk of DR development and progression. In this review, we discuss the relevance of the currently available imaging modalities for the evaluation of DR: colour fundus photography (CFP), ultrawide-field photography (UWFP), fundus fluorescein angiography (FFA), optical coherence tomography (OCT), OCT angiography (OCTA) and functional testing. Furthermore, we suggest where a particular imaging technique of DR may aid the evaluation of the disease in different clinical settings. Combining information from various imaging modalities may enable the design of more personalized care including the initiation of treatment and understanding the progression of disease more adequately.

Joint Diabetic Macular Edema Segmentation and Characterization in OCT Images

The automatic identification and segmentation of edemas associated with diabetic macular edema (DME) constitutes a crucial ophthalmological issue as they provide useful information for the evaluation of the disease severity. According to clinical knowledge, the DME disorder can be categorized into three main pathological types: serous retinal detachment (SRD), cystoid macular edema (CME), and diffuse retinal thickening (DRT). The implementation of computational systems for their automatic extraction and characterization may help the clinicians in their daily clinical practice, adjusting the diagnosis and therapies and consequently the life quality of the patients. In this context, this paper proposes a fully automatic system for the identification, segmentation and characterization of the three ME types using optical coherence tomography (OCT) images. In the case of SRD and CME edemas, different approaches were implemented adapting graph cuts and active contours for their identification and precise delimitation. In the case of the DRT edemas, given their fuzzy regional appearance that requires a complex extraction process, an exhaustive analysis using a learning strategy was designed, exploiting intensity, texture, and clinical-based information. The different steps of this methodology were validated with a heterogeneous set of 262 OCT images, using the manual labeling provided by an expert clinician. In general terms, the system provided satisfactory results, reaching Dice coefficient scores of 0.8768, 0.7475, and 0.8913 for the segmentation of SRD, CME, and DRT edemas, respectively.

Diabetic maculopathy: multicolour and SD-OCT versus fundus photography

Objective

The English Diabetic Eye Screening (DES) programme recommends patients with M1 diabetic maculopathy to be referred to hospital eye services. DES uses flash fundus photography as the reference standard for maculopathy grading. We compared multicolour versus non-stereoscopic fundus photography at identifying M1 maculopathy, with spectral domain optical coherence tomography (SD-OCT) identifying macular thickening.

Methods and analysis

This cross-sectional study included 345 patients with R1M1 referred from DES and reviewed in secondary care with fundus photographs, multicolour and SD-OCT. Maculopathy was graded based on DES exudate criteria on both multicolour and fundus photography in a blind fashion by two independent graders. Macular thickness was ascertained on SD-OCT.

Results

Intergrader agreement on grading maculopathy using fundus photography (Cohen's κ=0.91) and multicolour (Cohen's κ=0.82) was 'almost perfect'. Agreement between fundus photography and multicolour on grading maculopathy (Cohen's κ=0.76) was 'substantial'. Compared with fundus photography, multicolour had sensitivity of 87% (95% CI 81% to 93%) and specificity of 90% (95% CI 87% to 94%) in detecting M1 maculopathy. SD-OCT identified 84 eyes with macular thickening, 47 of which were graded as M0 by fundus photography. 5 eyes with exudates and severe macular oedema requiring urgent intervention were also missed on fundus photography but not on multicolour. Multicolour, when complemented by SD-OCT, did not miss any clinically significant macular oedema.

Conclusion

Multicolour integrates synergistically in a single platform with SD-OCT providing effective monitoring of M1 diabetic maculopathy. The need for fundus photography is eliminated by multicolour/SD-OCT in dedicated R1M1 virtual clinics not requiring parallel diabetic retinopathy grading.

A study of therapeutic effects of 670 nm irradiation in different types of diabetic macular edema

The purpose of this study was to investigate the therapeutic effects of 670 nm irradiation in patients with diabetic macular edema. In several studies, positive effects of red/near-infrared irradiation showed in a range of ocular diseases such as macular degeneration, macular edema, and retinitis pigmentosa. This study was conducted on forty five eyes of 26 diabetic patients with macular edema between the ages of 51 and 80.

Measurement of visual acuity and slit lamp examination, funduscopy, and optical coherence tomography were performed in all subjects. None of the patients had proliferative retinopathy. We used a portable LED device (Warp 10, Quantum Devices) for treatment. Patients held this device at a distance of 3 cm from their eyes for 240 seconds for three months. Full ophthalmic examinations were repeated 1, 2, and 3 months after treatment.

