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Chun R, Deemer A, Fujiwara K, Deremeik J, Bradley CK, Massof RW, Werblin FS. Comparative effectiveness between two types of head-mounted magnification modes using a smartphone-based virtual display. Optom Vis Sci 2024; 101:342-350. [PMID: 38551973 PMCID: PMC11239311 DOI: 10.1097/opx.0000000000002115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2024] Open
Abstract
SIGNIFICANCE This work shows the benefits of using two different magnification strategies to improve the reading ability of low-vision patients using a head-mounted technology. PURPOSE The aim of this study was to conduct a comparative clinical trial evaluating the effectiveness of two magnification strategies in a head-mounted virtual reality display. METHODS Eighty-eight eligible low-vision subjects were randomized into two arms: (1) the full-field magnification display or (2) the virtual bioptic telescope mode. Subjects completed baseline testing and received training on how to use the device properly and then took the device home for a 2- to 4-week intervention period. An adaptive rating scale questionnaire (Activity Inventory) was administered before and after the intervention (home trial) period to measure the effect of the system. A Simulator Sickness Questionnaire was also administered. Baseline and follow-up results were analyzed using Rasch analysis to assess overall effectiveness of each magnification mode for various functional domain categories. RESULTS Both magnification modes showed a positive effect for reading, visual information, and the overall goals functional domain categories, with only reading reaching statistical significance after correction for multiple comparisons. However, there were no significant between-group differences between the two modes. The results of the Simulator Sickness Questionnaire showed that the magnification modes of the head-mounted display device were overall well tolerated among low-vision users. CONCLUSIONS Both the full-field and virtual bioptic magnification strategies were effective in significantly improving functional vision outcomes for self-reported reading ability.
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Affiliation(s)
| | - Ashley Deemer
- Marshall B. Ketchum University, Southern California College of Optometry, Fullerton, California
| | - Kyoko Fujiwara
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - James Deremeik
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Christopher K Bradley
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Robert W Massof
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
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Sadeghi R, Kartha A, Barry MP, Gibson P, Caspi A, Roy A, Geruschat DR, Dagnelie G. Benefits of thermal and distance-filtered imaging for wayfinding with prosthetic vision. Sci Rep 2024; 14:1313. [PMID: 38225344 PMCID: PMC10789760 DOI: 10.1038/s41598-024-51798-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 01/09/2024] [Indexed: 01/17/2024] Open
Abstract
Visual prostheses such as the Argus II provide partial vision for individuals with limited or no light perception. However, their effectiveness in daily life situations is limited by scene complexity and variability. We investigated whether additional image processing techniques could improve mobility performance in everyday indoor environments. A mobile system connected to the Argus II provided thermal or distance-filtered video stimulation. Four participants used the thermal camera to locate a person and the distance filter to navigate a hallway with obstacles. The thermal camera allowed for finding a target person in 99% of trials, while unfiltered video led to confusion with other objects and a success rate of only 55% ([Formula: see text]). Similarly, the distance filter enabled participants to detect and avoid 88% of obstacles by removing background clutter, whereas unfiltered video resulted in a detection rate of only 10% ([Formula: see text]). For any given elapsed time, the success rate with filtered video was higher than with unfiltered video. After 90 s, participants' success rate reached above 50% with filtered video and 24% and 3% with normal camera in the first and second tasks, respectively. Despite individual variations, all participants showed significant improvement when using the thermal and distance filters compared to unfiltered video. Adding a thermal and distance filter to a visual prosthesis system can enhance the performance of mobility activities by removing clutter in the background, showing people and warm objects with the thermal camera, or nearby obstacles with the distance filter.
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Affiliation(s)
- Roksana Sadeghi
- Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, MD, USA.
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, CA, USA.
| | - Arathy Kartha
- Department of Biological and Vision Sciences, State University of New York College of Optometry, New York, NY, USA
- Department of Ophthalmology, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Michael P Barry
- Department of Ophthalmology, Johns Hopkins School of Medicine, Baltimore, MD, USA
- Pritzker Institute for Biomedical Science and Engineering, Illinois Institute of Technology, Chicago, IL, USA
| | - Paul Gibson
- Advanced Medical Electronics Corporation, Maple Grove, MN, USA
| | - Avi Caspi
- Jerusalem College of Technology, Jerusalem, Israel
| | | | - Duane R Geruschat
- Department of Ophthalmology, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Gislin Dagnelie
- Department of Ophthalmology, Johns Hopkins School of Medicine, Baltimore, MD, USA
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Kartha A, Sadeghi R, Bradley C, Livingston B, Tran C, Gee W, Dagnelie G. Measuring visually guided motor performance in ultra low vision using virtual reality. Front Neurosci 2023; 17:1251935. [PMID: 38178831 PMCID: PMC10765526 DOI: 10.3389/fnins.2023.1251935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 11/29/2023] [Indexed: 01/06/2024] Open
Abstract
Introduction Ultra low vision (ULV) refers to profound visual impairment where an individual cannot read even the top line of letters on an ETDRS chart from a distance of 0.5 m. There are limited tools available to assess visual ability in ULV. The aim of this study was to develop and calibrate a new performance test, Wilmer VRH, to assess hand-eye coordination in individuals with ULV. Methods A set of 55 activities was developed for presentation in a virtual reality (VR) headset. Activities were grouped into 2-step and 5-step items. Participants performed a range of tasks involving reaching and grasping, stacking, sorting, pointing, throwing, and cutting. Data were collected from 20 healthy volunteers under normal vision (NV) and simulated ULV (sULV) conditions, and from 33 participants with ULV. Data were analyzed using the method of successive dichotomizations (MSD), a polytomous Rasch model, to estimate item (difficulty) and person (ability) measures. MSD was applied separately to 2-step and 5-step performance data, then merged to a single equal interval scale. Results The mean ± SD of completion rates were 98.6 ± 1.8%, 78.2 ± 12.5% and 61.1 ± 34.2% for NV, sULV and ULV, respectively. Item measures ranged from -1.09 to 5.7 logits and - 4.3 to 4.08 logits and person measures ranged from -0.03 to 4.2 logits and -3.5 to 5.2 logits in sULV and ULV groups, respectively. Ninety percent of item infits were within the desired range of [0.5,1.5], and 97% of person infits were within that range. Together with item and person reliabilities of 0.94 and 0.91 respectively, this demonstrates unidimensionality of Wilmer VRH. A Person Item map showed that the items were well-targeted to the sample of individuals with ULV in the study. Discussion We present the development of a calibrated set of activities in VR that can be used to assess hand-eye coordination in individuals with ULV. This helps bridge a gap in the field by providing a validated outcome measure that can be used in vision restoration trials that recruit people with ULV, and to assess rehabilitation outcomes in people with ULV.
