Quantitative approaches in multimodal fundus imaging: State of the art and future perspectives

Optical coherence tomography angiography in diabetic retinopathy: A major review

Diabetic retinopathy (DR) is characterized by retinal vasculopathy and is a leading cause of visual impairment. Optical coherence tomography angiography (OCTA) is an innovative imaging technology that can detect various pathologies and quantifiable changes in retinal microvasculature. We briefly describe its functional principles and advantages over fluorescein angiography and perform a comprehensive review on its clinical applications in the screening or management of people with prediabetes, diabetes without clinical retinopathy (NDR), nonproliferative DR (NPDR), proliferative DR (PDR), and diabetic macular edema (DME). OCTA reveals early microvascular alterations in prediabetic and NDR eyes, which may coexist with sub-clinical neuroretinal dysfunction. Its applications in NPDR include measuring ischemia, detecting retinal neovascularization, and timing of early treatment through predicting the risk of retinopathy worsening or development of DME. In PDR, OCTA helps characterize the flow within neovascular complexes and evaluate their progression or regression in response to treatment. In eyes with DME, OCTA perfusion parameters may be of predictive value regarding the visual and anatomical gains associated with treatment. We further discussed the limitations of OCTA and the benefits of its incorporation into an updated DR severity scale.

Mitochondrial retinopathies and optic neuropathies: The impact of retinal imaging on modern understanding of pathogenesis, diagnosis, and management

Advancements in ocular imaging have significantly broadened our comprehension of mitochondrial retinopathies and optic neuropathies by examining the structural and pathological aspects of the retina and optic nerve in these conditions. This article aims to review the prominent imaging characteristics associated with mitochondrial retinopathies and optic neuropathies, aiming to deepen our insight into their pathogenesis and clinical features. Preceding this exploration, the article provides a detailed overview of the crucial genetic and clinical features, which is essential for the proper interpretation of in vivo imaging. More importantly, we will provide a critical analysis on how these imaging modalities could serve as biomarkers for characterization and monitoring, as well as in guiding treatment decisions. However, these imaging methods have limitations, which will be discussed along with potential strategies to mitigate them. Lastly, the article will emphasize the potential advantages and future integration of imaging techniques in evaluating patients with mitochondrial eye disorders, considering the prospects of emerging gene therapies.

Quantitative multimodal imaging characterization of intraretinal cysts vs degenerative pseudocysts in neovascular age-related macular degeneration

OBJECTIVE

To differentiate intraretinal fluid (IRF) cysts from degenerative pseudocysts in neovascular age-related macular degeneration by quantitative multimodal imaging.

DESIGN

Observational, cross-sectional.

PARTICIPANTS

Patients affected by macular neovascularization (MNV) secondary to AMD.

METHODS

All patients were analyzed by optical coherence tomography (OCT), optical coherence tomography angiography (OCTA) and dense ART (DART) OCTA. Newly onset cysts were considered IRF, whereas those cysts that were found to be persistent persistent for at least 3 months have been categorized as degenerative pseudocysts. Intraretinal cysts were automatically segmented to calculate cyst circularity. Peri-cyst space was quantitatively analyzed to assess the presence of perfusion signal and hyperreflective foci (HF).

MAIN OUTCOME MEASURES

Best-corrected visual acuity (BCVA), cyst circularity, peri-cyst perfusion, peri-cyst HF, fibrosis, outer retinal atrophy.

RESULTS

We analyzed 387 cysts collected from 35 eyes of 35 neovascular AMD patients (14 males; mean age 80±5 years). We classified 302 IRF cysts and 85 degenerative pseudocysts. IRF cysts were characterized by significantly higher circularity (0.86 (range 0.81-0.91), perfusion signal in the peri-cyst space and peri-cyst HF in 89% of cases (all p<0.05). Degenerative pseudocysts showed significantly lower circularity (0.68 (range 0.64-0.76), no perfusion signal in the peri-cyst space and peri-cyst HF only in 29% of cases (all p<0.05). The adopted quantitative metrics significantly correlated with disease duration, number of injections, fibrosis and outer retinal atrophy.

