Lužnik Marzidovšek Z, Blanco T, Sun Z, Alemi H, Ortiz G, Nakagawa H, Chauhan SK, Taylor AW, Jurkunas UV, Yin J, Dana R. The neuropeptide alpha-melanocyte-stimulating hormone is critical for corneal endothelial cell protection and graft survival after transplantation. Am J Pathol 2021;Abstract
Corneal transplantation is the most common form of tissue transplantation. The success of corneal transplantation mainly relies on the integrity of corneal endothelial cells (CEnCs), which maintain tissue transparency by pumping out excess water from the cornea. After transplantation, the rate of CEnC loss far exceeds that seen with normal aging, and this can threaten sight. The underlying mechanisms are poorly understood. Alpha-melanocyte-stimulating hormone (α-MSH) is a neuropeptide that is constitutively found in the aqueous humor with both cytoprotective and immunomodulatory effects. We found high expression of melanocortin 1 receptor (MC1R), the receptor for α-MSH, on CEnCs. We then set to determine the effect of α-MSH/MC1R signaling on endothelial function and allograft survival in vitro and in vivo using MC1R signaling-deficient mice (Mc1re/e mice with a nonfunctional MC1R). Herein, we show that in addition to its well-known immunomodulatory effect, α-MSH has cytoprotective effects on CEnCs after corneal transplantation and the loss of MC1R signaling significantly decreases long-term graft survival in vivo. In conclusion, α-MSH/MC1R signaling is critical for CEnC function and graft survival after corneal transplantation.
Scott HA, Larson A, Rong SS, Mehrotra S, Butcher R, Chao KR, Wiggs J, Place EM, Pierce EA, Bujakowska KM. A Hidden Structural Variation in a Known IRD Gene: A Cautionary Tale of Two New Disease Candidate Genes. Cold Spring Harb Mol Case Stud 2021;Abstract
Rod cone dystrophy (RCD), also known as retinitis pigmentosa, is an inherited condition leading to vision loss, affecting 1/3500 people. Over 270 genes are known to be implicated in the inherited retinal degenerations (IRDs), yet genetic diagnosis for ~30% IRD of patients remains elusive despite advances in sequencing technologies. The goal of this study was to determine the genetic causality in a family with Rod-cone dystrophy (RCD). Family members were given a full ophthalmic exam at the Retinal Service at MEE and consented to genetic testing. Whole exome sequencing (WES) was performed and variants of interest were Sanger validated. Functional assays were conducted in zebrafish along with splicing assays in relevant cell lines to determine the impact on retinal function. WES identified variants in two potential candidate genes that segregated with disease: GNL3 (G Protein Nucleolar 3) c.1187+3A>C and c.1568-8C>A; and PDE4DIP (Phosphodiester 4D Interacting Protein) c.3868G>A (p.Glu1290Lys) and c.4603G>A (p.Ala1535Thr). Both genes were promising candidates based on their retinal involvement (development and interactions with IRD-associated proteins), however the functional assays did not validate either gene. Subsequent WES reanalysis with an updated bioinformatics pipeline and widened search parameters led to the detection of a 94bp duplication in PRPF31 (pre-mRNA Processing Factor 31) c.73_266dup (p.Asp56GlyfsTer33) as the causal variant. Our study demonstrates the importance of thorough functional characterization of new disease candidate genes, and the value of reanalyzing NGS sequence data, which in our case led to identification of a hidden pathogenic variant in a known IRD gene.
