Association between albuminuria and retinal microvascular parameters measured with swept-source optical coherence tomography angiography in patients with diabetic retinopathy.

PURPOSE: To evaluate the relationship between urine albumin excretion (UAE) and retinal microvascular parameters assessed using swept-source optical coherence tomography angiography (SS-OCTA) in patients with diabetic retinopathy (DR). METHODS: This retrospective cross-sectional study included 180 patients with diabetes and 50 age-matched controls. Patients with diabetes were grouped according to the five-stage DR severity, combined with the presence of albuminuria. All subjects underwent 12×12mm2 field SS-OCTA. The foveal avascular zone metrics, vessel density, and capillary nonperfusion area (NPA) were quantified using a semi-automatic software algorithm on three different rectangular fields (3×3 mm2, 6×6 mm2, and 10×10 mm2). The correlations between albuminuria and the four OCTA parameters were analyzed. RESULTS: A total of 105 subjects had normal UAE, and 75 subjects had albuminuria. Of the 102 subjects whose DR severity was higher than mild non-proliferative DR (NPDR), capillary NPA on the 3×3 mm2, 6×6 mm2, and 10×10 mm2 fields was significantly larger in the albuminuria group. None of the OCTA parameters were significantly different between the two groups in subjects with mild NPDR or without DR. Multiple logistic regression analysis showed that an increase in NPA in the 6×6 mm2 and 10×10 mm2 fields was a significant risk factor for the presence of albuminuria (odds ratio = 1.92 and 1.35). CONCLUSION: An increase in capillary NPA was independently associated with albuminuria in patients with clinically significant DR levels. SS-OCTA imaging can be a useful marker for the early detection of diabetic nephropathy.

Seven-year outcomes of combined treatment of anti-vascular endothelial growth factor with photodynamic therapy for polypoidal choroidal vasculopathy; according to polypoidal lesion regression.

PURPOSE: To evaluate the long-term prognosis of polypoidal choroidal vasculopathy (PCV) treated with anti-vascular endothelial growth factor (anti-VEGF) combined with verteporfin photodynamic therapy (PDT), according to polypoidal lesion regression. METHODS: This study retrospectively reviewed the data of 33 naïve eyes with PCV treated with anti-VEGF combined with verteporfin PDT and followed-up for at least 7 years. The collected data included demographic profile, best-corrected visual acuity (BCVA), central foveal thickness (CFT), PED volume, and presence of submacular hemorrhage. Regression of polypoidal lesion was determined using indocyanine green angiography and optical coherence tomography. All eyes were divided into regression or persistent groups, based on the polypoidal lesion regression one year after the initial combined treatment. RESULTS: BCVA improvement was maintained for 3 years in the regression (p = 0.001) and 1 year in the persistent (p = 0.006) groups, respectively. The mean BCVA of the regression group was better than that of the persistent group over 7 years, but the difference was significant only at 1 year (p = 0.037). The number of eyes which maintained BCVA less than or equal to 0.3 logMAR at 7 years was 11 eyes (64.7%) in regression group and 4 eyes (25.0%) in persistent group (p = 0.022). CONCLUSIONS: Regression of the polypoidal lesion at 1 year after the initial combination treatment was associated with favorable long-term visual prognosis, particularly in terms of maintaining good visual acuity.

Diagnosing Polypoidal Choroidal Vasculopathy Using Color Fundus Photography, Optical Coherence Tomography, and Optical Coherence Tomography Angiography.

PURPOSE: To compare the diagnostic accuracy of differentiating polypoidal choroidal vasculopathy (PCV) from exudative age-related macular degeneration (AMD), using color fundus photography (CFP), optical coherence tomography (OCT), and swept-source OCT angiography (SS-OCTA) without using indocyanine green angiography (ICGA). METHODS: Treatment-naive eyes with exudative AMD that underwent CFP, OCT, SS-OCTA, and ICGA imaging before treatment were identified. Images of each patient were categorized into two sets (set A, CFP + OCT; set B, CFP + SS-OCTA). In set B, both the en face and cross-sectional B scans were analyzed. Each set was reviewed by two graders, and it was determined whether the presumed diagnosis was PCV. Sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) for the diagnosis of PCV were assessed for each set by comparing diagnoses that included ICGA. The number of polypoidal lesions in each set was calculated and compared to ICGA. RESULTS: A total of 94 eyes from 94 patients with AMD were included in the study, of which 66.0% were male, and the mean age was 71.8 ± 9.0 years. The PCV diagnosis rate using ICGA was 45.7%. The sensitivity was 0.88 for set A and 0.93 for set B, while the specificity was 0.94 for set A and 0.96 for set B. The AUC was 0.90 (95% confidence interval [CI], 0.83-0.97) for set A and 0.96 (95% CI, 0.90-1.00) for set B. Set A detected 1.28 ± 0.91 polypoidal lesions, while set B detected 1.47 ± 1.01; ICGA showed 1.51 ± 0.86. CONCLUSIONS: This study highlights that, without using ICGA, both CFP combined with OCT and CFP combined with SS-OCTA demonstrate high sensitivity, specificity, and AUC in diagnosing PCV. It is evident that SS-OCTA contributes to enhancing sensitivity, specificity, and AUC for PCV diagnosis.