CONCLUSIONS

IRF can be discriminated from degenerative pseudocysts by quantitative multimodal imaging approach. These findings resulted clinically relevant and should be included in future training models for artificial intelligence algorithms to improve the diagnostic power and the fluids monitoring in neovascular AMD.

Cross-modal attention network for retinal disease classification based on multi-modal images

Multi-modal eye disease screening improves diagnostic accuracy by providing lesion information from different sources. However, existing multi-modal automatic diagnosis methods tend to focus on the specificity of modalities and ignore the spatial correlation of images. This paper proposes a novel cross-modal retinal disease diagnosis network (CRD-Net) that digs out the relevant features from modal images aided for multiple retinal disease diagnosis. Specifically, our model introduces a cross-modal attention (CMA) module to query and adaptively pay attention to the relevant features of the lesion in the different modal images. In addition, we also propose multiple loss functions to fuse features with modality correlation and train a multi-modal retinal image classification network to achieve a more accurate diagnosis. Experimental evaluation on three publicly available datasets shows that our CRD-Net outperforms existing single-modal and multi-modal methods, demonstrating its superior performance.

Clinical and Imaging Biomarkers Associated with Outer Retinal Atrophy Onset in Exudative Age-Related Macular Degeneration: A Real-Word Prospective Study

INTRODUCTION

Macular neovascularization (MNV) secondary to age-related macular degeneration (AMD) is well managed by anti-vascular endothelial growth factor (anti-VEGF) intravitreal injections. However, outer retinal atrophy represents an unavoidable occurrence detected during follow-up. Several imaging metrics have been proposed as clinically relevant in stratifying the risk of onset of outer retinal atrophy. The main goal of this study is to evaluate the impact of noninvasive imaging metrics on the assessment of outer retinal atrophy onset in a large cohort of eyes with neovascular AMD managed in a real-world setting.

METHODS

This study was a prospective, observational, case series. We included patients affected by newly diagnosed neovascular AMD, requiring anti-VEGF intravitreal injections. We collected clinical and imaging data, with a planned follow-up of 24 months. The multimodal imaging protocol included optical coherence tomography, optical coherence tomography angiography, and fundus autofluorescence. We collected noninvasive imaging metrics and we assessed the relationship with the morphological and functional outcome evaluated at 12-month and 24-month time points.

RESULTS

We included 370 eyes of 370 patients with exudative AMD (210 male; mean age 79 ± 8 years). MNV were classified as follows: type 1, 198 (54%); type 2, 89 (24%); polypoidal choroidal vasculopathy, 29 (7%); and type 3, 54 (15%). A total of 120 out of 370 eyes (33%) showed complete outer retinal atrophy at the end of the 2-year follow-up. The presence of intraretinal fluid, thinning of the Sattler choroidal layer, late anti-VEGF switch, the overall number of anti-VEGF injections, and the perfusion characteristics of the MNV were found to be the most relevant factors associated with the onset of outer retinal atrophy. The other collected metrics were found to be less clinically relevant, also showing no cumulative effect in the multivariate analysis (p > 0.05).

CONCLUSIONS

We identified imaging metrics significantly associated with the 2-year risk onset of outer retinal atrophy. These metrics might pave the way for the development of future customized anti-VEGF treatment strategies.

Machine learning and optical coherence tomography-derived radiomics analysis to predict persistent diabetic macular edema in patients undergoing anti-VEGF intravitreal therapy

BACKGROUND

Diabetic macular edema (DME) is a leading cause of vision loss in patients with diabetes. This study aimed to develop and evaluate an OCT-omics prediction model for assessing anti-vascular endothelial growth factor (VEGF) treatment response in patients with DME.

METHODS

A retrospective analysis of 113 eyes from 82 patients with DME was conducted. Comprehensive feature engineering was applied to clinical and optical coherence tomography (OCT) data. Logistic regression, support vector machine (SVM), and backpropagation neural network (BPNN) classifiers were trained using a training set of 79 eyes, and evaluated on a test set of 34 eyes. Clinical implications of the OCT-omics prediction model were assessed by decision curve analysis. Performance metrics (sensitivity, specificity, F1 score, and AUC) were calculated.