Xu J, Emmermann B, Bowers AR. Auditory Reminder Cues to Promote Proactive Scanning on Approach to Intersections in Drivers With Homonymous Hemianopia: Driving With Hemianopia, IX. JAMA Ophthalmol 2021;Abstract
Importance: Individuals with homonymous hemianopia (HH) are permitted to drive in some jurisdictions. They could compensate for their hemifield vision loss by scanning toward the blind side. However, some drivers with HH do not scan adequately well to the blind side when approaching an intersection, resulting in delayed responses to hazards. Objective: To evaluate whether auditory reminder cues promoted proactive scanning on approach to intersections. Design, Setting, and Participants: This cross-sectional, single-visit driving simulator study was conducted from October 2018 to May 2019 at a vision rehabilitation research laboratory. A volunteer sample of individuals with HH without visual neglect are included in this analysis. This post hoc analysis was completed in July and August 2020. Main Outcomes and Measures: Participants completed drives with and without scanning reminder cues (a single tone from a speaker on the blind side). Scanning was quantified by the percentage of intersections at which an early large scan was made (a scan with a head movement of at least 20° made before 30 m from the intersection). Responses to motorcycle hazards at intersections were quantified by the time to the first fixation and the time to the horn-press response. Results: Sixteen individuals were recruited and completed the study. Two were subsequently excluded from analyses. Thus, data from 14 participants (median [IQR] age, 54 [36-66] years; 13 men [93%]) were included. Stroke was the primary cause of the HH (10 participants [71%]). Six (43%) had right-sided HH. Participants were more likely to make an early large scan to the blind side in drives with vs without cues (65% vs 45%; difference, 20% [95% CI, 5%-37%]; P < .001). When participants made an early large scan to the blind side, they were faster to make their first fixation on blind-side motorcycles (mean [SD], 1.77 [1.34] vs 3.88 [1.17] seconds; difference, -2.11 [95% CI, -2.46 to -1.75] seconds; P < .001) and faster to press the horn (mean [SD], 2.54 [1.19] vs 4.54 [1.37] seconds; difference, -2.00 [95% CI, -2.38 to -1.62] seconds; P < .001) than when they did not make an early scan. Conclusions and Relevance: This post hoc analysis suggests that auditory reminder cues may promote proactive scanning, which may be associated with faster responses to hazards. This hypothesis should be considered in future prospective studies.
Zekavat SM, Raghu VK, Trinder M, Ye Y, Koyama S, Honigberg MC, Yu Z, Pampana A, Urbut S, Haidermota S, O'Regan DP, Zhao H, Ellinor PT, Segrè AV, Elze T, Wiggs JL, Martone J, Adelman RA, Zebardast N, Del Priore L, Wang JC, Natarajan P. Deep Learning of the Retina Enables Phenome- and Genome-wide Analyses of the Microvasculature. Circulation 2021;Abstract
Background: The microvasculature, the smallest blood vessels in the body, has key roles in maintenance of organ health as well as tumorigenesis. The retinal fundus is a window for human in vivo non-invasive assessment of the microvasculature. Large-scale complementary machine learning-based assessment of the retinal vasculature with phenome-wide and genome-wide analyses may yield new insights into human health and disease. Methods: We utilized 97,895 retinal fundus images from 54,813 UK Biobank participants. Using convolutional neural networks to segment the retinal microvasculature, we calculated fractal dimension (FD) as a measure of vascular branching complexity, and vascular density. We associated these indices with 1,866 incident ICD-based conditions (median 10y follow-up) and 88 quantitative traits, adjusting for age, sex, smoking status, and ethnicity. Results: Low retinal vascular FD and density were significantly associated with higher risks for incident mortality, hypertension, congestive heart failure, renal failure, type 2 diabetes, sleep apnea, anemia, and multiple ocular conditions, as well as corresponding quantitative traits. Genome-wide association of vascular FD and density identified 7 and 13 novel loci respectively, which were enriched for pathways linked to angiogenesis (e.g., VEGF, PDGFR, angiopoietin, and WNT signaling pathways) and inflammation (e.g., interleukin, cytokine signaling). Conclusions: Our results indicate that the retinal vasculature may serve as a biomarker for future cardiometabolic and ocular disease and provide insights on genes and biological pathways influencing microvascular indices. Moreover, such a framework highlights how deep learning of images can quantify an interpretable phenotype for integration with electronic health records, biomarker, and genetic data to inform risk prediction and risk modification.
