Lee HS, Schlereth SL, Park EY, Emami-Naeini P, Chauhan SK, Dana R. A novel pro-angiogenic function for interferon-γ-secreting natural killer cells. Invest Ophthalmol Vis Sci 2014;55(5):2885-92.Abstract
PURPOSE: To explore the function of natural killer (NK) cells in inflammatory angiogenesis in mice. METHODS: To study ocular angiogenic responses we used the cornea BFGF micropellet and the laser-induced choroidal neovascularization (CNV) mouse models (C57BL/6). To deplete NK cells in these models, we injected an anti-NK1.1 antibody or an isotype antibody as a control. Corneas or choroids were immunohistochemically stained for blood vessels (CD31), macrophages (F4/80), or CNV (isolectin-IB4). Vascular endothelial growth factors (VEGF), IFN-γ, or TNF-α levels were measured by real-time quantitative PCR (qPCR) or flow cytometry. A coculture assay of macrophages, NK cells, and human umbilical vein endothelial cells (HUVECs) was analyzed morphometrically to examine the ability of NK cells to induce angiogenesis in vitro. RESULTS: Our data demonstrate that in vivo depletion of NK cells leads to a significant reduction of corneal angiogenesis and CNV. Furthermore, NK cell depletion reduces macrophage infiltration into the cornea and mRNA expression levels of VEGF-A, VEGF-C, and VEGFR3 at day 7 after micropellet insertion. In the laser-induced CNV model, our data show that NK cell depletion leads to decreased areas of CNV and significantly reduced mRNA expression of VEGFs and IFN-γ in the choroid. An in vitro coculture assay shows an IFN-γ-dependent increase in VEGF expression levels, thereby increasing endothelial cell proliferation. CONCLUSIONS: Our findings demonstrate a novel pro-angiogenic function for NK cells, indicating that IFN-γ-secreting NK cells can induce angiogenesis by promoting enhanced VEGF expression by macrophages.
Connors EC, Chrastil ER, Sánchez J, Merabet LB. Action video game play and transfer of navigation and spatial cognition skills in adolescents who are blind. Front Hum Neurosci 2014;8:133.Abstract
For individuals who are blind, navigating independently in an unfamiliar environment represents a considerable challenge. Inspired by the rising popularity of video games, we have developed a novel approach to train navigation and spatial cognition skills in adolescents who are blind. Audio-based Environment Simulator (AbES) is a software application that allows for the virtual exploration of an existing building set in an action video game metaphor. Using this ludic-based approach to learning, we investigated the ability and efficacy of adolescents with early onset blindness to acquire spatial information gained from the exploration of a target virtual indoor environment. Following game play, participants were assessed on their ability to transfer and mentally manipulate acquired spatial information on a set of navigation tasks carried out in the real environment. Success in transfer of navigation skill performance was markedly high suggesting that interacting with AbES leads to the generation of an accurate spatial mental representation. Furthermore, there was a positive correlation between success in game play and navigation task performance. The role of virtual environments and gaming in the development of mental spatial representations is also discussed. We conclude that this game based learning approach can facilitate the transfer of spatial knowledge and further, can be used by individuals who are blind for the purposes of navigation in real-world environments.
Cho HY, Nasir HH, Sobrin L. Focal laser photocoagulation and photodynamic therapy for lupus choroidopathy. Lupus 2014;23(4):412-6.Abstract
PURPOSE: To describe the results of photodynamic therapy (PDT) and/or focal laser photocoagulation in the treatment of serous retinal detachments secondary to lupus choroidopathy. METHODS: The medical records of three patients with serous detachments secondary to lupus choroidopathy who were treated with PDT and/or focal laser photocoagulation were reviewed. Concomitant systemic medical therapy as well as visual acuity and optical coherence tomography (OCT) outcomes were recorded. RESULTS: All patients received systemic immunosuppressive therapy and had control of their extraocular manifestations prior to PDT and/or laser photocoagulation. One patient received only focal laser photocoagulation and had complete resolution of the subretinal fluid on OCT. The two other patients received a combination of PDT and focal laser treatment. One had improvement in vision and resolution of subretinal fluid on OCT. The second patient, who had longstanding lupus choroidopathy and associated subretinal fluid and macular edema, had only a significant decrease in fluid on OCT but no vision improvement. CONCLUSION: In conjunction with control of systemic disease, PDT and/or focal laser photocoagulation can be successful in resolving subretinal fluid secondary to lupus choroidopathy.
