Development of a Semi-automated Computer-based Tool for the Quantification of Vascular Tortuosity in the Murine Retina.

Purpose: The murine oxygen-induced retinopathy (OIR) model is one of the most widely used animal models of ischemic retinopathy, mimicking hallmark pathophysiology of initial vaso-obliteration (VO) resulting in ischemia that drives neovascularization (NV). In addition to NV and VO, human ischemic retinopathies, including retinopathy of prematurity (ROP), are characterized by increased vascular tortuosity. Vascular tortuosity is an indicator of disease severity, need to treat, and treatment response in ROP. Current literature investigating novel therapeutics in the OIR model often report their effects on NV and VO, and measurements of vascular tortuosity are less commonly performed. No standardized quantification of vascular tortuosity exists to date despite this metric's relevance to human disease. This proof-of-concept study aimed to apply a previously published semi-automated computer-based image analysis approach (iROP-Assist) to develop a new tool to quantify vascular tortuosity in mouse models. Design: Experimental study. Subjects: C57BL/6J mice subjected to the OIR model. Methods: In a pilot study, vasculature was manually segmented on flat-mount images of OIR and normoxic (NOX) mice retinas and segmentations were analyzed with iROP-Assist to quantify vascular tortuosity metrics. In a large cohort of age-matched (postnatal day 12 [P12], P17, P25) NOX and OIR mice retinas, NV, VO, and vascular tortuosity were quantified and compared. In a third experiment, vascular tortuosity in OIR mice retinas was quantified on P17 following intravitreal injection with anti-VEGF (aflibercept) or Immunoglobulin G isotype control on P12. Main Outcome Measures: Vascular tortuosity. Results: Cumulative tortuosity index was the best metric produced by iROP-Assist for discriminating between OIR mice and NOX controls. Increased vascular tortuosity correlated with disease activity in OIR. Treatment of OIR mice with aflibercept rescued vascular tortuosity. Conclusions: Vascular tortuosity is a quantifiable feature of the OIR model that correlates with disease severity and may be quickly and accurately quantified using the iROP-Assist algorithm. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Applications of Deep Learning: Automated Assessment of Vascular Tortuosity in Mouse Models of Oxygen-Induced Retinopathy.

Objective: To develop a generative adversarial network (GAN) to segment major blood vessels from retinal flat-mount images from oxygen-induced retinopathy (OIR) and demonstrate the utility of these GAN-generated vessel segmentations in quantifying vascular tortuosity. Design: Development and validation of GAN. Subjects: Three datasets containing 1084, 50, and 20 flat-mount mice retina images with various stains used and ages at sacrifice acquired from previously published manuscripts. Methods: Four graders manually segmented major blood vessels from flat-mount images of retinas from OIR mice. Pix2Pix, a high-resolution GAN, was trained on 984 pairs of raw flat-mount images and manual vessel segmentations and then tested on 100 and 50 image pairs from a held-out and external test set, respectively. GAN-generated and manual vessel segmentations were then used as an input into a previously published algorithm (iROP-Assist) to generate a vascular cumulative tortuosity index (CTI) for 20 image pairs containing mouse eyes treated with aflibercept versus control. Main Outcome Measures: Mean dice coefficients were used to compare segmentation accuracy between the GAN-generated and manually annotated segmentation maps. For the image pairs treated with aflibercept versus control, mean CTIs were also calculated for both GAN-generated and manual vessel maps. Statistical significance was evaluated using Wilcoxon signed-rank tests (P ≤ 0.05 threshold for significance). Results: The dice coefficient for the GAN-generated versus manual vessel segmentations was 0.75 ± 0.27 and 0.77 ± 0.17 for the held-out test set and external test set, respectively. The mean CTI generated from the GAN-generated and manual vessel segmentations was 1.12 ± 0.07 versus 1.03 ± 0.02 (P = 0.003) and 1.06 ± 0.04 versus 1.01 ± 0.01 (P < 0.001), respectively, for eyes treated with aflibercept versus control, demonstrating that vascular tortuosity was rescued by aflibercept when quantified by GAN-generated and manual vessel segmentations. Conclusions: GANs can be used to accurately generate vessel map segmentations from flat-mount images. These vessel maps may be used to evaluate novel metrics of vascular tortuosity in OIR, such as CTI, and have the potential to accelerate research in treatments for ischemic retinopathies. Financial Disclosures: The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Incomplete cisplatin regimens in chemoradiation and its effect on outcomes for locally advanced cervical cancer.