Magno MS, Olafsson J, Beining M, Moschowits E, Lagali N, Wolffsohn JS, Craig JP, Dartt DA, Vehof J, Utheim TP. Chambered warm moist air eyelid warming devices - a review. Acta Ophthalmol 2021;Abstract
BACKGROUND: Eyelid warming is an important treatment for meibomian gland dysfunction (MGD). Specialized chambered devices, using warm moist air have been developed. PURPOSE: To critically evaluate the literature on the safety and efficacy of chambered warm moist air devices in MGD treatment and pinpoint areas of future research. METHODS: PubMed and Embase were searched on 06 June 2021. The search term was '(warm OR heat OR steam OR goggle OR spectacle OR moist air) AND (meibomian OR MGD OR blepharitis OR eyelid OR dry eye OR DED)'. All relevant articles with available English full text were included. RESULTS: Eighteen articles assessing the application of chambered warm moist air eyelid warming devices were identified. In single-application studies, steam-based eyelid warming increased the eyelid temperature and improved symptoms, lipid layer thickness, and tear film breakup time (TBUT). In treatment studies, the steam-based devices improved TBUT and symptom scores. However, in the only randomized controlled trial (RCT) comparing chambered steam-based heat to hot towel treatment, there was no difference between groups for the primary outcome measure; the proportion of subjects noting symptom improvement after 4 weeks. CONCLUSION: Currently available chambered warm moist air eyelid warming devices are safe and effective at raising eyelid temperature to therapeutic levels and improving signs and symptoms of dry eye. However, it is not clear if they provide a greater benefit than other eyelid warming therapies. Further well-conducted RCTs comparing moist and dry heat devices should be conducted on patients across the range of DED severities and subtype spectrum.
Sena DF, Kilian R, Liu S-H, Rizzo S, Virgili G. Pneumatic retinopexy versus scleral buckle for repairing simple rhegmatogenous retinal detachments. Cochrane Database Syst Rev 2021;11:CD008350.Abstract
BACKGROUND: A rhegmatogenous retinal detachment (RRD) is a separation of the neurosensory retina from the retinal pigment epithelium caused by a full-thickness break associated with vitreous traction. While pneumatic retinopexy (PR), scleral buckle (SB), and vitrectomy are all well-received surgical interventions for eyes with RRD, their relative effectiveness has remained controversial. OBJECTIVES: To assess the effectiveness and safety of PR versus SB or PR versus a combination treatment of SB and vitrectomy for people with RRD and to summarize any data on economic measures and quality of life. SEARCH METHODS: We searched CENTRAL; which contains the Cochrane Eyes and Vision Trials Register; 2021, Issue 3); Ovid MEDLINE; Ovid Embase; and four other databases on 11 March 2021. We used no date or language restrictions in the electronic searches for trials. SELECTION CRITERIA: We included all randomized or quasi-randomized controlled trials comparing the effectiveness of PR versus SB (with or without vitrectomy) for eyes with RRD. DATA COLLECTION AND ANALYSIS: After screening for eligibility, two review authors independently extracted study characteristics, methods, and outcomes. We followed systematic review standards as set by Cochrane. MAIN RESULTS: In this update, we identified and included one new randomized controlled trial. Together with two trials from the 2015 version of the review, we included three trials (276 eyes of 274 participants) comparing the effectiveness of PR versus SB. None compared PR versus a combined treatment of SB and vitrectomy.  Of the three trials, one was a small study (published in 1996) with 20 participants (20 eyes) enrolled in Ireland and followed for a mean of 16 months; the second (published in 1989) included 196 participants (198 eyes) in the US followed for at least six months, and the third (published in 2021) was conducted in Italy and enrolled 58 participants (58 eyes) with a follow-up of 12 months. Overall, poor reporting quality resulted in unclear or high risks of bias.  