Publications

2018

Latremoliere A, Cheng L, DeLisle M, Wu C, Chew S, Hutchinson E, Sheridan A, Alexandre C, Latremoliere F, Sheu SH, Golidy S, Omura T, Huebner E, Fan Y, Whitman M, Nguyen E, Hermawan C, Pierpaoli C, Tischfield M, Woolf C, Engle E. Neuronal-Specific TUBB3 Is Not Required for Normal Neuronal Function but Is Essential for Timely Axon Regeneration. Cell Rep. 2018;24(7):1865–1879.e9.
We generated a knockout mouse for the neuronal-specific β-tubulin isoform Tubb3 to investigate its role in nervous system formation and maintenance. Tubb3 mice have no detectable neurobehavioral or neuropathological deficits, and upregulation of mRNA and protein of the remaining β-tubulin isotypes results in equivalent total β-tubulin levels in Tubb3 and wild-type mice. Despite similar levels of total β-tubulin, adult dorsal root ganglia lacking TUBB3 have decreased growth cone microtubule dynamics and a decreased neurite outgrowth rate of 22% in vitro and in vivo. The effect of the 22% slower growth rate is exacerbated for sensory recovery, where fibers must reinnervate the full volume of the skin to recover touch function. Overall, these data reveal that, while TUBB3 is not required for formation of the nervous system, it has a specific role in the rate of peripheral axon regeneration that cannot be replaced by other β-tubulins.
Li Z, Cestari D, Fortin E. Thyroid eye disease: what is new to know?. Curr Opin Ophthalmol. 2018;29(6):528–534.
PURPOSE OF REVIEW: The pathophysiology of thyroid eye disease (TED) is still not fully understood. However, recently described risk factors and molecular findings have brought new insights into the mechanisms of TED and could lead to the emerging use of more targeted therapies. This article aims to review the clinical findings of TED, and the most recent advances in our understanding of the risk factors and therapeutic options for TED. RECENT FINDINGS: Smoking has been recently shown to have an impact on specific gene expression involved in several disease-related pathways, which seems to be reversible with smoking cessation. This finding further emphasizes the importance of smoking cessation in the prevention and treatment of TED. Selenium deficiency and high-serum cholesterol have been described to be potential independent risk factors for TED and their management could decrease the incidence and severity of TED. In terms of therapeutic options, immunomodulatory medications have shown some promising results for disease control in TED over the past years, but further randomized prospective studies with larger sample sizes are still needed to prove their efficacy. A new technique of P brachytherapy was shown to have quick therapeutic effects on TED without significant side effects and could be a promising therapy for selected cases of TED. SUMMARY: TED is one of the most common autoimmune inflammatory disorders of the orbit. Although its pathophysiology remains unclear, newly described genetic findings and risk factors could help in explaining its occurrence and guide future therapies. Immunosuppressant medications are increasingly used in the management of TED, but further studies are needed to confirm their effectiveness.
Madriz Peralta G, Cestari D. An update of idiopathic intracranial hypertension. Curr Opin Ophthalmol. 2018;29(6):495–502.
PURPOSE OF REVIEW: We aim to provide a comprehensive and updated review on idiopathic intracranial hypertension (IIH), including the most current studies and treatment options. Special focus will be put on recent theories about the pathophysiology, and on newer prospective studies on treatment modalities. RECENT FINDINGS: The Idiopathic Intracranial Hypertension Treatment Trial (IIHTT) provided evidence supporting acetazolamide as a well tolerated first-line therapy in IIH patients with mild vision loss. Recent studies have shown venous sinus stenting as a well tolerated and effective surgical alternative for patients with refractory IIH. SUMMARY: Idiopathic intracranial hypertension is a vision-threatening disorder that predominantly affects obese women of childbearing age. This disorder is becoming more prevalent as the obesity epidemic continues to increase. As our understanding of this disorder continues to evolve, diagnosis and management approaches have changed over time. However, the pathogenesis for IIH remains unclear. Several theories have been proposed, including abnormalities in cerebrospinal dynamics, metabolic causes and genetics. The diagnostic criteria are based on the revised Dandy criteria. Traditionally, treatment was based on clinical experiences and retrospective studies. However, a new, prospective, randomized, controlled trial, the IIHTT, provided evidence-based data to help guide medical therapy. Additionally new, prospective studies are underway for the different surgical alternatives to treat IIH.