After 3 months, the mean visual acuity improved from 0.44 ± 0.38 log MAR to 0.27 ± 0.24 log MAR and vision increased by 1.52 ± 1.16 lines post treatment (р<0.001). The mean central macula thickness decreased from 381.49 ± 144.40 μm to 359.72 ± 128.84 μm (р=0.050). In patients with mild and moderate nonproliferative diabetic retinopathy, the mean central retinal thickness decreased 52.06 ± 67.78 μm and 39.27 ± 44.69 μm, respectively, but patients with severe type showed an increase of 34.93 ± 65.65 μm in the mean central retinal thickness (р<0.001). Also, the severity of macular edema had no effect on final outcomes (р>0.05). Photobiomodulation can positively affect diabetic macular edema, especially in patients with mild to moderate diabetic retinopathy.

Alone laser versus bevacizumab plus laser for diffuse diabetic macular edema (ALBA randomized trial)

Purpose:

To report the 12-month results of laser (treatment G1) versus intravitreal bevacizumab combined with laser (treatment G2) in patients with diffuse diabetic macular edema (DME).

Methods:

In this single-center randomized independent controlled trial, 32 patients were randomized to G1 (n = 15) or G2 (n = 17). In G1, laser was given at baseline and then pro re nata (PRN). In G2, three intravitreal bevacizumab (1.25 mg) injections were given once every 6 weeks, then laser and then PRN. Analysis was performed by treatment as administered. This study was registered in clinicaltrials.gov as NCT01572350 and EU Clinical Trial Registry as 2009-014654-15.

Results:

G2 was superior to G1 improving best corrected visual acuity (BCVA) with respect baseline (+8.0 vs + 3.0; p < 0.01). At month 12, a significantly greater proportion of patients had a BCVA letter score >15 and >73 in G2 (3 of 15 (20%) and 8 of 15 (53%), respectively) versus G1 (1 of 17 (6%) and 4 of 18 (23%), respectively). Health-related quality of life, assessed through National Eye Institute Visual Function Questionnaire, at 12 months was statistically indistinguishable between both groups.

Conclusion:

G2 provided superior visual acuity gains over G1 in patients with visual impairment due to center-involving diffuse DME, associated with significant gains in VFQ-25 scores.

Evaluation of real-world early response of DMO to aflibercept therapy to inform future clinical trial design of novel investigational agents

New clinical trials for diabetic macular oedema (DMO) are being designed to prove superiority over aflibercept when this agent is already very effective in improving visual acuity (VA) and DMO. The aim of this study was to determine the optimal inclusion–exclusion criteria for trials to aim for superiority in visual outcomes with newer agents. As Phase 1 studies are short duration, we aimed to evaluate the early response of aflibercept in a real-world cohort initiated on monthly aflibercept for 3 consecutive injections and observed the effects at 4 months. The sub-optimal responders were pre-defined based on different cut-offs for VA and central sub-field thickness (CST). 200 patients with treatment naïve DMO treated with 3 loading doses of aflibercept were included in the study. We found that those presenting with baseline VA of 35–54 ETDRS letters (n = 43) had higher proportion of sub-optimal responders compared to other categories (p < 0.001). Patients with baseline CST of less than 400 µm (n = 96) responded less well functionally and anatomically to loading dose than eyes with baseline CST of 400 µm or more (n = 104, p = 0.02), indicating that eyes with CST ≥ 400 µm is another inclusion criteria. There was minimal correlation between change in CST and change in VA at 4 months (r = − 0.27), suggesting that both these inclusion criteria are non-exclusive. However, for maximal efficacy, patients that meet both these inclusion criteria are more likely to show benefit from an alternative intervention. New trials should aim to include patients with treatment naïve DMO with VA between 35–54 letters and CST of 400 µm or more when aflibercept is used as the comparator.

Infrared retinal images for flashless detection of macular edema

This study evaluates the use of infrared (IR) images of the retina, obtained without flashes of light, for machine-based detection of macular oedema (ME). A total of 41 images of 21 subjects, here with 23 cases and 18 controls, were studied. Histogram and gray-level co-occurrence matrix (GLCM) parameters were extracted from the IR retinal images. The diagnostic performance of the histogram and GLCM parameters was calculated in hindsight based on the known labels of each image. The results from the one-way ANOVA indicated there was a significant difference between ME eyes and the controls when using GLCM features, with the correlation feature having the highest area under the curve (AUC) (A_Z) value. The performance of the proposed method was also evaluated using a support vector machine (SVM) classifier that gave sensitivity and specificity of 100%. This research shows that the texture of the IR images of the retina has a significant difference between ME eyes and the controls and that it can be considered for machine-based detection of ME without requiring flashes of light.

