Masland RH. Systems neuroscience: Diversity in sight. Nature 2017;542(7642):418-419.
Michalak SM, Whitman MC, Park JG, Tischfield MA, Nguyen EH, Engle EC. Ocular Motor Nerve Development in the Presence and Absence of Extraocular Muscle. Invest Ophthalmol Vis Sci 2017;58(4):2388-2396.Abstract

Purpose: To spatially and temporally define ocular motor nerve development in the presence and absence of extraocular muscles (EOMs). Methods: Myf5cre mice, which in the homozygous state lack EOMs, were crossed to an IslMN:GFP reporter line to fluorescently label motor neuron cell bodies and axons. Embryonic day (E) 11.5 to E15.5 wild-type and Myf5cre/cre:IslMN:GFP whole mount embryos and dissected orbits were imaged by confocal microscopy to visualize the developing oculomotor, trochlear, and abducens nerves in the presence and absence of EOMs. E11.5 and E18.5 brainstems were serially sectioned and stained for Islet1 to determine the fate of ocular motor neurons. Results: At E11.5, all three ocular motor nerves in mutant embryos approached the orbit with a trajectory similar to that of wild-type. Subsequently, while wild-type nerves send terminal branches that contact target EOMs in a stereotypical pattern, the Myf5cre/cre ocular motor nerves failed to form terminal branches, regressed, and by E18.5 two-thirds of their corresponding motor neurons died. Comparisons between mutant and wild-type embryos revealed novel aspects of trochlear and oculomotor nerve development. Conclusions: We delineated mouse ocular motor nerve spatial and temporal development in unprecedented detail. Moreover, we found that EOMs are not necessary for initial outgrowth and guidance of ocular motor axons from the brainstem to the orbit but are required for their terminal branching and survival. These data suggest that intermediate targets in the mesenchyme provide cues necessary for appropriate targeting of ocular motor axons to the orbit, while EOM cues are responsible for terminal branching and motor neuron survival.

Mikolajczak J, Zimmermann H, Kheirkhah A, Kadas EM, Oberwahrenbrock T, Muller R, Ren A, Kuchling J, Dietze H, Prüss H, Paul F, Hamrah P, Brandt AU. Patients with multiple sclerosis demonstrate reduced subbasal corneal nerve fibre density. Mult Scler 2017;23(14):1847-1853.Abstract
BACKGROUND: Many studies in multiple sclerosis (MS) have investigated the retina. Little, however, is known about the effect of MS on the cornea, which is innervated by the trigeminal nerve. It is the site of neural-immune interaction with local dendritic cells reacting in response to environmental stimuli. OBJECTIVE: This study aims to investigate the effect of MS on corneal nerve fibres and dendritic cells in the subbasal nerve plexus using in vivo confocal microscopy (IVCM). METHODS: We measured the corneal nerve fibre and dendritic cell density in 26 MS patients and matched healthy controls using a Heidelberg Retina Tomograph with cornea module. Disease severity was assessed with the Multiple Sclerosis Functional Composite, Expanded Disability Status Scale, visual acuity and retinal optical coherence tomography. RESULTS: We observed significant reduction in total corneal nerve fibre density in MS patients compared to controls. Dendritic cell density was similar in both groups. Reduced total nerve fibre density was associated with worse clinical severity but not with previous clinical trigeminal symptoms, retinal neuro-axonal damage, visual acuity or disease duration. CONCLUSION: Corneal nerve fibre density is a promising new imaging marker for the assessment of disease severity in MS and should be investigated further.