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Affiliation(s)
- Arathy Kartha
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD, United States
- Department of Biological and Vision Sciences, State University of New York College of Optometry, New York, NY, United States
| | - Roksana Sadeghi
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD, United States
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, Berkeley, CA, United States
| | - Chris Bradley
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Brittnee Livingston
- Central Association for the Blind and Visually Impaired, Utica, NY, United States
| | - Chau Tran
- BMORE VIRTUAL LLC, Baltimore, MD, United States
| | - Will Gee
- BMORE VIRTUAL LLC, Baltimore, MD, United States
| | - Gislin Dagnelie
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD, United States
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Kartha A, Singh RK, Bradley C, Dagnelie G. Self-Reported Visual Ability Versus Task Performance in Individuals With Ultra-Low Vision. Transl Vis Sci Technol 2023; 12:14. [PMID: 37847202 PMCID: PMC10584017 DOI: 10.1167/tvst.12.10.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 09/15/2023] [Indexed: 10/18/2023] Open
Abstract
Purpose Visual functioning questionnaires are commonly used as patient-reported outcome measures to estimate visual ability. Performance measures, on the other hand, provide a direct measure of visual ability. For individuals with ultra-low vision (ULV; visual acuity (VA) <20/1600), the ultra-low vision visual functioning questionnaire (ULV-VFQ) and the Wilmer VRI-a virtual reality-based performance test-estimate self-reported and actual visual ability, respectively, for activities of daily living. But how well do self-reports from ULV-VFQ predict actual task performance in the Wilmer VRI? Methods We administered a subset of 10 matching items from the ULV-VFQ and Wilmer VRI to 27 individuals with ULV. We estimated item measures (task difficulty) and person measures (visual ability) using Rasch analysis for ULV-VFQ and using latent variable signal detection theory for the Wilmer VRI. We then used regression analysis to compare person and item measure estimates from self-reports and task performance. Results Item and person measures were modestly correlated between the two instruments, with r2 = 0.47 (P = 0.02) and r2 = 0.36 (P = 0.001), demonstrating that self-reports are an imperfect predictor of task difficulty and performance. Conclusions While self-reports impose a lower demand for equipment and personnel, actual task performance should be measured to assess visual ability in ULV. Translational Relevance Visual performance measures should be the preferred outcome measure in clinical trials recruiting individuals with ULV. Virtual reality can be used to standardize tasks.
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Affiliation(s)
| | - Ravnit Kaur Singh
- Zanvyl Krieger School of Arts and Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Chris Bradley
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Gislin Dagnelie
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Kartha A, Sadeghi R, Bradley C, Tran C, Gee W, Dagnelie G. Measuring visual information gathering in individuals with ultra low vision using virtual reality. Sci Rep 2023; 13:3143. [PMID: 36823360 PMCID: PMC9950080 DOI: 10.1038/s41598-023-30249-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 02/20/2023] [Indexed: 02/25/2023] Open
Abstract
People with ULV (visual acuity ≤ 20/1600 or 1.9 logMAR) lack form vision but have rudimentary levels of vision that can be used for a range of activities in daily life. However, current clinical tests are designed to assess form vision and do not provide information about the range of visually guided activities that can be performed in daily life using ULV. This is important to know given the growing number of clinical trials that recruit individuals with ULV (e.g., gene therapy, stem cell therapy) or restore vision to the ULV range in the blind (visual prosthesis). In this study, we develop a set of 19 activities (items) in virtual reality involving spatial localization/detection, motion detection, and direction of motion that can be used to assess visual performance in people with ULV. We estimated measures of item difficulty and person ability on a relative d prime (d') axis using a signal detection theory based analysis for latent variables. The items represented a range of difficulty levels (- 1.09 to 0.39 in relative d') in a heterogeneous group of individuals with ULV (- 0.74 to 2.2 in relative d') showing the instrument's utility as an outcome measure in clinical trials.
