Retina

PURPOSE: We sought to characterize the angiofibrotic and apoptotic effects of vascular endothelial growth factor (VEGF)-inhibition on fibrovascular epiretinal membranes in eyes with traction retinal detachment because of proliferative diabetic retinopathy. METHODS: Membranes were excised from 20 eyes of 19 patients (10 randomized to intravitreal bevacizumab, 10 controls) at vitrectomy. Membranes were stained with antibodies targeting connective tissue growth factor (CTGF) or VEGF and colabeled with antibodies directed against endothelial cells (CD31), myofibroblasts, or retinal pigment epithelium markers. Quantitative and colocalization analyses of antibody labeling were obtained through immunofluorescence confocal microscopy. Masson trichrome staining, cell counting of hematoxylin and eosin sections, and terminal dUTP nick-end labeling staining were performed. RESULTS: High levels of fibrosis were observed in both groups. Cell apoptosis was higher (P = 0.05) in bevacizumab-treated membranes compared with controls. The bevacizumab group had a nonsignificant reduction in colocalization in CD31-CTGF and cytokeratin-VEGF studies compared with controls. Vascular endothelial growth factor in extracted membranes was positively correlated with vitreous levels of VEGF; CTGF in extracted membranes was negatively correlated with vitreous levels of CTGF. CONCLUSION: Bevacizumab suppresses vitreous VEGF levels, but does not significantly alter VEGF or CTGF in diabetic membranes that may be explained by high baseline levels of fibrosis. Bevacizumab may cause apoptosis within fibrovascular membranes.

Optic neuropathy is one of the leading causes of irreversible blindness caused by retinal ganglion cell (RGC) degeneration. The development of induced pluripotent stem cell (iPSC)-based therapy opens a therapeutic window for RGC degeneration, and tissue engineering may further promote the efficiency of differentiation process of iPSCs. The present study was designed to evaluate the effects of a novel biomimetic polybenzyl glutamate (PBG) scaffold on culturing iPSC-derived RGC progenitors. The iPSC-derived neural spheres cultured on PBG scaffold increased the differentiated retinal neurons and promoted the neurite outgrowth in the RGC progenitor layer. Additionally, iPSCs cultured on PBG scaffold formed the organoid-like structures compared to that of iPSCs cultured on cover glass within the same culture period. With RNA-seq, we found that cells of the PBG group were differentiated toward retinal lineage and may be related to the glutamate signaling pathway. Further ontological analysis and the gene network analysis showed that the differentially expressed genes between cells of the PBG group and the control group were mainly associated with neuronal differentiation, neuronal maturation, and more specifically, retinal differentiation and maturation. The novel electrospinning PBG scaffold is beneficial for culturing iPSC-derived RGC progenitors as well as retinal organoids. Cells cultured on PBG scaffold differentiate effectively and shorten the process of RGC differentiation compared to that of cells cultured on coverslip. The new culture system may be helpful in future disease modeling, pharmacological screening, autologous transplantation, as well as narrowing the gap to clinical application.

Reactive microglia and infiltrating peripheral monocytes have been implicated in many neurodegenerative diseases of the retina and CNS. However, their specific contribution in retinal degeneration remains unclear. We recently showed that peripheral monocytes that infiltrate the retina after ocular injury in mice become permanently engrafted into the tissue, establishing a proinflammatory phenotype that promotes neurodegeneration. In this study, we show that microglia regulate the process of neuroglia remodeling during ocular injury, and their depletion results in marked upregulation of inflammatory markers, such as , , and in the retina, and abnormal engraftment of peripheral CCR2 CX3CR1 monocytes into the retina, which is associated with increased retinal ganglion cell loss, retinal nerve fiber layer thinning, and pigmentation onto the retinal surface. Furthermore, we show that other types of ocular injuries, such as penetrating corneal trauma and ocular hypertension also cause similar changes. However, optic nerve crush injury-mediated retinal ganglion cell loss evokes neither peripheral monocyte response in the retina nor pigmentation, although peripheral CX3CR1 and CCR2 monocytes infiltrate the optic nerve injury site and remain present for months. Our study suggests that microglia are key regulators of peripheral monocyte infiltration and retinal pigment epithelium migration, and their depletion results in abnormal neuroglia remodeling that exacerbates neuroretinal tissue damage. This mechanism of retinal damage through neuroglia remodeling may be clinically important for the treatment of patients with ocular injuries, including surgical traumas.