Mishra A, Browning D, Haviland MJ, Jackson ML, Luff D, Meyer EC, Talcott K, Kloek CE. Communication Skills Training in Ophthalmology: Results of a Needs Assessment and Pilot Training Program. J Surg Educ 2017;Abstract
OBJECTIVE: To conduct a needs assessment to identify gaps in communication skills training in ophthalmology residency programs and to use these results to pilot a communication workshop that prepares residents for difficult conversations. DESIGN: A mixed-methods design was used to perform the needs assessment. A pre-and postsurvey was administered to workshop participants. SETTING: Mass Eye and Ear Infirmary, Harvard Medical School (HMS), Department of Ophthalmology. PARTICIPANTS: HMS ophthalmology residents from postgraduate years 2-4 participated in the needs assessment and the workshop. Ophthalmology residency program directors in the United States participated in national needs assessment. METHODS: Ophthalmology program directors across the United States were queried on their perception of resident communication skills training through an online survey. A targeted needs assessment in the form of a narrative exercise captured resident perspectives on communication in ophthalmology from HMS residents. A group of HMS residents participated in the pilot workshop and a pre- and postsurvey was administered to participants to assess its effectiveness. RESULTS: The survey of program directors yielded a response rate of 40%. Ninety percent of respondents agreed that the communication skills training in their programs could be improved. Fifteen of 24 residents (62%) completed the needs assessment. Qualitative analysis of the narrative material revealed four themes; (1) differing expectations, (2) work role and environment, (3) challenges specific to ophthalmology, and (4) successful strategies adopted. Nine residents participated in the workshop. There was a significant improvement post-workshop in resident reported scores on their ability to manage their emotions during difficult conversations (p = 0.03). CONCLUSIONS: There is an opportunity to improve communication skills training in ophthalmology residency through formalized curriculum.
Modjtahedi BS, Finn AP, Eliott D. Association of Endogenous Endophthalmitis With Intravenous Drug Use: An Emerging Public Health Challenge. JAMA Ophthalmol 2017;
Mombaerts I, Bilyk JR, Rose GE, McNab AA, Fay A, Dolman PJ, Allen RC, Devoto MH, Harris GJ, of the Society EPO. Consensus on Diagnostic Criteria of Idiopathic Orbital Inflammation Using a Modified Delphi Approach. JAMA Ophthalmol 2017;Abstract
Importance: Current practice to diagnose idiopathic orbital inflammation (IOI) is inconsistent, leading to frequent misdiagnosis of other orbital entities, including cancer. By specifying criteria, diagnosis of orbital inflammation will be improved. Objective: To define a set of criteria specific for the diagnosis of IOI. Design, Setting, and Participants: A 3-round modified Delphi process with an expert panel was conducted from June 8, 2015, to January 25, 2016. Fifty-three orbital scientist experts, identified through membership in the Orbital Society, were invited to participate in on online survey and they scored, using 5-point Likert scales, items that are eligible as diagnostic criteria from the literature and from personal experience. The items were clustered around the anatomic subtypes of IOI: idiopathic dacryoadenitis and idiopathic orbital fat inflammation (2 nonmyositic IOIs), and idiopathic orbital myositis (myositic IOI). Items with dissensus were rescored in the second round, and all items with consensus (median, ≥4; interquartile range, ≤1) were ranked by importance in the third round. Main Outcomes and Measures: Consensus on items to be included in the criteria. Results: Of the 53 experts invited to participate, a multinational panel of 35 (66%) individuals with a mean (SD) years of experience of 31 (11) years were included. Consensus was achieved on 7 of 14 clinical and radiologic items and 5 of 7 pathologic items related to diagnosis of nonmyositic IOI, and 11 of 14 clinical and radiologic items and 1 of 5 pathologic items for myositic IOI. There was agreement among panelists to focus on surgical tissue biopsy results in the diagnosis of nonmyositic IOI and on a trial with systemic corticosteroids in myositic IOI. Panelists agreed that a maximum number of 30 IgG4-positive plasma cells per high-power field in the orbital tissue is compatible with the diagnosis of IOI. Conclusions and Relevance: An international panel of experts endorsed consensus diagnostic criteria of IOI. These criteria define a level of exclusion suggested for diagnosis and include tissue biopsy for lesions not confined to the extraocular muscles. This consensus is a step toward developing guidelines for the management of IOI, which needs to be followed by validation studies of the criteria.