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Affiliation(s)
- Arathy Kartha
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Roksana Sadeghi
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Chris Bradley
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Chau Tran
- BaltiVirtual Inc., Baltimore, MD, USA
| | - Will Gee
- BaltiVirtual Inc., Baltimore, MD, USA
| | - Gislin Dagnelie
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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6
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Stingl K, Kempf M, Jung R, Kortüm F, Righetti G, Reith M, Dimopoulos S, Ott S, Kohl S, Stingl K. Therapy with voretigene neparvovec. How to measure success? Prog Retin Eye Res 2023; 92:101115. [PMID: 36096933 DOI: 10.1016/j.preteyeres.2022.101115] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 08/17/2022] [Accepted: 08/19/2022] [Indexed: 02/01/2023]
Abstract
Retinal gene supplementation therapy such as the first approved one, voretigene neparvovec, delivers a functioning copy of the missing gene enabling the protein transcription in retinal cells and restore visual functions. After gene supplementation for the genetic defect, a complex network of functional regeneration is the consequence, whereas the extent is very individualized. Diagnostic and functional testings that have been used routinely by ophthalmologists so far to define the correct diagnosis, cannot be applied in the new context of defining small, sometimes subtle changes in visual functions. New view on retinal diagnostics is needed to understand this processes that define safety and efficacy of the treatment. Not only does vision have many aspects that must be addressed by specific evaluations and imaging techniques, but objective readouts of local retinal function for rods and cones separately have been an unmet need until recently. A reliable test-retest variability is necessary in rare diseases such as inherited retinal dystrophies, because statistics are often not applicable due to a low number of participants. Methods for a reliable individual evaluation of the therapy success are needed. In this manuscript we present an elaboration on retinal diagnostics combining psychophysics (eg. full-field stimulus threshold or dark adapted perimetry) as well as objective measures for local retinal function (eg. photopic and scotopic chromatic pupil campimetry) and retinal imaging for a meaningful workflow to apply in evaluation of the individual success in patients receiving gene therapy for photoreceptor diseases.
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Affiliation(s)
- Krunoslav Stingl
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany; Center for Rare Eye Diseases, University of Tuebingen, Tuebingen, Germany.
| | - Melanie Kempf
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany; Center for Rare Eye Diseases, University of Tuebingen, Tuebingen, Germany.
| | - Ronja Jung
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany.
| | - Friederike Kortüm
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany.
| | - Giulia Righetti
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany.
| | - Milda Reith
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany.
| | - Spyridon Dimopoulos
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany.
| | - Saskia Ott
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany.
| | - Susanne Kohl
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Center for Ophthalmology, University of Tuebingen, Tuebingen, Germany.
| | - Katarina Stingl
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany; Center for Rare Eye Diseases, University of Tuebingen, Tuebingen, Germany.
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Aleman TS, Miller AJ, Maguire KH, Aleman EM, Serrano LW, O'Connor KB, Bedoukian EC, Leroy BP, Maguire AM, Bennett J. A Virtual Reality Orientation and Mobility Test for Inherited Retinal Degenerations: Testing a Proof-of-Concept After Gene Therapy. Clin Ophthalmol 2021; 15:939-952. [PMID: 33688162 PMCID: PMC7936670 DOI: 10.2147/opth.s292527] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 01/22/2021] [Indexed: 12/19/2022] Open
Abstract
Purpose To test the ability of a virtual reality (VR) orientation and mobility (O&M) protocol to serve a measure of functional vision for patients with inherited retinal degenerations (IRDs). Methods A VR-O&M protocol designed using a commercially available VR hardware was tested in normally sighted control subjects (n=7; ages 10–35yo; Average 22.5yo) and patients with RPE65-associated Leber Congenital Amaurosis (n=3; ages 7–18yo; Average 12.7yo), in two of them before and after gene therapy. Patients underwent perimetry and full-field sensitivity testing. VR-O&M parameters correlated with the visual dysfunction. Results Visual acuities in RPE65 patients were on average worse than 20/200, dark-adapted sensitivity losses >5 log units, and fields constricted between 20° and 40°. Before treatment, patients required ~1000-fold brighter environment to navigate, had at least x4 more collisions, and were slower both to orient and navigate compared to control subjects. Improvements in cone- (by 1–2 L.u.) and rod-mediated (by >4 L.u.) sensitivities post-treatment led to fewer collisions (at least by half) at ~100-fold dimmer luminances, and to x4 times faster navigation times. Conclusion This study provides proof-of-concept data in support for the use of VR-O&M systems to quantify the impact that the visual dysfunction and improvement of vision following treatments has on functional vision in IRDs. The VR-O&M was useful in potentially challenging scenarios such as in pediatric patients with severe IRDs. Translational Relevance A VR-O&M test will provide much needed flexibility, both in its deployment as well as in the possibility to test various attributes of vision that may be impacted by gene therapy in the setting of translational studies. Precis This study provides proof-of-concept data in support for the use of a virtual reality orientation and mobility test to quantify the impact of the disease and of treatments thereof on functional vision in inherited retinal degenerations.