OBJECTIVE: To identify factors associated with receipt of incomplete cisplatin during chemoradiation for locally advanced cervical cancer and its impact on outcomes. METHODS: Patients with locally advanced cervical cancer treated with chemoradiation at our institution between November 2015 and August 2020 were retrospectively identified. Patients who received ≤4 cycles were identified as the 'incomplete' cohort and those who received 5-6 cycles as the 'complete' cohort. The primary endpoint of incomplete chemotherapy was evaluated with multivariable logistic regression. Secondary endpoints of locoregional failure, overall survival, and distant failure were evaluated in multivariable Cox and Fine-Gray models. RESULTS: Of 140 patients with locally advanced cervical cancer that underwent chemoradiation, 22 (15.7%) received an incomplete cisplatin regimen (8 with 0 cycles, 14 with 1-4 cycles). The most common reasons for receiving incomplete treatment were comorbidities/infections (41%), unmet laboratory parameters (27%), and cisplatin intolerance (14%). In multivariable models, only poor (2-4) Eastern Cooperative Oncology Group performance status was a significant predictor as these patients were 41 times more likely to receive incomplete chemotherapy (odds ratio (OR), 95% confidence interval (CI) 4.57 to 375.15, p<0.001). Median follow-up time was 20 months (range 4-64). In multivariable models, receipt of incomplete cisplatin was significantly associated with higher recurrence (locoregional failure hazard ratio (HR) 3.02, 95% CI 1.08 to 8.45, p=0.03; distant failure HR 2.71, 95% CI 1.13 to 6.47, p=0.02) and worse survival (overall survival HR 4.91, 95% CI 1.27 to 18.98, p=0.02). CONCLUSION: Incomplete cisplatin regimen was associated with worse oncologic outcomes. Poor performance status was the only factor associated with receiving an incomplete regimen. This notable proportion of patients may be a target for better tolerated novel targeted anticancer agents in order to improve outcomes.

Bioactive extracellular vesicles from a subset of endothelial progenitor cells rescue retinal ischemia and neurodegeneration.

Disruption of the neurovascular unit (NVU) underlies the pathophysiology of various CNS diseases. One strategy to repair NVU dysfunction uses stem/progenitor cells to provide trophic support to the NVU's functionally coupled and interdependent vasculature and surrounding CNS parenchyma. A subset of endothelial progenitor cells, endothelial colony-forming cells (ECFCs) with high expression of the CD44 hyaluronan receptor (CD44hi), provides such neurovasculotrophic support via a paracrine mechanism. Here, we report that bioactive extracellular vesicles from CD44hi ECFCs (EVshi) are paracrine mediators, recapitulating the effects of intact cell therapy in murine models of ischemic/neurodegenerative retinopathy; vesicles from ECFCs with low expression levels of CD44 (EVslo) were ineffective. Small RNA sequencing comparing the microRNA cargo from EVshi and EVslo identified candidate microRNAs that contribute to these effects. EVshi may be used to repair NVU dysfunction through multiple mechanisms to stabilize hypoxic vasculature, promote vascular growth, and support neural cells.

Deletion of Tgfß signal in activated microglia prolongs hypoxia-induced retinal neovascularization enhancing Igf1 expression and retinal leukostasis.