Perifoveal Microvascular Changes following Internal Limiting Membrane Peeling Surgery for Epiretinal Membrane and Macular Hole.

INTRODUCTION: The aim of the study was to evaluate perifoveal microvasculature changes following pars plana vitrectomy with internal limiting membrane peeling for the epiretinal membrane (ERM) and macular hole (MH). METHODS: This retrospective study included 59 eyes from 59 patients. Subjects were divided into two groups: an ERM group (n = 43) and an MH group (n = 16) based on the initial diagnosis. Swept-source optical coherence tomography angiography (SS-OCTA) was performed in the macular area, pre- and postoperatively. Perifoveal microvascular changes were calculated using MATLAB from the 6 × 6 mm SS-OCTA images, excluding the foveal avascular zone. Pre- and postoperative perifoveal vessel densities (pfVDs) were separately analyzed in six sectors (superior, superotemporal, inferotemporal, inferior, inferonasal, and superonasal) in the superficial capillary plexus (SCP) and deep capillary plexus (DCP). The baseline characteristics and other clinical factors were compared between the ERM and MH groups. RESULTS: The postoperative best-corrected visual acuity significantly improved in both groups (p < 0.05). One year after surgery, the pfVD in the SCP of the ERM group significantly decreased in the inferotemporal sector (p = 0.049). The postoperative pfVD in the DCP of the MH group significantly decreased in temporal sectors (p < 0.05). The postoperative mean pfVD in the SCP in the MH group was significantly lower than that in the ERM group (p = 0.003). The presence of a dissociated optic nerve fiber layer (DONFL) was 75% in the MH group and 22% in the ERM group (p = 0.018). The correlation between the pfVD and DONFL was not statistically significant. CONCLUSION: Postoperative pfVD reduction in the temporal sector, a corresponding area in which DONFL is present after MH surgery, was significantly observed. After vitreoretinal surgery in MH patients, OCTA may serve as a useful tool for monitoring perifoveal microvascular changes, especially in temporal sectors.

Optical coherence tomography angiography biomarkers in a bi-monthly maintenance dosing aflibercept in patients with neovascular age-related macular degeneration.

PURPOSE: To evaluate the correlations between swept-source optical coherence tomography angiography (SS-OCTA) parameters and clinical outcomes in eyes with neovascular age-related macular degeneration (nAMD) administered a bimonthly intravitreal aflibercept regimen. METHODS: This prospective, single-arm, interventional study enrolled 33 patients with treatment-naïve nAMD. The eyes received three monthly aflibercept injections followed by five bi-monthly regimens (total 50 weeks). The structural parameters including central subfield thickness (CST) and 5 mm pigment epithelial detachment (PED) volume and microvascular parameters including macular neovascularization (MNV) area, vessel density (VD), and vessel length density (VLD) were recorded every before and 1 week after treatment. RESULTS: Patients who gained > 5 letters of best-corrected visual acuity (BCVA) from the baseline showed greater decreases in VD and VLD during the loading phase. Patients without recurrent or persistent fluid during the maintenance phase showed greater decreases in CST and 5 mm PED volume after the first injection. The decrease in mean VD during the loading phase was significantly correlated with the final BCVA (r = -0.820, p = 0.004). Moreover, the decrease in mean VLD during the loading phase was significantly correlated with the improvement in the final BCVA (r = -0.726, p = 0.017). CONCLUSIONS: The decrease in mean VD during the loading phase was significantly negatively correlated with the final BCVA at the last visit. The decrease in mean VLD during the loading phase, mean CST during the loading phase, and the improvement in final BCVA showed significant correlations. Therefore, early changes in OCTA microvascular and OCT structural parameters could help predict clinical outcomes in nAMD. TRIAL REGISTRATION: The trial was registered with the Clinical Research Information Service (CRIS), which joined the WHO International Clinical Trials Registry Platform (ICTRP) (Registration number: KCT0007375, Date of first trial registration: 10/06/2022).

