Alasil T, Wang K, Keane PA, Lee H, Baniasadi N, de Boer JF, Chen TC. Analysis of normal retinal nerve fiber layer thickness by age, sex, and race using spectral domain optical coherence tomography. J Glaucoma 2013;22(7):532-41.Abstract
PURPOSE: To determine the effects of age, sex, and race on the retinal nerve fiber layer (RNFL) in the normal human eye as measured by the spectral domain optical coherence tomography (SD-OCT) Spectralis machine (Heidelberg Engineering). METHODS: Peripapillary SD-OCT RNFL thickness measurements were determined in normal subjects seen at a university-based clinic. One randomly selected eye per subject was used for analysis in this cross-sectional study. Multiple regression analysis was applied to assess the effects of age, sex, ethnicity, and mean refractive error on peripapillary RNFL thickness. Results are expressed as means±SD wherever applicable. RESULTS: The study population consisted of 190 healthy participants from 9 to 86 years of age. Of the 190 participants, 62 (33%) were men, 125 (66%) Caucasians, 26 (14%) African Americans, 14 (7%) Hispanics, 16 (8%) Asians, and 9 (5%) other races. The mean RNFL thickness for the normal population studied was 97.3 ± 9.6 µm. Normal RNFL thickness values follow the ISNT rule with decreasing RNFL thickness values starting from the thickest quadrant inferiorly to the thinnest quadrant temporally: inferior quadrant (126 ± 15.8), superior quadrant (117.2±16.13), nasal quadrant (75 ± 13.9), and temporal quadrant (70.6 ± 10.8 µm). Thinner RNFL measurements were associated with older age (P<0.001); being Caucasian, versus being either Hispanic or Asian (P=0.02 and 0.009, respectively); or being more myopic (P<0.001). For every decade of increased age, mean RNFL thickness measured thinner by approximately 1.5 µm (95% confidence interval, 0.24-0.07). Comparisons between ethnic groups revealed that Caucasians had mean RNFL values (96 ± 9.2 µm) slightly thinner than those of Hispanics (102.9 ± 11 µm; P=0.02) or Asians (100.7 ± 8.5 µm; P=0.009). African Americans RNFL values (99.2 ± 10.2 µm) were not significantly different when compared with Caucasians. There was no relationship between RNFL thickness and sex. CONCLUSIONS: The thickest RNFL measurements were found in the inferior quadrant, followed by the superior, nasal, and temporal quadrants (ISNT rule applied to the RNFL). Thinner RNFL measurements were associated with older age and increasing myopia. Caucasians tend to have thinner RNFL values when compared with Hispanics and Asians. SD-OCT analysis of the normal RNFL showed results similar to time domain OCT studies.
Amparo F, Sadrai Z, Jin Y, Alfonso-Bartolozzi B, Wang H, Shikari H, Ciolino JB, Chodosh J, Jurkunas U, Schaumberg DA, Dana R. Safety and efficacy of the multitargeted receptor kinase inhibitor pazopanib in the treatment of corneal neovascularization. Invest Ophthalmol Vis Sci 2013;54(1):537-44.Abstract
PURPOSE: To evaluate the safety and efficacy of topical pazopanib in the treatment of corneal neovascularization (CNV). METHODS: Twenty eyes of 20 patients with stable CNV were enrolled in a prospective, open label, noncomparative study and treated with topical pazopanib 0.5% for 3 weeks, and followed for 12 weeks. The primary endpoint was to determine the tolerability and safety of topical pazopanib in the treatment of CNV defined by the occurrence of ocular and systemic adverse events during the study. The secondary endpoint was to evaluate the effect of topical pazopanib on the reduction of (1) neovascular area (NA), defined as the area of the corneal vessels themselves, (2) invasion area (IA), defined as the fraction of the total cornea into which the vessels extend, (3) vessel length (VL), defined as the mean measurement of the extent of vessels from end to end, and (4) vessel caliber (VC), defined as the mean diameter of the corneal vessels. RESULTS: There were no severe adverse events following the use of topical pazopanib. Compared with the baseline visit, NA and VL showed a statistically significant decrease at week 3 (P = 0.02 and 0.01, respectively); and NA, IA, and VL statistically significantly decreased at week 12 (P = 0.03, 0.04, and <0.01, respectively). Visual acuity maintained without changes after the 12 week follow-up. CONCLUSIONS: This preliminary study suggests that topical treatment with pazopanib 0.5% is safe, well tolerated, and may have a role as an alternative for the treatment of CNV (ClinicalTrials.gov number, NCT01257750).
