Hudry E, Vandenberghe LH. Therapeutic AAV Gene Transfer to the Nervous System: A Clinical Reality. Neuron 2019;101(5):839-862.Abstract
Gene transfer has long been a compelling yet elusive therapeutic modality. First mainly considered for rare inherited disorders, gene therapy may open treatment opportunities for more challenging and complex diseases such as Alzheimer's or Parkinson's disease. Today, examples of striking clinical proof of concept, the first gene therapy drugs coming onto the market, and the emergence of powerful new molecular tools have broadened the number of avenues to target neurological disorders but have also highlighted safety concerns and technology gaps. The vector of choice for many nervous system targets currently is the adeno-associated viral (AAV) vector due to its desirable safety profile and strong neuronal tropism. In aggregate, the clinical success, the preclinical potential, and the technological innovation have made therapeutic AAV drug development a reality, particularly for nervous system disorders. Here, we discuss the rationale, opportunities, limitations, and progress in clinical AAV gene therapy.
Busch C, Iglicki M, Okada M, Gabrielle P-H, Cohen S, Mariussi M, Amphornphruet A, Cebeci Z, Chaikitmongkol V, Couturier A, Fraser-Bell S, Fung AT, Iannetta D, Radecka L, Laíns I, Rodrigues TM, Lupidi M, Ozimek M, Sala-Puigdollers A, Rehak M, Loewenstein A, Zur D, Zur D. Causative Pathogens of Endophthalmitis after Intravitreal Anti-VEGF Injection: An International Multicenter Study. Ophthalmologica 2019;241(4):211-219.Abstract
PURPOSE: The main objective of this study was to investigate the microbiological spectrum of endophthalmitis after anti-VEGF injections and to compare streptococcal with non-streptococcus-associated cases with regard to baseline characteristics and injection procedure. METHODS: Retrospective, international multicenter study of patients with culture-positive endophthalmitis after intravitreal anti-VEGF injection at 17 different retina referral centers. RESULTS: Eighty-three cases with 87 identified pathogens were included. Coagulase-negative staphylococci (59%) and viridans streptococci (15%) were the most frequent pathogens found. The use of postoperative antibiotics and performance of injections in an operating room setting significantly reduced the rate of streptococcus-induced endophthalmitis cases (p = 0.01 for both). CONCLUSION: We found a statistically significant lower rate of postinjectional local antibiotic therapy and operating room-based procedures among the streptococcus-induced cases compared to cases caused by other organisms.
Wu W, Hutcheon AEK, Sriram S, Tran JA, Zieske JD. Initiation of fibrosis in the integrin Αvβ6 knockout mice. Exp Eye Res 2019;180:23-28.Abstract
We previously demonstrated that β6 knockout mice showed impaired wound repair in corneal debridement and keratectomy wounds. In the current investigation, we continued our examination of integrin αvβ6 in order to determine if it was required for the initiation of wound healing in a corneal wound model that normally heals in a fibrotic manner. A full-thickness corneal incision was made in C57BL/6 J wild type (WT) and C57BL/6-Itgb6 KO (β6) mice. The mice were observed at 3, 7, 14, and 28 days post-incision. The morphology of corneal restoration was observed in tissue sections stained with hemotoxilin and eosin (H&E). In addition, indirect-immunofluorescence (IF) was performed on sections and/or whole mounts to evaluate the immunolocalization of α-smooth muscle actin (SMA) and thrombospondin-1 (TSP-1). H&E staining revealed that the corneas in β6 mice healed slower than those in WT mice, with an obvious delay in the restoration of the stromal matrix and epithelium. In sections at 3 and 7 days, SMA and TSP-1 were greatly reduced in the β6 mice as compared to WT, but peaked at 28 days after incision. Whole mount SMA IF results were consistent with those from sections. Therefore, the initiation of fibrosis was inhibited by the lack of αvβ6; however, there appeared to be an alternate mechanism that initiated fibrosis 7-14 days later. Localization of TSP-1 correlated with expression of SMA whether wound healing was delayed or initiated immediately after wounding.