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Affiliation(s)
- Tomas S Aleman
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, PA, USA.,Division of Ophthalmology at the Children's Hospital of Philadelphia of the Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, USA
| | - Alexander J Miller
- Neurology Virtual Reality Laboratory of the Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - Katherine H Maguire
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
| | - Elena M Aleman
- Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
| | - Leona W Serrano
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
| | - Keli B O'Connor
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
| | - Emma C Bedoukian
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Bart P Leroy
- Division of Ophthalmology at the Children's Hospital of Philadelphia of the Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, USA.,Department of Pediatrics, Ghent University, Ghent, Belgium.,Department of Ophthalmology, Ghent University, Ghent, Belgium.,Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Albert M Maguire
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, PA, USA.,Division of Ophthalmology at the Children's Hospital of Philadelphia of the Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, USA
| | - Jean Bennett
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
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Fischer MD, Michalakis S, Wilhelm B, Zobor D, Muehlfriedel R, Kohl S, Weisschuh N, Ochakovski GA, Klein R, Schoen C, Sothilingam V, Garcia-Garrido M, Kuehlewein L, Kahle N, Werner A, Dauletbekov D, Paquet-Durand F, Tsang S, Martus P, Peters T, Seeliger M, Bartz-Schmidt KU, Ueffing M, Zrenner E, Biel M, Wissinger B. Safety and Vision Outcomes of Subretinal Gene Therapy Targeting Cone Photoreceptors in Achromatopsia: A Nonrandomized Controlled Trial. JAMA Ophthalmol 2021; 138:643-651. [PMID: 32352493 PMCID: PMC7193523 DOI: 10.1001/jamaophthalmol.2020.1032] [Citation(s) in RCA: 92] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Question What are the safety and vision outcomes associated with gene therapy for achromatopsia? Findings In this nonrandomized controlled trial of 9 patients with confirmed CNGA3-linked achromatopsia, gene therapy applying an adeno-associated viral vector encoding CNGA3, was not associated with substantial safety concerns and was associated with improvements of vision in patients. Meaning This study provides clinical proof of concept for viral vector–mediated gene supplementation therapy of inherited day blindness caused by pathogenic variants in the cone photoreceptor-specific gene CNGA3. Importance Achromatopsia linked to variations in the CNGA3 gene is associated with day blindness, poor visual acuity, photophobia, and involuntary eye movements owing to lack of cone photoreceptor function. No treatment is currently available. Objective To assess safety and vision outcomes of supplemental gene therapy with adeno-associated virus (AAV) encoding CNGA3 (AAV8.CNGA3) in patients with CNGA3-linked achromatopsia. Design, Setting, and Participants This open-label, exploratory nonrandomized controlled trial tested safety and vision outcomes of gene therapy vector AAV8.CNGA3 administered by subretinal injection at a single center. Nine patients (3 per dose group) with a clinical diagnosis of achromatopsia and confirmed biallelic disease-linked variants in CNGA3 were enrolled between November 5, 2015, and September 22, 2016. Data analysis was performed from June 6, 2017, to March 12, 2018. Intervention Patients received a single unilateral injection of 1.0 × 1010, 5.0 × 1010, or 1.0 × 1011 total vector genomes of AAV8.CNGA3 and were followed up for a period of 12 months (November 11, 2015, to October 10, 2017). Main Outcomes and Measures Safety as the primary end point was assessed by clinical examination of ocular inflammation. Systemic safety was assessed by vital signs, routine clinical chemistry testing, and full and differential blood cell counts. Secondary outcomes were change in visual function from baseline in terms of spatial and temporal resolution and chromatic, luminance, and contrast sensitivity throughout a period of 12 months after treatment. Results Nine patients (mean [SD] age, 39.6 [11.9] years; age range, 24-59 years; 8 [89%] male) were included in the study. Baseline visual acuity letter score (approximate Snellen equivalent) ranged from 34 (20/200) to 49 (20/100), whereas baseline contrast sensitivity log scores ranged from 0.1 to 0.9. All 9 patients underwent surgery and subretinal injection of AAV8.CNGA3 without complications. No substantial safety problems were observed during the 12-month follow-up period. Despite the congenital deprivation of cone photoreceptor–mediated vision in achromatopsia, all 9 treated eyes demonstrated some level of improvement in secondary end points regarding cone function, including mean change in visual acuity of 2.9 letters (95% CI, 1.65-4.13; P = .006, 2-sided t test paired samples). Contrast sensitivity improved by a mean of 0.33 log (95% CI, 0.14-0.51 log; P = .003, 2-sided t test paired samples). Conclusions and Relevance Subretinal gene therapy with AAV8.CNGA3 was not associated with substantial safety problems and was associated with cone photoreceptor activation in adult patients, as reflected by visual acuity and contrast sensitivity gains. Trial Registration ClinicalTrials.gov Identifier: NCT02610582
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Affiliation(s)
- M Dominik Fischer
- University Eye Hospital, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany.,Institute for Ophthalmic Research, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany.,Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - Stylianos Michalakis
- Center for Integrated Protein Science Munich, Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-University of Munich, Munich, Germany.,Department of Ophthalmology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Barbara Wilhelm
- Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - Ditta Zobor
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - Regine Muehlfriedel
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - Susanne Kohl
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - Nicole Weisschuh
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - G Alex Ochakovski
- University Eye Hospital, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - Reinhild Klein
- Department of Internal Medicine II, University Hospital Tübingen, Germany
| | - Christian Schoen
- Center for Integrated Protein Science Munich, Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Vithiyanjali Sothilingam
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - Marina Garcia-Garrido
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - Laura Kuehlewein
- University Eye Hospital, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - Nadine Kahle
- University Eye Hospital, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany.,Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - Annette Werner
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - Daniyar Dauletbekov
