Correlations between Clinical and Histopathologic Characteristics in Idiopathic Epiretinal Membrane.

PURPOSE: To investigate correlations between clinical and histopathologic characteristics of idiopathic epiretinal membrane (ERM). DESIGN: Retrospective interventional case series. PARTICIPANTS: In total, 87 eyes from 87 patients with idiopathic ERM who underwent pars plana vitrectomy with peeling of the ERM from 2019 to 2020 were included. METHODS: The outcomes of clinical ophthalmic examination, including measurement of best-corrected visual acuity (BCVA) and spectral-domain OCT (SD-OCT), before and after surgery were reviewed. Surgical specimens were fixed in formalin and embedded in paraffin for histologic and immunohistochemical analysis. MAIN OUTCOMES MEASURES: The association between morphological characteristics revealed on SD-OCT images and the cellular composition of the surgically excised ERM demonstrated with immunohistochemical staining were the main outcome measures. Changes in the BCVA and central macular thickness (CMT) were assessed through a comparison of preoperative and postoperative measurements. RESULTS: Based on SD-OCT morphological characteristics in the foveal area, 15 cases were classified into group 1A (mainly outer retinal thickening), 39 into group 1B (more tenting of the outer retina and distorted inner retina), and 33 into group 1C (prominent inner retina thickening). Overall, postoperative final BCVA and CMT at 1 year improved in all groups. Patients who presented with a better initial BCVA exhibited a more favorable final BCVA. Epiretinal membranes in group 1C demonstrated the greatest decrease in CMT compared with those in groups 1B and 1A, but the final CMT did not differ among the groups. A negative correlation between the density of hyalocytes (P = 0.003) and myofibroblasts (P = 0.047) was noted between the 3 groups. Total cell density and glial cell density of the ERMs were strongly associated with poor final BCVA and BCVA improvement. CONCLUSIONS: The present study provides new histopathologic information regarding the formation and progression of idiopathic ERM. Glial cell proliferation plays a predominant role in these processes. Epiretinal membranes with high cellularity and glial cell density may cause damage to the retina structure, resulting in poor postoperative visual outcomes. These findings provide additional evidence supporting early surgical intervention in patients with idiopathic ERM reported with visual disturbance.

Visual outcomes and incidence of pseudophakic cystoid macular oedema in eyes with cataract and idiopathic epiretinal membrane after two-step sequential surgery.

OBJECTIVES: To determine whether pars plana vitrectomy (PPV) or cataract surgery should be performed first in concurrent epiretinal membrane (ERM) and cataract treatment with respect to visual outcome and pseudophakic cystoid macular oedema (PCMO) incidence. METHODS: Patients who underwent PPV and cataract surgery sequentially at a tertiary medical centre were retrospectively recruited. Best-corrected visual acuity (BCVA) and central macular thickness (CMT) measured from optical coherence tomography (OCT) images collected before and after each surgery were documented. OCT-defined PCMO incidence and its influence on visual outcomes were analysed. RESULTS: In total, 259 and 159 eyes received PPV (ERM-CATA) before and after cataract surgery (CATA-ERM), respectively. The ERM-CATA group had better final BCVA (logMAR: 0.274 vs. 0.558, p < 0.001) and greater BCVA gain (logMAR VA change: -0.379 vs. -0.220, p = 0.001) than did the CATA-ERM group. Baseline BCVA was positively correlated with final BCVA (p < 0.001), whereas baseline CMT, final CMT, and postoperative CMT changes were not. PCMO incidence did not differ significantly between the two groups (15.4% vs. 19.5%, p = 0.287), and final BCVA changes did not significantly differ between eyes with and without PCMO. PCMO incidence was much higher (29.40% vs. 16.30%, p = 0.008) in eyes with baseline CMT ≥ 500 µm. CONCLUSIONS: When managing ERM and cataract, PPV should be performed before cataract surgery to yield better visual outcomes. Both surgical sequences yield similar PCMO rates. Greater baseline CMT is a risk factor for PCMO after cataract surgery.

Deep learning and ensemble stacking technique for differentiating polypoidal choroidal vasculopathy from neovascular age-related macular degeneration.

Polypoidal choroidal vasculopathy (PCV) and neovascular age-related macular degeneration (nAMD) share some similarity in clinical imaging manifestations. However, their disease entity and treatment strategy as well as visual outcomes are very different. To distinguish these two vision-threatening diseases is somewhat challenging but necessary. In this study, we propose a new artificial intelligence model using an ensemble stacking technique, which combines a color fundus photograph-based deep learning (DL) model and optical coherence tomography-based biomarkers, for differentiation of PCV from nAMD. Furthermore, we introduced multiple correspondence analysis, a method of transforming categorical data into principal components, to handle the dichotomous data for combining with another image DL system. This model achieved a robust performance with an accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve of 83.67%, 80.76%, 84.72%, and 88.57%, respectively, by training nearly 700 active cases with suitable imaging quality and transfer learning architecture. This work could offer an alternative method of developing a multimodal DL model, improve its efficiency for distinguishing different diseases, and facilitate the broad application of medical engineering in a DL model design.