PREDICTION OF DIABETIC RETINOPATHY SEVERITY USING A COMBINATION OF RETINAL NEURODEGENERATION AND CAPILLARY NONPERFUSION ON OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

PURPOSE: To generate a prediction model of diabetic retinopathy (DR) severity stages based on retinal neurodegeneration and capillary nonperfusion area (NPA) detected using optical coherence tomography (OCT) and OCT angiography (OCTA). METHODS: A total of 155 treatment-naïve eyes were retrospectively included. Macular ganglion cell/inner plexiform layer (mGCIPL) thickness in six macular regions was measured. A custom algorithm was used to calculate capillary NPA from 3 × 3 mm 2 and 12 × 12 mm 2 field OCTA images. The region of interest was selected as circular areas of 3 mm and 12 mm diameter and divided into six subsections. Classification and regression tree analysis identified the best predictors to discriminate between the five DR stages. RESULTS: Inferotemporal sector showed the largest mean NPA, and the inferior hemispheric NPA was significantly larger compared with the superior hemisphere. The mean mGCIPL thickness was significantly correlated with NPA of 12 × 12 mm 2 field in participants with early stage DR. Inferior hemispheric NPA of 12 × 12 mm 2 field and mean mGCIPL thickness were the two best variables to discriminate no DR versus mild nonproliferative DR (NPDR) and mild versus moderate NPDR (accuracy: 88.8% and 93.5%). Meanwhile, a combination of NPA of 12 × 12 mm 2 and 3 × 3 mm 2 fields was the best prediction model to discriminate moderate versus severe NPDR and severe NPDR versus PDR (accuracy: 91.8% and 94.1%). CONCLUSION: A combination model of capillary NPA and mGCIPL thickness may be a novel biomarker for predicting DR severity. Capillary nonperfusion seems to initially occur in the midperipheral retina with macular neurodegeneration and progress posteriorly.

Peripapillary microvasculature changes after vitrectomy in epiretinal membrane via swept-source OCT angiography.

PURPOSE: To evaluate the peripapillary microvasculature changes in patients with epiretinal membrane (ERM) following pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling using swept-source optical coherence tomography angiography (SS-OCTA). METHOD: Medical records and multimodal imaging data of 33 eyes after PPV for ERM were retrospectively reviewed. Peripapillary SS-OCTA images of 6×6 mm2 were recorded at at pre- and post-operatively every 6 months for 1 year. A semi-automated method was used to analyzed SS-OCTA images, excluding the optic disc area, using the MATLAB software. The peripapillary vessel density (pVD) of superficial capillary plexus (SCP) and deep capillary plexus (DCP) was quantified in four quadrants (superior, inferior, nasal and temporal). RESULT: The mean pVD in SCP and DCP decreased at 6- and 12-months follow-up. In sectoral analysis, superior, inferior, and temporal quadrants pVD in SCP and DCP were significantly reduced at 1 year after vitrectomy (all p < 0.05). Meanwhile, inferior quadrants pVD in SCP and DCP showed the earliest significant reduction at 6-months (p = 0.022 and 0.048, respectively). A reduction of post-operative mean pVD in DCP was significantly greater in patients with diabetic retinopathy (p = 0.043). CONCLUSION: Peripapillary capillary density significantly decreased after surgical removal of ERM. Vitrectomy with ILM peeling can cause peripapillary microvascular damage starting in inferior sector.

Clinical Characteristics and Long-term Outcomes in Diabetic Macular Edema Patients: With or without Additional Injection Following Ranibizumab Loading.