Amparo F, Dastjerdi MH, Okanobo A, Ferrari G, Smaga L, Hamrah P, Jurkunas U, Schaumberg DA, Dana R. Topical interleukin 1 receptor antagonist for treatment of dry eye disease: a randomized clinical trial. JAMA Ophthalmol 2013;131(6):715-723.Abstract
IMPORTANCE: The immunopathogenic mechanisms of dry eye disease (DED), one of the most common ophthalmic conditions, is incompletely understood. Data from this prospective, double-masked, randomized trial demonstrate that targeting interleukin 1 (IL-1) by topical application of an IL-1 antagonist is efficacious in significantly reducing DED-related patient symptoms and corneal epitheliopathy. OBJECTIVE: To evaluate the safety and efficacy of treatment with the topical IL-1 receptor antagonist anakinra (Kineret; Amgen Inc) in patients having DED associated with meibomian gland dysfunction. DESIGN AND SETTING: Prospective phase 1/2, randomized, double-masked, vehicle-controlled clinical trial. PARTICIPANTS: Seventy-five patients with refractory DED. INTERVENTIONS: Participants were randomized to receive treatment with topical anakinra, 2.5% (n = 30), anakinra, 5% (n = 15), or vehicle (1% carboxymethylcellulose) (n = 30) 3 times daily for 12 weeks. MAIN OUTCOMES AND MEASURES: Primary outcomes were corneal fluorescein staining (CFS), complete bilateral CFS clearance, dry eye-related symptoms as measured by the Ocular Surface Disease Index, tear film breakup time, and meibomian gland secretion quality. RESULTS: Topical anakinra was well tolerated compared with vehicle, with no reports of serious adverse reactions attributable to the therapy. After 12 weeks of therapy, participants treated with anakinra, 2.5%, achieved a 46% reduction in their mean CFS score (P = .12 compared with vehicle and P < .001 compared with baseline); participants treated with anakinra, 5%, achieved a 17% reduction in their mean CFS score (P = .88 compared with vehicle and P = .33 compared with baseline); and patients treated with vehicle achieved a 19% reduction in their mean CFS score (P = .11). Complete bilateral CFS clearance was noted in 8 of 28 patients (29%) treated with anakinra, 2.5%, vs in 2 of 29 patients (7%) treated with vehicle (P = .03). By week 12, treatment with anakinra, 2.5%, and treatment with anakinra, 5%, led to significant reductions in symptoms of 30% and 35%, respectively (P = .02 and P = .01, respectively, compared with vehicle); treatment with vehicle led to a 5% reduction in symptoms. CONCLUSIONS AND RELEVANCE: Treatment with topical anakinra, 2.5%, for 12 weeks was safe and significantly reduced symptoms and corneal epitheliopathy in patients with DED. These data suggest that the use of an IL-1 antagonist may have a role as a novel therapeutic option for patients with DED. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00681109.