We found low-certainty evidence that PR may achieve retinal reattachment slightly less often than SB (risk ratio [RR] 0.91, 95% confidence interval [CI] 0.81 to 1.02; I2 = 0%; 3 studies, 276 eyes). Eyes undergoing PR may also display a higher risk of recurrent retinal detachment (low-certainty evidence), but the RR estimates were very imprecise (RR 1.70, 95% CI 0.97 to 2.98; I2 = 0%; 3 studies, 276 eyes). All three studies described the final visual acuity (VA) after the two procedures. However, the results were reported using different metrics and could not be combined. One study (196 participants) reported the proportion of eyes with a final VA of 20/40 or greater and favored PR (RR 1.31, 95% CI 1.04 to 1.65; low-certainty evidence), whereas in the 2021 study, both groups showed an improvement in final VA and there was no evidence of a difference between the two (mean difference [MD] -0.03, 95% CI -0.25 to 0.19; low-certainty evidence). No study reported data on quality of life or economic measures. Postoperative safety outcomes generally favored PR versus SB (low/very low-certainty evidence); however, there was considerable uncertainty regarding the risk of any operative ocular adverse events (RR 0.55 CI 0.28 to 1.11; 276 eyes), glaucoma (RR 0.31, 95% CI 0.01 to 7.46; 198 eyes), macular pucker (RR 0.65, 95% CI 0.20 to 2.11; 256 eyes), proliferative vitreoretinopathy (RR 0.94, 95% CI 0.30 to 2.96; 276 eyes), and persistent diplopia (RR 0.24, 95% CI 0.03 to 2.09; 256 eyes). Eyes undergoing PR experienced fewer postoperative cataract developments (RR 0.40, 95% CI 0.21 to 0.75; 153 eyes), choroidal detachments (RR 0.17, 95% CI 0.05 to 0.57; 198 eyes), and myopic shift (RR 0.03, 95% CI 0.01 to 0.10; 256 eyes). AUTHORS' CONCLUSIONS: The current update confirms the findings of the previous review. PR may result in lower rates of reattachment and higher rates of recurrence than SB, but carries a lower burden of postoperative complications. The effects of these two procedures on other functional outcomes and quality of life remain uncertain. The available evidence remains insufficient and of low quality.
Warkad VU, Hunter DG, Dagi AF, MacKinnon S, Kazlas MA, Heidary G, Staffa SJ, Dagi LR. Impact of Adding Augmented Superior Rectus Transpositions to Medial Rectus Muscle Recessions When Treating Esotropic Moebius Syndrome. Am J Ophthalmol 2021;Abstract
PURPOSE: Describe outcomes after treatment of Moebius syndrome (MBS) esotropia by adjustable bilateral medial rectus recession (BMR) with and without augmented superior rectus transposition (SRT) DESIGN: Retrospective case series METHODS: Patients meeting 2014 diagnostic criteria for MBS and treated at Boston Children's Hospital between 2003 and 2019 were identified via billing records and chart review. Visual acuity, sensorimotor evaluations, strabismus procedures, and other clinical features were recorded. Surgical outcomes for patients treated with strabismus surgery (excluding those with prior surgery elsewhere) were evaluated. Primary outcome measure was post-operative alignment comparing treatment by adjustable BMR versus adjustable BMR+SRT. RESULTS: Twenty patients had MBS, 12/20 (60%) were male. Fifteen (75%) had primary position esotropia, and all had bilateral abduction deficit. Eight of 20 met inclusion criteria for primary strabismus surgery outcome. Five had undergone adjustable BMR ranging from 4.5-6.5 mm. Three had undergone adjustable BMR+SRT, all with 4 mm medial rectus muscle recessions. Mean pre-operative esotropia before treatment by BMR was 39.5 PD (+/- 15 PD) with mean post-operative esotropia 9 PD (+/- 7.9 PD) at six months. Mean pre-operative esotropia before treatment by BMR+SRT was 70.8 PD (+/- 5.9 PD) with mean post-operative esotropia 2.5 PD (+/- 3.5 PD) at six months. Significantly greater reduction in esotropia resulted from BMR+SRT than BMR (P=0.036). CONCLUSIONS: BMR proved sufficient to treat esotropia < 50 PD and BMR+SRT for greater esotropia in patients with MBS-associated abduction limitation.