BACKGROUND: To evaluate changes in image sharpness across ultrawide field (UWF) images and the effect of phase-plate adjustment on image contrast and extent of visible retinal area (VRA). METHODS: This was a single site evaluation of 200° UWF images acquired with phase-plate adjustment (California, Optos, plc) and without (200TX, Optos, plc). Images were acquired using standardized protocol. VRA was manually outlined on each image and quantified using customized software. Mean image sharpness was evaluated using an automated method within the full VRA of each image and within the peripheral region of the VRA. The VRA and image sharpness were evaluated and compared between the two devices. RESULTS: Twenty eyes of 10 healthy volunteers were evaluated. Devices with and without phase-plate adjustment produced a similar extent of VRA. Eye steering increased VRA in devices with and without phase-plate adjustment by 39.3% and 34.3%, respectively. Regardless of gaze direction, mean sharpness of the full VRA was reduced in peripheral area with or without phase-plate adjustment. Compared to images without phase-plate adjustment, use of phase-plate adjustment reduced the loss of peripheral image sharpness in all fields (-4.2 to -26.0%; p < 0.001 all fields). The sharpness of the peripheral area for on-axis images was 61.5% higher with phase-plate adjustment. CONCLUSIONS: The use of phase-plate adjustment does not alter the extent of VRA. However, for on-axis images the loss of sharpness in the periphery is 4.5-fold less with phase-plate adjustment, potentially reducing the need to steer images and improving lesion detection in these areas.

The dysfunction and cell death of retinal pigment epithelial (RPE) cells are hallmarks of late-stage dry (atrophic) age-related macular degeneration (AMD), for which no effective therapy has yet been developed. Previous studies have indicated that iron accumulation is a source of excess free radical production in RPE, and age-dependent iron accumulation in RPE is accelerated in patients with dry AMD. Although the pathogenic role of oxidative stress in RPE in the development of dry AMD is widely accepted, the mechanisms of oxidative stress-induced RPE cell death remain elusive. Here, we show that ferroptotic cell death, a mode of regulated necrosis mediated by iron and lipid peroxidation, is implicated in oxidative stress-induced RPE cell death in vitro. In ARPE-19 cells we observed that the ferroptosis inhibitors ferrostatin-1 and deferoxamine (DFO) rescued tert-butyl hydroperoxide (tBH)-induced RPE cell death more effectively than inhibitors of apoptosis or necroptosis. tBH-induced RPE cell death was accompanied by the three characteristics of ferroptotic cell death: lipid peroxidation, glutathione depletion, and ferrous iron accumulation, which were all significantly attenuated by ferrostatin-1 and DFO. Exogenous iron overload enhanced tBH-induced RPE cell death, but this effect was also attenuated by ferrostatin-1 and DFO. Furthermore, mRNA levels of numerous genes known to regulate iron metabolism were observed to be influenced by oxidative stress. Taken together, our observations suggest that multiple modes of cell death are involved in oxidative stress-induced RPE cell death, with ferroptosis playing a particularly important role.

PURPOSE: To describe the study design and characteristics at first visit of participants in the longitudinal Scotopic Microperimetric Assessment of Rod Function in Stargardt Disease (SMART) study. METHODS: Scotopic microperimetry (sMP) was performed in one designated study eye in a subset of participants with molecularly proven ABCA4-associated Stargardt disease (STGD1) enrolled in a multicenter natural history study (ProgStar). Study visits were every 6 months over a period ranging from 6 to 24 months, and also included fundus autofluorescence (FAF). RESULTS: SMART enrolled 118 participants (118 eyes). At the first visit of SMART, the mean sensitivity in mesopic microperimetry was 11.48 (±5.05; range 0.00-19.88) dB and in sMP 11.25 (±5.26; 0-19.25) dB. For FAF, all eyes had a lesion of decreased autofluorescence (mean lesion size 3.62 [±3.48; 0.10-21.46] mm2), and a total of 76 eyes (65.5%) had a lesion of definitely decreased autofluorescence with a mean lesion size of 3.46 (±3.60; 0.21-21.46) mm2. CONCLUSIONS: Rod function is impaired in STGD1 and can be assessed by sMP. Testing rod function may serve as a potential outcome measure for future clinical treatment trials. This is evaluated in the SMART study.