Amparo F, Wang H, Emami-Naeini P, Karimian P, Dana R. The Ocular Redness Index: a novel automated method for measuring ocular injection. Invest Ophthalmol Vis Sci 2013;54(7):4821-6.Abstract
PURPOSE: To develop and validate a novel automated system to assess ocular redness (OR) in clinical images. METHODS: We developed a novel software that quantifies OR in digital images based on a mathematic algorithm using a centesimal continuous scoring scale. Subsequently, we conducted a study to validate the scores obtained with this system by correlating them with those obtained by two physicians using two image-based comparative subjective scales, the Efron and the Validated Bulbar Redness (VBR) grading scales. Additionally, we evaluated the level of clinical agreement between the Ocular Redness Index (ORI) score and the two image-based methods by means of the Bland-Altman analysis. Main outcome measures included correlation and level of agreement between the ORI score, Efron score, and the VBR score. RESULTS: One hundred and two clinical photographs of eyes with OR were evaluated. The ORI scores significantly correlated with the scores obtained by the two clinicians using the Efron (Observer 1, R=0.925, P<0.001; Observer 2, R=0.857, P<0.001), and VBR (Observer 1, R=0.830, P<0.001; Observer 2, R=0.821, P<0.001) scales. The Bland-Altman analysis revealed levels of disagreement of up to 30 and 27 units for the ORI-Efron and ORI-VBR score comparisons, respectively. CONCLUSIONS: The ORI provides an objective and continuous scale for evaluating ocular injection in an automated manner, and without need for a trained physician for scoring. The ORI may be used as a new alternative for objective OR evaluation in clinics and in clinical trials.
Argüeso P. Glycobiology of the ocular surface: mucins and lectins. Jpn J Ophthalmol 2013;57(2):150-5.Abstract
Glycosylation is an important and common form of posttranscriptional modification of proteins in cells. During the last decade, a vast array of biological functions has been ascribed to glycans because of a rapid evolution in glycomic technologies. Glycogenes that are highly expressed at the human ocular surface include families of glycosyltransferases, proteoglycans, and glycan degradation proteins, as well as mucins and carbohydrate-binding proteins, such as the galectins. On the apical glycocalyx, mucin O-glycans promote boundary lubrication, prevent bacterial adhesion and endocytic activity, and maintain epithelial barrier function through interactions with galectins. The emerging roles attributed to glycans are contributing to the appreciation of their biological capabilities at the ocular surface.
Baris HN, Chan W-M, Andrews C, Behar DM, Donovan DJ, Morton CC, Ranells J, Pal T, Ligon AH, Engle EC. Complex cytogenetic rearrangements at the DURS1 locus in syndromic Duane retraction syndrome. Clin Case Rep 2013;1(1)
Baxter SL, Pistilli M, Pujari SS, Liesegang TL, Suhler EB, Thorne JE, Foster SC, Jabs DA, Levy-Clarke GA, Nussenblatt RB, Rosenbaum JT, Kempen JH. Risk of choroidal neovascularization among the uveitides. Am J Ophthalmol 2013;156(3):468-477.e2.Abstract
PURPOSE: To evaluate the risk, risk factors, and visual impact of choroidal neovascularization (CNV) in uveitis cases. DESIGN: Retrospective cohort study. METHODS: Standardized medical record review at 5 tertiary centers. RESULTS: Among 15,137 uveitic eyes (8868 patients), CNV was rare in the cases of anterior or intermediate uveitis. Among the 4041 eyes (2307 patients) with posterior uveitis or panuveitis, 81 (2.0%) had CNV at presentation. Risk factors included posterior uveitis in general and specific uveitis syndromes affecting the outer retina-retinal pigment epithelium-choroid interface. Among the 2364 eyes (1357 patients) with posterior uveitis or panuveitis and free of CNV at the time of cohort entry, the cumulative 2-year incidence of CNV was 2.7% (95% confidence interval [CI], 1.8% to 3.5%). Risk factors for incident CNV included currently active inflammation (adjusted hazard ratio [aHR], 2.13; 95% CI, 1.26 to 3.60), preretinal neovascularization (aHR, 3.19; 95% CI, 1.30 to 7.80), and prior diagnosis of CNV in the contralateral eye (aHR, 5.79; 95% CI, 2.77 to 12.09). Among specific syndromes, the incidence was greater in Vogt-Koyanagi-Harada syndrome (aHR, 3.37; 95% CI, 1.52 to 7.46) and punctate inner choroiditis (aHR, 8.67; 95% CI, 2.83 to 26.54). Incident CNV was associated with a 2-line loss of visual acuity (+0.19 logarithm of the minimal angle of resolution units; 95% CI, 0.079 to 0.29) from the preceding visit. CONCLUSIONS: CNV is an uncommon complication of uveitis associated with visual impairment that occurs more commonly in forms affecting the outer retina-retinal pigment epithelium-choroid interface, during periods of inflammatory activity, in association with preretinal neovascularization, and in second eyes of patients with unilateral CNV. Because CNV is treatable, a systematic approach to early detection in high-risk patients may be appropriate.
