Ophthalmologies
Abstract
Glaucoma is a highly heritable disease that is a leading cause of blindness worldwide. Here, we identified heterozygous thrombospondin 1 (THBS1) missense alleles altering p.Arg1034, a highly evolutionarily conserved amino acid, in 3 unrelated and ethnically diverse families affected by congenital glaucoma, a severe form of glaucoma affecting children. Thbs1R1034C-mutant mice had elevated intraocular pressure (IOP), reduced ocular fluid outflow, and retinal ganglion cell loss. Histology revealed an abundant, abnormal extracellular accumulation of THBS1 with abnormal morphology of juxtacanalicular trabecular meshwork (TM), an ocular tissue critical for aqueous fluid outflow. Functional characterization showed that the THBS1 missense alleles found in affected individuals destabilized the THBS1 C-terminus, causing protein misfolding and extracellular aggregation. Analysis using a range of amino acid substitutions at position R1034 showed that the extent of aggregation was correlated with the change in protein-folding free energy caused by variations in amino acid structure. Extracellular matrix (ECM) proteins, especially fibronectin, which bind to THBS1, also accumulated within THBS1 deposits. These results show that missense variants altering THBS1 p.Arg1034 can cause elevated IOP through a mechanism involving impaired TM fluid outflow in association with accumulation of aggregated THBS1 in the ECM of juxtacanalicular meshwork with altered morphology.
Authors
Haojie Fu, Owen M. Siggs, Lachlan S.W. Knight, Sandra E. Staffieri, Jonathan B. Ruddle, Amy E. Birsner, Edward Ryan Collantes, Jamie E. Craig, Janey L. Wiggs, Robert J. D’Amato
Abstract
BACKGROUND. Studies assessing the efficacy of therapies for neovascular age-related macular degeneration (nvAMD) have demonstrated that aflibercept may have a longer treatment interval than its lesser-expensive alternative, bevacizumab. However, whether this benefit justifies the additional cost of aflibercept remains under debate. We have recently reported that a “treat-and-extend-pause/monitor” (TEP/M) approach can be used to successfully wean 31% of nvAMD patients off anti-VEGF therapy. Here we examine whether the choice of therapy influences the outcomes of this approach. METHODS. In this retrospective analysis, 122 eyes of 106 patients with nvAMD underwent 3 consecutive monthly injections with either aflibercept (n=70) or bevacizumab (n=52) followed by a treat-and-extend protocol in which the decision to extend the interval between treatments was based on visual acuity, clinical exam, and the presence or absence of fluid on optical coherence tomography (OCT). Eyes that remained stable 12 weeks from their prior treatment were given a 6-week trial of holding further treatment, followed by quarterly monitoring. Treatment was resumed for worsening vision, clinical exam, or OCT findings. RESULTS. At the end of one year, eyes receiving bevacizumab had similar vision but required more injections (8.7 ±0.3 vs. 7.2 ±0.3) compared to aflibercept. However, eyes treated with aflibercept were almost 3-times more likely to be weaned off treatment (43% vs. 15%) compared to eyes treated with bevacizumab at the end of one year. CONCLUSIONS. These observations expose a previously unappreciated advantage of aflibercept over bevacizumab and have important clinical implications for the selection of therapy for patients with nvAMD.