Bowers AR, Ananyev E, Mandel AJ, Goldstein RB, Peli E. Driving with hemianopia: IV. Head scanning and detection at intersections in a simulator. Invest Ophthalmol Vis Sci 2014;55(3):1540-8.Abstract
PURPOSE: Using a driving simulator, we examined the effects of homonymous hemianopia (HH) on head scanning behaviors at intersections and evaluated the role of inadequate head scanning in detection failures. METHODS: Fourteen people with complete HH and without cognitive decline or visual neglect and 12 normally sighted (NV) current drivers participated. They drove in an urban environment following predetermined routes, which included multiple intersections. Head scanning behaviors were quantified at T-intersections (n = 32) with a stop or yield sign. Participants also performed a pedestrian detection task. The relationship between head scanning and detection was examined at 10 intersections. RESULTS: For HH drivers, the first scan was more likely to be toward the blind than the seeing hemifield. They also made a greater proportion of head scans overall to the blind side than did the NV drivers to the corresponding side (P = 0.003). However, head scan magnitudes of HH drivers were smaller than those of the NV group (P < 0.001). Drivers with HH had impaired detection of blind-side pedestrians due either to not scanning in the direction of the pedestrian or to an insufficient scan magnitude (left HH detected only 46% and right HH 8% at the extreme left and right of the intersection, respectively). CONCLUSIONS: Drivers with HH demonstrated compensatory head scan patterns, but not scan magnitudes. Inadequate scanning resulted in blind-side detection failures, which might place HH drivers at increased risk for collisions at intersections. Scanning training tailored to specific problem areas identified in this study might be beneficial.
Amparo F, Jin Y, Hamrah P, Schaumberg DA, Dana R. What is the value of incorporating tear osmolarity measurement in assessing patient response to therapy in dry eye disease?. Am J Ophthalmol 2014;157(1):69-77.e2.Abstract
PURPOSE: To evaluate the correlation between changes in tear osmolarity, symptoms, and corneal fluorescein staining in patients with dry eye disease (DED). DESIGN: Retrospective, clinic-based cohort study. METHODS: In this single-institution study, we reviewed the charts of 186 patients with DED from whom we had data on tear osmolarity, symptoms, and corneal fluorescein staining from 2 separate visits. Main outcomes included the correlation of the changes between the 2 visits for tear osmolarity (TearLab system), symptoms (Ocular Surface Disease Index), and corneal fluorescein staining (modified Oxford scheme). For tear osmolarity and corneal fluorescein staining the scores from the eye with highest readings were analyzed. The correlations were repeated on subgroups based on proposed cutoffs for DED severity and on patients' treatment. RESULTS: We found a modest, though statistically significant, correlation between changes in corneal fluorescein staining and symptoms of DED (R = 0.31; P < .001). However, there was no correlation between the recorded change in tear osmolarity and symptoms (R = -0.091; P = .38) or between changes in tear osmolarity and corneal fluorescein staining (R = -0.02; P = .80). This lack of correlation was consistent in all the subgroups studied. A multivariate analysis revealed that changes in corneal fluorescein staining had predictive value on symptom changes, whereas tear osmolarity changes did not. CONCLUSIONS: Changes in tear osmolarity do not correlate significantly with changes in patient symptoms or corneal fluorescein staining in dry eye disease.