Flow signal change in polyps after anti-vascular endothelial growth factor therapy.

Optical coherence tomography angiography (OCTA) is a novel, non-invasive imaging tool used to detect vascular flow. The absence of a flow signal in OCTA in polyps revealed by indocyanine green angiography (ICGA) in patients with polypoidal choroidal vasculopathy (PCV) may indicate slow or compromised filling of blood flow from choroidal vessels. Naïve patients with PCV treated with intravitreal injections of aflibercept (IVI-A) were enrolled in this study to validate the hypothesis that baseline flow may affect the outcome of polyp regression in ICGA. The flow signal of polyps in OCTA was detected by manual segmentation in the corresponding location by ICGA. Polyps were defined as high-flow if both OCTA and ICGA showed positive findings, and low-flow if OCTA showed a negative flow signal in 3 consecutive horizontal scans at the polyp area shown in ICGA. A total of 24 polyps were identified in 13 PCV patients at baseline. Of these 24 polyps, 22 (91.7%) were high-flow and 2 (8.3%) were low-flow. After 3 monthly IVI-A, all low-flow polyps had complete regression in ICGA. Among 17 (77%) high-flow polyps at baseline that had regression after treatment, 10 (58.8%) became low-flow, while 5 (22.7%) persistent polyps remained high-flow. Flow signal of polyps as detected by OCTA could be a predictive factor for treatment response in patients with PCV. Monitoring changes in flow signal after treatment is clinically relevant.

Connexin channel and its role in diabetic retinopathy.

Diabetic retinopathy is the leading cause of blindness in the working age population. Unfortunately, there is no cure for this devastating ocular complication. The early stage of diabetic retinopathy is characterized by the loss of various cell types in the retina, namely endothelial cells and pericytes. As the disease progresses, vascular leakage, a clinical hallmark of diabetic retinopathy, becomes evident and may eventually lead to diabetic macular edema, the most common cause of vision loss in diabetic retinopathy. Substantial evidence indicates that the disruption of connexin-mediated cellular communication plays a critical role in the pathogenesis of diabetic retinopathy. Yet, it is unclear how altered communication via connexin channel mediated cell-to-cell and cell-to-extracellular microenvironment is linked to the development of diabetic retinopathy. Recent observations suggest the possibility that connexin hemichannels may play a role in the pathogenesis of diabetic retinopathy by allowing communication between cells and the microenvironment. Interestingly, recent studies suggest that connexin channels may be involved in regulating retinal vascular permeability. These cellular events are coordinated at least in part via connexin-mediated intercellular communication and the maintenance of retinal vascular homeostasis. This review highlights the effect of high glucose and diabetic condition on connexin channels and their impact on the development of diabetic retinopathy.

Acute macular edema and peripapillary soft exudate after pancreas transplantation with accelerated progression of diabetic retinopathy.

BACKGROUND: The effect of pancreas transplantation on diabetic retinopathy remains inconclusive. Herein, we report six patients with type 1 diabetes mellitus (DM) who underwent pancreas transplantation and developed acute macular edema and peripapillary soft exudate with rapid progression to proliferative diabetic retinopathy. METHODS: In this retrospective observational study, diabetic patients who underwent pancreas transplantation in a single medical center and developed symptomatic acute macular edema and peripapillary soft exudate within 3 months after the operation were enrolled. The complete ophthalmic course and medical records of the patients were retrospectively reviewed. Diabetic retinopathy and progression following treatment after pancreas transplantation were measured. RESULTS: Six Chinese women with type 1 DM were enrolled in this study. Mean hemoglobin (Hb) A1c was 13.4% prior to transplantation and decreased rapidly to 6.5% within 2 months postsurgery. The patients had no or mild pretransplant diabetic retinopathy and developed acute symptomatic macular edema and peripapillary soft exudate in both eyes after pancreas transplantation. All macular edema resolved either with or without treatment. Five cases progressed to proliferative diabetic retinopathy and received panretinal photocoagulation. Diabetic retinopathy remained stable in all eyes after treatment, and the visual prognosis was good, except in one eye that had macular branch retinal artery occlusion with foveal involvement. CONCLUSION: Acute macular edema after pancreas transplantation has a favorable treatment outcome despite rapid progression to proliferative diabetic retinopathy. High pretransplant HbA1c and abrupt blood sugar normalization may be related to the disease course.

Sensitivity, Specificity, and Limitations of Optical Coherence Tomography Angiography in Diagnosis of Polypoidal Choroidal Vasculopathy.