Classification of advanced and early stages of diabetic retinopathy from non-diabetic subjects by an ordinary least squares modeling method applied to OCTA images

As the prevalence of diabetic retinopathy (DR) continues to rise, there is a need to develop computer-aided screening methods. The current study reports and validates an ordinary least squares (OLS) method to model optical coherence tomography angiography (OCTA) images and derive OLS parameters for classifying proliferative DR (PDR) and no/mild non-proliferative DR (NPDR) from non-diabetic subjects. OLS parameters were correlated with vessel metrics quantified from OCTA images and were used to determine predicted probabilities of PDR, no/mild NPDR, and non-diabetics. The classification rates of PDR and no/mild NPDR from non-diabetic subjects were 94% and 91%, respectively. The method had excellent predictive ability and was validated. With further development, the method may have potential clinical utility and contribute to image-based computer-aided screening and classification of stages of DR and other ocular and systemic diseases.

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.

Automatic Identification and Intuitive Map Representation of the Epiretinal Membrane Presence in 3D OCT Volumes

Optical Coherence Tomography (OCT) is a medical image modality providing high-resolution cross-sectional visualizations of the retinal tissues without any invasive procedure, commonly used in the analysis of retinal diseases such as diabetic retinopathy or retinal detachment. Early identification of the epiretinal membrane (ERM) facilitates ERM surgical removal operations. Moreover, presence of the ERM is linked to other retinal pathologies, such as macular edemas, being among the main causes of vision loss. In this work, we propose an automatic method for the characterization and visualization of the ERM's presence using 3D OCT volumes. A set of 452 features is refined using the Spatial Uniform ReliefF (SURF) selection strategy to identify the most relevant ones. Afterwards, a set of representative classifiers is trained, selecting the most proficient model, generating a 2D reconstruction of the ERM's presence. Finally, a post-processing stage using a set of morphological operators is performed to improve the quality of the generated maps. To verify the proposed methodology, we used 20 3D OCT volumes, both with and without the ERM's presence, totalling 2428 OCT images manually labeled by a specialist. The most optimal classifier in the training stage achieved a mean accuracy of 91 . 9 % . Regarding the post-processing stage, mean specificity values of 91 . 9 % and 99 . 0 % were obtained from volumes with and without the ERM's presence, respectively.

Classifications of diabetic macular edema

Diabetic retinopathy is a major cause worldwide of vision loss from diabetic maculopathy or proliferative retinopathy. Without widely accepted classifications of diabetic retinopathy and diabetic maculopathy, it is difficult to compare results of clinical trials or monitor clinical care. The European School of Advanced Studies in Ophthalmology has developed an international classification of diabetic maculopathy based upon spectral domain optical coherence tomography, which could be helpful for both initial evaluation and subsequent follow-up of diabetic patients in both clinical practice and experimental trials.

An optical coherence tomography-based grading of diabetic maculopathy proposed by an international expert panel: The European School for Advanced Studies in Ophthalmology classification

AIMS

To present an authoritative, universal, easy-to-use morphologic classification of diabetic maculopathy based on spectral domain optical coherence tomography.

METHODS

The first draft of the project was developed based on previously published classifications and a literature search regarding the spectral domain optical coherence tomography quantitative and qualitative features of diabetic maculopathy. This draft was sent to an international panel of retina experts for a first revision. The panel met at the European School for Advanced Studies in Ophthalmology headquarters in Lugano, Switzerland, and elaborated the final document.

RESULTS

Seven tomographic qualitative and quantitative features are taken into account and scored according to a grading protocol termed TCED-HFV, which includes foveal thickness (T), corresponding to either central subfoveal thickness or macular volume, intraretinal cysts (C), the ellipsoid zone (EZ) and/or external limiting membrane (ELM) status (E), presence of disorganization of the inner retinal layers (D), number of hyperreflective foci (H), subfoveal fluid (F), and vitreoretinal relationship (V). Four different stages of the disease, that is, early diabetic maculopathy, advanced diabetic maculopathy, severe diabetic maculopathy, and atrophic maculopathy, are based on the first four variables, namely the T, C, E, and D. The different stages reflect progressive severity of the disease.

CONCLUSION

A novel grading system of diabetic maculopathy is hereby proposed. The classification is aimed at providing a simple, direct, objective tool to classify diabetic maculopathy (irrespective to the treatment status) even for non-retinal experts and can be used for therapeutic and prognostic purposes, as well as for correct evaluation and reproducibility of clinical investigations.

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.