Brown EE, Scandura MJ, Mehrotra S, Wang Y, Du J, Pierce EA. Reduced nuclear NAD+ drives DNA damage and subsequent immune activation in the retina. Hum Mol Genet 2021;Abstract
Mutations in NMNAT1, a key enzyme involved in the synthesis of NAD+ in the nucleus, lead to an early onset severe inherited retinal degeneration (IRD). We aimed to understand the role of nuclear NAD+ in the retina and to identify the molecular mechanisms underlying NMNAT1-associated disease, using a mouse model that harbors the p.V9M mutation in Nmnat1 (Nmnat1V9M/V9M). We identified temporal transcriptional reprogramming in the retinas of Nmnat1V9M/V9M mice prior to retinal degeneration, which begins at 4 weeks of age, with no significant alterations in gene expression at 2 weeks of age and over 2600 differentially expressed genes by 3 weeks of age. Expression of the primary consumer of NAD+ in the nucleus, PARP1, an enzyme involved in DNA damage repair and transcriptional regulation, as well as 7 other PARP family enzymes, was elevated in the retinas of Nmnat1V9M/V9M. This was associated with elevated levels of DNA damage, PARP-mediated NAD+ consumption, and migration of Iba1+/CD45+ microglia/macrophages to the subretinal space in the retinas of Nmnat1V9M/V9M mice. These findings suggest that photoreceptor cells are especially sensitive to perturbation of genome homeostasis, and that PARP-mediated cell death may play a role in other genetic forms of IRDs, and potentially other forms of neurodegeneration.
Cai LZ, Lin J, Starr MR, Obeid A, Ryan EH, Ryan C, Forbes NJ, Arias D, Ammar MJ, Patel LG, Capone A, Emerson GG, Joseph DP, Eliott D, Gupta OP, Regillo CD, Hsu J, Yonekawa Y, Yonekawa Y. PRO score: predictive scoring system for visual outcomes after rhegmatogenous retinal detachment repair. Br J Ophthalmol 2021;Abstract
BACKGROUND/AIMS: To compare risk factors for poor visual outcomes in patients undergoing primary rhegmatogenous retinal detachment (RRD) repair and to develop a scoring system. METHODS: Analysis of the Primary Retinal detachment Outcomes (PRO) study, a multicentre interventional cohort of consecutive primary RRD surgeries performed in 2015. The main outcome measure was a poor visual outcome (Snellen VA ≤20/200). RESULTS: A total of 1178 cases were included. The mean preoperative and postoperative logMARs were 1.1±1.1 (20/250) and 0.5±0.7 (20/63), respectively. Multivariable logistic regression identified preoperative risk factors predictive of poor visual outcomes (≤20/200), including proliferative vitreoretinopathy (PVR) (OR 1.26; 95% CI 1.13 to 1.40), history of antivascular endothelial growth factor (VEGF) injections (1.38; 1.11 to 1.71), >1-week vision loss (1.17; 1.08 to 1.27), ocular comorbidities (1.18; 1.00 to 1.38), poor presenting VA (1.06 per initial logMAR unit; 1.02 to 1.10) and age >70 (1.13; 1.04 to 1.23). The data were split into training (75%) and validation (25%) and a scoring system was developed and validated. The risk for poor visual outcomes was 8% with a total score of 0, 17% with 1, 29% with 2, 47% with 3, and 71% with 4 or higher. CONCLUSIONS: Independent risk factors were compared for poor visual outcomes after RRD surgery, which included PVR, anti-VEGF injections, vision loss >1 week, ocular comorbidities, presenting VA and older age. The PRO score was developed to provide a scoring system that may be useful in clinical practice.