Retinal neovascularization (NV) is the major cause of severe visual impairment in patients with ischemic eye diseases. While it is known that retinal microglia contribute to both physiological and pathological angiogenesis, the molecular mechanisms by which these glia regulate pathological NV have not been fully elucidated. In this study, we utilized a retinal microglia-specific Transforming Growth Factor-ß (Tgfß) receptor knock out mouse model and human iPSC-derived microglia to examine the role of Tgfß signaling in activated microglia during retinal NV. Using a tamoxifen-inducible, microglia-specific Tgfß receptor type 2 (Tgfßr2) knockout mouse [Tgfßr2 KO (ΔMG)] we show that Tgfß signaling in microglia actively represses leukostasis in retinal vessels. Furthermore, we show that Tgfß signaling represses expression of the pro-angiogenic factor, Insulin-like growth factor 1 (Igf1), independent of Vegf regulation. Using the mouse model of oxygen-induced retinopathy (OIR) we show that Tgfß signaling in activated microglia plays a role in hypoxia-induced NV where a loss in Tgfß signaling microglia exacerbates and prolongs retinal NV in OIR. Using human iPSC-derived microglia cells in an in vitro assay, we validate the role of Transforming Growth Factor-ß1 (Tgfß1) in regulating Igf1 expression in hypoxic conditions. Finally, we show that Tgfß signaling in microglia is essential for microglial homeostasis and that the disruption of Tgfß signaling in microglia exacerbates retinal NV in OIR by promoting leukostasis and Igf1 expression.

CNTF Prevents Development of Outer Retinal Neovascularization Through Upregulation of CxCl10.

Purpose: Ciliary neurotrophic factor (CNTF) is a well-characterized neurotrophic factor currently in clinical trials for the treatment of macular telangiectasia type II. Our previous work showed that CNTF-induced STAT3 signaling is a potent inhibitor of pathologic preretinal neovascular tuft formation in the mouse model of oxygen-induced retinopathy. In this study, we investigated the effect of CNTF on outer retinal and choroidal angiogenesis and the mechanisms that underpin the observed decrease in outer retinal neovascularization following CNTF treatment. Methods: In the Vldlr-/- and laser-CNV mouse models, mice received a one-time injection (on postnatal day [P] 12 in the Vldlr-/- model and 1 day after laser in the Choroidal Neovascularization (CNV) model) of recombinant CNTF or CxCl10, and the extent of neovascular lesions was assessed 6 days posttreatment. STAT3 downstream targets affected by CNTF treatment were identified using quantitative PCR analysis. A proteome array was used to compare media conditioned by CNTF-treated and control-treated primary Müller cells to screen for CNTF-induced changes in secreted angiogenic factors. Results: Intravitreal treatment with recombinant CNTF led to significant reduction in neovascularization in the Vldlr-/- and laser-CNV mouse models. Treatment effect in the Vldlr-/- was long-lasting but time sensitive, requiring intravitreal treatment before P19. Mechanistic workup in vitro as well as in vivo confirmed significant activation of the STAT3-signaling pathway in Müller cells in response to CNTF treatment and upregulation of CxCl10. Intravitreal injections of recombinant CxCl10 significantly reduced outer retinal neovascularization in vivo in both the Vldlr-/- and laser-CNV mouse models. Conclusions: CNTF treatment indirectly affects outer retinal and choroidal neovascularization by inducing CxCl10 secretion from retinal Müller cells.

Fully automated, deep learning segmentation of oxygen-induced retinopathy images.

Oxygen-induced retinopathy (OIR) is a widely used model to study ischemia-driven neovascularization (NV) in the retina and to serve in proof-of-concept studies in evaluating antiangiogenic drugs for ocular, as well as nonocular, diseases. The primary parameters that are analyzed in this mouse model include the percentage of retina with vaso-obliteration (VO) and NV areas. However, quantification of these two key variables comes with a great challenge due to the requirement of human experts to read the images. Human readers are costly, time-consuming, and subject to bias. Using recent advances in machine learning and computer vision, we trained deep learning neural networks using over a thousand segmentations to fully automate segmentation in OIR images. While determining the percentage area of VO, our algorithm achieved a similar range of correlation coefficients to that of expert inter-human correlation coefficients. In addition, our algorithm achieved a higher range of correlation coefficients compared with inter-expert correlation coefficients for quantification of the percentage area of neovascular tufts. In summary, we have created an open-source, fully automated pipeline for the quantification of key values of OIR images using deep learning neural networks.