Automatic identification and characterization of the epiretinal membrane in OCT images

Optical coherence tomography (OCT) is a medical image modality that is used to capture, non-invasively, high-resolution cross-sectional images of the retinal tissue. These images constitute a suitable scenario for the diagnosis of relevant eye diseases like the vitreomacular traction or the diabetic retinopathy. The identification of the epiretinal membrane (ERM) is a relevant issue as its presence constitutes a symptom of diseases like the macular edema, deteriorating the vision quality of the patients. This work presents an automatic methodology for the identification of the ERM presence in OCT scans. Initially, a complete and heterogeneous set of features was defined to capture the properties of the ERM in the OCT scans. Selected features went through a feature selection process to further improve the method efficiency. Additionally, representative classifiers were trained and tested to measure the suitability of the proposed approach. The method was tested with a dataset of 285 OCT scans labeled by a specialist. In particular, 3,600 samples were equally extracted from the dataset, representing zones with and without ERM presence. Different experiments were conducted to reach the most suitable approach. Finally, selected classifiers were trained and compared using different metrics, providing in the best configuration an accuracy of 89.35%.

An evidence-based approach to the routine use of optical coherence tomography

Optical coherence tomography is an imaging technology that has revolutionised the detection, assessment and management of ocular disease. It is now a mainstream technology in clinical practice and is performed by non-specialised personnel in some settings. This article provides a clinical perspective on the implications of that movement and describes best practice using multimodal imaging and an evidence-based approach. Practical, illustrative guides on the interpretation of optical coherence tomography are provided for three major diseases of the ocular fundus, in which optical coherence tomography is often crucial to management: age-related macular degeneration, diabetic retinopathy and glaucoma. Topics discussed include: cross-sectional and longitudinal signs in ocular disease, so-called 'red-green' disease whereby clinicians rely on machine/statistical comparisons for diagnosis in managing treatment-naïve patients, and the utility of optical coherence tomography angiography and machine learning.

Intravitreal injection of a Rho-kinase inhibitor (fasudil) combined with bevacizumab versus bevacizumab monotherapy for diabetic macular oedema: a pilot randomised clinical trial

Background/aims

To compare the efficacy of combined intravitreal injection of bevacizumab and a Rho-kinase inhibitor, fasudil (intravitreal bevacizumab (IVB)/intravitreal fasudil (IVF)), with IVB alone for centre-involving diabetic macular oedema (DME).

Methods

In this prospective randomised clinical trial, 44 eyes with centre-involving DME were randomised into two groups. The combined group received three consecutive injections of IVB (1.25 mg) and IVF (50 µM/L) monthly, while the monotherapy group received only one IVB (1.25 mg) injection per month for 3 months. Changes in best-corrected visual acuity (BCVA) and central macular thickness (CMT) were compared between the two groups at months 3 and 6. The primary outcome measure was the mean change in BCVA at month 6.

Results

Mean BCVA was significantly improved in both groups at month 3 (P<0.001), but it persisted up to month 6 only in the IVB/IVF group. Improvement of BCVA was greater in the IVB/IVF group at both time points (P=0.008, P<0.001). In the IVB/IVF and IVB groups, 54.5% versus 10% of the eyes gained≥15 ETDRS letters at month 6 (P=0.026). Between months 3 and 6, mean BCVA significantly decreased by 5±7 ETDRS letters in the IVB group (P=0.002), while no significant deterioration was observed in the IVB/IVF group. Corresponding with the BCVA changes, CMT was significantly reduced in both groups at month 3 (p=0.006, p<0.001) but this reduction sustained only in the IVB/IVF group up to month 6 (p<0.001).

Conclusion

Adjunctive intravitreal injection of a Rho-kinase inhibitor may enhance and prolong the therapeutic effects of anti-vascular endothelial growth factor drugs for centre- involving DME.

THE RELATIONSHIP BETWEEN FOVEAL AVASCULAR ZONE AREA, VESSEL DENSITY, AND CYSTOID CHANGES IN DIABETIC RETINOPATHY: AN OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY STUDY

PURPOSE

To measure the foveal avascular zone (FAZ) areas and vessel densities of patients with diabetic retinopathy and to study their relationship with diabetic cystoid changes and retinal thickness.

METHODS

Prospective case series of 51 eyes of 31 patients with diabetic retinopathy. The eyes were grouped based on the presence or absence of cystoid edema and evaluated using optical coherence tomography angiography. The FAZ areas and vessel density were compared.

RESULTS

The FAZ area at the superficial capillary plexus level was equal between the eyes with and without cystoid edema. Vessel density did not differ as well. There was no correlation with retinal thickness. In eyes with cystoid changes, FAZ area changes at the deep capillary plexus level were difficult to interpret.