Beier KT, Saunders AB, Oldenburg IA, Sabatini BL, Cepko CL. Vesicular stomatitis virus with the rabies virus glycoprotein directs retrograde transsynaptic transport among neurons in vivo. Front Neural Circuits 2013;7:11.Abstract
Defining the connections among neurons is critical to our understanding of the structure and function of the nervous system. Recombinant viruses engineered to transmit across synapses provide a powerful approach for the dissection of neuronal circuitry in vivo. We recently demonstrated that recombinant vesicular stomatitis virus (VSV) can be endowed with anterograde or retrograde transsynaptic tracing ability by providing the virus with different glycoproteins. Here we extend the characterization of the transmission and gene expression of recombinant VSV (rVSV) with the rabies virus glycoprotein (RABV-G), and provide examples of its activity relative to the anterograde transsynaptic tracer form of rVSV. rVSV with RABV-G was found to drive strong expression of transgenes and to spread rapidly from neuron to neuron in only a retrograde manner. Depending upon how the RABV-G was delivered, VSV served as a polysynaptic or monosynaptic tracer, or was able to define projections through axonal uptake and retrograde transport. In animals co-infected with rVSV in its anterograde form, rVSV with RABV-G could be used to begin to characterize the similarities and differences in connections to different areas. rVSV with RABV-G provides a flexible, rapid, and versatile tracing tool that complements the previously described VSV-based anterograde transsynaptic tracer.
Bever GJ, Jakobiec FA, Mendoza PR, Hatton MP. Congenital megacaruncle: a unique and innocent ocular adnexal anomaly. JAMA Ophthalmol 2013;131(12):1641-3.
Blanco-Mezquita JT, Hutcheon AEK, Zieske JD. Role of thrombospondin-1 in repair of penetrating corneal wounds. Invest Ophthalmol Vis Sci 2013;54(9):6262-8.Abstract
PURPOSE: Thrombospondin-1 (THBS1) has been suggested as a corneal wound-healing modulator. Therefore, we compromised the integrity of the cornea to elucidate the role of THBS1. METHODS: Full-thickness penetrating corneal incisions (1.5 mm) were created in wild type (WT, 129S2/SvPas) and THBS1-deficient mice (Thbs1⁻/⁻), 129S2/SvPas-Thbs1(tm1Hyn)/Thbs1(tm1Hyn)), and allowed to heal up to 1 month, while being monitored by slit-lamp and intravital corneal examinations. Corneas also were examined by transmission electron microscopy and indirect immunofluorescence. To determine how THBS1 was involved in the healing process, we examined THBS1 and α-smooth muscle actin (SMA), a marker of myofibroblasts and myoepithelial cells. RESULTS: In WT mice by 1 month, corneas appeared transparent with a thin scar, and endothelium and Descemet's membrane (DM) were restored. In contrast, Thbs1⁻/⁻ corneas exhibited chronic edema and persistent opacity after wounding. The DM and endothelium were not restored, and wound contraction was impaired. The THBS1 was localized in epithelial cells at early stages of the healing process, and in the stroma and endothelial cells during later stages. The SMA-positive epithelial cells and myofibroblasts were observed within the healing area at day 4, peaked at day 14, and disappeared at day 30. The SMA-positive cells were reduced greatly in Thbs1⁻/⁻ mice. CONCLUSIONS: In the current study, we demonstrated that corneal restoration is strikingly compromised by a penetrating incision in Thbs1⁻/⁻ mice. The wound results in persistent edema and wound gaping. This appears to be the result of the lack of endothelial migration and DM restoration. In addition, myofibroblast formation is compromised, resulting in the lack of wound contraction.