- University Eye Hospital, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany.,Institute for Ophthalmic Research, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - François Paquet-Durand
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - Stephen Tsang
- Department of Ophthalmology, College of Physicians and Surgeons, Columbia University, New York, New York
| | - Peter Martus
- Institute for Clinical Epidemiology and Applied Biostatistics, University Hospital Tübingen, Tübingen, Germany
| | - Tobias Peters
- Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - Mathias Seeliger
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | | | - Marius Ueffing
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - Eberhart Zrenner
- University Eye Hospital, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany.,Institute for Ophthalmic Research, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - Martin Biel
- Center for Integrated Protein Science Munich, Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Bernd Wissinger
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
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Ayton LN, Rizzo JF, Bailey IL, Colenbrander A, Dagnelie G, Geruschat DR, Hessburg PC, McCarthy CD, Petoe MA, Rubin GS, Troyk PR. Harmonization of Outcomes and Vision Endpoints in Vision Restoration Trials: Recommendations from the International HOVER Taskforce. Transl Vis Sci Technol 2020; 9:25. [PMID: 32864194 PMCID: PMC7426586 DOI: 10.1167/tvst.9.8.25] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 12/08/2019] [Indexed: 01/05/2023] Open
Abstract
Translational research in vision prosthetics, gene therapy, optogenetics, stem cell and other forms of transplantation, and sensory substitution is creating new therapeutic options for patients with neural forms of blindness. The technical challenges faced by each of these disciplines differ considerably, but they all face the same challenge of how to assess vision in patients with ultra-low vision (ULV), who will be the earliest subjects to receive new therapies. Historically, there were few tests to assess vision in ULV patients. In the 1990s, the field of visual prosthetics expanded rapidly, and this activity led to a heightened need to develop better tests to quantify end points for clinical studies. Each group tended to develop novel tests, which made it difficult to compare outcomes across groups. The common lack of validation of the tests and the variable use of controls added to the challenge of interpreting the outcomes of these clinical studies. In 2014, at the bi-annual International "Eye and the Chip" meeting of experts in the field of visual prosthetics, a group of interested leaders agreed to work cooperatively to develop the International Harmonization of Outcomes and Vision Endpoints in Vision Restoration Trials (HOVER) Taskforce. Under this banner, more than 80 specialists across seven topic areas joined an effort to formulate guidelines for performing and reporting psychophysical tests in humans who participate in clinical trials for visual restoration. This document provides the complete version of the consensus opinions from the HOVER taskforce, which, together with its rules of governance, will be posted on the website of the Henry Ford Department of Ophthalmology (www.artificialvision.org). Research groups or companies that choose to follow these guidelines are encouraged to include a specific statement to that effect in their communications to the public. The Executive Committee of the HOVER Taskforce will maintain a list of all human psychophysical research in the relevant fields of research on the same website to provide an overview of methods and outcomes of all clinical work being performed in an attempt to restore vision to the blind. This website will also specify which scientific publications contain the statement of certification. The website will be updated every 2 years and continue to exist as a living document of worldwide efforts to restore vision to the blind. The HOVER consensus document has been written by over 80 of the world's experts in vision restoration and low vision and provides recommendations on the measurement and reporting of patient outcomes in vision restoration trials.
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Affiliation(s)
- Lauren N. Ayton
- Department of Optometry and Vision Sciences and Department of Surgery (Ophthalmology), The University of Melbourne, Parkville, Australia
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
| | - Joseph F. Rizzo
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Ian L. Bailey
- School of Optometry, University of California-Berkeley, Berkeley, CA, USA
| | - August Colenbrander
- Smith-Kettlewell Eye Research Institute and California Pacific Medical Center, San Francisco, CA, USA
| | - Gislin Dagnelie
- Lions Vision Research and Rehabilitation Center, Johns Hopkins Wilmer Eye Institute, Baltimore, MD, USA
| | - Duane R. Geruschat
- Lions Vision Research and Rehabilitation Center, Johns Hopkins Wilmer Eye Institute, Baltimore, MD, USA
| | - Philip C. Hessburg
- Detroit Institute of Ophthalmology, Henry Ford Health System, Grosse Pointe Park, MI, USA
| | - Chris D. McCarthy
- Department of Computer Science & Software Engineering, Swinburne University of Technology, Melbourne, Australia
| | | | - Gary S. Rubin
- University College London Institute of Ophthalmology, London, UK
| | - Philip R. Troyk
- Armour College of Engineering, Illinois Institute of Technology, Chicago, IL, USA
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Zhao Y, Szpiro S, Shi L, Azenkot S. Designing and Evaluating a Customizable Head-mounted Vision Enhancement System for People with Low Vision. ACM TRANSACTIONS ON ACCESSIBLE COMPUTING 2020. [DOI: 10.1145/3361866] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Recent advances in head-mounted displays (HMDs) present an opportunity to design vision enhancement systems for people with
low vision
, whose vision cannot be corrected with glasses or contact lenses. We aim to understand whether and how HMDs can aid low vision people in their daily lives. We designed
ForeSee
, an HMD prototype that enhances people’s view of the world with image processing techniques such as magnification and edge enhancement. We evaluated these vision enhancements with 20 low vision participants who performed four viewing tasks: image recognition and reading tasks from near- and far-distance. We found that participants needed to combine and adjust the enhancements to comfortably complete the viewing tasks. We then designed two input modes to enable fast and easy customization: speech commands and smartwatch-based gestures. While speech commands are commonly used for eyes-free input, our novel set of onscreen gestures on a smartwatch can be used in scenarios where speech is not appropriate or desired. We evaluated both input modes with 11 low vision participants and found that both modes effectively enabled low vision users to customize their visual experience on the HMD. We distill design insights for HMD applications for low vision and spur new research directions.