Singh RB, Das S, Chodosh J, Sharma N, Zegans ME, Kowalski RP, Jhanji V. Paradox of complex diversity: Challenges in the diagnosis and management of bacterial keratitis. Prog Retin Eye Res 2021;:101028.Abstract
Bacterial keratitis continues to be one of the leading causes of corneal blindness in the developed as well as the developing world, despite swift progress since the dawn of the "anti-biotic era". Although, we are expeditiously developing our understanding about the different causative organisms and associated pathology leading to keratitis, extensive gaps in knowledge continue to dampen the efforts for early and accurate diagnosis, and management in these patients, resulting in poor clinical outcomes. The ability of the causative bacteria to subdue the therapeutic challenge stems from their large genome encoding complex regulatory networks, variety of unique virulence factors, and rapid secretion of tissue damaging proteases and toxins. In this review article, we have provided an overview of the established classical diagnostic techniques and therapeutics for keratitis caused by various bacteria. We have extensively reported our recent in-roads through novel tools for accurate diagnosis of mono- and poly-bacterial corneal infections. Furthermore, we outlined the recent progress by our group and others in understanding the sub-cellular genomic changes that lead to antibiotic resistance in these organisms. Finally, we discussed in detail, the novel therapies and drug delivery systems in development for the efficacious management of bacterial keratitis.
Nahum AS, Vongsachang H, Friedman DS, Collins ME. Parental Trust in School-Based Health Care: A Systematic Review. J Sch Health 2021;Abstract
BACKGROUND: Health care delivery in schools is a frequently adopted approach to reduce health care inequalities. Lack of parental trust has been identified as impacting participation in school-based health care programs (SBHPs). The aim of our systematic review is to outline themes related to parental trust in SBHPs. METHODS: We searched MEDLINE, Embase, CINHAL, ERIC, PsycInfo, and Web of Science for articles published between 1969 and 2019. Eligible studies (1) were peer-reviewed primary research articles; (2) were school-based health interventions or screening programs; (3) included parental trust data; and (4) were carried out on schoolchildren from pre-K to grade 12. Study location, data collection date, number of participants, demographics, intervention type, study aim and methodology, and all trust themes mentioned, were extracted. Studies were critically appraised using the CASP checklist for qualitative research. RESULTS: We identified 9 themes related to parental trust in SBHPs: (1) safety; (2) effectiveness; (3) health professionals' training and credentials; (4) communication; (5) confidentiality; (6) providers; (7) government, authorities, and health service; (8) the pharmaceutical industry; and (9) research and data sharing. CONCLUSIONS: The themes identified provide a framework for examining trust in SBHPs, and may guide the development of interventions to increase trust and engagement in SBHPs.
Yemanyi F, Bora K, Blomfield AK, Wang Z, Chen J. Wnt Signaling in Inner Blood-Retinal Barrier Maintenance. Int J Mol Sci 2021;22(21)Abstract
The retina is a light-sensing ocular tissue that sends information to the brain to enable vision. The blood-retinal barrier (BRB) contributes to maintaining homeostasis in the retinal microenvironment by selectively regulating flux of molecules between systemic circulation and the retina. Maintaining such physiological balance is fundamental to visual function by facilitating the delivery of nutrients and oxygen and for protection from blood-borne toxins. The inner BRB (iBRB), composed mostly of inner retinal vasculature, controls substance exchange mainly via transportation processes between (paracellular) and through (transcellular) the retinal microvascular endothelium. Disruption of iBRB, characterized by retinal edema, is observed in many eye diseases and disturbs the physiological quiescence in the retina's extracellular space, resulting in vision loss. Consequently, understanding the mechanisms of iBRB formation, maintenance, and breakdown is pivotal to discovering potential targets to restore function to compromised physiological barriers. These unraveled targets can also inform potential drug delivery strategies across the BRB and the blood-brain barrier into retinas and brain tissues, respectively. This review summarizes mechanistic insights into the development and maintenance of iBRB in health and disease, with a specific focus on the Wnt signaling pathway and its regulatory role in both paracellular and transcellular transport across the retinal vascular endothelium.