Authors
Xuan Cao, Jaron Castillo Sanchez, Tapan P. Patel, Zhiyong Yang, Chuanyu Guo, Danyal Malik, Anuoluwapo Sopeyin, Silvia Montaner, Akrit Sodhi
Abstract
Normal-tension glaucoma (NTG) is a heterogeneous disease characterized by retinal ganglion cell (RGC) death leading to cupping of the optic nerve head and visual field loss at normal intraocular pressure (IOP). The pathogenesis of NTG remains unclear. Here, we described a single nucleotide mutation in exon 2 of the methyltransferase like 23 (METTL23) gene identified in a three-generation Japanese NTG family. This mutation caused METTL23 mRNA aberrant splicing, which abolished normal protein production and altered subcellular localization. Mettl23 knock-in (Mettl23+/G & Mettl23G/G) and knockout (Mettl23+/- & Mettl23-/-) mice developed a glaucoma phenotype without elevated IOP. METTL23 is a histone arginine methyltransferase expressed in murine and macaque RGCs. However, the novel mutation reduced Mettl23 expression in RGCs of Mettl23G/G mice, which recapitulated both clinical and biological phenotypes. Moreover, our findings demonstrated that Mettl23 catalyzed the dimethylation of H3R17 in the retina, and was required for the transcription of pS2, an estrogen receptor α target gene that was critical to RGC homeostasis through the negative regulation of NF-κB-mediated TNF-α/IL-1β feedback. These findings suggest an etiologic role of METTL23 in NTG with tissue-specific pathology.
Authors
Yang Pan, Akiko Suga, Itaru Kimura, Chojiro Kimura, Yuriko Minegishi, Mao Nakayama, Kazutoshi Yoshitake, Daisuke Iejima, Naoko Minematsu, Megumi Yamamoto, Fumihiko Mabuchi, Mitsuko Takamoto, Yukihiro Shiga, Makoto Araie, Kenji Kashiwagi, Makoto Aihara, Toru Nakazawa, Takeshi Iwata
Abstract
Background Deep learning has been widely used for glaucoma diagnosis. However, there is no clinically validated algorithm for glaucoma incidence and progression prediction. This study aims to develop a clinically feasible deep-learning system for predicting and stratifying the risk of glaucoma onset and progression based on color fundus photographs (CFPs), with clinical validation of performance in external population cohorts.Methods We established data sets of CFPs and visual fields collected from longitudinal cohorts. The mean follow-up duration was 3 to 5 years across the data sets. Artificial intelligence (AI) models were developed to predict future glaucoma incidence and progression based on the CFPs of 17,497 eyes in 9346 patients. The area under the receiver operating characteristic (AUROC) curve, sensitivity, and specificity of the AI models were calculated with reference to the labels provided by experienced ophthalmologists. Incidence and progression of glaucoma were determined based on longitudinal CFP images or visual fields, respectively.Results The AI model to predict glaucoma incidence achieved an AUROC of 0.90 (0.81–0.99) in the validation set and demonstrated good generalizability, with AUROCs of 0.89 (0.83–0.95) and 0.88 (0.79–0.97) in external test sets 1 and 2, respectively. The AI model to predict glaucoma progression achieved an AUROC of 0.91 (0.88–0.94) in the validation set, and also demonstrated outstanding predictive performance with AUROCs of 0.87 (0.81–0.92) and 0.88 (0.83–0.94) in external test sets 1 and 2, respectively.Conclusion Our study demonstrates the feasibility of deep-learning algorithms in the early detection and prediction of glaucoma progression.FUNDING National Natural Science Foundation of China (NSFC); the High-level Hospital Construction Project, Zhongshan Ophthalmic Center, Sun Yat-sen University; the Science and Technology Program of Guangzhou, China (2021), the Science and Technology Development Fund (FDCT) of Macau, and FDCT-NSFC.