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Affiliation(s)
- Yuhang Zhao
- Information Science, Cornell Tech, Cornell University, New York, NY, USA
| | - Sarit Szpiro
- The Special Education Department, University of Haifa, Haifa, Israel
| | - Lei Shi
- Information Science, Cornell Tech, Cornell University, New York, NY, USA
| | - Shiri Azenkot
- Jacobs Technion-Cornell Institute, Cornell Tech, Cornell University, USA
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11
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An update on retinal prostheses. Clin Neurophysiol 2019; 131:1383-1398. [PMID: 31866339 DOI: 10.1016/j.clinph.2019.11.029] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 11/13/2019] [Accepted: 11/14/2019] [Indexed: 11/23/2022]
Abstract
Retinal prostheses are designed to restore a basic sense of sight to people with profound vision loss. They require a relatively intact posterior visual pathway (optic nerve, lateral geniculate nucleus and visual cortex). Retinal implants are options for people with severe stages of retinal degenerative disease such as retinitis pigmentosa and age-related macular degeneration. There have now been three regulatory-approved retinal prostheses. Over five hundred patients have been implanted globally over the past 15 years. Devices generally provide an improved ability to localize high-contrast objects, navigate, and perform basic orientation tasks. Adverse events have included conjunctival erosion, retinal detachment, loss of light perception, and the need for revision surgery, but are rare. There are also specific device risks, including overstimulation (which could cause damage to the retina) or delamination of implanted components, but these are very unlikely. Current challenges include how to improve visual acuity, enlarge the field-of-view, and reduce a complex visual scene to its most salient components through image processing. This review encompasses the work of over 40 individual research groups who have built devices, developed stimulation strategies, or investigated the basic physiology underpinning retinal prostheses. Current technologies are summarized, along with future challenges that face the field.
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12
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Abstract
In humans high quality, high acuity visual experience is mediated by the fovea, a tiny, specialized patch of retina containing the locus of fixation. Despite this, vision restoration strategies are typically developed in animal models without a fovea. While electrical prostheses have been approved by regulators, as yet they have failed to restore high quality, high acuity vision in patients. Approaches under pre-clinical development include regenerative cell therapies, optogenetics and chemical photosensitizers. All retinal vision restoration therapies require reactivation of inner retina that has lost photoreceptor input and that the restored signals can be interpreted at a behavioural level. A greater emphasis on tackling these challenges at the fovea may accelerate progress toward high quality vision restoration.
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Affiliation(s)
- Juliette E McGregor
- Center for Visual Science, University of Rochester, 601 Crittenden Blvd, Rochester, New York, USA
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13
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Lam BL, Gregori NZ. Successes and Challenges of Retinal Implants for Profound Visual Loss From Outer Retinal Degeneration. JAMA Ophthalmol 2019; 137:903-904. [PMID: 31145438 DOI: 10.1001/jamaophthalmol.2019.1057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Byron L Lam
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Ninel Z Gregori
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida
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14
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Goldstein JE, Fenwick E, Finger RP, Gothwal V, Jackson ML, Lamoureux E, Rees G, Massof R. Calibrating the Impact of Vision Impairment (IVI): Creation of a Sample-Independent Visual Function Measure for Patient-Centered Outcomes Research. Transl Vis Sci Technol 2018; 7:38. [PMID: 30619658 PMCID: PMC6314226 DOI: 10.1167/tvst.7.6.38] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 10/14/2018] [Indexed: 11/30/2022] Open
Abstract
PURPOSE Provide item calibrations estimated for the Impact of Vision Impairment (IVI) questionnaire by pooling data from several studies of people with vision impairment (VI) representing a variety of countries and causes of VI. METHODS Eight data sets from six principal investigators representing responses to IVI items from 2867 VI patients were pooled for analysis. Eligible patients were 18 years or older and from Australia, India, and the United States. Rasch analysis, using the Andrich Rating Scale Model (Winsteps version 3.65), was performed on preintervention IVI responses to estimate item and person measures, reliability coefficients, and response category thresholds. Differential item functioning (DIF) analysis and analysis of variance (ANOVA) were used to examine the effects different data sets and covariates on item estimates. RESULTS Patient age range was 18 to 103 years (median 62 years); 55% were male. Visual acuity ranged from 20/20 to no light perception and primary diagnosis was macular degeneration in 29% of patients. Item measure estimates showed good separation reliability (R 2 = 0.99). DIF magnitude did not preclude use of all IVI-28 data. ANOVA showed VA (P < 0.001) and gender (P < 0.002) were predictors of visual ability. CONCLUSIONS Analysis from pooled data support the provision of calibrated IVI item measures for researchers and clinicians to use, thus better enabling direct comparisons of patients with VI. TRANSLATIONAL RELEVANCE Validity testing of the IVI show that we can combine disparate data sets of patient responses to calibrate item measures and response category thresholds, and provide to others for use in comparing patients across clinical trials and on an individual basis.