Shirzaei Sani E, Kheirkhah A, Rana D, Sun Z, Foulsham W, Sheikhi A, Khademhosseini A, Dana R, Annabi N. Sutureless repair of corneal injuries using naturally derived bioadhesive hydrogels. Sci Adv 2019;5(3):eaav1281.Abstract
Corneal injuries are common causes of visual impairment worldwide. Accordingly, there is an unmet need for transparent biomaterials that have high adhesion, cohesion, and regenerative properties. Herein, we engineer a highly biocompatible and transparent bioadhesive for corneal reconstruction using a visible light cross-linkable, naturally derived polymer, GelCORE (gel for corneal regeneration). The physical properties of GelCORE could be finely tuned by changing prepolymer concentration and photocrosslinking time. GelCORE revealed higher tissue adhesion compared to commercial adhesives. Furthermore, in situ photopolymerization of GelCORE facilitated easy delivery to the cornea, allowing for bioadhesive curing precisely according to the required geometry of the defect. In vivo experiments, using a rabbit stromal defect model, showed that bioadhesive could effectively seal corneal defects and induce stromal regeneration and re-epithelialization. Overall, GelCORE has many advantages including low cost and ease of production and use. This makes GelCORE a promising bioadhesive for corneal repair.
Owen LA, Shakoor A, Morgan DJ, Hejazi AA, McEntire WM, Brown JJ, Farrer LA, Kim I, Vitale A, Deangelis MM. The Utah Protocol for Postmortem Eye Phenotyping and Molecular Biochemical Analysis. Invest Ophthalmol Vis Sci 2019;60(4):1204-1212.Abstract
Purpose: Current understanding of local disease pathophysiology in AMD is limited. Analysis of the human disease-affected tissue is most informative, as gene expression, expressed quantitative trait loci, microenvironmental, and epigenetic changes can be tissue, cell type, and location specific. Development of a novel translational treatment and prevention strategies particularly for earlier forms of AMD are needed, although access to human ocular tissue analysis is challenging. We present a standardized protocol to study rapidly processed postmortem donor eyes for molecular biochemical and genomic studies. Methods: We partnered with the Utah Lions Eye Bank to obtain donor human eyes, blood, and vitreous, within 6 hours postmortem. Phenotypic analysis was performed using spectral-domain optical coherence tomography (SD-OCT) and color fundus photography. Macular and extramacular tissues were immediately isolated, and the neural retina and retinal pigment epithelium/choroid from each specimen were separated and preserved. Ocular disease phenotype was analyzed using clinically relevant grading criteria by a group of four ophthalmologists incorporating data from SD-OCT retinal images, fundus photographs, and medical records. Results: The use of multimodal imaging leads to greater resolution of retinal pathology, allowing greater phenotypic rigor for both interobserver phenotype and known clinical diagnoses. Further, our analysis resulted in excellent quality RNA, which demonstrated appropriate tissue segregation. Conclusions: The Utah protocol is a standardized methodology for analysis of disease mechanisms in AMD. It uniquely allows for simultaneous rigorous phenotypic, molecular biochemical, and genomic analysis of both systemic and local tissues. This better enables the development of disease biomarkers and therapeutic interventions.
Deng SX, Borderie V, Chan CC, Dana R, Figueiredo FC, Gomes JAP, Pellegrini G, Shimmura S, Kruse FE, and Group TILSCDW. Global Consensus on Definition, Classification, Diagnosis, and Staging of Limbal Stem Cell Deficiency. Cornea 2019;38(3):364-375.Abstract
PURPOSE: Despite extensive knowledge gained over the last 3 decades regarding limbal stem cell deficiency (LSCD), the disease is not clearly defined, and there is lack of agreement on the diagnostic criteria, staging, and classification system among treating physicians and research scientists working on this field. There is therefore an unmet need to obtain global consensus on the definition, classification, diagnosis, and staging of LSCD. METHODS: A Limbal Stem Cell Working Group was first established by The Cornea Society in 2012. The Working Group was divided into subcommittees. Four face-to-face meetings, frequent email discussions, and teleconferences were conducted since then to obtain agreement on a strategic plan and methodology from all participants after a comprehensive literature search, and final agreement was reached on the definition, classification, diagnosis, and staging of LSCD. A writing group was formed to draft the current manuscript, which has been extensively revised to reflect the consensus of the Working Group. RESULTS: A consensus was reached on the definition, classification, diagnosis, and staging of LSCD. The clinical presentation and diagnostic criteria of LSCD were clarified, and a staging system of LSCD based on clinical presentation was established. CONCLUSIONS: This global consensus provides a comprehensive framework for the definition, classification, diagnosis, and staging of LSCD. The newly established criteria will aid in the correct diagnosis and formulation of an appropriate treatment for different stages of LSCD, which will facilitate a better understanding of the condition and help with clinical management, research, and clinical trials in this area.