CONCLUSION

The FAZ area and vessel density at the superficial capillary plexus level are reproducible and independent of the presence of cystoid edema.

Evaluation of systemic risk factors in different optical coherence tomographic patterns of diabetic macular edema

AIM

To elucidate the relationship between systemic risk factors and different patterns of diabetic macular edema (DME) determined with optical coherence tomography (OCT).

METHODS

In this cross-sectional study, DME was classified by OCT as diffuse retinal thickness (DRT), cystoid macular edema (CME) and serous retinal detachment (SRD) and the relationship between the systemic risk factors and DME patterns was evaluated.

RESULTS

Of the 57 patients with DME, 21 (36.8%) had DRT, 24 (42.1%) had CME and 12 (21.0%) had SRD. Micro- or macro-albuminuria was significantly higher in the DRT pattern (61.9%) compared with the SRD (50.0%) and CME patterns (25.0%; P=0.040). Hemoglobin A1c (HbA1c) level was significantly higher and patients were younger in the DRT pattern group (P=0.034, P=0.032). Best corrected visual acuity was the worst and central macular thickness was the thickest in the CME pattern group.

CONCLUSION

Micro- or macro-albuminuria may be more frequent and HbA1c level may be higher in patients with DRT. These patients are also seen to be younger than patients with non-DRT.

Qualitative and quantitative assessment of posterior segment optical coherence tomography images using standard photos: the Liwan Eye Study

BACKGROUND/AIMS

To develop a standardised grading scheme, using standard photos, for spectral-domain ocular coherence tomography (SD-OCT) images of the posterior eye and evaluate the interobserver agreement among trained ophthalmologists in identifying pathological changes.

METHODS

Subjects were recruited from Liwan District, Guangzhou, with SD-OCT data collection from June 2013 to November 2013 as part of 10-year follow-up visits from the Liwan Eye Study. All subjects underwent SD-OCT imaging of the macula with scanning lines analysed by two ophthalmologists to assess for the presence of 12 different posterior segment lesions. Per cent agreement for each lesion between the graders and quantitative measures of dome-shaped macula (DSM) height and choroidal thickness were calculated.

RESULTS

A total of 679 SD-OCT images from 679 subjects were independently evaluated by the two graders. Each of the 12 lesions was successfully graded as present or absent in over 96% of images. For all lesions, per cent agreement between observers was over 90%, ranging from 90.7% for epiretinal membranes and retinal pigment epithelium thickenings to 99.7% for full thickness macular holes and retinal detachments. Quantitative measurements of DSM height and choroidal thickness at three locations of the eye all exhibited intraclass correlation scores between the two graders of greater than 0.9.

CONCLUSION

Our study demonstrates high concordance between graders in characterising posterior segment lesions using SD-OCT images, validating the continued use of this imaging modality in the diagnosis of posterior eye disease.

ReLayNet: retinal layer and fluid segmentation of macular optical coherence tomography using fully convolutional networks

Optical coherence tomography (OCT) is used for non-invasive diagnosis of diabetic macular edema assessing the retinal layers. In this paper, we propose a new fully convolutional deep architecture, termed ReLayNet, for end-to-end segmentation of retinal layers and fluid masses in eye OCT scans. ReLayNet uses a contracting path of convolutional blocks (encoders) to learn a hierarchy of contextual features, followed by an expansive path of convolutional blocks (decoders) for semantic segmentation. ReLayNet is trained to optimize a joint loss function comprising of weighted logistic regression and Dice overlap loss. The framework is validated on a publicly available benchmark dataset with comparisons against five state-of-the-art segmentation methods including two deep learning based approaches to substantiate its effectiveness.

Optical Coherence Tomography-Guided Decisions in Retinoblastoma Management

PURPOSE

Assess the role of handheld optical coherence tomography (OCT) in guiding management decisions during diagnosis, treatment, and follow-up of eyes affected by retinoblastoma.

DESIGN

Retrospective, noncomparative, single-institution case series.

PARTICIPANTS

All children newly diagnosed with retinoblastoma from January 2011 to December 2015 who had an OCT session during their active treatment at The Hospital for Sick Children (SickKids) in Toronto, Canada. The OCT sessions for fellow eyes of unilateral retinoblastoma without any suspicious lesion and those performed more than 6 months after the last treatment were excluded.

METHODS

Data collected included age at presentation, sex, family history, RB1 mutation status, 8th edition TNMH cancer staging and International Intraocular Retinoblastoma Classification (IIRC), and number of OCT sessions per eye. Details of each session were scored for indication-related details (informative or not) and assessed for guidance (directive or not), diagnosis (staging changed, new tumors found or excluded), treatment (modified, stopped, or modality shifted), or follow-up modified.