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Affiliation(s)
| | - Eva Fenwick
- Population Health, Singapore Eye Research Institute, Singapore, Singapore
| | | | - Vijaya Gothwal
- Deshpande Centre for Sight Enhancement Brien Holden Eye Research Centre – Patient Reported Outcomes Unit, Hyderabad, India
| | - Mary Lou Jackson
- University of British Columbia Department of Ophthalmology and Visual Sciences, Vancouver, BC, Canada
| | - Ecosse Lamoureux
- Population Health, Singapore Eye Research Institute, Singapore, Singapore
| | - Gwyneth Rees
- University of Melbourne, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
| | - Robert Massof
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
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Fernandez E. Development of visual Neuroprostheses: trends and challenges. Bioelectron Med 2018; 4:12. [PMID: 32232088 PMCID: PMC7098238 DOI: 10.1186/s42234-018-0013-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Accepted: 07/27/2018] [Indexed: 02/06/2023] Open
Abstract
Visual prostheses are implantable medical devices that are able to provide some degree of vision to individuals who are blind. This research field is a challenging subject in both ophthalmology and basic science that has progressed to a point where there are already several commercially available devices. However, at present, these devices are only able to restore a very limited vision, with relatively low spatial resolution. Furthermore, there are still many other open scientific and technical challenges that need to be solved to achieve the therapeutic benefits envisioned by these new technologies. This paper provides a brief overview of significant developments in this field and introduces some of the technical and biological challenges that still need to be overcome to optimize their therapeutic success, including long-term viability and biocompatibility of stimulating electrodes, the selection of appropriate patients for each artificial vision approach, a better understanding of brain plasticity and the development of rehabilitative strategies specifically tailored for each patient.
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Affiliation(s)
- Eduardo Fernandez
- Institute of Bioengineering, University Miguel Hernández and CIBER-BBN, Avda de la Universidad, s/n, 03202 Alicante, Elche Spain.,2John A. Moran Eye Center, University of Utah, Salt Lake City, USA
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16
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Finn AP, Grewal DS, Vajzovic L. Argus II retinal prosthesis system: a review of patient selection criteria, surgical considerations, and post-operative outcomes. Clin Ophthalmol 2018; 12:1089-1097. [PMID: 29942114 PMCID: PMC6005308 DOI: 10.2147/opth.s137525] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Retinitis pigmentosa (RP) is a group of heterogeneous inherited retinal degenerative disorders characterized by progressive rod and cone dysfunction and ensuing photoreceptor loss. Many patients suffer from legal blindness by their 40s or 50s. Artificial vision is considered once patients have lost all vision to the point of bare light perception or no light perception. The Argus II retinal prosthesis system is one such artificial vision device approved for patients with RP. This review focuses on the factors important for patient selection. Careful pre-operative screening, counseling, and management of patient expectations are critical for the successful implantation and visual rehabilitation of patients with the Argus II device.
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Affiliation(s)
- Avni P Finn
- Department of Ophthalmology, Duke University Eye Center, Durham, NC, USA
| | - Dilraj S Grewal
- Department of Ophthalmology, Duke University Eye Center, Durham, NC, USA
| | - Lejla Vajzovic
- Department of Ophthalmology, Duke University Eye Center, Durham, NC, USA
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Abstract
Restoring vision to the blind by retinal repair has been a dream of medicine for centuries, and the first successful procedures have recently been performed. Although we are still far from the restoration of high-resolution vision, step-by-step developments are overcoming crucial bottlenecks in therapy development and have enabled the restoration of some visual function in patients with specific blindness-causing diseases. Here, we discuss the current state of vision restoration and the problems related to retinal repair. We describe new model systems and translational technologies, as well as the clinical conditions in which new methods may help to combat blindness.
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18
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Markowitz M, Rankin M, Mongy M, Patino BE, Manusow J, Devenyi RG, Markowitz SN. Rehabilitation of lost functional vision with the Argus II retinal prosthesis. Can J Ophthalmol 2018; 53:14-22. [PMID: 29426432 DOI: 10.1016/j.jcjo.2017.12.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 11/28/2017] [Accepted: 12/05/2017] [Indexed: 10/18/2022]
Abstract
The Argus II retinal prosthesis is the first commercially available device for restoration of vision in patients with Retinitis Pigmentosa or with similar retinal pathology who still have minimal residual native vision. The technology is able to restore vision with production of artificial visual percepts which usually are given adequate useful interpretation by the visual system in most implanted patients. The technology usually produces visual perception at the level of shape identification or better in some cases enabling in many less dependence on vision substitution devices and skills. There is no consensus among vision rehabilitation practitioners on single methods for assessments, outcome measures and training, yet there is constant progress in these areas of concern. Hence the current vision rehabilitation practice related to the implantation of the Argus II retinal prosthesis is a work in progress with many learning opportunities for all involved. All agree that implementation of this technology in clinical practice requires the combined work of a multi-disciplinary team which includes a specialized surgical team as well as a specialized rehabilitation team in order to obtain optimal results. Our own experience is presented in this paper and indicates so far that the Argus II technology is beneficial to patients and that it could be successfully managed within the Canadian heath care system.