Care of Older Adults: Role of Primary Care Physicians in the Treatment of Cataracts and Macular Degeneration.

This article aims to facilitate optimal management of cataracts and age-related macular degeneration (AMD) by providing information on indications, risk factors, referral guidelines, and treatments and to describe techniques to maximize quality of life (QOL) for people with irreversible vision loss. A review of PubMed and other online databases was performed for peer-reviewed English-language articles from 1980 through August 2012 on visual impairment in elderly adults. Search terms included vision loss, visual impairment, blind, low vision, QOL combined with age-related, elderly, and aging. Articles were selected that discussed vision loss in elderly adults, effects of vision impairment on QOL, and care strategies to manage vision loss in older adults. The ability of primary care physicians (PCPs) to identify early signs of cataracts and AMD in individuals at risk of vision loss is critical to early diagnosis and management of these common age-related eye diseases. PCPs can help preserve vision by issuing aptly timed referrals and encouraging behavioral modifications that reduce risk factors. With knowledge of referral guidelines for soliciting low-vision rehabilitation services, visual aids, and community support resources, PCPs can considerably increase the QOL of individuals with uncorrectable vision loss. By offering appropriately timed referrals, promoting behavioral modifications, and allocating low-vision care resources, PCPs may play a critical role in preserving visual health and enhancing the QOL for the elderly population.

EFFICACY AND SAFETY OF TREATMENT OPTIONS FOR VITREOMACULAR TRACTION: A Case Series and Meta-Analysis.

PURPOSE: To evaluate treatment options for vitreomacular traction (VMT). METHODS: A retrospective, consecutive case series and a literature search with Boolean search logic. A random-effects meta-analysis was conducted to combine the rates of VMT resolution per treatment. Patients from studies analyzed were placed into cohorts based on the treatment received. CASE SERIES: Zero of 10 control, 3 of 7 intravitreal ocriplasmin (IVO, P = 0.10), 7 of 8 intravitreal expansile gas (pneumatic vitreolysis, PV, P < 0.01), and 10 of 10 pars plana vitrectomy (P < 0.01)-treated eyes experienced VMT release (VMTr) at Day 28. No patients developed retinal tears or detachment. One PV-treated (12.5%) eye developed a macular hole. Meta-analysis: Twenty-three of 131 prospective or retrospective and consecutive articles were included. Sixty-three eyes were treated with PV, 726 eyes were treated with intravitreal ocriplasmin, and 253 eyes were characterized as the control group (saline injection). The weighted rate of VMT resolution for the control group was 0.09 (95% confidence interval [CI]: 0.06-0.13), PV was 0.84 (95% CI: 0.76-0.92), and intravitreal ocriplasmin was 0.26 (95% CI: 0.23-0.29). CONCLUSION: Our analysis found that PV releases VMT in most patients and suggest that PV may be as effective or superior to nonsurgical options for VMTr at Day 28 with a similar risk profile.

Angiogenic and Inflammatory Vitreous Biomarkers Associated With Increasing Levels of Retinal Ischemia.