Mueller SK, Freitag SK, Lefebvre DR, Bleier BS. Endoscopic DCR using bipedicled interlacing mucosal flaps. Laryngoscope 2018;128(4):794-797.Abstract
OBJECTIVE: Obstruction of the nasolacrimal duct is a relatively common condition that affects patients of all ages, races, and sexes. The surgical gold standard for complete nasolacrimal duct obstruction and dacryocystitis is dacryocystorhinostomy (DCR). The purpose of this study was to describe a novel, bipedicled interlacing mucosal sparing flap technique for endoscopic DCR (eDCR). METHODS: A posteriorly based mucosal flap over the fundus is combined with a novel, anteriorly based mucosal flap over the intraosseus portion of the nasolacrimal duct (NLD). This exposes a wide area of the maxillary bone, allowing for exposure and identification of the NLD/sac complex in a safer, more inferior position. The interlacing mucosal flaps may be replaced at the conclusion of the procedure, thereby minimizing bone exposure and maintaining excellent long-term patency. RESULTS: The authors have utilized this technique in 55 procedures with 100% positive identification of the NLD and lacrimal sac, 0% complication rate, 100% anatomical patency rate, and 96.4% success rate after a minimal follow-up of 6 months. DISCUSSION: The bipedicled interlacing flap technique for eDCR provides for safe and reproducible identification of the NLD and lacrimal sac while minimizing bone exposure and restenosis rate. CONCLUSION: The bipedicled interlacing flap technique for eDCR provides for safe and reproducible identification of the NLD and lacrimal sac while minimizing bone exposure and restenosis rate. LEVEL OF EVIDENCE: NA. Laryngoscope, 128:794-797, 2018.
Mueller SK, Freitag SK, Bleier BS. Morphometric Analysis of the Orbital Process of the Palatine Bone and its Relationship to Endoscopic Orbital Apex Surgery. Ophthalmic Plast Reconstr Surg 2018;34(3):254-257.Abstract
BACKGROUND: Endoscopic approaches to the orbit improve the ability to directly access apical lesions while minimizing manipulation of normal structures. Inferomedial orbital access is limited by the orbital process of the palatine bone (OPPB) which prevents dissection and retraction in the inferolateral vector. OBJECTIVE: The objective of this study was to examine the morphometric characteristics of the OPPB and quantify the benefit of complete resection to surgical access. METHODS: Morphometric osteologic measurements of the OPPB were performed in 59 human skulls. A radius subtended by the OPPB was calculated to generate a hemispheric dissection corridor achievable by complete resection of the OPPB. Cadaveric and live surgical dissections were then performed on 15 orbits to develop discreet endoscopic surgical landmarks which could be used to both identify the OPPB and verify complete resection. RESULTS: The mean(± SD) radius of the OPPB was 0.47 ± 0.28 cm. Complete OPPB resection provided an additional 0.36 ± 0.42 cm of surgical exposure within the inferomedial apex. Relative to the Caucasian (n = 27) skulls, the radii in the Asian (n = 27) and African (n = 5) skulls were significantly smaller (p < 0.001 and p = 0.02, respectively). CONCLUSION: The OPPB significantly limits surgical access to the inferomedial orbital apex during endoscopic approaches. Complete surgical resection of the OPPB improves surgical exposure facilitating retraction of the inferior rectus muscle and circumferential dissection of lesions within this space. Knowledge of the morphology and clinical relevance of this structure provides an opportunity to improve surgical exposure for relevant pathologic assessment and optimize endoscopic surgical outcomes.