MAIN OUTCOME MEASURES

Frequency of OCT-guided management decisions, stratified by indication and type of guidance (confirmatory vs. influential).

RESULTS

Sixty-three eyes of 44 children had 339 OCT sessions over the course of clinical management (median number of OCT scans per eye, 5; range, 1-15). The age at presentation and presence of a heritable RB1 mutation significantly correlated with an increased number of OCT sessions. Indications included evaluation of post-treatment scar (55%) or fovea (16%), and posterior pole scanning for new tumors (11%). Of all sessions, 92% (312/339) were informative; 19 of 27 noninformative sessions had large, elevated lesions; of these, 14 of 19 were T2a or T2b (IIRC group C or D) eyes. In 94% (293/312) of the informative sessions, OCT directed treatment decisions (58%), diagnosis (16%), and follow-up (26%). Optical coherence tomography influenced and changed management from pre-OCT clinical plans in 15% of all OCT sessions and 17% of directive sessions.

CONCLUSIONS

Optical coherence tomography improves the accuracy of clinical evaluation in retinoblastoma management.

Recommendations for the Appropriate Management of Diabetic Macular Edema: Light on DME Survey and Consensus Document by an Expert Panel

Purpose

The Light on DME survey was designed to address several issues concerning the management of diabetic macular edema (DME) with the objective of producing practical recommendations for the appropriate treatment of this condition.

Methods

The recommendations considered aspects of DME treatment that are controversial and insufficiently supported by the evidence and were based on a consensus reached by an expert panel. Consensus was achieved by means of the Delphi method. Thirty-one Italian retinologists were asked to rate the appropriateness of a comprehensive set of scenarios typically encountered in the management of DME in clinical practice. The results of the appropriateness evaluation were analyzed by the study panel and a second assessment round was conducted for those scenarios on which no consensus was reached.

Results

Consensus was reached on several relevant aspects of current DME management, namely the initiation and course of treatment with anti-vascular endothelial growth factor (VEGF) therapy, assessment of the outcomes of anti-VEGF therapy based on both functional and morphologic outcomes, combination of anti-VEGF with laser therapy, and management of nonresponders to anti-VEGFs. A few issues, including the definition of DME based on novel diagnostic tools, the need for stable metabolic parameters before initiating anti-VEGF therapy, and the use of a second anti-VEFG after failure of the first anti-VEGF, proved controversial.

Conclusions

A clear consensus among DME experts was reached on several relevant aspects of DME management. Based on this consensus, detailed and practical recommendations to guide ophthalmologists in the use of novel approaches to DME could be developed.

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.

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.

The Vitreomacular Interface in Diabetic Retinopathy

Diabetic retinopathy (DR) is a leading health concern and a major cause of blindness. DR can be complicated by scar tissue formation, macular edema, and tractional retinal detachment. Optical coherence tomography has found that patients with DR often have diffuse retinal thickening, cystoid macular edema, posterior hyaloid traction, and tractional retinal detachment. Newer imaging techniques can even detect fine tangential folds and serous macular detachment. The interplay of the vitreous and the retina in the progression of DR involves multiple chemokine and other regulatory factors including VEGF. Understanding the cells infiltrating pathologic membranes at the vitreomacular interface has opened up the possibility of new targets for pharmacotherapy. Vitrectomies for DR remain a vital tool to help relieve tension on the macula by removing membranes, improving edema absorption, and eliminating the scaffold for new membrane formation. Newer treatments such as triamcinolone acetonide and VEGF inhibitors have become essential as a rapid way to control DR at the vitreomacular interface, improve macular edema, and reduce retinal neovascularization. These treatments alone, and in conjunction with PRP, help to prevent worsening of the VMI in patients with DR.

Volcano like pattern in optical coherence tomography in chronic diabetic macular edema

In this article we herein report an interesting vitreo-macular interface abnormality associated with chronic diabetic cystoid macular edema. It is an observational case study of three diabetic patients examined in the diabetic clinic. All the patients had proliferative diabetic retinopathy with chronic macular edema. A serial cross sectional OCT examination and tracking of both the longitudinal progression of macular thickening and vitreo-macular interface revealed cystoid macular edema with a characteristic hyperreflective vitreous shadow emerging from the vitreofoveal interface. All the patients had dehiscence of inner retinal layers. This particular morphological feature at the vitreo-foveolar interface, which we name as "volcano sign", has not been described earlier. The probable mechanism of such a finding probably could be due to slow progressive leakage of chronic cytoid fluid into the vitreous with condensation of the overlying vitreous. Vitreo-macular traction followed by posterior vitreous detachment probably would have contributed to such a morphological event.