PURPOSE: To characterize the angiogenic and inflammatory vitreous biomarker profiles in a spectrum of ischemic retinopathies, including neovascular glaucoma. METHODS: This institutional review board-approved study retrospectively analyzed 80 undiluted vitreous samples obtained during pars vitrectomy. The specimens were frozen (-80°C) and sent for concentration analysis of 34 proteins by Bio-Plex Pro assays. Specimens were divided into four groups: patients undergoing epiretinal membrane (ERM) peeling and/or macular hole (MH) surgery with no history of diabetes (non-DM group), patients undergoing ERM peeling, and/or MH surgery with a history of diabetes (DM group), patients with proliferative diabetic retinopathy (PDR group), and patients with neovascular glaucoma (NVG group). Parametric and nonparametric analyses of demographics and cytokine levels were performed using SPSS. RESULTS: There were no significant differences in demographics among cohorts. Numerous proteins were significantly elevated between non-DM and DM (G-CSF, sCD40L, Endoglin, IL-6, placental growth factor [PlGF], VEGF-D), DM and PDR (leptin, IL-8, PlGF, VEGF-A), and PDR and NVG (G-CSF, leptin, TIE-2, sCD40L, EGF, HB-EGF, IL-6, IL-8, PlGF, TNF-α). Only PlGF was significantly elevated between each successive cohort. The most potent drivers of NVG were PlGF, VEGF-A, IL-6, and IL-8. CONCLUSIONS: While the role of angioproliferative growth factors is well documented in ischemic retinopathy, our study delineates the importance of inflammatory and previously underreported angiogenic proteins. It also demonstrates a significant incremental increase in certain factors with increasing levels of ischemia. Both of these findings may guide the development of future therapies for ischemic retinopathies.

Case-matched comparison of vitrectomy, peripheral retinal endolaser, and endocyclophotocoagulation versus standard care in neovascular glaucoma.

PURPOSE: To evaluate the efficacy of combination pars plana vitrectomy, endoscopic peripheral panretinal photocoagulation, and endocyclophotocoagulation (ECP) as compared with standard care in patients with neovascular glaucoma. METHODS: This age-matched case-controlled retrospective series of 54 eyes compared the clinical outcomes between a consecutive series of combination pars plana vitrectomy/panretinal photocoagulation/ECP (n = 27) versus the current standard of care (n = 27) for patients with neovascular glaucoma. "Standard" treatments for patients with neovascular glaucoma include panretinal photocoagulation, intravitreal bevacizumab, filtration surgery, pars plana vitrectomy, and Ahmed valve placement. RESULTS: After 1 year, mean intraocular pressure reduced from 40.7 ± 12.40 mmHg preoperatively to 12.3 ± 4.84 mmHg (P < 0.001) in the ECP group and from 34.7 ± 12.38 mmHg to 23.2 ± 12.34 mmHg in the control group (P = 0.002). Compared with controls, the mean drop in intraocular pressure in the ECP group was significantly greater at all postoperative visits. Logarithm of the minimal angle of resolution visual acuity outcomes were similar in both groups. There were 2 cases (7.4%) of postoperative phthisis bulbi in each group. CONCLUSION: Endoscopic pars plana vitrectomy, panretinal photocoagulation, and ECP seem to control intraocular pressure to a greater extent than standard glaucoma treatments in patients with neovascular glaucoma. In this aged-matched comparative case series, there was no significant difference between the two treatments' effects on visual acuity.

PERIODONTAL DISEASE AND AGE-RELATED MACULAR DEGENERATION: Results From the National Health and Nutrition Examination Survey III.

PURPOSE: To study the association between periodontal disease (PD) and age-related macular degeneration (AMD). METHODS: For this cross-sectional analysis, 8,208 adults aged 40 years or older with retinal photographs graded for AMD were used from the National Health and Nutrition Examination Survey III. National Health and Nutrition Examination Survey III standardized dental measurements of PD status (defined as loss of >3 mm of attachment between the gum and tooth in at least 10% of sites measured). Participants were stratified into 60 years or younger and older than 60 years of age groups. Association between PD and AMD was assessed while controlling for sex, race, education, poverty income ratio, smoking, hypertension, body mass index, cardiovascular disease, and C-reactive protein. RESULTS: In this population, a total of 52.30% had PD, and the prevalence of AMD was 11.45%. Logistic regression model controlled for confounders and stratified by age 60 years or younger versus older than 60 years showed PD to be independently associated with an increased risk for AMD (odds ratio = 1.96, 95% confidence interval = 1.22-3.14, P = 0.006) for those aged 60 years or younger but not for subjects older than 60 years (odds ratio = 1.32, confidence interval = 0.93-1.90, P = 0.120). CONCLUSION: In this population-based study, PD is independently associated with AMD in those aged 60 years or younger.