Mueller SK, Miyake MM, Lefebvre DR, Freitag SK, Bleier BS. Long-term impact of endoscopic orbital decompression on sinonasal-specific quality of life. Laryngoscope 2018;128(4):785-788.Abstract
OBJECTIVE: Endoscopic orbital decompression (EOD) is the workhorse surgical intervention for severe thyroid eye disease in Graves disease. Although EOD is a safe and effective procedure, the objective of this study is to determine the impact of orbital decompression on long-term sinonasal-pecific quality of life. METHODS: Retrospective study of 27 patients who underwent EOD by a single surgeon. The primary endpoint was change in preoperative 22-item Sinonasal Outcomes Test (SNOT-22) score at a minimum of 1 year. The secondary endpoint was to determine whether the performance of septoplasty for surgical access in patients without nasal obstruction impacted domain 1 (i.e., rhinologic domain) and total SNOT-22 scores. RESULTS: The mean follow-up was 25.7 ± 11.4 months. Domain 1 scores significantly increased at the first postoperative visit (P ≤ 0.01) and returned to baseline values between 1 and 3 months. At 1 year, significant improvements in both total score and domain 4 and 5 (psychological and sleep dysfunction, respectively) scores were seen (P < 0.01 for all scores). Septoplasty was not associated with a significant change in SNOT-22 score at 1 year (P = 0.48). CONCLUSION: Endoscopic orbital decompression is associated at 1 year with a significant improvement in sinonasal-specific quality of life, which is driven by the psychological and sleep dysfunction domains. Adjunctive septoplasty has no significant impact on SNOT-22 scores. LEVEL OF EVIDENCE: 4. Laryngoscope, 128:785-788, 2018.
Nanji KC, Roberto SA, Morley MG, Bayes J. Preventing Adverse Events in Cataract Surgery: Recommendations From a Massachusetts Expert Panel. Anesth Analg 2018;126(5):1537-1547.Abstract
Massachusetts health care facilities reported a series of cataract surgery-related adverse events (AEs) to the state in recent years, including 5 globe perforations during eye blocks performed by 1 anesthesiologist in a single day. The Betsy Lehman Center for Patient Safety, a nonregulatory Massachusetts state agency, responded by convening an expert panel of frontline providers, patient safety experts, and patients to recommend strategies for mitigating patient harm during cataract surgery. The purpose of this article is to identify contributing factors to the cataract surgery AEs reported in Massachusetts and present the panel's recommended strategies to prevent them. Data from state-mandated serious reportable event reports were supplemented by online surveys of Massachusetts cataract surgery providers and semistructured interviews with key stakeholders and frontline staff. The panel identified 2 principal categories of contributing factors to the state's cataract surgery-related AEs: systems failures and choice of anesthesia technique. Systems failures included inadequate safety protocols (48.7% of contributing factors), communication challenges (18.4%), insufficient provider training (17.1%), and lack of standardization (15.8%). Choice of anesthesia technique involved the increased relative risk of needle-based eye blocks. The panel's surveys of Massachusetts cataract surgery providers show wide variation in anesthesia practices. While 45.5% of surgeons and 69.6% of facilities reported increased use of topical anesthesia compared to 10 years earlier, needle-based blocks were still used in 47.0% of cataract surgeries performed by surgeon respondents and 40.9% of those performed at respondent facilities. Using a modified Delphi approach, the panel recommended several strategies to prevent AEs during cataract surgery, including performing a distinct time-out with at least 2 care-team members before block administration; implementing standardized, facility-wide safety protocols, including a uniform site-marking policy; strengthening the credentialing and orientation of new, contracted and locum tenens anesthesia staff; ensuring adequate and documented training in block administration for any provider who is new to a facility, including at least 10 supervised blocks before practicing independently; using the least invasive form of anesthesia appropriate to the patient; and finally, adjusting anesthesia practices, including preferred techniques, as evidence-based best practices evolve. Future research should focus on evaluating the impact of these recommendations on patient outcomes.
Nelson DJ, Craig JP, Akpek EK, Azar DT, Belmonte C, Bron AJ, Clayton JA, Dogru M, Dua HS, Foulks GN, Gomes JAP, Hammitt KM, Holopainen J, Jones L, Joo C-K, Liu Z, Nichols JJ, Nichols KK, Novack GD, Sangwan V, Stapleton F, Tomlinson A, Tsubota K, Willcox MDP, Wolffsohn JS, Sullivan DA. TFOS DEWS II Introduction. Ocul Surf 2017;15(3):269-275.