Borodic GE. Use of fillers as adjunct therapy for the treatment of lower face hemifacial spasm. Ophthalmic Plast Reconstr Surg 2013;29(3):225-6.Abstract
The treatment of hemifacial spasm with periorbital injections of higher doses of botulinum toxin can create disfiguring and undesirable weakness in the lower face during active facial movements. The use of asymmetric hyaluronidate filler injections to the lower face provides a refinement allowing for a lowered neurotoxin dose. The filler creates a ballasting effect and involuntary facial movement. The conventional filler effect also further reduces asymmetric nasolabial folds and marionette lines. Fifteen of 18 patients with lower facial spasms found the filler toxin combination an improvement over neurotoxin alone.
Bowers AR, Anastasio JR, Sheldon SS, O'Connor MG, Hollis AM, Howe PD, Horowitz TS. Can we improve clinical prediction of at-risk older drivers?. Accid Anal Prev 2013;59:537-47.Abstract
OBJECTIVES: To conduct a pilot study to evaluate the predictive value of the Montreal Cognitive Assessment test (MoCA) and a brief test of multiple object tracking (MOT) relative to other tests of cognition and attention in identifying at-risk older drivers, and to determine which combination of tests provided the best overall prediction. METHODS: Forty-seven currently licensed drivers (58-95 years), primarily from a clinical driving evaluation program, participated. Their performance was measured on: (1) a screening test battery, comprising MoCA, MOT, Mini-Mental State Examination (MMSE), Trail-Making Test, visual acuity, contrast sensitivity, and Useful Field of View (UFOV) and (2) a standardized road test. RESULTS: Eighteen participants were rated at-risk on the road test. UFOV subtest 2 was the best single predictor with an area under the curve (AUC) of .84. Neither MoCA nor MOT was a better predictor of the at-risk outcome than either MMSE or UFOV, respectively. The best four-test combination (MMSE, UFOV subtest 2, visual acuity and contrast sensitivity) was able to identify at-risk drivers with 95% specificity and 80% sensitivity (.91 AUC). CONCLUSIONS: Although the best four-test combination was much better than a single test in identifying at-risk drivers, there is still much work to do in this field to establish test batteries that have both high sensitivity and specificity.
Bressler SB, Almukhtar T, Aiello LP, Bressler NM, Ferris FL, Glassman AR, Greven CM, Greven CM. Green or yellow laser treatment for diabetic macular edema: exploratory assessment within the Diabetic Retinopathy Clinical Research Network. Retina 2013;33(10):2080-8.Abstract
PURPOSE: Explore differences in green compared with yellow focal/grid laser treatment on functional and anatomical endpoints in eyes with diabetic macular edema. METHODS: Data from two randomized clinical trials were evaluated for differences in visual acuity and optical coherence tomography parameters for eyes assigned to sham injection + prompt laser, ranibizumab + prompt laser, or prompt laser only: among subgroups of eyes treated exclusively and electively with either green or yellow laser. RESULTS: In the sham injection + prompt laser group, the mean visual acuity letter score change for eyes receiving green and yellow laser treatment, respectively, was +2.4 ± 14 and +5.1 ± 13 at the 52-week visit (P = 0.06) and +2.4 ± 15 and +6.0 ± 13 at the 104-week visit (P = 0.13), with no corresponding evidence of differences in optical coherence tomography thickness. When comparing wavelength groups in the ranibizumab + prompt laser and prompt laser-only groups, meaningful differences in visual acuity and optical coherence tomography thickness were not detected at 1 year or 2 years. CONCLUSION: A trend toward improved vision outcome with yellow laser observed in one trial was not corroborated by anatomical outcomes or by the other trial. In this study, without random assignment to different wavelengths controlling for bias and confounding, it is not possible to determine whether one wavelength is better than the other.