The diagnostic function of OCT in diabetic maculopathy

Diabetic maculopathy (DM) is one of the major causes of vision impairment in individuals with diabetes. The traditional approach to diagnosis of DM includes fundus ophthalmoscopy and fluorescein angiography. Although very useful clinically, these methods do not contribute much to the evaluation of retinal morphology and its thickness profile. That is why a new technique called optical coherence tomography (OCT) was utilized to perform cross-sectional imaging of the retina. It facilitates measuring the macular thickening, quantification of diabetic macular oedema, and detecting vitreoretinal traction. Thus, OCT may assist in patient selection with DM who can benefit from treatment, identify what treatment is indicated, guide its implementing, and allow precise monitoring of treatment response. It seems to be the technique of choice for the early detection of macular oedema and for the followup of DM.

Optical coherence tomography classification of diabetic cystoid macular edema

Purpose

To propose a new classification of diabetic cystoid macular edema (CME) based on optical coherence tomography (OCT) findings and cover all new important findings.

Patients and methods

A retrospective study was carried out in the El-Minia Investigation Eye Center between January 2012 and November 2012. It included 104 eyes of 86 patients, aged between 50 and 71 years, all with type II diabetes mellitus of duration from 5 to 20 years. All patients were diagnosed to have CME, as assessed by OCT, with measurement of the vertical size of the largest macular cyst and maximum macular thickness, and the relation between them.

Results

Patients were divided into four groups. Eyes with cysts less than 30% of macular thickness were considered to have CME I (n = 4, 3.84%), while those between 30% and 60% were considered to have CME II (n = 62, 59.62%). Eyes with cysts between 60% and 90% of macular thickness were considered to have CME III (n = 36, 34.62%). CME IV was diagnosed when the size of the cyst became more than 90% of the macular thickness, and this was encountered in two eyes (1.92%).

Conclusions

OCT is a useful technique for quantitative measurement and helps in better anatomical characterization of CME, and this classification of diabetic CME may be of value in classification of CME due to causes other than diabetes.

Association of systemic comorbidity in diabetic serous macular detachment and comparison of various combination therapies in its management

BACKGROUND

The purpose of this research was to study the association between systemic comorbidity in diabetic serous macular detachment (DSMD) and the effect of different forms of combination therapies in its management.

METHODS

In this prospective analysis, 34 eyes from 34 patients with DSMD were investigated for the presence of systemic comorbidity including anemia, dyslipidemia, nephropathy, and cardiac disease, and treated with combination therapy of either intravitreal bevacizumab + laser (group 1, n = 14) or intravitreal triamcinolone + laser (group 2, n = 20). Sequential macular laser was done 2 weeks after intravitreal pharmacotherapy in both groups. Outcome measures included visual acuity and central foveal thickness at 1 and 3 months.

RESULTS

The mean age of the patients was 55.6 ± 7.6 years. The commonest systemic association was nephropathy (82.3%). In group 1, mean visual acuity improved marginally from 6/17 at baseline to 6/16 at 1 month (P = 0.0001) and was maintained at 3 months (P = 0.008); and mean central foveal thickness decreased from 488.7 μm to 318.7 μm at 1 month (P = 0.0001) but increased to 414.4 μm at 3 months (P = 0.049). In group 2, mean visual acuity improved from 6/22 at baseline to 6/19 at 1 month (P = 0.0001) and 6/12 at 3 months (P = 0.0001); and mean central foveal thickness decreased from 428.8 μm to 323.8 μm at 1 month (P = 0.0001) to 269.2 μm at 3 months (P = 0.0001).

CONCLUSION

Nephropathy should be ruled out in patients with DSMD. Although at 1 month both intravitreal triamcinolone and bevacizumab improved vision and decreased central foveal thickness in eyes with DSMD when administered along with focal laser treatment, the former had a more long-lasting effect in maintaining this gain at 3 months.

Effect of panretinal photocoagulation on macular morphology and thickness in eyes with proliferative diabetic retinopathy without clinically significant macular edema

Background

The purpose of this study was to investigate the effect of panretinal photocoagulation (PRP) on macular morphology and thickness in eyes with proliferative diabetic retinopathy (PDR) and without clinically significant macular edema.

Methods

This was a prospective study of 76 eyes from 68 patients diagnosed to have PDR without clinically significant macular edema. Baseline and post PRP visual acuity, morphological changes on optical coherence tomography (OCT), and central foveal thickness were evaluated at one week, one month, and 3 months.