AIMS: The aim of our study was to image choroidal lesions with swept-source optical coherence tomography (SS-OCT) and to identify the morphological characteristics associated with optimal visualisation. METHODS: This was a prospective, cross-sectional study. Patients with choroidal melanocytic lesions <3 mm in thickness on B-scan ultrasonography were recruited. All participants underwent SS-OCT. On SS-OCT we evaluated qualitative (eg, lesion outline, detection of scleral-choroidal interface and quality of the image) and quantitative (measurement of maximum lesion thickness and the largest basal diameter) parameters. Probability of optimal image quality was examined using ordered logistic regression models. The main outcome measure was quality of the choroidal lesion images on SS-OCT, defined as: optimal, suboptimal or poor. RESULTS: We included 85 choroidal lesions of 82 patients. There were 24 choroidal lesions (29%) for which image quality was classified as optimal, 31 lesions (37%) as suboptimal and 30 lesions (36%) as poor. The factors associated with optimal image quality were distance closer to the fovea (OR 0.76, p<0.001), posterior pole location (OR 3.87, p=0.05), lower ultrasonography thickness (OR 0.44, p=0.04), lighter lesion pigmentation (OR 0.12, p=0.003) and smaller lesion diameter (OR 0.73, p<0.001). In the multivariable analysis, closer distance to the fovea (OR 0.81, p=0.005), lighter lesion pigmentation (OR 0.11, p=0.01) and smaller lesion diameter (OR 0.76, p=0.006) remained statistically significant. CONCLUSION: SS-OCT is useful in imaging most choroidal melanocytic lesions. Image quality is best when the choroidal lesion is closer to the fovea, has a smaller diameter and a lighter choroidal pigmentation.

PURPOSE: To evaluate the capacity of spectral domain optical coherence tomography macular findings to predict best-corrected visual acuity (BCVA) outcomes after treatment for symptomatic vitreomacular traction. METHODS: This consecutive, retrospective study included 24 patients (29 eyes) who experienced vitreomacular traction release with pneumatic vitreolysis (n = 9), intravitreal ocriplasmin (n = 6), or pars plana vitrectomy (n = 14). Preoperative and postoperative spectral domain optical coherence tomography images were used to determine the cone outer segment tips (COST) line, inner segment/outer segment line, and other frequently used features. Correlations between optical coherence tomography findings and BCVA were determined using regression analyses. RESULTS: Postoperative BCVA was correlated with length of the COST line and inner segment/outer segment line defects at 1, 3, 6, and 12 months postoperatively (P < 0.05) by simple linear regression analysis. However, multivariable regression analysis showed that only length of the COST line defect was significantly correlated with BCVA preoperatively and postoperatively (P < 0.05). Postoperative BCVA improvement at 12 months was significantly correlated with preoperative length of the COST line defect (P < 0.01). CONCLUSION: Recovery of the COST line and inner segment/outer segment line defects as observed by spectral domain optical coherence tomography is positively correlated with visual acuity improvement after successful vitreomacular traction treatment. Best-corrected visual acuity improvement may be predicted using the length of the preoperative COST line defect.

PURPOSE: To evaluate microstructural retinal abnormalities on spectral domain optical coherence tomography (SD-OCT) imaging of eyes with Coats disease. METHODS: This is a multicenter, retrospective study in which SD-OCT images of patients with treatment-naive Coats disease were correlated with clinical examination and visual acuity and, when available, followed longitudinally over time. RESULTS: Macular SD-OCT of 27 eyes with Coats disease revealed intraretinal edema (59%), intraretinal exudates (67%), subretinal fluid (37%), subretinal exudate (48%), ellipsoid zone disruption (52%), external limiting membrane disruption (41%), and subfoveal nodule (26%). All these microstructural abnormalities correlated with worse baseline and final visual acuities (P < 0.05) on univariate analysis, except for intraretinal edema which exhibited a nonstatistically significant trend toward worse baseline visual acuity (P = 0.16). Within stage 2b eyes, external limiting membrane disruption and subretinal nodule on SD-OCT were associated with worse baseline visual acuity (P = 0.02 for both), and there was a trend toward worse final visual acuity with external limiting membrane disruption and subretinal nodule (P = 0.17 for both) and worse baseline (P = 0.08) and final (P = 0.13) visual acuities with ellipsoid zone disruption. No microstructural abnormalities were noted on OCT of fellow eyes. CONCLUSION: Spectral domain OCT can identify microstructural abnormalities in Coats disease that are associated on univariate analysis with worse baseline visual acuity and visual prognosis. Further larger studies are necessary.