Nguyen HV, Jakobiec FA, Zakka FR, Yoon MK. Bilateral Upper and Lower Eyelid Margin Swelling and Madarosis due to Lymphoma. Surv Ophthalmol 2017;Abstract
Over a 2 year period a 32-year-old woman developed swellings of all 4 eyelid margins accompanied by complete loss of eyelashes. An inflammatory dermatologic condition was considered the most likely cause. A full thickness right lower eyelid biopsy revealed a multinodular lymphoid tumor at the eyelid margin which immunophenotypically and genetically was diagnosed as an extranodal marginal zone lymphoma. The mode of presentation of the disease was considered to be most unusual, as was its B cell lineage, since the majority of primary cutaneous lymphomas are of T-cell origin. Systemic workup demonstrated bilateral involvement of the external auditory canals.
Nihalani BR, VanderVeen DK. Benchmarks for outcome indicators in pediatric cataract surgery. Eye (Lond) 2017;31(3):417-421.Abstract

PurposeThe purpose of this study was to establish benchmarks for outcome indicators that may help ascertain the quality of pediatric cataract surgery with primary intraocular lens (IOL) implantation.Patients and methodsA retrospective chart review of patients older than 2 years undergoing cataract surgery with primary IOL implantation, by multiple surgeons in a tertiary-care center, from November 2005 to February 2016 was conducted. Patients with ocular comorbidities that would affect the outcomes were excluded. The outcome measures chosen were as follows: (1) final best corrected Snellen visual acuity (BCVA) in patients who had bilateral cataract surgery analyzed at the last clinic visit; (2) prediction error (PE)=expected refraction-actual refraction. Mean PE and mean absolute PE were assessed 1 month postoperatively, irrespective of age or laterality.ResultsMean age at surgery was 8.3±4.6 years and mean follow-up duration was 3.7±2.7 years. The results of outcome measures were as follows: (1) BCVA was 20/40 or better in 96% (n=124 eyes, mean patient age: 8.3±4.6 years). Remaining five eyes had amblyopia with two eyes having BCVA worse than 20/100 that did not respond to amblyopia treatment. (2) Mean PE was 0.3±1.1 D and mean absolute PE was 0.9±0.7 D. PE was within ±0.5 D in 43.0%, ±1.0 D in 66%, and ±2.0 D in 95% (n=235 eyes).ConclusionGood visual acuity after cataract surgery should be expected for children with bilateral cataracts, setting a high benchmark similar to that recommended in adult cataract surgery. Prediction error is greater in pediatric eyes than in adult eyes, setting a lower benchmark. This study establishes benchmark for outcome indicators in pediatric patients older than 2 years undergoing cataract surgery with primary IOL implantation.

Nocera AL, Miyake MM, Seifert P, Han X, Bleier BS. Exosomes mediate interepithelial transfer of functional P-glycoprotein in chronic rhinosinusitis with nasal polyps. Laryngoscope 2017;127(9):E295-E300.Abstract
OBJECTIVE: P-glycoprotein (P-gp) drives type-2 helper T-cell inflammation in chronic rhinosinusitis with nasal polyps (CRSwNP) through unknown posttranslational mechanisms of overexpression. A recent randomized clinical trial demonstrated that inhibition of P-gp was as effective as oral steroids and biologics in treating CRSwNP. Exosomes are 30- to 150-nm vesicles capable of intercellular membrane protein transfer. The aims of this study were 1) to determine whether CRSwNP mucus exosomes are enriched with P-gp, and 2) whether exosomal P-gp can be functionally transferred to autologous epithelial cells as a putative mechanism for the proinflammatory overexpression of P-gp in CRSwNP. STUDY DESIGN: Institutional review board-approved study in CRSwNP and control patients (n = 10 per group). METHODS: P-gp content of purified mucus exosomes was characterized by transmission electron microscopy and enzyme-linked immunosorbent assay. Epithelial transfer of exosomal P-gp was determined by time-lapse fluorescent microscopy and calcein acetoxymethylester functional P-gp assay. RESULTS: CD63+/P-gp+ exosomes were detected in both groups. P-gp was significantly enriched in CRSwNP exosomes relative to control (median 198.5; interquartile range 123.6-270.5 vs. 74.4; 41.3-95.0 pcg P-gp/10(9) exosomes, P = 0.002). Exosomes were absorbed by epithelial cells within 10 minutes, resulting in a significant increase in P-gp activity in CRSwNP patients relative to control (P = 0.006). CONCLUSION: Here we demonstrate the presence and P-gp enrichment of mucus-derived exosomes, or rhinosomes, in CRSwNP. These rhinosomes are capable of rapid intercellular transfer of P-gp, leading to increased P-gp function within recipient cells. This represents a novel mechanism for maintaining P-gp overexpression in CRSwNP, and more generally for interepithelial transfer of other proteins between mucosal epithelial cells. LEVEL OF EVIDENCE: NA. Laryngoscope, 127:E295-E300, 2017.
