Publications

2016

Coleman A, Lum F, Velentgas P, Campion D, Su Z, Gliklich R, RiGOR Study Group. RiGOR: a prospective observational study comparing the effectiveness of treatment strategies for open-angle glaucoma.. J Comp Eff Res. 2016;5(1):65–78.

AIMS: The RigOR study was designed to assess comparative effectiveness of medications, laser trabeculoplasty and incisional surgery in patients with open-angle glaucoma (OAG) in the community initiating a new or additional course of therapy as judged necessary by their ophthalmologist. This paper focuses specifically on demographic and clinical characteristics of OAG patients at enrollment. PATIENTS & METHODS: A total of 2597 with OAG already on medical therapy were enrolled from 45 community and academic practices throughout the USA. RESULTS: Overall, 784 (30%) patients were treated with laser surgery, 436 with other surgical procedures (17%), and 1377 with additional medication (53%). Patients had mild (35%) or moderate (31%) glaucoma, with 28% with severe glaucoma. CONCLUSION: The RiGOR study enrolled a diverse population and will provide valuable information regarding visual function and treatment patterns among different racial/ethnic populations. African-American and Hispanic patients entered the study with poorer visual acuity and more severe glaucoma.

Wen G, Aizenman A, Drew T, Wolfe J, Haygood TM, Markey M. Computational assessment of visual search strategies in volumetric medical images.. J Med Imaging (Bellingham). 2016;3(1):015501.

When searching through volumetric images [e.g., computed tomography (CT)], radiologists appear to use two different search strategies: "drilling" (restrict eye movements to a small region of the image while quickly scrolling through slices), or "scanning" (search over large areas at a given depth before moving on to the next slice). To computationally identify the type of image information that is used in these two strategies, 23 naïve observers were instructed with either "drilling" or "scanning" when searching for target T's in 20 volumes of faux lung CTs. We computed saliency maps using both classical two-dimensional (2-D) saliency, and a three-dimensional (3-D) dynamic saliency that captures the characteristics of scrolling through slices. Comparing observers' gaze distributions with the saliency maps showed that search strategy alters the type of saliency that attracts fixations. Drillers' fixations aligned better with dynamic saliency and scanners with 2-D saliency. The computed saliency was greater for detected targets than for missed targets. Similar results were observed in data from 19 radiologists who searched five stacks of clinical chest CTs for lung nodules. Dynamic saliency may be superior to the 2-D saliency for detecting targets embedded in volumetric images, and thus "drilling" may be more efficient than "scanning."

Jun, Ibrahim-Verbaas, Vronskaya, Lambert, Chung, Naj, Kunkle, Wang, Bis, Bellenguez, Harold, Lunetta, Destefano, Grenier-Boley, Sims, Beecham, Smith, Chouraki, Hamilton-Nelson, Ikram, Fievet, Denning, Martin, Schmidt, Kamatani, Dunstan, Valladares, Laza, Zelenika, Ramirez, Foroud, Choi, Boland, Becker, Kukull, Lee, Pasquier, Cruchaga, Beekly, Fitzpatrick, Hanon, Gill, Barber, Gudnason, Campion, Love, Bennett, Amin, Berr, Tsolaki M, Buxbaum, Lopez, Deramecourt, Fox, Cantwell, Tárraga, Dufouil, Hardy, Crane, Eiriksdottir, Hannequin, Clarke, Evans, Mosley, Letenneur, Brayne, Maier, De Jager, Emilsson, Dartigues, Hampel, Kamboh, Bruijn, Tzourio, Pastor, Larson, Rotter, O’Donovan, Montine, Nalls, Mead, Reiman, Jonsson, Holmes, St George-Hyslop, Boada, Passmore, Wendland, Schmidt, Morgan, Winslow, Powell, Carasquillo, Younkin, Jakobsdóttir, Kauwe, Wilhelmsen, Rujescu, Nöthen, Hofman, Jones, IGAP Consortium, Haines, Psaty, Van Broeckhoven, Holmans, Launer, Mayeux, Lathrop, Goate, Escott-Price, Seshadri S, Pericak-Vance, Amouyel, Williams, Duijn, Schellenberg, Farrer. A novel Alzheimer disease locus located near the gene encoding tau protein.. Mol Psychiatry. 2016;21(1):108–117.