RESULTS

The logistic, SVM, and BPNN classifiers demonstrated robust discriminative abilities in both the training and test sets. In the training set, the logistic classifier achieved a sensitivity of 0.904, specificity of 0.741, F1 score of 0.887, and AUC of 0.910. The SVM classifier showed a sensitivity of 0.923, specificity of 0.667, F1 score of 0.881, and AUC of 0.897. The BPNN classifier exhibited a sensitivity of 0.962, specificity of 0.926, F1 score of 0.962, and AUC of 0.982. Similar discriminative capabilities were maintained in the test set. The OCT-omics scores were significantly higher in the non-persistent DME group than in the persistent DME group (p < 0.001). OCT-omics scores were also positively correlated with the rate of decline in central subfield thickness after treatment (Pearson's R = 0.44, p < 0.001).

CONCLUSION

The developed OCT-omics model accurately assesses anti-VEGF treatment response in DME patients. The model's robust performance and clinical implications highlight its utility as a non-invasive tool for personalized treatment prediction and retinal pathology assessment.

Retinal Vessel Analysis and Microvascular Abnormalities in Patients with Philadelphia-Negative Chronic Myeloproliferative Neoplasms

Background: Philadelphia-negative chronic myeloproliferative neoplasms are a group of clonal hematopoietic disorders including polycythemia vera, essential thrombocythemia, and primary myelofi-brosis. These neoplasms are characterized by an increased risk of thrombotic complications. Several studies have highlighted that the study of vessels of the retina offers the opportunity to visualize, in vivo, the damage to microcirculation that is common in various systemic pathologies. Methods: in our study, forty patients underwent an ophthalmological examination, using non-invasive imaging tech-niques, for analyses of their retinal vascularization. The objective was to correlate the findings ob-tained from this study of the retina with different markers of thrombotic risk, to demonstrate the usefulness of studying retinal vessels as a possible new prognostic biomarker of thrombotic risk in patients affected by Philadelphia-negative chronic myeloproliferative neoplasms. Results: retinal imaging demonstrated changes in the microcirculation, with a reduced vascular density of the deep and superficial capillary plexuses with respect to a normal group, and a correlation between retinal changes and blood parameters. Conclusions: additional research will allow us to determine whether retinal changes in individuals with chronic myeloproliferative neoplasms could be predictive of the development of thrombotic events in these subjects.

Association between obstructive coronary disease and diabetic retinopathy: Cross-sectional study of coronary angiotomography and multimodal retinal imaging

AIMS

To investigate the association between diabetic retinopathy (DR) and coronary artery disease (CAD) using coronary angiotomography (CCTA) and multimodal retinal imaging (MMRI) with ultra-widefield retinography and optical coherence tomography angiography and structural domain.

METHODS

Single-center, cross-sectional, single-blind. Patients with diabetes who had undergone CCTA underwent MMRI. Uni and multivariate analysis were used to assess the association between CAD and DR and to identify variables independently associated with DR.

RESULTS

We included 171 patients, 87 CAD and 84 non-CAD. Most CAD patients were males (74 % vs 38 %, P < 0.01), insulin users (52 % vs 38 %, p < 0.01) and revascularized (64 %). They had a higher prevalence of DR (48 % vs 22 %, p = 0.01), microaneurysms (25 % vs 13 %, p = 0.04), intraretinal cysts (22 % vs 8 %, p = 0.01) and areas of reduced capillary density (46 % vs 20 %, p < 0.01). CAD patients also had lower mean vascular density (MVD) (15.7 % vs 16.5,%, p = 0.049) and foveal avascular zone (FAZ) circularity (0.64 ± 0.1 vs 0.69 ± 0.1, p = 0.04). There were significant and negative correlations between Duke coronary score and MVD (r = -0.189; p = 0.03) and FAZ circularity (r = -0,206; p = 0.02). CAD, DM duration and insulin use independently associated with DR.

CONCLUSIONS

CAD patients had higher prevalence of DR and lower MVD. CAD, DM duration and insulin use were independently associated with DR.