Reversible vision loss and outer retinal abnormalities after intravitreal ocriplasmin injection.

PURPOSE: Ocriplasmin is a truncated form of the human serine protease plasmin, which was recently approved for the nonsurgical treatment of symptomatic vitreomacular adhesions. According to its FDA label, approximately 8% of subjects experienced acute transient vision loss during the first week after injection with no alternative explanation for the change. This report focuses on a recent case of recovered vision loss over a 3-month period after the injection. METHODS: A comprehensive ophthalmic examination was performed before the injection, during the day of the injection, and at 2 days, 2 weeks, 1 month, and 4 months after the injection. This examination included a full ophthalmic workup and imaging with spectral domain optical coherence tomography. A case of a 55-year-old woman who experienced acute severe vision loss 2 days after the treatment with ocriplasmin was reported. RESULTS: Distinct alterations, as seen with spectral domain optical coherence tomography, were observed in the ellipsoid zone of photoreceptors. These changes together with patient's visual acuity gradually recovered over a 3-month period after the injection. CONCLUSION: Further investigation may be warranted to fully elucidate the precise molecular mechanisms involved in patients with unexplained vision loss after ocriplasmin injection.

Indications and techniques of endoscope assisted vitrectomy.

The popularization of ophthalmic endoscopy has been promoted by recent technological advancements that increase the number of indications for endoscopy. These advancements have improved the endoscope's capabilities in its two fundamental surgical advantages: (1) bypassing anterior segment opacities, and (2) visualizing anteriorly positioned structures such as the ciliary bodies and sub-iris space. In this article, the current state of the ophthalmic endoscope is reviewed alongside its growing number of applications in glaucoma, vitreoretinal, and ocular trauma surgery. We describe the role of endoscopy in endocyclophotocoagulation for glaucoma, cyclitic membrane peeling in hypotony, retinal detachment surgery, intraocular foreign body removal, severe endophthalmitis, and pediatric traumatic vitreoretinal surgery. This review examines both the pearls and limitations of the ophthalmic application of endoscopy. In doing so, we hope to provide guidelines for using the endoscope and also to highlight applications of endoscopy that merit further study.

Surgical outcomes after epiretinal membrane peeling combined with cataract surgery.

OBJECTIVE: To compare functional and anatomical outcomes after idiopathic epiretinal membrane (ERM) peeling combined with phacoemulsification and intraocular lens implantation versus ERM peeling alone. METHODS: A retrospective, non-randomised comparative case series study was conducted of 81 eyes from 79 patients who underwent ERM peeling at the Beth Israel Deaconess Medical Center between 2001 and 2010. Eyes that underwent combined surgery for ERM and cataracts (group 1) were compared with those that had ERM peeling alone (group 2) with respect to best-corrected visual acuity at 6 months and 1 year after surgery, postoperative central macular thickness (CMT) as measured on optical coherence tomography, and rates of complications, including elevated intraocular pressure (IOP), ERM recurrence and need for reoperation. RESULTS: Mean logMAR visual acuity improved significantly in both groups at 6 months (p<0.001) and 1 year (p<0.001) after surgery. There was no statistical difference between the two groups in visual acuity improvement at 6 months (p=0.108) or 1 year (p=0.094). Mean CMT of both groups also significantly decreased after surgery (p=0.002), with no statistical difference in CMT reduction between the two groups, but a trend toward less CMT reduction in group 1 (p=0.061). The rates of complications, including IOP elevation, ERM recurrence and frequency of reoperation, were similar in the two groups, with non-statistical trends toward greater ERM recurrence (p=0.084) and need for reoperation (p=0.096) in those that had combined surgery. CONCLUSIONS: Combined surgery for ERMs and cataracts may potentially be as effective as membrane peeling alone with respect to visual and anatomical outcomes. Further studies are necessary to determine if there may be greater ERM recurrence or need for reoperation after combined surgery.