Buys ES, Ko Y-C, Alt C, Hayton SR, Jones A, Tainsh LT, Ren R, Giani A, Clerte' M, Abernathy E, Tainsh RET, Oh D-J, Malhotra R, Arora P, de Waard N, Yu B, Turcotte R, Nathan D, Scherrer-Crosbie M, Loomis SJ, Kang JH, Lin CP, Gong H, Rhee DJ, Brouckaert P, Wiggs JL, Gregory MS, Pasquale LR, Bloch KD, Ksander BR. Soluble Guanylate Cyclase a1-Deficient Mice: a novel murine model for Primary Open Angle Glaucoma. Ann Neurosci 2013;20(2):65-6.
Cepko CL, Vandenberghe LH. Retinal gene therapy coming of age. Hum Gene Ther 2013;24(3):242-4.
Chen J, Smith LEH. Altered cholesterol homeostasis in aged macrophages linked to neovascular macular degeneration. Cell Metab 2013;17(4):471-2.Abstract
Abnormal lipid metabolism has been linked to age-related macular degeneration (AMD); choroidal neovascularization in late AMD commonly causes blindness. Sene et al. (2013) now demonstrate that in aged macrophages decreased ABCA1 expression, regulated by liver X receptor and miR-33, impairs export of intracellular cholesterol, which promotes neovascular AMD.
Chen Y, Chauhan SK, Lee HS, Stevenson W, Schaumburg CS, Sadrai Z, Saban DR, Kodati S, Stern ME, Dana R. Effect of desiccating environmental stress versus systemic muscarinic AChR blockade on dry eye immunopathogenesis. Invest Ophthalmol Vis Sci 2013;54(4):2457-64.Abstract
PURPOSE: A majority of experimental data on dry eye disease (DED) immunopathogenesis have been derived from a murine model of DED that combines desiccating environmental stress with systemic muscarinic acetylcholine receptor (mAChR) inhibition. However, to our knowledge the effects of pharmacologic mAChR blockade on the pathogenesis of experimental DED have not been evaluated systemically. The purpose of our study was to investigate the differential effects of desiccating environmental stress and mAChR inhibition on the pathogenesis of DED. METHODS: DED was induced in female C57BL/6 mice by exposure to a desiccating environment in the controlled-environment chamber or to systemic scopolamine, or by performing extraorbital lacrimal gland excision. Clinical disease was assessed using corneal fluorescein staining (CFS) and the cotton thread test (CTT). Corneal CD11b(+) and conjunctival CD3(+) T-cell infiltration were evaluated by flow cytometry. T-cells from draining cervical lymph nodes (CLN) and distant inguinal lymph nodes (ILN) were analyzed for Th1, Th2, Th17, and Treg responses by flow cytometry and ELISA. RESULTS: Desiccating environmental stress and systemic mAChR blockade induced similar clinical signs of DED. However, desiccating environmental stress imparted higher conjunctival CD3(+) T-cell infiltration, and greater Th17-cell activity and Treg dysfunction than mAChR blockade, while mAChR blockade decreased tear secretion to a greater extent than desiccating environmental stress. Systemic mAChR blockade attenuated Th17 activity and enhanced Th2 and Treg responses without affecting Th1 activity. CONCLUSIONS: In vivo inhibition of mAChRs variably affects CD4(+) T-cell subsets, and desiccating environmental stress and systemic mAChR blockade induce DED through different primary pathogenic mechanisms.
Chen J, Michan S, Juan AM, Hurst CG, Hatton CJ, Pei DT, Joyal J-S, Evans LP, Cui Z, Stahl A, Sapieha P, Sinclair DA, Smith LEH. Neuronal sirtuin1 mediates retinal vascular regeneration in oxygen-induced ischemic retinopathy. Angiogenesis 2013;16(4):985-92.Abstract
Regeneration of blood vessels in ischemic neuronal tissue is critical to reduce tissue damage in diseases. In proliferative retinopathy, initial vessel loss leads to retinal ischemia, which can induce either regrowth of vessels to restore normal metabolism and minimize damage, or progress to hypoxia-induced sight-threatening pathologic vaso-proliferation. It is not well understood how retinal neurons mediate regeneration of vascular growth in response to ischemic insults. In this study we aim to investigate the potential role of Sirtuin 1 (Sirt1), a metabolically-regulated protein deacetylase, in mediating the response of ischemic neurons to regulate vascular regrowth in a mouse model of oxygen-induced ischemic retinopathy (OIR). We found that Sirt1 is highly induced in the avascular ischemic retina in OIR. Conditional depletion of neuronal Sirt1 leads to significantly decreased retinal vascular regeneration into the avascular zone and increased hypoxia-induced pathologic vascular growth. This effect is likely independent of PGC-1α, a known Sirt1 target, as absence of PGC-1α in knockout mice does not impact vascular growth in retinopathy. We found that neuronal Sirt1 controls vascular regrowth in part through modulating deacetylation and stability of hypoxia-induced factor 1α and 2α, and thereby modulating expression of angiogenic factors. These results indicate that ischemic neurons induce Sirt1 to promote revascularization into ischemic neuronal areas, suggesting a novel role of neuronal Sirt1 in mediating vascular regeneration in ischemic conditions, with potential implications beyond retinopathy.