Al-Moujahed A, Nicolaou F, Brodowska K, Papakostas TD, Marmalidou A, Ksander BR, Miller JW, Gragoudas E, Vavvas DG. Uveal melanoma cell growth is inhibited by aminoimidazole carboxamide ribonucleotide (AICAR) partially through activation of AMP-dependent kinase. Invest Ophthalmol Vis Sci 2014;55(7):4175-85.Abstract
PURPOSE: To evaluate the effects and mechanism of aminoimidazole carboxamide ribonucleotide (AICAR), an AMP-dependent kinase (AMPK) activator, on the growth of uveal melanoma cell lines. METHODS: Four different cell lines were treated with AICAR (1-4 mM). Cell growth was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay. Cell cycle analysis was conducted by flow cytometry; additionally, expression of cell-cycle control proteins, cell growth transcription factors, and downstream effectors of AMPK were determined by RT-PCR and Western blot. RESULTS: Aminoimidazole carboxamide ribonucleotide inhibited cell growth, induced S-phase arrest, and led to AMPK activation. Aminoimidazole carboxamide ribonucleotide treatment was associated with inhibition of eukaryotic translation initiation factor 4E-BP1 phosphorylation, a marker of mammalian target of rapamycin (mTOR) pathway activity. Aminoimidazole carboxamide ribonucleotide treatment was also associated with downregulation of cyclins A and D, but had minimal effects on the phosphorylation of ribosomal protein S6 or levels of the macroautophagy marker LC3B. The effects of AICAR were abolished by treatment with dipyridamole, an adenosine transporter inhibitor that blocks the entry of AICAR into cells. Treatment with adenosine kinase inhibitor 5-iodotubericidin, which inhibits the conversion of AICAR to its 5'-phosphorylated ribotide 5-aminoimidazole-4-carboxamide-1-D-ribofuranosyl-5'-monophosphate (ZMP; the direct activator of AMPK), reversed most of the growth-inhibitory effects, indicating that some of AICAR's antiproliferative effects are mediated at least partially through AMPK activation. CONCLUSIONS: Aminoimidazole carboxamide ribonucleotide inhibited uveal melanoma cell proliferation partially through activation of the AMPK pathway and downregulation of cyclins A1 and D1.
Damico FM, Takahashi BS, Acquesta FB. Transscleral delivery of Nd: YLF laser at 1,047 nm causes vascular occlusion in experimental pigmented choroidal melanoma. Retina 2014;34(4):792-800.Abstract
PURPOSE: The aims of this study were to determine the scleral attenuation of focused neodymium: yttrium-lanthanum-fluoride laser at 1,047 nm applied transsclerally and whether transscleral delivery can close the vascular supply at the base of experimental choroidal melanoma in rabbits. METHODS: Fifty-two New Zealand albino rabbits were included. Scleral laser attenuation was measured across fresh sclera. B16F10 melanomas were established in the subchoroidal space of 49 rabbits. Twenty-one animals were killed immediately after transscleral treatment, 14 were followed for 2 weeks to 4 weeks, and 14 were followed without treatment. Ophthalmoscopy, fundus photographs, and fluorescein angiography were performed before treatment, immediately after, and weekly during the follow-up. Eyes were examined by light microscopy. RESULTS: Sclera attenuated laser energy by 31% ± 7%. Immediately after treatment, angiography showed diffuse hypofluorescence in 71% (15 of 21 rabbits). Light microscopy showed vascular occlusion extending at least two thirds of the tumor thickness from the base. Seven of the 14 tumors followed for 15 days ± 8 days were eradicated. There was no correlation between tumor height and eradication. CONCLUSION: Rabbit sclera attenuated 31% ± 7% of laser energy. A single transscleral treatment causes tumor vascular closure at the base and may serve as an adjuvant therapy to ensure destruction of deep and intrascleral tumor cells.
Cohen LP, Pasquale LR. Clinical characteristics and current treatment of glaucoma. Cold Spring Harb Perspect Med 2014;4(6)Abstract
Glaucoma is a neurodegenerative disorder in which degenerating retinal ganglion cells (RGC) produce significant visual disability. Clinically, glaucoma refers to an array of conditions associated with variably elevated intraocular pressure (IOP) that contributes to RGC loss via mechanical stress, vascular abnormalities, and other mechanisms, such as immune phenomena. The clinical diagnosis of glaucoma requires assessment of the ocular anterior segment with slit lamp biomicroscopy, which allows the clinician to recognize signs of conditions that can produce elevated IOP. After measurement of IOP, a specialized prismatic lens called a gonioscope is used to determine whether the angle is physically open or closed. The structural manifestation of RGC loss is optic nerve head atrophy and excavation of the neuroretinal rim tissue. Treatment is guided by addressing secondary causes for elevated IOP (such as inflammation, infection, and ischemia) whenever possible. Subsequently, a variety of medical, laser, and surgical options are used to achieve a target IOP.