PURPOSE: The aim of this study is to describe the clinical presentation of vortex vein varices with multimodal imaging. METHODS: The authors carried out a retrospective case series of eight patients (7 female, 1 male) with an average age of 60.2 years (min 8, max 84, median 68.5) presenting with vortex vein varices. All patients were evaluated at the Sant'Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy and at Luigi Sacco Hospital, University of Milan, Milan, Italy. Patients underwent complete ophthalmologic examinations, including best corrected visual acuity, intraocular pressure, anterior segment, and fundus examination. Imaging studies, including fundus color photography, near-infrared reflectance imaging, fundus autofluorescence, fluorescein angiography, indocyanine green angiography, and spectral-domain enhanced depth imaging optical coherence tomography were also performed. Ultra-widefield fluorescein angiography and ultra-widefield indocyanine angiography using the Heidelberg Retina Angiograph and the Staurenghi 230 SLO Retina Lens were used to demonstrate the disappearance of all retinal lesions when pressure was applied to the globe. RESULTS: All eight cases initially presented to the emergency room. One patient presented secondary to trauma, two patients presented for suspected hemangioma, whereas the other five were referred to the authors' hospitals for suspected retinal lesions. On examination, retinal abnormalities were identified in all 8 patients, with 7 (87.5%) oculus dexter and 1 (12.5%) oculus sinister, and with 1 (12.5%) inferotemporally, 3 (37.5%) superonasally, 3 (37.5%) inferonasally, and 1 (12.5%) inferiorly. Fundus color photography showed an elevated lesion in seven patients and a nonelevated red lesion in one patient. In all patients, near-infrared reflectance imaging showed a hyporeflective lesion in the periphery of the retina. Fundus autofluorescence identified round hypofluorescent rings surrounding weakly hyperfluorescent lesions in all patients. On fluorescein angiography, all lesions were initially hyperfluorescent with a hypofluorescent ring, with the lesion becoming hyperfluorescent after injection of dye. Indocyanine green angiography demonstrated dilation of the vortex vein ampullae in all patients. Spectral-domain enhanced depth imaging optical coherence tomography demonstrated dilated choroidal vessels and a hyporeflective cavity without subretinal fluid in all patients. Ultra-widefield fluorescein angiography and ultra-widefield indocyanine angiography demonstrated disappearance of all retinal lesions when pressure was applied to the globe. Findings are consistent with the diagnosis of vortex vein varix in all eight patients, with six patients (75%) exhibiting a single varix and two patients (25%) exhibiting a double varix. CONCLUSION: The diagnosis of vortex vein varices can be confirmed through clinical examination through the use of digital pressure to the globe during ophthalmoscopic examination. Adjunctive multimodal imaging (fundus color photography, near-infrared reflectance imaging, fundus autofluorescence, fluorescein angiography, indocyanine angiography, and spectral-domain enhanced depth imaging optical coherence tomography) was useful in the diagnosis of vortex vein varices in the authors' clinical cases. However, in more challenging clinical cases, the authors' novel use of the ultra-widefield contact lens for application of ocular pressure with a resulting resolution of the varix proved to be a useful and easy diagnostic imaging method for confirming the presence of vortex vein varices.

The Wnt signaling pathway plays a pivotal role in vascular morphogenesis in various organs including the eye. Wnt ligands and receptors are key regulators of ocular angiogenesis both during the eye development and in vascular eye diseases. Wnt signaling participates in regulating multiple vascular beds in the eye including regression of the hyaloid vessels, and development of structured layers of vasculature in the retina. Loss-of-function mutations in Wnt signaling components cause rare genetic eye diseases in humans such as Norrie disease, and familial exudative vitreoretinopathy (FEVR) with defective ocular vasculature. On the other hand, experimental studies in more prevalent vascular eye diseases, such as wet age-related macular degeneration (AMD), diabetic retinopathy (DR), retinopathy of prematurity (ROP), and corneal neovascularization, suggest that aberrantly increased Wnt signaling is one of the causations for pathological ocular neovascularization, indicating the potential of modulating Wnt signaling to ameliorate pathological angiogenesis in eye diseases. This review recapitulates the key roles of the Wnt signaling pathway during ocular vascular development and in vascular eye diseases, and pharmaceutical approaches targeting the Wnt signaling as potential treatment options.

Despite advances in therapy for rheumatic diseases, hydroxychloroquine remains almost universally recommended for the treatment of systemic lupus erythematosus (SLE), and is often used in the management of other rheumatic diseases such as rheumatoid arthritis (RA). However, the major dose-limiting toxicity of hydroxychloroquine is retinopathy that can lead to loss of vision. New highly sensitive screening methods can identify early stages of retinopathy, and studies that include these modalities have indicated a substantially higher prevalence of hydroxychloroquine retinopathy than was previously recognized, resulting in revisions to ophthalmology guidelines and the recommendation of a low dose of hydroxychloroquine for many patients. However, the efficacy of low-dose hydroxychloroquine for treating SLE and other rheumatic diseases is unknown. Further studies are required to establish the effectiveness and retinal safety of the latest hydroxychloroquine treatment recommendations.