Non-vasogenic cystoid maculopathy in autosomal recessive bestrophinopathy: novel insights from NIR-FAF and OCTA imaging

BACKGROUND

Autosomal Recessive Bestrophinopathy (ARB) is an inherited retinal disease caused by biallelic mutations in the BEST1 gene. Herein, we report the multimodal imaging findings of ARB presenting with cystoid maculopathy and investigate the short-term response to combined systemic and topical carbonic anhydrase inhibitors (CAIs).

MATERIAL AND METHODS

An observational, prospective, case series on two siblings affected by ARB is presented. Patients underwent genetic testing and optical coherence tomography (OCT), blue-light fundus autofluorescence (BL-FAF), near-infrared fundus autofluorescence (NIR-FAF), fluorescein angiography (FA), MultiColor imaging, and OCT angiography (OCTA).

RESULTS

Two male siblings, aged 22 and 16, affected by ARB resulting from c.598C>T, p.(Arg200*) and c.728C>A, p.(Ala243Glu) BEST1 compound heterozygous variants, presented with bilateral multifocal yellowish pigment deposits scattered through the posterior pole that corresponded to hyperautofluorescent deposits on BL-FAF. Vice versa, NIR-FAF mainly disclosed wide hypoautofluorescent areas in the macula. A cystoid maculopathy and shallow subretinal fluid were evident on structural OCT, albeit without evidence of dye leakage or pooling on FA. OCTA demonstrated disruption of the choriocapillaris throughout the posterior pole and sparing of intraretinal capillary plexuses. Six months of combined therapy with oral acetazolamide and topical brinzolamide resulted in limited clinical benefit.

CONCLUSIONS

We reported two siblings affected by ARB, presenting as non-vasogenic cystoid maculopathy. Prominent alteration of NIR-FAF signal and concomitant choriocapillaris rarefaction on OCTA were noted in the macula. The limited short-term response to combined systemic and topical CAIs might be explained by the impairment of the RPE-CC complex.

Retro-Mode in NIDEK Mirante: A Comparative Analysis with Other Imaging Modalities for AMD and CSR

BACKGROUND

Retro-mode is a novel technique capable of creating pseudo-3D images of the retina. However, its clinical utility remains unknown. This study aimed to evaluate the Nidek Mirante multimodal imaging platform for ocular assessment in patients with various retinal conditions.

METHODS

A total of 115 participants with central serous chorioretinopathy (CSR) and age-related macular degeneration (AMD) were included. Two experienced graders independently evaluated the images, and statistical analysis was performed to assess interclass correlation coefficients (ICC) between graders and modalities; Results: For CSR detection, retro-mode demonstrated exceptionally high ICC rates (ICC = 1; 100%), while color and autofluorescence (FAF) showed moderate coefficients (0.69 and 0.78, respectively). The detection of pigment epithelial detachment was high across all methods, with only retro-mode deviated right (DR) allowing detection in 69% of cases, while retro-mode DR and deviated left (DL) achieved 100% detection. FAF-green achieved a 95% detection rate. In detecting retinal atrophy, most modalities demonstrated high detection rates, with the lowest detection rates offered by retro-mode DL (ICC = 0.85) and DR (ICC = 0.89), while retro-mode ring aperture offered 0.97. Infra-red and fluorescein angiography imaging offered the highest detection rates among the tested modalities, with 97% and 100%, respectively.

CONCLUSION

Retro-mode showed promise for comprehensive ocular evaluation and diagnosis, with certain imaging modalities demonstrating higher accuracy in detecting specific retinal features.

The Clinical Role of the Choroidal Assessment in High Myopia: Characteristics and Association With Neovascular and Atrophic Complications

Purpose

To investigate the clinical utility of choroidal quantitative assessment associated with the presence of macular neovascularization (MNV) or atrophy in high myopia.

Methods

The study was designed as a retrospective case series with two-year follow-up. We measured choroidal thickness (CT) and the presence and subtype of dome-shaped macula (DSM). In DSM eyes we also calculated the presence and type of choroidal deepening (CD). The eyes were categorized as Subgroup 1 (high myopia without complications), Subgroup 2 (high myopia complicated by MNV), and Subgroup 3 (high myopia complicated by macular or posterior pole atrophy). Main outcome measures were the detection of significant CT cutoffs associated with the three subgroups of eyes and the clinical impact of DSM and CD subtypes.