Chen L, Kim IK, Lane AM, Gauthier D, Munzenrider JE, Gragoudas ES, Miller JW. Proton beam irradiation for non-AMD CNV: 2-year results of a randomised clinical trial. Br J Ophthalmol 2014;98(9):1212-7.Abstract
AIMS: To evaluate safety and visual outcomes after proton beam irradiation (PBI) therapy for subfoveal choroidal neovascularisation (CNV) secondary to causes other than age-related macular degeneration (AMD). METHODS: This study is a prospective, unmasked and randomised clinical trial using two dosage regimens, conducted in the Massachusetts Eye and Ear Infirmary. The study included 46 patients with CNV secondary to non-AMD and best-corrected visual acuity of 20/320 or better. Patients were randomly assigned to receive 16 or 24 cobalt gray equivalents (CGE) of PBI in two equal fractions. Complete ophthalmological examinations, fundus photography and fluorescein angiography were performed at baseline and 6, 12, 18 and 24 months after treatment. RESULTS: At 1 year after treatment, 82% and 72% lost fewer than 1.5 lines of vision in the 16 CGE and in 24 CGE groups, respectively. At 2 years after therapy, 77% in the lower dose group and 64% in the higher dose group lost fewer than 1.5 lines of vision. Mild radiation complications such as radiation vasculopathy developed in 17.6% of patients. CONCLUSIONS: PBI is a safe and efficacious treatment for subfoveal CNV not due to AMD. The data with respect to visual outcomes and radiation complications trend in favour of the 16 CGE group, although differences do not reach statistical significance. PBI may be considered as an alternative to current therapies.
Buys ES, Potter LR, Pasquale LR, Ksander BR. Regulation of intraocular pressure by soluble and membrane guanylate cyclases and their role in glaucoma. Front Mol Neurosci 2014;7:38.Abstract
Glaucoma is a progressive optic neuropathy characterized by visual field defects that ultimately lead to irreversible blindness (Alward, 2000; Anderson et al., 2006). By the year 2020, an estimated 80 million people will have glaucoma, 11 million of which will be bilaterally blind. Primary open-angle glaucoma (POAG) is the most common type of glaucoma. Elevated intraocular pressure (IOP) is currently the only risk factor amenable to treatment. How IOP is regulated and can be modulated remains a topic of active investigation. Available therapies, mostly geared toward lowering IOP, offer incomplete protection, and POAG often goes undetected until irreparable damage has been done, highlighting the need for novel therapeutic approaches, drug targets, and biomarkers (Heijl et al., 2002; Quigley, 2011). In this review, the role of soluble (nitric oxide (NO)-activated) and membrane-bound, natriuretic peptide (NP)-activated guanylate cyclases that generate the secondary signaling molecule cyclic guanosine monophosphate (cGMP) in the regulation of IOP and in the pathophysiology of POAG will be discussed.
Artornsombudh P, Pistilli M, Foster SC, Pujari SS, Gangaputra SS, Jabs DA, Levy-Clarke GA, Nussenblatt RB, Rosenbaum JT, Suhler EB, Thorne JE, Kempen JH. Factors predictive of remission of new-onset anterior uveitis. Ophthalmology 2014;121(3):778-84.Abstract
PURPOSE: To identify factors predictive of remission of inflammation in new-onset anterior uveitis cases treated at tertiary uveitis care facilities. DESIGN: Retrospective cohort study. PARTICIPANTS: Patients seeking treatment at participating academic uveitis clinics within 90 days of initial diagnosis of anterior uveitis. METHODS: Retrospective cohort study based on standardized chart review. MAIN OUTCOME MEASURES: Factors predictive of remission (no disease activity without corticosteroid or immunosuppressive treatments at all visits during a 90-day period). RESULTS: Nine hundred ninety eyes (687 patients) had a first-ever diagnosis of anterior uveitis within 90 days before initial presentation and had follow-up visits thereafter. The median follow-up time was 160 days. Systemic diagnoses with juvenile idiopathic arthritis (JIA; adjusted hazard ratio [aHR], 0.38; 95% confidence interval [CI], 0.19-0.74) and Behçet's disease (aHR, 0.10; 95% CI, 0.01-0.85) were associated with a lower incidence of uveitis remission. Cases of bilateral uveitis (aHR, 0.68; 95% CI, 0.54-0.87) and those with a history of cataract surgery before presentation (aHR, 0.51; 95% CI, 0.29-0.87) also had a lower incidence of remission. Regarding clinical findings at the initial visit, a high degree of vitreous cells at initial presentation was associated with a lower incidence of remission (for 1+ or more vs. none: aHR, 0.72; 95% CI, 0.55-0.95). An initial visual acuity of 20/200 or worse, with respect to 20/40 or better, also was predictive of a lower incidence of remission (aHR, 0.52; 95% CI, 0.32-0.86). CONCLUSIONS: Factors associated with a lower incidence of remission among new-onset anterior uveitis cases included diagnosis with JIA, Behçet's disease, bilateral uveitis, history of cataract surgery, findings of 1+ or more vitreous cells at presentation, and an initial visual acuity of 20/200 or worse. Patients with these risk factors seem to be at higher risk of persistent inflammation; reciprocally, patients lacking these factors would be more likely to experience remission. Patients with risk factors for nonremission of uveitis should be managed taking into account the higher probability of a chronic inflammatory course.