Authors
Fei Li, Yuandong Su, Fengbin Lin, Zhihuan Li, Yunhe Song, Sheng Nie, Jie Xu, Linjiang Chen, Shiyan Chen, Hao Li, Kanmin Xue, Huixin Che, Zhengui Chen, Bin Yang, Huiying Zhang, Ming Ge, Weihui Zhong, Chunman Yang, Lina Chen, Fanyin Wang, Yunqin Jia, Wanlin Li, Yuqing Wu, Yingjie Li, Yuanxu Gao, Yong Zhou, Kang Zhang, Xiulan Zhang
Abstract
Human pluripotent stem cells (hPSCs) hold great promise for the treatment of various human diseases. However, their therapeutic benefits and mechanisms for treating corneal endothelial dysfunction remain undefined. Here, we developed a therapeutic regimen consisting of the combination of hPSC-derived corneal endothelial precursors (CEPs) with nicotinamide (NAM) for effective treatment of corneal endothelial dysfunction. In rabbit and nonhuman primate models, intracameral injection of CEPs and NAM achieved long-term recovery of corneal clarity and thickness, similar with the therapeutic outcome of cultured human corneal endothelial cells (CECs). The transplanted human CEPs exhibited structural and functional integration with host resident CECs. However, the long-term recovery relied on the stimulation of endogenous endothelial regeneration in rabbits, but predominantly on the replacing function of transplanted cells during the 3-year follow-up in nonhuman primates, which resemble human corneal endothelium with limited regenerative capacity. Mechanistically, NAM ensured in vivo proper maturation of transplanted CEPs into functional CECs by preventing premature senescence and endothelial-mesenchymal transition within the TGF-β–enriched aqueous humor. Together, we provide compelling experimental evidence and mechanistic insights of simultaneous delivery of CEPs and NAM as a potential approach for treating corneal endothelial dysfunction.
Authors
Zongyi Li, Haoyun Duan, Yanni Jia, Can Zhao, Wenjing Li, Xin Wang, Yajie Gong, Chunxiao Dong, Bochao Ma, Shengqian Dou, Bin Zhang, Dongfang Li, Yihai Cao, Lixin Xie, Qingjun Zhou, Weiyun Shi
Abstract
BACKGROUND. To reduce the treatment burden for patients with neovascular age-related macular degeneration (nvAMD), emerging therapies targeting vascular endothelial growth factor (VEGF) are being designed to extend the interval between treatments, thereby minimizing the number of intraocular injections. However, which patients will benefit from longer-acting agents is not clear. METHODS. Eyes with nvAMD (n=122) underwent 3 consecutive monthly injections with currently available anti-VEGF therapies, followed by a treat-and-extend protocol. Patients who remained quiescent 12 weeks from their prior treatment entered a “treatment pause” and were switched to pro re nata (PRN) treatment (based on vision, clinical exam, and/or imaging studies). Proteomic analysis was performed on aqueous fluid to identify proteins that correlate with patients’ response to treatment. RESULTS. At the end of 1 year, 38/122 eyes (31%) entered a treatment pause (≥30 weeks). Conversely, 21/122 eyes (17%) failed extension and required monthly treatment at the end of year 1. Proteomic analysis of aqueous fluid identified proteins that correlated with patients’ response to treatment including proteins previously implicated in AMD pathogenesis. Interestingly, apolipoprotein-B100 (ApoB100), a principal component of drusen implicated in the progression of non-neovascular AMD, was increased in treated patients who required less frequent injections. ApoB100 expression was higher in AMD eyes compared to controls but was lower in eyes that develop choroidal neovascularization (CNV), consistent with a protective role. Accordingly, mice over-expressing ApoB100 were partially protected from laser-induced CNV. CONCLUSIONS. Aqueous biomarkers could help identify nvAMD patients who may not require – nor benefit from – long-term treatment with anti-VEGF therapy.