Results

Our cohort (190 eyes affected by high myopia) was categorized as Subgroup 1 (66 eyes), Subgroup 2 (72 eyes) and Subgroup 3 (52 eyes). Baseline CT values allowed to separate the subgroups with myopic-related complications (area under the curve = 0.85; P < 0.05). In Subgroup 1, vertical DSM was the most frequent (54%), with CD absence characterizing the 46% of cases. Round DSM was the most represented subtype in Subgroup 2 (49%), with 55% of sub-dome CD subtypes; in these cases, MNV resulted always localized in the fovea. Subgroup 3 equally shown horizontal or vertical DSM (53% and 47%, respectively), with 80% of cases showing peri-dome CD.

Conclusions

Choroidal quantitative assessment can categorize three high myopia subgroups. MNV subgroup is characterized by intermediate choroidal thinning and higher prevalence of round DSM with sub-dome CD.

Foveal Eversion is Associated with High Persistence of Macular Edema and Visual Acuity Deterioration in Retinal Vein Occlusion

INTRODUCTION

Foveal eversion (FE) is a recently described optical coherence tomography (OCT) finding associated with negative outcome in diabetic macular edema. The main goal of the present study was to investigate the role of the FE metric in the diagnostic workup of retinal vein occlusion (RVO).

METHODS

This study was a retrospective, observational case series. We included 168 eyes (168 patients) affected by central RVO (CRVO) and 116 eyes (116 patients) affected by branch (RVO). We collected clinical and imaging data from CRVO and BRVO eyes affected by macular edema with a minimum follow-up of 12 months. On structural OCT, we classified FE as pattern 1a, characterized by thick vertical intraretinal columns, pattern 1b, presenting thin vertical intraretinal lines, and pattern 2, showing no signs of vertical lines in the context of the cystoid macular edema. For statistical purposes, we considered data collected at baseline, after 1 year and at the last follow-up.

RESULTS

The mean follow-up was 40 ± 25 months for CRVO eyes and 36 ± 24 months for BRVO eyes. We found FE in 64 of 168 CRVO eyes (38%) and in 25 of 116 BRVO eyes (22%). Most of the eyes developed FE during the follow-up. For CRVO eyes, we found 6 eyes (9%) with pattern 1a, 17 eyes (26%) with pattern 1b and 41 eyes (65%) with pattern 2. Of those BRVO eyes with FE, we found 8 eyes (32%) with pattern 1a + 1b and 17 eyes (68%) with pattern 2. In both CRVO and BRVO the presence of FE was significantly associated with higher persistence of macular edema and worse outcome, with FE pattern 2 representing the most severe condition. Remarkably, FE patterns 1a and 1b were characterized by BCVA stability over the follow-up, whereas FE pattern 2 showed significant bestcorrected visual acuity (BCVA) worsening at the end of the follow-up.

CONCLUSIONS

FE can be considered a negative prognostic biomarker in RVO, associated with higher persistence of macular edema and worse visual outcome. Müller cell impairment might represent the pathogenic mechanism leading to the loss of macular structural support and impairment of fluid homeostasis.

Confocal MultiColor Signal Depends on Perfusion Characteristics of Retinal Microaneurysms in Diabetic Retinopathy as Detected by OCTA

Purpose

To propose a noninvasive way of classifying multimodal imaging of retinal microaneurysms (MA) secondary to diabetic retinopathy (DR).

Methods

The research was designed as a cross-sectional, observational study of patients affected by DR. Multimodal imaging included confocal MultiColor imaging, optical coherence tomography (OCT) and OCT angiography (OCTA). MA green- and infrared-reflectance components were assessed by confocal MultiColor imaging, reflectivity properties by OCT, and MA perfusion features by OCTA. In addition, we included high-resolution (HR) and high-speed (HS) OCTA scans to assess HR-HS agreement in detecting retinal MA and to highlight different perfusion features detected by both OCTA acquisitions.