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Affiliation(s)
| | - Mark Rankin
- Vision Loss Rehabilitation Ontario, CNIB, Toronto, Ont
| | - Mohamed Mongy
- Low Vision Service (University Health Network Hospitals), Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Toronto, Ont
| | - Beatrice E Patino
- Low Vision Service (University Health Network Hospitals), Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Toronto, Ont
| | - Joshua Manusow
- Low Vision Service (University Health Network Hospitals), Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Toronto, Ont
| | - Robert G Devenyi
- Low Vision Service (University Health Network Hospitals), Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Toronto, Ont
| | - Samuel N Markowitz
- Low Vision Service (University Health Network Hospitals), Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Toronto, Ont.
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Dagnelie G, Jeter PE, Adeyemo O. Optimizing the ULV-VFQ for Clinical Use Through Item Set Reduction: Psychometric Properties and Trade-Offs. Transl Vis Sci Technol 2017; 6:12. [PMID: 28573076 PMCID: PMC5450924 DOI: 10.1167/tvst.6.3.12] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 10/10/2016] [Indexed: 11/24/2022] Open
Abstract
Purpose We examine the dimensionality of the 150-item visual functioning questionnaire for individuals with ultralow vision (ULV-VFQ) and develop representative abbreviated versions, facilitating clinical use, while retaining compatibility with a 17-item performance assessment. Methods Subsets with 50 and 23 items covering the full difficulty range were selected, with evenly spaced item measures (IMs) and good representation of visual aspects and functional domains. Person measures (PMs) for the anchored subsets were derived through Rasch analysis of data from 80 respondents. Results Fit statistics for the reduced item sets were similar to those for the full set, with reliabilities at or above 95%. Mean PMs in the reduced sets were within 0.8 standard errors (SEs) of those in the full set. SEs of the PMs increased from the SE for 150 items, roughly in inverse proportion with the square root of the set size. Unexplained variance levels (24%–27%) and variance of the first unexplained factor (3.3%–3.9%) were close to those (30% and 2.6%) for 150 items. Differential item functions for omitted items were negligible. Aspects and domains are adequately represented in the reduced sets. Conclusions Self-reported visual ability can be measured accurately using appropriately chosen anchored subsets of the ULV-VFQ. Functional ability of individuals with ULV is characterized adequately by a single dimension. Translational Relevance The ULV-VFQ50 and ULV-VFQ23, using anchored IMs from the 150-item ULV-VFQ, provide an efficient and reliable self-report assessment of visual ability in individuals whose visual impairment is too severe for assessment with VFQs currently in use.
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Affiliation(s)
- Gislin Dagnelie
- Lions Vision Research & Rehabilitation Center, Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Pamela E Jeter
- Lions Vision Research & Rehabilitation Center, Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Olukemi Adeyemo
- Lions Vision Research & Rehabilitation Center, Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Adeyemo O, Jeter PE, Rozanski C, Arnold E, Dalvin LA, Swenor B, Dagnelie G. Living with Ultra-Low Vision: An Inventory of Self-Reported Visually Guided Activities by Individuals with Profound Visual Impairment. Transl Vis Sci Technol 2017; 6:10. [PMID: 28573074 PMCID: PMC5450922 DOI: 10.1167/tvst.6.3.10] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 04/12/2017] [Indexed: 11/24/2022] Open
Abstract
Purpose To understand how individuals with profound visual impairment (ultra-low vision, ULV) use their remaining vision. Methods Forty-six participants with ULV (visual acuity ≤ 200/500 in the better seeing eye) were divided into nine focus groups (4–6 individuals per group) and met either in person (n = 2) or over the phone (n = 7). Discussions were guided by the Massof Activity Inventory. Audio recordings were transcribed and analyzed for visual activities that were then classified along two visual categorizations – functional domains and visual aspects. The latter was based on a Grounded Theory classification of participants' descriptions. Results Seven hundred sixty activities were reported. By functional domain they were classified as reading/shape recognition (10%), mobility (17%), visual motor (24%), and visual information gathering (49%). By visual aspects, they were classified as contrast (43%), luminance (17%), environmental lighting (9%), familiarity (3%), motion perception (5%), distance (7%), size (9%), eccentricity (5%), depth perception (1%), and other/miscellaneous (1%). More than one visual aspect may be critical for an activity: participants reported that contrast plays a role in 68% of visual activities, followed by luminance (27%), environmental lighting (14%), and size (14%). Conclusions Visual aspects, primarily contrast, were found to be critical factors enabling ULV individuals to perform visual activities. Translational Relevance This inventory, part of the Prosthetic Low Vision Rehabilitation (PLoVR) curriculum development study, provides a unique perspective into the visual world of the nearly blind, and can be used in the development of a Visual Functioning Questionnaire (VFQ) and visual performance measures suited for ULV populations.
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Affiliation(s)
- Olukemi Adeyemo
- Lions Vision Center, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Pamela E Jeter
- Lions Vision Center, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Collin Rozanski
- Lions Vision Center, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | | | - Lauren A Dalvin
- Department of Ophthalmology, Mayo Clinic, Rochester, MN, USA
| | - Bonnielin Swenor
- Lions Vision Center, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Gislin Dagnelie
- Lions Vision Center, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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