PURPOSE: To investigate the baseline characteristics in patients with diabetic macular edema (DME) during 7 years according to the need for additional treatments after intravitreal ranibizumab (RBZ) loading injections. METHODS: The medical records of 32 patients treated with intravitreal RBZ loading for DME during 7 years were reviewed. After three-consecutive monthly RBZ injections, additional treatment was decided according to the patient's response to RBZ loading. Based on whether the patients received treatment with or without additional injections, including intravitreal antivascular endothelial factor or steroid injection, they were divided into the "no add (NA)" or "add" groups, respectively. The baseline best-corrected visual acuity (BCVA), macular volume (MV), central subfoveal thickness, and other clinical factors were analyzed, and their 7-year changes were compared between the two groups. RESULTS: The BCVA of the NA group was better than that of the add group at 2, 3, 5, and 7 years (year 2, 3, and 5; p < 0.01, respectively). Baseline MV was significantly smaller in the NA group than in the add group (10.72 ± 0.88 µm vs. 11.98 ± 1.64 µm, p = 0.008). The DME duration before treatment in the NA group was significantly shorter than in the add group (1.03 ± 0.98 years vs. 1.91 ± 1.33 years, p = 0.042). The proportion of patients with serous retinal detachment or cystic macular edema was significantly lower in the NA group than in the add group (35.3% vs. 73.3%, p = 0.042). The NA group had smaller MV until 2 years than the add group (year 1, p = 0.002; year 2, p = 0.006). CONCLUSIONS: The DME patients without additional treatments during 7 years after the initial loading treatment had shorter duration of DME and diffuse retinal thickening morphologic type with lower MV at baseline, and better long-term visual prognosis.

A Smartphone-Based Near-Vision Testing System: Design, Accuracy, and Reproducibility Compared With Standard Clinical Measures.

BACKGROUND AND OBJECTIVE: Ophthalmologic telemedicine has emerged during the COVID-19 pandemic. The objective of this study is to assess the accuracy and reproducibility of a smartphone-based home vision monitoring system (Sightbook) and to compare it with existing clinical standards. PATIENTS AND METHODS: Near Snellen visual acuity (VA) was measured with Sightbook and compared with conventional measurements for distance and near VA at an academic medical center ophthalmology clinic in 200 patients with a variety of different specified preexisting ocular conditions. Measurements of contrast sensitivity were also compared by using an existing commercially available chart system in 15 normal patients and 15 patients with age-related macular degeneration. RESULTS: Sightbook VA tests were reproducible (SD = ±0.054 logMAR), and correlation with standard VA methods was significant (R > 0.87 and P < .001). Sightbook contrast sensitivity measurements were reproducible (SD/mean ratio, 0.02 to 0.04), yielding results similar to those of standard tests (R2 > 0.87 and P < .001). CONCLUSIONS: Smartphone-based VA and contrast sensitivity are highly correlated with standard charts and may be useful in augmenting limited inoffice care. [Ophthalmic Surg Lasers Imaging Retina. 2022;53:79-84.].

Subretinal fluid in a patient with systemic lupus erythematosus.

A 28-year-old male patient presented to the outpatient department with visual disturbance in both eyes. The patient had a history of stage IV lupus nephritis that was diagnosed at the age of 14 years and had undergone hemodialysis at the age of 23 years. After he started hemodialysis, the systemic condition was well controlled, and systemic steroids were not used. His best-corrected visual acuity (BCVA) was 20/200 in the right eye and 20/100 in the left eye. Funduscopic examination revealed shallow subretinal fluid (SRF) and serous retinal detachment in both eyes. The first impression of this patient was central serous chorioretinopathy. However, the late phase of fluorescein angiography (FA) demonstrated multiple subretinal leakages, and the late phase of indocyanine green angiography showed choroidal vascular engorgement and multiple hyperfluorescent plaques in both eyes. Systemic lupus erythematosus showed moderate activity according to the results of the systemic evaluation. Based on the clinical examination, lupus choroidopathy was suspected in both eyes. Half-fluence photodynamic therapy (PDT) was administered to both eyes rather than systemic steroids because the patient was systemically stable. Three months after PDT, no SRF was observed in either eye. In addition, multiple subretinal leakages on FA were reduced compared to those before treatment. There was no recurrence of SRF for 4 years after PDT, and the final BCVA was 20/70 in the right eye and 20/40 in the left eye. During this time, numerous hypoautofluorescence spots appeared adjacent to the major retinal vessels in fundus autofluorescence.

Central serous chorioretinopathy: Treatment.