Results

The mean patient age was 56.47 ± 6.55 years. Sixty-two eyes (81.58%) had stable or improved vision, while 14 eyes (18.42%) had worsened visual acuity at 3 months. Compared with baseline, mean visual acuity dropped as early as one week but was regained by 3 months. Mean preoperative central foveal thickness was 222.05 ± 59.11 μm, which increased significantly to 266.84 ± 84.67 μm at one week (P = 0.001), and remained higher at 264.05 ± 102.56 μm by one month (P = 0.01) and 256 ± 101.38 μm by 3 months (P = 0.04). Thirty-four percent of eyes with a normal macula showed morphological changes following PRP. The most common morphological change on OCT after PRP was spongy edema, seen in 48 eyes (31.6%), followed by cystoid macular edema in 36 eyes (23.7%), vitreomacular traction in 28 eyes (18.4%), epiretinal membrane in 24 eyes (15.8%), and subfoveal serous detachment in 16 eyes (10.5%).

Conclusion

PRP may cause a temporary drop in vision in the early post laser phase, and causes macular morphology/thickness changes in eyes with PDR and without clinically significant macular edema. In this study, the change in central foveal thickness did not correlate with a change in visual acuity, and the type of diabetic macular edema on OCT appeared more relevant and correlated better with the visual outcome.

Optical coherence tomographic patterns in diabetic macula edema can predict the effects of intravitreal bevacizumab injection as primary treatment

PURPOSE

To identify optical coherence tomography (OCT) patterns in diabetic macular edema (DME) that were predictive of visual outcomes after intravitreal bevacizumab (IVB) injection.

METHODS

This was a retrospective study. We examined 31 eyes (24 patients) with clinically significant macular edema that received IVB injections along with macular OCT data. The eyes were categorized into 4 groups by using OCT features: diffuse retinal thickening (DRT), cystoid macular edema (CME), serous retinal detachment (SRD), and vitreomacular interface abnormalities (VMIAs). Changes in retinal thickness, retinal volume, and visual acuity (VA) after IVB injection were compared on the basis of OCT patterns.

RESULTS

After IVB injections, changes in VA logarithm of the minimum angle of resolution were -0.06±0.36, -0.26±0.26, 0.09±0.13, and -0.08±0.15, respectively, for DRT, CME, SRD, and VMIA patterns. Central macular thickness decreased by 70.5±105.5, 110.67±97.28, 181±125.87, and 24.25±77.12 μm for the DRT, CME, SRD, and VMIA patterns, respectively. The CME group was associated with a greater reduction in retinal thickness (P=0.009) and volume (P=0.027) with superior VA improvement (P=0.012) as compared with the DRT, SRD, and VMIA groups.

CONCLUSIONS

Patients with CME gained greater improvement in visual acuity and macular thickness and volume after IVB injection had been administered as the primary treatment for DME, as compared with other patients. The OCT patterns of DME may indicate the appropriate treatment; we consider these patterns to be prognostic of the response to IVB injection for macular edema.

The management of diabetic macular oedema

Diabetic macular oedema (DMO) is a significant cause of visual loss in the working population. Focal/grid photocoagulation remains an effective treatment for DMO and the benchmark to which clinicians compare other newer treatment modalities. There are, however, patients who do not respond adequately or who are refractory to laser photocoagulation. This has led to the development of newer treatments such as the intravitreal injection of vascular endothelial growth factor (VEGF) inhibitors as well as intravitreal corticosteroid releasing delivery systems. Cataract formation and raised intraocular pressure remain the major disadvantages of corticosteroid use. There is mounting evidence that intravitreal VEGF inhibitors with or without combined laser photocoagulation will become the gold standard treatment for DMO.

Ocular coherence tomography and diabetic eye disease

Optical Coherence Tomography (OCT) is a high-resolution, cross-sectional imaging technique that allows detailed assessment of retinal thickness and morphologic evaluation of the neurosensory retinal layers. OCT imaging has rapidly been integrated into diagnosis and management of diabetic macular edema (DME) in routine clinical practice and clinical trials. OCT findings correlate well with other evaluation techniques for DME. Although there is a moderate correlation between OCT measured retinal thickness and visual acuity, OCT cannot replace visual acuity because there is a high degree of variability. Recent improvements in OCT technology have led to widespread interest in the use of spectral domain OCT, which is faster and has higher resolution than time domain OCT. Future research in OCT imaging will likely result in improvements in image quality. The ability to combine OCT with other various diagnostic modalities will further improve the evaluation of DME in both clinical practice and trials.