Norsworthy MW, Bei F, Kawaguchi R, Wang Q, Tran NM, Li Y, Brommer B, Zhang Y, Wang C, Sanes JR, Coppola G, He Z. Sox11 Expression Promotes Regeneration of Some Retinal Ganglion Cell Types but Kills Others. Neuron 2017;94(6):1112-1120.e4.Abstract
At least 30 types of retinal ganglion cells (RGCs) send distinct messages through the optic nerve to the brain. Available strategies of promoting axon regeneration act on only some of these types. Here we tested the hypothesis that overexpressing developmentally important transcription factors in adult RGCs could reprogram them to a "youthful" growth-competent state and promote regeneration of other types. From a screen of transcription factors, we identified Sox11 as one that could induce substantial axon regeneration. Transcriptome profiling indicated that Sox11 activates genes involved in cytoskeletal remodeling and axon growth. Remarkably, α-RGCs, which preferentially regenerate following treatments such as Pten deletion, were killed by Sox11 overexpression. Thus, Sox11 promotes regeneration of non-α-RGCs, which are refractory to Pten deletion-induced regeneration. We conclude that Sox11 can reprogram adult RGCs to a growth-competent state, suggesting that different growth-promoting interventions promote regeneration in distinct neuronal types.
Novack GD, Asbell P, Barabino S, Bergamini MVW, Ciolino JB, Foulks GN, Goldstein M, Lemp MA, Schrader S, Woods C, Stapleton F. TFOS DEWS II Clinical Trial Design Report. Ocul Surf 2017;15(3):629-649.Abstract
The development of novel therapies for Dry Eye Disease (DED) is formidable, and relatively few treatments evaluated have been approved for marketing. In this report, the Subcommittee reviewed challenges in designing and conducting quality trials, with special reference to issues in trials in patients with DED and present the regulatory perspective on DED therapies. The Subcommittee reviewed the literature and while there are some observations about the possible reasons why so many trials have failed, there is no obvious single reason other than the lack of correlation between signs and symptoms in DED. Therefore the report advocates for conducting good quality studies, as described, going forward. A key recommendation for future studies is conduct consistent with Good Clinical Practice (GCP), including use of Good Manufacturing Practice (GMP) quality clinical trial material. The report also recommends that the design, treatments, and sample size be consistent with the investigational treatment, the objectives of the study, and the phase of development. Other recommendations for pivotal studies are a priori selection of the outcome measure, and an appropriate sample size.
Occelli V, Lacey S, Stephens C, Merabet LB, Sathian K. Enhanced verbal abilities in the congenitally blind. Exp Brain Res 2017;235(6):1709-1718.Abstract
Numerous studies have found that congenitally blind individuals have better verbal memory than their normally sighted counterparts. However, it is not known whether this reflects superiority of verbal or memory abilities. In order to distinguish between these possibilities, we tested congenitally blind participants and normally sighted control participants, matched for age and education, on a range of verbal and spatial tasks. Congenitally blind participants were significantly better than sighted controls on all the verbal tasks but the groups did not differ significantly on the spatial tasks. Thus, the congenitally blind appear to have superior verbal, but not spatial, abilities. This may reflect greater reliance on verbal information and the involvement of visual cortex in language processing in the congenitally blind.