Central serous chorioretinopathy (CSC) is a pachychoroid spectrum disease characterized by serous detachment of the neurosensory retina with subretinal fluid in young and middle-aged adults. The pathogenesis of CSC is not yet fully understood. However, it is considered a multifactorial disease that is strongly associated with choroidal dysfunction or vascular engorgement. Although there is no consensus on the treatment of CSC, photodynamic therapy has been effectively used to manage serous retinal detachment (SRD) in CSC. Moreover, micropulse diode laser photocoagulation and focal laser treatment have also been used. Recently, oral medications, including mineralocorticoid receptor antagonists, have been proposed for the management of CSC. Multimodal imaging plays a significant role in the diagnosis and treatment of CSC. Optical coherence tomography angiography (OCTA) has the advantage of detecting vascular flow in the retina and choroid layer, allowing for a better understanding of the pathology, severity, prognosis, and chronicity of CSC. In addition, early detection of choroidal neovascularization in CSC is possible using OCTA. This review article aims to provide a comprehensive and updated understanding of CSC, focusing on treatment.

Choroidal Changes in Eyes With Polypoidal Choroidal Vasculopathy After Anti-VEGF Therapy Imaged With Swept-Source OCT Angiography.

Purpose: Swept-source optical coherence tomography angiography was used to investigate choroidal changes and their association with pigment epithelial detachments (PEDs) in eyes with polypoidal choroidal vasculopathy (PCV) after treatment with vascular endothelial growth factor (VEGF) inhibitors. Methods: Patients with treatment-naïve PCV were included and underwent anti-VEGF therapy. Mean choroidal thickness (MCT), choroidal vascularity index (CVI), and PED volume measurements were obtained before and after treatment. Results: Thirty-four treatment-naïve PCV eyes from 33 patients were included. The PED volume decreased after treatment (P < 0.05). The MCT decreased from 223.0 ± 79.6 µm at baseline to 210.9 ± 76.2 µm after treatment (P < 0.001). The CVI at baseline was 0.599 ± 0.024, and the CVI after treatment was 0.602 ± 0.023 (P = 0.16). There was a correlation between the decreased PED volumes and the decreased MCT measurements (r = 0.47; P = 0.006). Also, there was a correlation between the decreased PED volumes and the increased CVI measurements (r = -0.63; P < 0.001). Conclusions: In treatment-naïve eyes with PCV, the decreases in PED volumes were correlated with the decrease in MCT and the increase in CVI measurements. We propose that, at baseline, the PCV lesions serve as high-volume arteriovenous shunts between choroidal arterial and venous circulation, causing transudation into the choroidal stroma. We propose that, after treatment, the blood flow through the vascular shunt is reduced, the excess stromal transudation is resorbed, and the exudation from the neovascular lesion is reduced, resulting in thinning of the choroid, resolution of the PEDs, and an increase in the CVI due to the resorption of excess choroidal transudation.

Correlation between Topographic Progression of Geographic Atrophy and Visual Acuity Changes.

PURPOSE: To analyze topographic progression of geographic atrophy with different concentric circles centered on the fovea in correlation with decrease of visual acuity. METHODS: We retrospectively analyzed 36 eyes of 26 patients diagnosed with geographic atrophy and followed at least 1 year. One millimeter circular area at the foveal center were defined as zone 1, and doughnut shape areas from between 1 and 2 mm to between 5 and 6 mm were defined as zone 2 to 6. Then, changes of geographic atrophy area in each zone were measured with semi-automatic software. Correlation analysis and regression analysis were performed to determine the relationship between changes in visual acuity and atrophic area in each zone. RESULTS: Mean age was 76.9 years and follow-up period were 3.38 years. The mean atrophic area increased from 8.09 to 16.34 mm2 and visual acuity decreased from 0.39 to 0.69 on logarithm of the minimal angle of resolution. Mean change of total geographic atrophy area was not significantly correlated with visual acuity decrease. While geographic atrophy progression within zone 1, 2, and 3 showed significant causal relationship with decrease of visual acuity (all, p < 0.05). CONCLUSIONS: In contrast to the total geographic atrophy area, progression of geographic atrophy in parafoveal area was significantly correlated with decrease of visual acuity.

Plasma amino acids and oxylipins as potential multi-biomarkers for predicting diabetic macular edema.