APOE ɛ4, the most significant genetic risk factor for Alzheimer disease (AD), may mask effects of other loci. We re-analyzed genome-wide association study (GWAS) data from the International Genomics of Alzheimer's Project (IGAP) Consortium in APOE ɛ4+ (10 352 cases and 9207 controls) and APOE ɛ4- (7184 cases and 26 968 controls) subgroups as well as in the total sample testing for interaction between a single-nucleotide polymorphism (SNP) and APOE ɛ4 status. Suggestive associations (P<1 × 10(-4)) in stage 1 were evaluated in an independent sample (stage 2) containing 4203 subjects (APOE ɛ4+: 1250 cases and 536 controls; APOE ɛ4-: 718 cases and 1699 controls). Among APOE ɛ4- subjects, novel genome-wide significant (GWS) association was observed with 17 SNPs (all between KANSL1 and LRRC37A on chromosome 17 near MAPT) in a meta-analysis of the stage 1 and stage 2 data sets (best SNP, rs2732703, P=5·8 × 10(-9)). Conditional analysis revealed that rs2732703 accounted for association signals in the entire 100-kilobase region that includes MAPT. Except for previously identified AD loci showing stronger association in APOE ɛ4+ subjects (CR1 and CLU) or APOE ɛ4- subjects (MS4A6A/MS4A4A/MS4A6E), no other SNPs were significantly associated with AD in a specific APOE genotype subgroup. In addition, the finding in the stage 1 sample that AD risk is significantly influenced by the interaction of APOE with rs1595014 in TMEM106B (P=1·6 × 10(-7)) is noteworthy, because TMEM106B variants have previously been associated with risk of frontotemporal dementia. Expression quantitative trait locus analysis revealed that rs113986870, one of the GWS SNPs near rs2732703, is significantly associated with four KANSL1 probes that target transcription of the first translated exon and an untranslated exon in hippocampus (P⩽1.3 × 10(-8)), frontal cortex (P⩽1.3 × 10(-9)) and temporal cortex (P⩽1.2 × 10(-11)). Rs113986870 is also strongly associated with a MAPT probe that targets transcription of alternatively spliced exon 3 in frontal cortex (P=9.2 × 10(-6)) and temporal cortex (P=2.6 × 10(-6)). Our APOE-stratified GWAS is the first to show GWS association for AD with SNPs in the chromosome 17q21.31 region. Replication of this finding in independent samples is needed to verify that SNPs in this region have significantly stronger effects on AD risk in persons lacking APOE ɛ4 compared with persons carrying this allele, and if this is found to hold, further examination of this region and studies aimed at deciphering the mechanism(s) are warranted.

Jiang D, Xiao X, Fu T, Mashaghi A, Liu Q, Hong J. Transient Tear Film Dysfunction after Cataract Surgery in Diabetic Patients.. PLoS One. 2016;11(1):e0146752.

PURPOSE: Diabetes mellitus is an increasingly common systemic disease. Many diabetic patients seek cataract surgery for a better visual acuity. Unlike in the general population, the influence of cataract surgery on tear film function in diabetic patients remains elusive. The aim of this study was to evaluate the tear function in diabetic and nondiabetic patients following cataract surgery. METHODS: In this prospective, interventional case series, 174 diabetic patients without dry eye syndrome (DES) and 474 age-matched nondiabetic patients as control who underwent phacoemulsification were enrolled at two different eye centers between January 2011 and January 2013. Patients were followed up at baseline and at 7 days, 1 month, and 3 months postoperatively. Ocular symptom scores (Ocular Surface Disease Index, OSDI) and tear film function including tear film stability (tear film break-up time, TBUT), corneal epithelium integrity (corneal fluorescein staining, CFS), and tear secretion (Schirmer's I test, SIT) were evaluated. RESULTS: In total, 83.9% of the diabetic patients (146 cases with 185 eyes) and 89.0% of the nondiabetic patients (422 cases with 463 eyes) completed all check-ups after the interventions (P = 0.095). The incidence of DES was 17.1% in the diabetic patients and 8.1% in the nondiabetic patients at 7 days after cataract surgery. In the diabetic patients, the incidence of DES remained 4.8% at 1 month postoperatively and decreased to zero at 3 months after surgery. No DES was diagnosed in nondiabetic patients at either the 1-month or 3-month follow-up. Compared with the baseline, the diabetic patients had worse symptom scores and lower TBUT values at 7 days and 1 month but not at 3 months postoperatively. In the nondiabetic patients, symptom scores and TBUT values had returned to preoperative levels at 1-month check-up. CFS scores and SIT values did not change significantly postoperatively in either group (P = 0.916 and P = 0.964, respectively). CONCLUSIONS: Diabetic patients undergoing cataract surgery are prone to DES. Ocular symptoms and tear film stability are transiently worsened in diabetic patients and are restored more slowly than those in nondiabetic patients.

Taub D, Liu Q. The Role of Intraflagellar Transport in the Photoreceptor Sensory Cilium.. Adv Exp Med Biol. 2016;854:627–33.

The photoreceptor is a complex specialized cell in which a major component responsible for visual transduction is the photoreceptor sensory cilium (PSC). Building and maintenance of the PSC requires the transport of large proteins along microtubules that extend from the inner segments to the outer segments. A key process, termed intraflagellar transport (IFT), has been recognized as an essential phenomenon for photoreceptor development and maintenance, and exciting new studies have highlighted its importance in retinal and cilia related diseases. This review focuses on the important roles of IFT players, including motor proteins, IFT proteins, and photoreceptor-specific cargos in photoreceptor sensory cilium. In addition, specific IFT components that are involved in inherited human diseases are discussed.