Oke I, Alkharashi M, Petersen RA, Ashenberg A, Shah AS. Treatment of Ocular Pyogenic Granuloma With Topical Timolol. JAMA Ophthalmol 2017;135(4):383-385.Abstract

Importance: Pyogenic granulomas, acquired vascular lesions, form on the ocular or palpebral surface related to inflammation from chalazia, trauma, or surgery. They can be unsightly, spontaneously bleed, and cause irritation to patients. Observations: A case series is presented of 4 consecutive children with acquired ocular surface pyogenic granulomas treated at Boston Children's Hospital from 2014 to 2016 with only topical timolol, 0.5%, twice daily for a minimum of 21 days. In all cases, complete resolution occurred within the treatment period with no recurrence for at least 3 months. There were no adverse effects from the timolol during follow-up. Conclusions and Relevance: This case series of 4 children, while limited to no greater than 12 weeks of follow-up and without control children, suggests that ocular surface pyogenic granulomas respond to topical timolol treatment, which has a lower adverse-effect profile than conventional topical steroid treatments or other medical or surgical therapies. If confirmed in larger studies with longer follow-up and controls, this may be the desired treatment modality.

Olivares AM, Han Y, Soto D, Flattery K, Marini J, Molemma N, Haider A, Escher P, Deangelis MM, Haider NB. The nuclear hormone receptor gene Nr2c1 (Tr2) is a critical regulator of early retina cell patterning. Dev Biol 2017;429(1):343-355.Abstract
Nuclear hormone receptors play a major role in the development of many tissues. This study uncovers a novel role for testicular receptor 2 (Tr2, Nr2c1) in defining the early phase of retinal development and regulating normal retinal cell patterning and topography. The mammalian retina undergoes an overlapping yet biphasic period of development to generate all seven retinal cell types. We discovered that Nr2c1 expression coincides with development of the early retinal cells. Loss of Nr2c1 causes a severe vision deficit and impacts early, but not late retina cell types. Retinal cone cell topography is disrupted with an increase in displaced amacrine cells. Additionally, genetic background significantly impacts phenotypic outcome of cone photoreceptor cells but not amacrine cells. Chromatin-IP experiments reveal NR2C1 regulates early cell transcription factors that regulate retinal progenitor cells during development, including amacrine (Satb2) and cone photoreceptor regulators thyroid and retinoic acid receptors. This study supports a role for Nr2c1 in defining the biphasic period of retinal development and specifically influencing the early phase of retinal cell fate.
Olivares AM, Althoff K, Chen GF, Wu S, Morrisson MA, Deangelis MM, Haider N. Animal Models of Diabetic Retinopathy. Curr Diab Rep 2017;17(10):93.Abstract
PURPOSE OF REVIEW: Diabetic retinopathy (DR) is one of the most common complications associated with chronic hyperglycemia seen in patients with diabetes mellitus. While many facets of DR are still not fully understood, animal studies have contributed significantly to understanding the etiology and progression of human DR. This review provides a comprehensive discussion of the induced and genetic DR models in different species and the advantages and disadvantages of each model. RECENT FINDINGS: Rodents are the most commonly used models, though dogs develop the most similar morphological retinal lesions as those seen in humans, and pigs and zebrafish have similar vasculature and retinal structures to humans. Nonhuman primates can also develop diabetes mellitus spontaneously or have focal lesions induced to simulate retinal neovascular disease observed in individuals with DR. DR results in vascular changes and dysfunction of the neural, glial, and pancreatic β cells. Currently, no model completely recapitulates the full pathophysiology of neuronal and vascular changes that occur at each stage of diabetic retinopathy; however, each model recapitulates many of the disease phenotypes.