Margeta M, Lad E, Proia A. CD163+ macrophages infiltrate axon bundles of postmortem optic nerves with glaucoma. Graefes Arch Clin Exp Ophthalmol. 2018;256(12):2449–2456.
PURPOSE: Prior research in animal models has shown that macrophages and microglia play an important role in pathogenesis of glaucoma, but the phenotype and distribution of macrophages in human glaucomatous tissue have not been sufficiently characterized. METHODS: We analyzed H&E, CD68-, and CD163-immunostained slides from 25 formaldehyde-fixed, paraffin-embedded autopsy eyes: 12 control eyes and 13 eyes with glaucoma. The diagnosis of glaucoma was made based on a history of glaucoma as reported in the medical record and histological changes characteristic of glaucoma. Glaucoma cases and controls were matched in terms of age, sex, and race. RESULTS: Qualitative analysis of the conventional outflow pathway and the optic nerve revealed that all eyes contained CD163+ cells but a negligible number of CD68+ cells. CD163+ macrophages infiltrated the trabecular meshwork and surrounded Schlemm's canal of normal eyes and eyes with glaucoma, but the pattern was variable and qualitatively similar between groups. In optic nerves of control eyes, CD163+ macrophages were present at low levels and restricted to septa between axon bundles. In glaucomatous optic nerves, the number of CD163+ cells was increased both qualitatively and quantitatively (glaucoma 5.1 ± 0.6 CD163+ cells/mm, control 2.5 ± 0.3 CD163+ cells/mm, p < 0.001), with CD163+ cells infiltrating axon bundles in cases of both mild and severe diseases. CONCLUSIONS: The increase in CD163+ cell number in eyes with mild and severe glaucoma is the first demonstration of macrophage infiltration in glaucomatous human optic nerves. This finding supports a role for macrophages in glaucoma pathogenesis and progression.
Rhiu S, Michalak S, Phanphruk W, Hunter D. Anomalous Vertical Deviations in Attempted Abduction Occur in the Majority of Patients With Esotropic Duane Syndrome. Am J Ophthalmol. 2018;195:171–175.
PURPOSE: To describe a phenomenon, depression in attempted abduction, not previously recognized as a feature of Duane syndrome (DS). DESIGN: Retrospective, observational case series. METHODS: Setting: Institutional practice. PATIENT POPULATION: Patients diagnosed with esotropic DS at Boston Children's Hospital from 2002 to 2015. Patients with clinical photographs documenting horizontal gaze were included. Patients with prior strabismus surgery were excluded. OBSERVATION PROCEDURES: Patients were classified into 3 groups according to their vertical eye position in attempted abduction: midline group, depression group, and elevation group. Group assignment was performed by 3 independent ophthalmologists. Baseline characteristics, eye movement, and ocular deviation were compared among the 3 groups. MAIN OUTCOME MEASURES: Horizontal and vertical deviation on attempted abduction in the DS eye. RESULTS: Depression in attempted abduction was present in 74 of 113 unilateral patients (66%) and 18 of 42 gradable eyes (43%) of bilateral patients. Abduction limitation was significantly less severe in the midline group (median: -3.0) than in the depression group (median: -4.0) (P = .01). Vertical deviation in attempted abduction was more severe in the elevation group than in the depression group (P = .003). CONCLUSIONS: Depression of the eye in attempted abduction has not been widely described, yet it is present in the majority of DS patients. It is more likely to occur with more severe abduction limitation. This phenomenon is likely another form of dysinnervation in DS, the result either of anomalous vertical rectus muscle activation or asymmetric lateral rectus muscle innervation during attempted abduction. Awareness of vertical deviation in attempted abduction may facilitate surgical planning in affected patients.
Satitpitakul V, Sun Z, Suri K, Amouzegar A, Katikireddy K, Jurkunas U, Kheirkhah A, Dana R. Vasoactive Intestinal Peptide Promotes Corneal Allograft Survival. Am J Pathol. 2018;188(9):2016–2024.
Corneal transplantation is the most prevalent form of tissue transplantation. The success of corneal transplantation mainly relies on the integrity of corneal endothelial cells (CEnCs), which maintain graft transparency. CEnC density decreases significantly after corneal transplantation even in the absence of graft rejection. To date, different strategies have been used to enhance CEnC survival. The neuropeptide vasoactive intestinal peptide (VIP) improves CEnC integrity during donor cornea tissue storage and protects CEnCs against oxidative stress-induced apoptosis. However, little is known about the effect of exogenous administration of VIP on corneal transplant outcomes. We found that VIP significantly accelerates endothelial wound closure and suppresses interferon-γ- and tumor necrosis factor-α-induced CEnC apoptosis in vitro in a dose-dependent manner. In addition, we found that intracameral administration of VIP to mice undergoing syngeneic corneal transplantation with endothelial injury increases CEnC density and decreases graft opacity scores. Finally, using a mouse model of allogeneic corneal transplantation, we found for the first time that treatment with VIP significantly suppresses posttransplantation CEnC loss and improves corneal allograft survival.