Results

We analyzed 216 retinal MAs, divided into green (46; 21%), red (58; 27%) and mixed types (112; 52%). Green MAs were mainly hyper-reflective on OCT, with no or poor filling on OCTA. Red MAs were characterized by an isoreflective signal on OCT and full filling on OCTA. Mixed MAs showed a hyper-reflective border and a hyporeflective core on OCT and partial filling on OCTA. No differences in red MA HR/HS size discrepancy and reflectivity were found, whereas these progressively increased as the MA MultiColor signal changed from infrared to green. MA types significantly correlated with visual acuity, DR duration, and DR severity.

Conclusions

Retinal MA can be classified reliably by means of a fully noninvasive multimodal imaging-based assessment. MA types are matched with visual acuity, DR duration and DR severity. Both HR and HS OCTA are highly effective in detecting MA, although HR OCTA is to be preferred in the presence of fibrotic evolution.

Translational Relevance

This study outlines a proposed novel MA classification based on noninvasive multimodal imaging. The findings presented in this paper endorse the clinical relevance of this approach, highlighting how this classification is associated with both DR duration and severity.

High-resolution/High-Speed Gap Can Distinguish Different Intraretinal Perfusion Signals by Optical Coherence Tomography Angiography

Purpose

The development of optical coherence tomography angiography (OCTA) has radically changed the diagnostic assessment of the intraretinal vascular network. Two different OCTA acquisition modalities have recently been introduced in clinical practice, namely high-resolution (HR) and high-speed (HS) scans. HR OCTA requires more acquisition time and provides higher quality data, whereas HS OCTA is faster but furnishes lower quality data. The main aim of the present study is to gauge how much extra blood flow perfusion information can be obtained through the combined use of HR and HS OCTA.

Methods

We compared HR and HS OCTA acquisitions to assess the reliability of both techniques, also putting forward a new set of quantitative metrics to measure the HR/HS OCTA gap and to highlight different perfusion information.

Results

In essence, both HR and HS OCTA acquisitions proved highly feasible in detecting the intraretinal vascular flow signal, as confirmed by the stability of quantitative OCTA metrics, thus displaying their suitability for use in clinical practice. We detected an HR/HS overlapping gap of 21.6 ± 6.5% for intraretinal capillaries, and 4.3 ± 1.2% for choriocapillaris, highlighting the greater information obtained by HR OCTA.

Conclusions

This novel HR/HS OCTA gap assessment might pave the way for the development of new quantitative metrics for retinal diseases that would focus on the earlier detection of perfusion impairment and relate it to the stage of the disease and its progression.

Translational Relevance

This study proposes a new quantitative way to detect different perfusion signals based on OCTA. The findings presented in this paper can lay the foundations for the development of new quantitative metrics focused on the separate analysis of high flow and low flow signals, enabling very early changes in intraretinal perfusion to be detected.

Optical Coherence Tomography Angiography in CRB1-Associated Retinal Dystrophies

AIM OF THE STUDY

To report optical coherence tomography angiography (OCTA) findings in patients affected by CRB1-associated retinal dystrophies.

METHOD

Patients affected by a genetically confirmed CRB1-associated retinal dystrophy were prospectively enrolled in an observational study, along with age- and sex-matched healthy volunteers as control subjects. All study and control subjects received a complete ophthalmic examination and multimodal retinal imaging, including OCTA.

RESULT

A total of 12 eyes from 6 patients were included in the study. The mean BCVA of patients was 0.42 ± 0.25 logMAR. Two patients showed large central atrophy, with corresponding definite hypo-autofluorescence on fundus autofluorescence (FAF). Another four patients disclosed different degrees of RPE mottling, with uneven FAF. On OCTA, the macular deep capillary plexus and choriocapillaris had a lower vessel density in eyes affected by CRB1-associated retinopathy when compared to healthy controls. On the other hand, vessel density at the peripapillary radial capillary plexus, superficial capillary plexus, and deep capillary plexus was significantly altered with respect to control eyes. Statistical analyses disclosed a negative correlation between the deep capillary plexus and both LogMAR best corrected visual acuity and central retinal thickness.