PURPOSE: To evaluate the sensitivity and specificity of optical coherence tomography angiography (OCTA) in differentiating polypoidal choroidal vasculopathy (PCV) from age-related macular degeneration (AMD). METHODS: Fundus color photographs, spectral-domain optical coherence tomography, and fluorescein angiography (step 1) and OCTA (step 2) of 50 eyes that had PCV or AMD were presented to two ophthalmologists. The final diagnoses of PCV were masked. Sensitivity and specificity were calculated and compared to the 2-step approach (before and after OCTA) in detecting PCV. The limitations were also evaluated. RESULTS: Of the 50 eyes, 31 were PCV and 19 were non-PCV. The sensitivity increased from 69.5% to 90% after OCTA; however, there was no significant improvement in specificity after OCTA. 70.9% of the eyes with PCV had clear or obvious branching vascular nets (BVNs) in OCTA with high sensitivity (97.5%) after OCTA. Contrarily, 29.1% had insignificant BVNs with a low sensitivity (72.5%) after OCTA. 27% of the occult choroidal neovascularization (CNV) cases were overdiagnosed as PCV when OCTA was applied. CONCLUSIONS: OCTA based on clear BVNs at the choroidal level increased sensitivity of diagnosis of PCV by 20%. However, the false-positive rate also increased in occult CNV. Several limitations for a correct diagnosis of PCV were noted.

Prevalence and associated risk factors of myopic maculopathy in elderly Chinese: the Shihpai eye study.

PURPOSE: To assess the prevalence and associated risk factors of myopic maculopathy in an elderly Chinese population in Taiwan. METHODS: Population-based, cross-sectional study. A total of 1361 Chinese aged 65 years or older residing in Shihpai, Taipei, Taiwan, underwent a detailed ophthalmic examination. Of the 1361 participants, 1058 subjects had at least one gradable fundus photograph and were recruited for analysis. High myopia was defined as spherical equivalent of less than -6.0 diopter (D) in the phakic eyes or axial length greater than 26.5 mm in pseudophakic or aphakic eyes. Myopic maculopathy was defined as the appearance of lacquer cracks, focal area of deep choroidal atrophy and macular choroidal neovascularization, or geographic atrophy in the presence of high myopia. RESULTS: The prevalence of high myopia was 4.2% (44/1058). Signs of myopic maculopathy were present in 32 (72.7%) of the 44 high myopics, representing a prevalence of 3.0% (95% confidence interval, 2.0%-4.0%). Subjects with high myopia with myopic maculopathy had higher systolic blood pressure than those without maculopathy (146.4 ± 16.2 mm Hg vs. 127.0 ± 15.9 mm Hg, P = 0.001), and the difference persisted (P = 0.018) after adjustment for age, sex, smoking, body mass index, diastolic blood pressure, educational levels, alcohol drinking, and histories of diabetes or taking anti-hypertension medication. Of the 65 high myopic eyes, eyes with maculopathy had a greater myopic degree (-12.8 ± 5.1 D vs. -7.6 ± 1.5 D, P = 0.001) and poorer corrected visual acuity (logMAR 0.72 ± 0.6 vs. 0.27 ± 0.2, P = 0.001) than those without. CONCLUSIONS: The prevalence of high myopia and myopic maculopathy in this elderly Chinese population group was high. Of the major risk factors examined, high systolic blood pressure may be associated with myopic maculopathy.

Population-based study of nonproliferative diabetic retinopathy among type 2 diabetic patients in Kinmen, Taiwan.

PURPOSE: This study was conducted to assess the prevalence and associated factors of nonproliferative diabetic retinopathy among type 2 diabetic patients in Kinmen, Taiwan. METHODS: From 1991 to 1993, 971 type 2 diabetic patients in Kinmen underwent diabetic retinopathy screening performed by a panel of ophthalmologists using indirect ophthalmoscopy and 45 degrees color fundus retinal photographs. RESULTS: Of the 971 patients screened in 1991-1993, 578 (59.5%) were examined for this study. Diabetic retinopathy was diagnosed in 127 patients (22.0%), including nonproliferative diabetic retinopathy in 13.3%, proliferative diabetic retinopathy in 1.4%, legal blindness in 1.4%, and ungradable diabetic retinopathy in 5.9%. Significant associated factors of nonproliferative diabetic retinopathy based on multiple logistic regression analysis were fasting plasma glucose (FPG) at baseline [> or =126 mg/dl vs. <126 mg/dl; odds ratio (OR) = 2.89; 95% confidence interval (CI), 1.01-9.09], 2-h postload at baseline (> or =200 vs. <200 mg/dl; OR = 1.48; 95% CI, 1.09-2.07); HbA1c at follow-up (> or =7% vs. <7%; OR = 6.54; 95% CI, 3.01-14.20), duration of diabetes (> or =15 years vs. <10 years; OR = 6.72; 95% CI, 2.13-21.18), and incremental systolic blood pressure between baseline and follow-up (OR = 1.02; 95% CI, 1.00-1.04). CONCLUSIONS: In addition to the longer duration of type 2 diabetes, FPG at baseline, poorly controlled glucose concentration, and altered blood pressure may increase the risk of nonproliferative diabetic retinopathy in type 2 diabetic patients.