Shaaban S, MacKinnon S, Andrews C, Staffieri S, Maconachie G, Chan WM, Whitman M, Morton S, Yazar S, Macgregor S, Elder J, Traboulsi E, Gottlob I, Hewitt A, Strabismus Genetics Research Consortium, Hunter D, Mackey D, Engle E. Genome-Wide Association Study Identifies a Susceptibility Locus for Comitant Esotropia and Suggests a Parent-of-Origin Effect. Invest Ophthalmol Vis Sci. 2018;59(10):4054–4064.
Purpose: To identify genetic variants conferring susceptibility to esotropia. Esotropia is the most common form of comitant strabismus, has its highest incidence in European ancestry populations, and is believed to be inherited as a complex trait. Methods: White European American discovery cohorts with nonaccommodative (826 cases and 2991 controls) or accommodative (224 cases and 749 controls) esotropia were investigated. White European Australian and United Kingdom cohorts with nonaccommodative (689 cases and 1448 controls) or accommodative (66 cases and 264 controls) esotropia were tested for replication. We performed a genome-wide case-control association study using a mixed linear additive model. Meta-analyses of discovery and replication cohorts were then conducted. Results: A significant association with nonaccommodative esotropia was discovered (odds ratio [OR] = 1.41, P = 2.84 × 10-09) and replicated (OR = 1.23, P = 0.01) at rs2244352 [T] located within intron 1 of the WRB (tryptophan rich basic protein) gene on chromosome 21 (meta-analysis OR = 1.33, P = 9.58 × 10-11). This single nucleotide polymorphism (SNP) is differentially methylated, and there is a statistically significant skew toward paternal inheritance in the discovery cohort. Meta-analysis of the accommodative discovery and replication cohorts identified an association with rs912759 [T] (OR = 0.59, P = 1.89 × 10-08), an intergenic SNP on chromosome 1p31.1. Conclusions: This is the first genome-wide association study (GWAS) to identify significant associations in esotropia and suggests a parent-of-origin effect. Additional cohorts will permit replication and extension of these findings. Future studies of rs2244352 and WRB should provide insight into pathophysiological mechanisms underlying comitant strabismus.
Song C, Baharozian C, Hatch K, Talamo J. Assessment of surgeon experience with femtosecond laser-assisted cataract surgery. Clin Ophthalmol. 2018;12:1373–1377.
Purpose: To evaluate the collective user experience with an image-guided femtosecond laser (FSL) for cataract surgery in a high-volume, multi-surgeon, ambulatory surgical center. Subjects and methods: A detailed online survey was distributed to all surgeons in a single ambulatory surgical center who had performed cataract surgery using a FSL since its acquisition in December 2012. Information collected included the number of cases performed, typical surgical techniques and parameters, satisfaction with individual features of the laser (rated on a scale from 1=completely unsatisfied to 10=extremely satisfied) and commentary on ease of use and suggested improvements. Results: Seventeen of 30 surgeons (56.7%) completed the survey, representing a case volume of 1,967 eyes. Fourteen surgeons (82.4%) felt they required ≤10 cases with the FSL to operate with the same safety and control as in standard phacoemulsification surgery. Satisfaction was highest for capsulotomies, lens fragmentation, lens softening, arcuate incisions and the graphic user interface (mean scores 9.4, 8.7, 8.7, 7.2 and 8.9, respectively). Preferred capsulotomy diameter was 4.8-5.2 mm (64.7% of respondents). About half (52.9%) of respondents centered the capsulotomy on the pupil and the other 47.1% centered the capsulotomy using optical coherence tomography. Most respondents (81.3%) preferred transepithelial arcuate incisions compared to intrastromal incisions. Satisfaction was lowest with FSL-created, main, clear corneal incisions and paracenteses (mean scores 4.4 and 4.2, respectively). Conclusion: Laser-assisted cataract surgery has a short learning curve and a high rate of user satisfaction. Further software and hardware development is warranted to improve user satisfaction with peripheral and clear corneal incisions.