CONCLUSION

Our study reveals that CRB1-associated retinal dystrophies are characterized by vascular alterations both in the macular and peripapillary region, as assessed by OCTA.

Characterizing macular edema in retinitis pigmentosa through a combined structural and microvascular optical coherence tomography investigation

The aim of the study was to characterize macular edema (ME) in retinitis pigmentosa (RP) by means of quantitative optical coherence tomography (OCT)-based imaging. The study was designed as observational, prospective case series, with 1-year follow-up. All RP patients underwent complete ophthalmologic assessment, including structural OCT, OCT angiography, and microperimetry (MP). The primary outcome was the characterization through quantitative OCT-based imaging of RP eyes complicated by ME. A total of 68 RP patients' eyes (68 patients) and 68 eyes of 68 healthy controls were recruited. Mean BCVA was 0.14 ± 0.17 LogMAR at baseline and 0.18 ± 0.23 LogMAR at 1-year follow-up (p > 0.05). Thirty-four eyes (17 patients; 25%) showed ME, with a mean ME duration of 8 ± 2 months. Most of the eyes were characterized by recurrent ME. The ME was mainly localized in the inner nuclear layer in all eyes. LogMAR BCVA was similar in all RP eyes, whether with or without ME, although those with ME were associated with higher vessel density values, as well as thicker choroidal layers, than those without ME. In conclusion, the inner retina is closely involved in the pathogenesis of ME. The impairment of retinal-choroidal exchanges and Müller cell disruption might be a major pathogenic factor leading to the onset of ME in RP.

Peripheral and central capillary non-perfusion in diabetic retinopathy: An updated overview

Capillary non-perfusion (CNP) is one of the key hallmarks of diabetic retinopathy (DR), which may develop both in the periphery and at the posterior pole. Our perspectives on CNP have extended with the introduction of optical coherence tomography angiography (OCTA) and ultra-widefield imaging, and the clinical consequences of peripheral and macular CNP have been well characterized. Fluorescein angiography (FA) continues to be the gold standard for detecting and measuring CNP, particularly when ultra-widefield imaging is available. OCTA, on the other hand, is a quicker, non-invasive approach that allows for a three-dimensional examination of CNP and may soon be regarded as an useful alternative to FA. In this review, we provide an updated scenario regarding the characteristics, clinical impact, and management of central and peripheral CNP in DR.

Clinical Correlation Between Optical Coherence Tomography Biomarkers and Retinal Sensitivity in Best Vitelliform Macular Dystrophy

Purpose

To investigate the clinical and imaging features associated with retinal sensitivity in Best vitelliform macular dystrophy (BVMD).

Methods

This was a cross-sectional, single-center, observational study. Each patient underwent optical coherence tomography (OCT), near-infrared fundus autofluorescence, and OCT angiography. Macular integrity assessment microperimetry under mesopic conditions was performed to obtain retinal sensitivity thresholds from 68 testing points in the central macula. Structural OCT was used to classify BVMD lesions into four types according to their composition: vitelliform, mixed, subretinal fluid, and atrophy. Multilevel, mixed-effects linear regression was used to determine the factors associated with retinal sensitivity.

Results

The study included 57 eyes of 30 patients with BVMD, 48 of which (84%) were in a clinical stage. Mean retinal sensitivity varied according to the composition of the lesion: the vitelliform type registering the highest (22 ± 4.1 dB), followed by mixed (18.73 ± 2.7 dB), subretinal fluid (15.68 ± 4.2 dB), and atrophy types (11.85 ± 4.6 dB). The factors most strongly associated with mean retinal sensitivity in BVMD proved to be the OCT lesion type and outer nuclear layer thickness.

Conclusions

Retinal sensitivity in BVMD is influenced by lesion composition and outer nuclear layer thickness. Further studies with long-term follow-up are warranted to examine retinal sensitivity over time and to validate retinal sensitivity changes as biomarkers for BVMD.

Translational Relevance

Assessing retinal sensitivity in BVMD provides a new instrument in the clinical characterization of the disease and offers the opportunity to identify imaging biomarkers for use as outcome measures in future clinical trials.