Alberti CF, Peli E, Bowers AR. Driving with hemianopia: III. Detection of stationary and approaching pedestrians in a simulator. Invest Ophthalmol Vis Sci 2014;55(1):368-74.Abstract
PURPOSE: To compare blind-side detection performance of drivers with homonymous hemianopia (HH) for stationary and approaching pedestrians, initially appearing at small (4°) or large (14°) eccentricities in a driving simulator. While the stationary pedestrians did not represent an imminent threat, as their eccentricity increased rapidly as the vehicle advanced, the approaching pedestrians maintained a collision course with approximately constant eccentricity, walking or running, toward the travel lane as if to cross. METHODS: Twelve participants with complete HH and without spatial neglect pressed the horn whenever they detected a pedestrian while driving along predetermined routes in two driving simulator sessions. Miss rates and reaction times were analyzed for 52 stationary and 52 approaching pedestrians. RESULTS: Miss rates were higher and reaction times longer on the blind than the seeing side (P < 0.01). On the blind side, miss rates were lower for approaching than stationary pedestrians (16% vs. 29%, P = 0.01), especially at larger eccentricities (20% vs. 54%, P = 0.005), but reaction times for approaching pedestrians were longer (1.72 vs. 1.41 seconds; P = 0.03). Overall, the proportion of potential blind-side collisions (missed and late responses) was not different for the two paradigms (41% vs. 35%, P = 0.48), and significantly higher than for the seeing side (3%, P = 0.002). CONCLUSIONS: In a realistic pedestrian detection task, drivers with HH exhibited significant blind-side detection deficits. Even when approaching pedestrians were detected, responses were often too late to avoid a potential collision.
Connors EC, Chrastil ER, Sánchez J, Merabet LB. Virtual environments for the transfer of navigation skills in the blind: a comparison of directed instruction vs. video game based learning approaches. Front Hum Neurosci 2014;8:223.Abstract
For profoundly blind individuals, navigating in an unfamiliar building can represent a significant challenge. We investigated the use of an audio-based, virtual environment called Audio-based Environment Simulator (AbES) that can be explored for the purposes of learning the layout of an unfamiliar, complex indoor environment. Furthermore, we compared two modes of interaction with AbES. In one group, blind participants implicitly learned the layout of a target environment while playing an exploratory, goal-directed video game. By comparison, a second group was explicitly taught the same layout following a standard route and instructions provided by a sighted facilitator. As a control, a third group interacted with AbES while playing an exploratory, goal-directed video game however, the explored environment did not correspond to the target layout. Following interaction with AbES, a series of route navigation tasks were carried out in the virtual and physical building represented in the training environment to assess the transfer of acquired spatial information. We found that participants from both modes of interaction were able to transfer the spatial knowledge gained as indexed by their successful route navigation performance. This transfer was not apparent in the control participants. Most notably, the game-based learning strategy was also associated with enhanced performance when participants were required to find alternate routes and short cuts within the target building suggesting that a ludic-based training approach may provide for a more flexible mental representation of the environment. Furthermore, outcome comparisons between early and late blind individuals suggested that greater prior visual experience did not have a significant effect on overall navigation performance following training. Finally, performance did not appear to be associated with other factors of interest such as age, gender, and verbal memory recall. We conclude that the highly interactive and immersive exploration of the virtual environment greatly engages a blind user to develop skills akin to positive near transfer of learning. Learning through a game play strategy appears to confer certain behavioral advantages with respect to how spatial information is acquired and ultimately manipulated for navigation.