The retinal expression patterns were analyzed following the injection of serotype 8 adeno-associated virus (AAV8) vectors that utilize two broadly active and commonly used sets of transcription regulatory sequences. These include the human cytomegalovirus (CMV) immediate early (IE) enhancer/promoter and the hybrid CAG element (also known as CAGGS or CBA) composed of a partial human CMV IE enhancer and the chicken β-actin promoter and intron. Subretinal delivery to postnatal day 0 (P0) or 6 (P6) mouse eyes resulted in efficient labeling of retinal cells, but with very distinct patterns. With P0 delivery, AAV8-CMV-GFP selectively labelled photoreceptors, while AAV8-CAG-GFP efficiently labeled both outer and inner retinal neurons, including photoreceptors, horizontal cells, amacrine cells and retinal ganglion cells. With P6 delivery, both vectors led to efficient labeling of photoreceptors and Müller glia cells, but not of inner retinal neurons. Our results suggest that the cell types that express the genes encoded by subretinally delivered AAV8 vectors are determined by both the timing of the injection and the regulatory sequences.

Since the lipofuscin of retinal pigment epithelial (RPE) cells has been implicated in the pathogenesis of Best vitelliform macular dystrophy, we quantified fundus autofluorescence (quantitative fundus autofluorescence, qAF) as an indirect measure of RPE lipofuscin levels. Mean non-lesion qAF was found to be within normal limits for age. By spectral domain optical coherence tomography (SD-OCT) vitelliform lesions presented as fluid-filled subretinal detachments containing reflective material. We discuss photoreceptor outer segment debris as the source of the intense fluorescence of these lesions and loss of anion channel functioning as an explanation for the bullous photoreceptor-RPE detachment. Unexplained is the propensity of the disease for central retina.

Carvalho L, Vandenberghe L. Understanding Cone Photoreceptor Cell Death in Achromatopsia.. Adv Exp Med Biol. 2016;854:231–6.

Colour vision is only achieved in the presence of healthy and functional cone photoreceptors found in the retina. It is an essential component of human vision and usually the first complaint patients undergoing vision degeneration have is the loss of daylight colour vision. Therefore, an understanding of the biology and basic mechanisms behind cone death under the degenerative state of retinal dystrophies and how the activation of the apoptotic pathway is triggered will provide valuable knowledge. It will also have broader applications for a spectrum of visual disorders and will be critical for future advances in translational research.

Fernandez-Godino R, Pierce E, Garland D. Extracellular Matrix Alterations and Deposit Formation in AMD.. Adv Exp Med Biol. 2016;854:53–8.

Age related macular degeneration (AMD) is the primary cause of vision loss in the western world (Friedman et al., Arch Ophthalmol 122:564-572, 2004). The first clinical indication of AMD is the presence of drusen. However, with age and prior to the formation of drusen, extracellular basal deposits accumulate between the retinal pigment epithelium (RPE) and Bruch's membrane (BrM). Many studies on the molecular composition of the basal deposits and drusen have demonstrated the presence of extracellular matrix (ECM) proteins, complement components and cellular debris. The evidence reviewed here suggests that alteration in RPE cell function might be the primary cause for the accumulation of ECM and cellular debri found in basal deposits. Further studies are obviously needed in order to unravel the specific pathways that lead to abnormal formation of ECM and complement activation.

Castle M, Turunen H, Vandenberghe L, Wolfe J. Controlling AAV Tropism in the Nervous System with Natural and Engineered Capsids.. Methods Mol Biol. 2016;1382:133–49.

More than one hundred naturally occurring variants of adeno-associated virus (AAV) have been identified, and this library has been further expanded by an array of techniques for modification of the viral capsid. AAV capsid variants possess unique antigenic profiles and demonstrate distinct cellular tropisms driven by differences in receptor binding. AAV capsids can be chemically modified to alter tropism, can be produced as hybrid vectors that combine the properties of multiple serotypes, and can carry peptide insertions that introduce novel receptor-binding activity. Furthermore, directed evolution of shuffled genome libraries can identify engineered variants with unique properties, and rational modification of the viral capsid can alter tropism, reduce blockage by neutralizing antibodies, or enhance transduction efficiency. This large number of AAV variants and engineered capsids provides a varied toolkit for gene delivery to the CNS and retina, with specialized vectors available for many applications, but selecting a capsid variant from the array of available vectors can be difficult. This chapter describes the unique properties of a range of AAV variants and engineered capsids, and provides a guide for selecting the appropriate vector for specific applications in the CNS and retina.