Ciolino JB, Belin MW, Todani A, Al-Arfaj K, Rudnisky CJ, Group BKTS1. Retention of the Boston keratoprosthesis type 1: multicenter study results. Ophthalmology 2013;120(6):1195-200.Abstract
OBJECTIVE: To report the retention rate of the Boston keratoprosthesis type 1 and to identify risk factors for keratoprosthesis loss. DESIGN: Cohort study. PARTICIPANTS: A total of 300 eyes of 300 patients who underwent implantation of the Boston keratoprosthesis type I device between January 2003 and July 2008 by 19 surgeons at 18 medical centers. METHODS: Forms reporting preoperative, intraoperative, and postoperative parameters were prospectively collected and subsequently analyzed at a central data collection site. MAIN OUTCOME MEASURES: Keratoprosthesis retention. RESULTS: A total cumulative number of 422 life-years of device implantation are included in this analysis. The average duration of follow-up was 17.1 ± 14.8 months, with a range of 1 week to >6.1 years. Ninety-three percent of the 300 Boston keratoprosthesis implants were retained at their last follow-up, corresponding to a retention time of 396 patient-years or 1.42 years/keratoprosthesis. The probability of retention after 1 year and 2 years was 94% and 89%, respectively. During the study period, 21 (7%) eyes failed to retain the device; the reasons for keratoprosthesis loss include sterile keratolysis (9), fungal infections (8), dense retroprosthetic membranes (3), and bacterial endophthalmitis (1). Multivariate analysis demonstrated 3 independent risk factors for keratoprosthesis loss: autoimmune cause (hazard ratio [HR], 11.94; 95% confidence interval [CI], 3.31-43.11), ocular surface exposure requiring a concomitant tarsorrhaphy (HR, 3.43; 95% CI, 1.05-11.22), and number of prior failed penetrating keratoplasties (HR, 1.64; 95% CI, 1.18-2.28). CONCLUSIONS: The Boston keratoprosthesis type 1 seems to be a viable option for eyes that are not candidates for penetrating keratoplasty (PK). Ocular surface disease due to an autoimmune cause demonstrated the lowest retention rate. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.
Connors EC, Yazzolino LA, Sánchez J, Merabet LB. Development of an audio-based virtual gaming environment to assist with navigation skills in the blind. J Vis Exp 2013;(73)Abstract
Audio-based Environment Simulator (AbES) is virtual environment software designed to improve real world navigation skills in the blind. Using only audio based cues and set within the context of a video game metaphor, users gather relevant spatial information regarding a building's layout. This allows the user to develop an accurate spatial cognitive map of a large-scale three-dimensional space that can be manipulated for the purposes of a real indoor navigation task. After game play, participants are then assessed on their ability to navigate within the target physical building represented in the game. Preliminary results suggest that early blind users were able to acquire relevant information regarding the spatial layout of a previously unfamiliar building as indexed by their performance on a series of navigation tasks. These tasks included path finding through the virtual and physical building, as well as a series of drop off tasks. We find that the immersive and highly interactive nature of the AbES software appears to greatly engage the blind user to actively explore the virtual environment. Applications of this approach may extend to larger populations of visually impaired individuals.