Authors
Xuan Cao, Jaron Castillo Sanchez, Aumreetam Dinabandhu, Chuanyu Guo, Tapan P. Patel, Zhiyong Yang, Ming-Wen Hu, Lijun Chen, Yuefan Wang, Danyal Malik, Kathleen Jee, Yassine J. Daoud, James T. Handa, Hui Zhang, Jiang Qian, Silvia Montaner, Akrit Sodhi
Abstract
BACKGROUND. Noninvasive assessment of metabolic processes that sustain regeneration of human retinal visual pigments (visual cycle) is essential to improve ophthalmic diagnostics and to accelerate development of new treatments to counter retinal diseases. Fluorescent vitamin A derivatives, which are the chemical intermediates of these processes, are highly sensitive to UV light; thus, safe analyses of these processes in humans are currently beyond the reach of even the most modern ocular imaging modalities. METHODS. We present a compact fluorescence scanning laser ophthalmoscope (TPEF-SLO) and spectrally resolved images of the human retina based on two-photon excitation (TPE) with near-infrared (IR) light. A custom Er:fiber laser with integrated pulse selection, along with intelligent post-processing of data, enables excitation with low laser power and precise measurement of weak signals. RESULTS. We demonstrate spectrally resolved TPE fundus images of human subjects. Comparison of TPE data between human and mouse models of retinal diseases revealed similarity with mouse models that rapidly accumulate bisretinoid condensation products. Thus, visual cycle intermediates and toxic byproducts of this metabolic pathway can be measured and quantified by TPE imaging. CONCLUSION. Our work establishes a TPE instrument and measurement method for noninvasive metabolic assessment of the human retina. This approach opens the possibility for monitoring eye diseases in the earliest stages before structural damage to the retina occurs. FUNDING. NIH, Research to Prevent Blindness, Foundation for Polish Science, European Regional Development Fund, Polish National Agency for Academic Exchange and Polish Ministry of Science and Higher Education.
Authors
Jakub Boguslawski, Grazyna Palczewska, Slawomir Tomczewski, Jadwiga Milkiewicz, Piotr Kasprzycki, Dorota Stachowiak, Katarzyna Komar, Marcin J. Marzejon, Bartosz L. Sikorski, Arkadiusz Hudzikowski, Aleksander Głuszek, Zbigniew Łaszczych, Karol Karnowski, Grzegorz Soboń, Krzysztof Palczewski, Maciej Wojtkowski
Abstract
BACKGROUND. A long-held dream of scientists is to transfer information directly to the visual cortex of blind individuals, thereby restoring a rudimentary form of sight. However, no clinically available cortical visual prosthesis yet exists. METHODS.We implanted an intracortical microelectrode array consisting of 96 electrodes in the visual cortex of a 57-year-old person with complete blindness for a six- month period. We measured thresholds and the characteristics of the visual percepts elicited by intracortical microstimulation. RESULTS. Implantation and subsequent explantation of intracortical microelectrodes were carried out without complications. The mean stimulation threshold for single electrodes was 66.8 ± 36.5 μA. We consistently obtained high-quality recordings from visually deprived neurons and the stimulation parameters remained stable over time. Simultaneous stimulation via multiple electrodes were associated with a significant reduction in thresholds (p<0.001, ANOVA test) and evoked discriminable phosphene percepts, allowing the blind participant to identify some letters and recognize object boundaries. Furthermore, we observed a learning process that helped the subject to recognize complex patterns over time. CONCLUSIONS. Our results demonstrate the safety and efficacy of chronic intracortical microstimulation via a large number of electrodes in human visual cortex, showing its high potential for restoring functional vision in the blind. TRIAL REGISTRATION. ClinicalTrials.gov identifier NCT02983370. FUNDING. Funding was provided by grant RTI2018-098969-B-100 from the Spanish Ministerio de Ciencia Innovación y Universidades, by grant PROMETEO/2019/119 from the Generalitat Valenciana (Spain), by the Bidons Egara Research Chair of the University Miguel Hernández (Spain) and by the John Moran Eye Center of the University of Utah (US).