Bothun ED, Wilson EM, Traboulsi EI, Diehl NN, Plager DA, VanderVeen DK, Freedman SF, Yen KG, Weil NC, Loh AR, Morrison D, Anderson JS, Lambert SR, and (TAPS) TAPSG. Outcomes of Unilateral Cataracts in Infants and Toddlers 7 to 24 Months of Age: Toddler Aphakia and Pseudophakia Study (TAPS). Ophthalmology 2019;126(8):1189-1195.Abstract
PURPOSE: To evaluate outcomes of unilateral cataract surgery in children 7 to 24 months of age. DESIGN: Retrospective case series at 10 Infant Aphakia Treatment Study (IATS) sites. PARTICIPANTS: The Toddler Aphakia and Pseudophakia Study is a registry of children treated by surgeons who participated in the IATS. METHODS: Children underwent unilateral cataract surgery with or without intraocular lens (IOL) placement during the IATS enrollment years of 2004 and 2010. MAIN OUTCOME MEASURES: Intraoperative complications, adverse events (AEs), visual acuity, and strabismus. RESULTS: Fifty-six children were included with a mean postoperative follow-up of 47.6 months. Median age at cataract surgery was 13.9 months (range, 7.2-22.9). Ninety-two percent received a primary IOL. Intraoperative complications occurred in 4 patients (7%). At 5 years of age, visual acuity of treated eyes was very good (≥20/40) in 11% and poor (≤20/200) in 44%. Adverse events were identified in 24%, with a 4% incidence of glaucoma suspect. An additional unplanned intraocular surgery occurred in 14% of children. Neither AEs nor intraocular reoperations were more common for children with surgery at 7 to 12 months of age than for those who underwent surgery at 13 to 24 months of age (AE rate, 21% vs. 25% [P = 0.60]; reoperation rate, 13% vs. 16% [P = 1.00]). CONCLUSIONS: Although most children underwent IOL implantation concurrent with unilateral cataract removal, the incidence of complications, reoperations, and glaucoma was low when surgery was performed between 7 and 24 months of age and compared favorably with same-site IATS data for infants undergoing surgery before 7 months of age. Our study showed that IOL implantation is relatively safe in children older than 6 months and younger than 2 years.
Utheim OA, Pasovic L, Raeder S, Eidet JR, Fostad IG, Sehic A, Roald B, de la Paz MF, Lyberg T, Dartt DA, Utheim TP. Effects of explant size on epithelial outgrowth, thickness, stratification, ultrastructure and phenotype of cultured limbal epithelial cells. PLoS One 2019;14(3):e0212524.Abstract
PURPOSE: Transplantation of limbal stem cells is a promising therapy for limbal stem cell deficiency. Limbal cells can be harvested from either a healthy part of the patient's eye or the eye of a donor. Small explants are less likely to inflict injury to the donor site. We investigated the effects of limbal explant size on multiple characteristics known to be important for transplant function. METHODS: Human limbal epithelial cells were expanded from large versus small explants (3 versus 1 mm of the corneal circumference) for 3 weeks and characterized by light microscopy, immunohistochemistry, and transmission electron microscopy. Epithelial thickness, stratification, outgrowth, ultrastructure and phenotype were assessed. RESULTS: Epithelial thickness and stratification were similar between the groups. Outgrowth size correlated positively with explant size (r = 0.37; P = 0.01), whereas fold growth correlated negatively with explant size (r = -0.55; P < 0.0001). Percentage of cells expressing the limbal epithelial cell marker K19 was higher in cells derived from large explants (99.1±1.2%) compared to cells derived from small explants (93.2±13.6%, P = 0.024). The percentage of cells expressing ABCG2, integrin β1, p63, and p63α that are markers suggestive of an immature phenotype; Keratin 3, Connexin 43, and E-Cadherin that are markers of differentiation; and Ki67 and PCNA that indicate cell proliferation were equal in both groups. Desmosome and hemidesmosome densities were equal between the groups. CONCLUSION: For donor- and culture conditions used in the present study, large explants are preferable to small in terms of outgrowth area. As regards limbal epithelial cell thickness, stratification, mechanical strength, and the attainment of a predominantly immature phenotype, both large and small explants are sufficient.