To investigate the pathophysiologic characteristics of diabetic complications, we identified differences in plasma metabolites in subjects with type 2 diabetes (T2DM) with or without diabetic macular edema (DME) and a disease duration > 15 years. An cohort of older T2DM patients with prolonged disease duration was established, and clinical information and biospecimens were collected following the guidelines of the National Biobank of Korea. DME phenotypes were identified by ophthalmologic specialists. For metabolomics studies, propensity matched case and control samples were selected. To discover multi-biomarkers in plasma, non-targeted metabolite profiling and oxylipin profiling in the discovery cohort were validated in an extended cohort. From metabolomic studies, 5 amino acids (asparagine, aspartic acid, glutamic acid, cysteine, and lysine), 2 organic compounds (citric acid and uric acid) and 4 oxylipins (12-oxoETE, 15-oxoETE, 9-oxoODE, 20-carboxy leukotriene B4) were identified as candidate multi-biomarkers which can guide DME diagnosis among non-DME subjects. Receiver operating characteristic curves revealed high diagnostic value of the combined 5 amino acids and 2 organic compounds (AUC = 0.918), and of the 4 combined oxylipins (AUC = 0.957). Our study suggests that multi-biomarkers may be useful for predicting DME in older T2DM patients.

Automatic segmentation of corneal dystrophy on photographic images based on texture analysis.

PURPOSE: To develop an automatic algorithm to analyze dystrophic lesions on photographic images of corneal dystrophy. METHODS: The dataset included 32 images of corneal dystrophy. The dystrophic area was manually segmented twice. Manually labeled dystrophy areas were compared with automatically segmented images. First, we manually removed the light reflex from the image of the cornea. Using an automatic approach, we extracted the brown color of the iris. Then, the program detected the circular region of the pupil and the corneal surface. A whitish dystrophy area was defined based on the image intensity on the iris and the pupil. The sliding square kernel was applied to clearly define the dystrophic region. RESULTS: For the manual analysis and the twice automatic approach, the Dice similarity was 0.804 and 0.801, respectively. The Pearson correlation coefficient was 0.807 and 0.806, respectively. The total number of distinct dystrophic areas showed no significant difference between the manual and automatic approaches according to the Wilcoxon signed-rank test (p < 0.0001, both). CONCLUSIONS: We proposed an automatic algorithm for detecting the dystrophy areas on photographic images with an accuracy of approximately 0.80. This system can be applied to detect and predict the progression of corneal dystrophy.

Quantification of retinal microvascular parameters by severity of diabetic retinopathy using wide-field swept-source optical coherence tomography angiography.

PURPOSE: To investigate the diagnostic utility of microvascular parameters for grading the severity of diabetic retinopathy (DR) with a range of views using wide-field swept-source optical coherence tomography angiography (SS-OCTA). METHODS: This retrospective study grouped 235 eyes with diabetes into the five grades: diabetes without retinopathy (no-DR), mild non-proliferative DR (NPDR), moderate NPDR, severe NPDR, and proliferative DR (PDR). Foveal avascular zone (FAZ) metrics, vessel density (VD), and the capillary nonperfusion area (NPA) were quantified with a customized, semiautomatic software algorithm. Regions of interest were selected from three rectangular fields of different sizes (i.e., 3 × 3 mm2, 6 × 6 mm2, and 10 × 10 mm2), perpendicular to the fovea-optic disc axis. RESULTS: NPA obtained from the 6 × 6mm2 and 10 × 10mm2 areas was the only discriminating parameter for the three NPDR stages. ROC curve analysis revealed that NPA from the 10 × 10mm2 field exhibited the best performance for grading DR into five stages. The NPA cutoff values were 3.7% (area under the curve (AUC): 0.91), 4.7% (AUC: 0.94), 9.3% (AUC: 0.94), and 21.4% (AUC: 0.90) for grading no-DR, mild from moderate NPDR, moderate from severe NPDR, and severe NPDR from PDR, respectively. CONCLUSIONS: Increasing DR severity as assessed by conventional grading systems is accompanied with increasing retinal ischemia on SS-OCTA. NPA measured from the larger 10 × 10 mm2 scan area showed the highest sensitivity for determining five-grade DR severity. In the future, the addition of quantitative NPA may provide a more clinically feasible DR grading system.

Longitudinal changes in retinal microvasculature after panretinal photocoagulation in diabetic retinopathy using swept-source OCT angiography.