Authors
Eduardo Fernández, Arantxa Alfaro, Cristina Soto-Sánchez, Pablo González-López, Antonio M. Lozano Ortega, Sebastian Peña, María Dolores Grima, Alfonso Rodil, Bernardeta Gómez, Xing Chen, Pieter R. Roelfsema, John D. Rolston, Tyler S. Davis, Richard A. Normann
Abstract
Therapies targeting VEGF have proven only modestly effective for the treatment of proliferative sickle cell retinopathy (PSR), the leading cause of blindness in patients with sickle cell disease. Here, we shift our attention upstream from the genes that promote retinal neovascularization (NV) to the transcription factors that regulate their expression. We demonstrated increased expression of HIF-1α and HIF-2α in the ischemic inner retina of PSR eyes. Although both HIFs participated in promoting VEGF expression by hypoxic retinal Müller cells, HIF-1 alone was sufficient to promote retinal NV in mice, suggesting that therapies targeting only HIF-2 would not be adequate to prevent PSR. Nonetheless, administration of a HIF-2–specific inhibitor currently in clinical trials (PT2385) inhibited NV in the oxygen-induced retinopathy (OIR) mouse model. To unravel these discordant observations, we examined the expression of HIFs in OIR mice and demonstrated rapid but transient accumulation of HIF-1α but delayed and sustained accumulation of HIF-2α; simultaneous expression of HIF-1α and HIF-2α was not observed. Staggered HIF expression was corroborated in hypoxic adult mouse retinal explants but not in human retinal organoids, suggesting that this phenomenon may be unique to mice. Using pharmacological inhibition or an in vivo nanoparticle-mediated RNAi approach, we demonstrated that inhibiting either HIF was effective for preventing NV in OIR mice. Collectively, these results explain why inhibition of either HIF-1α or HIF-2α is equally effective for preventing retinal NV in mice but suggest that therapies targeting both HIFs will be necessary to prevent NV in patients with PSR.
Authors
Jing Zhang, Yaowu Qin, Mireya Martinez, Miguel Flores-Bellver, Murilo Rodrigues, Aumreetam Dinabandhu, Xuan Cao, Monika Deshpande, Yu Qin, Silvia Aparicio-Domingo, Yuan Rui, Stephany Y. Tzeng, Shaima Salman, Jin Yuan, Adrienne W. Scott, Jordan J. Green, M. Valeria Canto-Soler, Gregg L. Semenza, Silvia Montaner, Akrit Sodhi
Abstract
Leber’s hereditary optic neuropathy (LHON) is a maternally inherited eye disease. X-linked nuclear modifiers were proposed to modify the phenotypic manifestation of LHON-associated mitochondrial DNA (mtDNA) mutations. By whole exome sequencing, we identified the X-linked LHON modifier (c.157C>T, p. Arg53Trp) in the PRICKLE3 encoding a mitochondrial protein linked to biogenesis of ATPase in three Chinese families. All affected individuals carried both ND4 11778G>A and p.Arg53Trp mutations, while subjects bearing only single mutation exhibited normal vision. The cells carrying the p.Arg53Trp mutation exhibited the defective assembly, stability and function of ATP synthase, verified by PRICKLE3 knock-down cells. Co-immunoprecipitation indicated the direct interaction of PRICKLE3 with ATP synthase via ATP8. Strikingly, mutant cells bearing both p.Arg53Trp and m.11778G>A mutations displayed greater mitochondrial dysfunctions than those carrying only single mutation. These indicated that the p.Arg53Trp mutation acted in synergy with m.11778G>A mutation and deteriorated mitochondrial dysfunctions necessary for the expression of LHON. Furthermore, we demonstrated that Prickle3 deficient mice exhibited the pronounced ATPase deficiencies. Prickle3 knock-out mice recapitulated LHON phenotypes with retina deficiencies including degeneration of retinal ganglion cells and abnormal vasculature. Our findings provided new insights into pathophysiology of LHON that were manifested by interaction between mtDNA mutation and X-linked nuclear modifier.
Authors
Jialing Yu, Xiaoyang Liang, Yanchun Ji, Cheng Ai, Junxia Liu, Ling Zhu, Zhipeng Nie, Xiaofen Jin, Chenghui Wang, Juanjuan Zhang, Fuxin Zhao, Shuang Mei, Xiaoxu Zhao, Xiangtian Zhou, Minglian Zhang, Meng Wang, Taosheng Huang, Pingping Jiang, Min-Xin Guan
Copyright © 2023 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)