Roohipoor R, Alvarez R, Brodowska K, Yaseri M, Kloek C, Riazi M, Nourinia R, Nikkhah H, Prajna VN, Krishnan C, Tuli S, Green L, Srikumaran D, Shah AS, Mantagos IS, Chiang M, Chan PRV, Loewenstein J. Evaluation of computer-based retinopathy of prematurity (ROP) education for ophthalmology residents: a randomized, controlled, multicenter study. J AAPOS 2019;Abstract
PURPOSE: To evaluate the effect of a computer-based training program-Massachusetts Eye & Ear ROP Trainer-on residents' knowledge of retinopathy of prematurity (ROP) management. METHODS: In this prospective, randomized study, ophthalmology residents from nine different training programs consented to participate. Those who completed the study were randomly assigned to either the Trainer or the control group. The ROP Trainer was created using clinical cases encompassing the stages of ROP in digital pictures and videos. It includes sections on screening decisions, examination techniques, and diagnosis, and a reference section with the expert video clips and a searchable image library. Subjects in the control group were asked to study standard print material on ROP. A pre- and post-test, consisting of theoretical and practical (diagnosis) questions, and a post-intervention satisfaction test were administered. Accuracy of ROP diagnosis was assessed. RESULTS: A total of 180 residents agreed to participate, of whom 60 completed the study. Residents in the Trainer group had statistically significant improvements (P = 0.003) in ROP knowledge and diagnostic ability (P = 0.005). Residents randomized to the Trainer group were more satisfied with the training materials than were those in the control group. There was no significant difference in improving knowledge by year of training, sex, or country. Considering all training levels, a statistically significant increase was observed in sensitivity for the diagnosis of preplus or worse, zone I or II, ROP stage, category, and aggressive posterior ROP in the Trainer group. CONCLUSIONS: In this study, the Trainer was shown to significantly improve ROP knowledge and diagnostic skills of residents, regardless of sex, year, of training, or country.
Gomes PJ, Abelson MB, Stein L, Viirre E, Villafranca EJ, Lasser EC. Iodixanol nasal solution reduces allergic rhinoconjunctivitis signs and symptoms in Allergen BioCube: a randomized clinical trial. J Asthma Allergy 2019;12:71-81.Abstract
Purpose: Allergic rhinitis (AR) affects ~20% of the population worldwide. The objectives of this study were to evaluate the safety and efficacy of iodixanol nasal solution (Nasapaque) for AR treatment, using the Allergen BioCube (ABC), an environmental exposure unit. Iodixanol is a commonly used contrast media agent that shows efficacy on the signs and symptoms of AR. Patients and methods: Seventy-three adult subjects with AR were randomized to iodixanol or placebo treatment in a double-masked efficacy and safety study conducted outside of ragweed pollen season. In-office treatment was administered after BioCube ragweed pollen exposure, and again 8 days later prior to ragweed exposure. Nasal and ocular efficacy and safety assessments were conducted before and after treatment. Results: Iodixanol treatment resulted in statistically significantly lower total nasal symptom scores as compared to placebo at several time points post-treatment and ABC exposure. Individual nasal and ocular symptoms, notably nasal itching and ocular itching, showed evidence of lower scores in the iodixanol group. Peak nasal inspiratory flow (PNIF) improved (9%-16%) with iodixanol from baseline as compared to PNIF in the placebo group which ranged from 3% worsening to improvement of 2%. Few (9) adverse events occurred. Conclusion: Iodixanol nasal solution demonstrated efficacy for relief of several nasal and ocular allergic rhinoconjunctivitis signs and symptoms, and was safe and well tolerated in this early Phase II exploratory trial. Further studies with iodixanol are warranted. Allergy challenge models such as the ABC provide valuable assessments of allergen exposures and drug efficacies. Study Identification Number: NCT02377895.