This study evaluated quantitative changes in microvascular parameters after panretinal photocoagulation (PRP) in diabetic retinopathy (DR), using swept-source OCT Angiography (SS-OCTA). A total of 27 treatment-naïve eyes were subjected to PRP and followed-up for > 12 months after the procedure. Foveal avascular zone (FAZ) area, macular perfusion density (PD), and vessel length density (VLD) were calculated on a 3 × 3 mm en face OCTA image and nonperfusion area (NPA) was obtained on a 12 × 12 mm en face OCTA image. One month after PRP, PD and VLD of superficial and deep capillary plexus decreased and subsequently, increased progressively across the next 12 months, with statistically significant differences (P = 0.015 and 0.02). Continuous decreasing trends in total NPA values was observed across 12 months after PRP (P = 0.125). A difference in PD of the superficial capillary plexus between baseline and 6 months post PRP, was significantly associated with the progression of DR, 12 months after PRP (OR 0.528; P = 0.025). We found significant longitudinal retinal microvascular changes after PRP in DR. Overall macular perfusion status was impaired and progressively recovered across the next 12 months, compared to the baseline. Additionally, the early treatment responses in PD can predict the long-term outcomes of PDR after PRP.

Longitudinal Microvascular Changes on Optical Coherence Tomographic Angiography after Macula-Off Rhegmatogenous Retinal Detachment Repair Surgery.

PURPOSE: To investigate longitudinal changes and associated factors for microvascular parameters in macula-off rhegmatogenous retinal detachment (RRD) after repair surgery. METHODS: This is a retrospective study of 34 eyes with macula-off RRD. The foveal avascular zone (FAZ) area and parafoveal vessel density were recorded every 3 months for 1 year after surgery. We analyzed 3 × 3 mm and 6 × 6 mm swept-source optical coherence tomographic (OCT) angiography images to quantify microvascular parameters. Individual clinical factors and pre- and postoperative OCT images were analyzed to find factors associated with changes in the FAZ area and vessel density 12 months after surgery. RESULTS: The differences in FAZ area and vessel density between the operated and fellow eye at 3, 6, 9, and 12 months postoperatively were 0.127 ± 0.05, 0.111 ± 0.06, 0.108 ± 0.07, and 0.105 ± 0.06 mm2 and 4.33 ± 1.42, 3.56 ± 2.05, 2.73 ± 1.72, and 2.61 ± 1.71/mm. Preoperative sensory retina thickness and surgical methods significantly correlated with decreased vessel density at 12 months. Surgical method-based analysis found that postoperative vessel density damage in the pars plana vitrectomy (PPV) group was more prominent than in the buckling group. CONCLUSION: After macula-off RRD surgery, microvascular parameters were impaired after successful anatomical repair but recovered over 12 months. The PPV group exhibited significantly lower postoperative parafoveal vessel density than the buckling group.

Convolutional Network With Twofold Feature Augmentation for Diabetic Retinopathy Recognition From Multi-Modal Images.

OBJECTIVE: With the scenario of limited labeled dataset, this paper introduces a deep learning-based approach that leverages Diabetic Retinopathy (DR) severity recognition performance using fundus images combined with wide-field swept-source optical coherence tomography angiography (SS-OCTA). METHODS: The proposed architecture comprises a backbone convolutional network associated with a Twofold Feature Augmentation mechanism, namely TFA-Net. The former includes multiple convolution blocks extracting representational features at various scales. The latter is constructed in a two-stage manner, i.e., the utilization of weight-sharing convolution kernels and the deployment of a Reverse Cross-Attention (RCA) stream. RESULTS: The proposed model achieves a Quadratic Weighted Kappa rate of 90.2% on the small-sized internal KHUMC dataset. The robustness of the RCA stream is also evaluated by the single-modal Messidor dataset, of which the obtained mean Accuracy (94.8%) and Area Under Receiver Operating Characteristic (99.4%) outperform those of the state-of-the-arts significantly. CONCLUSION: Utilizing a network strongly regularized at feature space to learn the amalgamation of different modalities is of proven effectiveness. Thanks to the widespread availability of multi-modal retinal imaging for each diabetes patient nowadays, such approach can reduce the heavy reliance on large quantity of labeled visual data. SIGNIFICANCE: Our TFA-Net is able to coordinate hybrid information of fundus photos and wide-field SS-OCTA for exhaustively exploiting DR-oriented biomarkers. Moreover, the embedded feature-wise augmentation scheme can enrich generalization ability efficiently despite learning from small-scale labeled data.