Busch C, Fraser-Bell S, Zur D, Rodríguez-Valdés PJ, Cebeci Z, Lupidi M, Fung AT, Gabrielle P-H, Giancipoli E, Chaikitmongkol V, Okada M, Laíns I, Santos AR, Kunavisarut P, Sala-Puigdollers A, Chhablani J, Ozimek M, Hilely A, Unterlauft JD, Loewenstein A, Iglicki M, Rehak M, Rehak M. Real-world outcomes of observation and treatment in diabetic macular edema with very good visual acuity: the OBTAIN study. Acta Diabetol 2019;56(7):777-784.Abstract
AIMS: To describe and compare the functional and anatomical outcomes of untreated and treated diabetic macular edema (DME) in eyes with very good baseline visual acuity (VA) in a real-world setting. METHODS: A 12-month, retrospective, multicenter, observational cohort study, including DME patients with baseline visual acuity (VA) ≤ 0.1 logMAR (≥ 20/25 Snellen) and central subfield thickness (CST) > 250 µm with intra- and/or subretinal fluid seen on optical coherence tomography. RESULTS: A total of 249 eyes were included, of which 155 were treated and 94 were non-treated during follow-up. Most eyes maintained vision (VA gain or VA loss < 5 letters) at 12 months (treated: 58.1%; non-treated: 73.4%). In non-treated eyes with stable VA within the first 6 months, VA was maintained throughout the follow-up in most cases (86.3%). In non-treated eyes with VA loss ≥ 5 letters within 6 months (36.7%), further observation led to worse visual outcome than treatment (- 4.2 vs. - 7.8 letters, p = 0.013). In eyes in which treatment was initiated at baseline (n = 102), treatment with 8-12 anti-VEGF injections led to better visual outcome compared to treatment with less injections (- 0.3 ± 3.6 letters vs. - 3.8 ± 6.2 letters, p = 0.003). CONCLUSION: In a real-world setting, the majority of DME patients with very good VA maintained vision at 12 months, regardless of whether the DME was treated or not. This study supports close observation of eyes with DME and very good VA with consideration of treatment when a one line drop in vision is observed.
Sheptulin V, Fedorov A, Prause J, Fay A, Grusha Y. Hyaluronic Acid Gel Biodegradation After Intrapalpebral and Intraorbital Injection in Experimental Study. Ophthalmic Plast Reconstr Surg 2019;35(6):558-561.Abstract
PURPOSE: Amid the increasing clinical application of hyaluronic acid (HA) fillers in the ocular adnexa is a paucity of histological data concerning the fate of the injected material. The current study documents the in vivo biodegradation of HA deposited in the eyelid and orbit. METHODS: The study included 22 chinchilla rabbits. The right upper eyelid of 12 rabbits received a single 0.2 ml Restylane (Galderma, Uppsala, Sweden) subcutaneous injection. In 10 different rabbits, the right orbit was injected with 1.0 ml Restylane SubQ (Galderma, Uppsala, Sweden) in the extraconal space. The rabbits in the eyelid group were euthanized at 2 weeks, 1 month, 2, 4, 6, and 9 months, while the rabbits in the orbit group were euthanized at 1 month, 3, 6, 12, and 18 months. Histological analysis was performed on the harvested samples. RESULTS: In the eyelid, the HA assumed a sponge-like structure that diminished gradually over time. At 9 months, the injected HA partially persisted, mainly in the peripheral areas of injection. A similar histologic pattern was observed in the injected orbits, with slow changes persisting at the eighteenth month. In both cohorts, clear signs of collagen deposition and pseudocapsule formation were observed around HA droplets, with no signs inflammation. CONCLUSIONS: HA injected subcutaneously into the eyelid and orbit of rabbits undergoes slow and gradual biodegradation, with HA persisting to no less than 9 months in the eyelid and 18 months in orbit. Neocollagen synthesis and lack of hyaluronidase activity could explain the unexpectedly prolonged HA persistence.