[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"trial:NCT04424979":3,"trial-entities:NCT04424979":99,"trial-summary:NCT04424979":103},{"id":4,"nct_id":4,"org_study_id":5,"brief_title":6,"official_title":7,"overall_status":8,"completion_date":9,"status_verified_date":10,"last_update_date":11,"start_date":12,"sponsor_name":13,"lead_sponsor_class":14,"has_dmc":15,"brief_summary":16,"detailed_description":17,"conditions":18,"keywords":24,"study_type":30,"primary_purpose":31,"phases":32,"enrollment_info":34,"interventions":37,"primary_outcomes":43,"secondary_outcomes":48,"sex":52,"minimum_age":53,"maximum_age":54,"healthy_volunteers":15,"eligibility_criteria":55,"std_ages":68,"locations":72,"central_contacts":82,"overall_officials":88,"references":93,"see_also_links":98},"NCT04424979","MPP_Feasibility1","Feasibility Tests for Various Prism Configurations for Visual Field Loss","Visual Field Expansion Through Innovative Multi-Periscopic Prism Design","RECRUITING","2026-12","2025-09","2025-09-23","2020-11-06","Massachusetts Eye and Ear Infirmary","OTHER",false,"The investigators will develop and test different configurations of high-power prisms to expand the field of vision of patients with visual field loss to assist them with obstacle detection when walking. The study will involve multiple visits (typically four) to Schepens Eye Research Institute for fitting and testing with the prism glasses. The overall objective is to determine best designs and fitting parameters for implementation in prism devices for future clinical trials.",null,[19,20,21,22,23],"Hemianopia, Homonymous","Tunnel Vision","Visual Field Defect, Peripheral","Visual Field Constriction Bilateral","Visual Field Defect Homonymous Bilateral",[25,26,27,28,29],"Visual field expansion","Prisms","Hemianopsia","Tunnel vision","Visual field loss","INTERVENTIONAL","DEVICE_FEASIBILITY",[33],"NA",{"count":35,"type":36},20,"ESTIMATED",[38],{"type":39,"name":40,"description":41,"armGroupLabels":42},"DEVICE","High power prisms","High power prisms designed to shift images from blind areas into portions of the wearer's remaining, seeing, field of vision",[40],[44],{"measure":45,"description":46,"timeFrame":47},"Field of view expansion","Horizontal and vertical extent of the expansion (in degrees) of the field of view","Through study completion, an average of four months",[49],{"measure":50,"description":51,"timeFrame":47},"Pedestrian detection rate","Proportion of pedestrians detected (in simulated walking or simulated driving)","ALL","7 Years","80 Years",{"inclusion":56,"exclusion":63,"raw_text":67},[57,58,59,60,61,62],"Visual field loss, either peripheral field loss or hemianopic field loss","Visual acuity of at least 20\u002F50 in the better eye","In sufficiently good health to be able to complete sessions lasting 2-4 hours","Able to independently walk short distances","Able to give voluntary, informed consent","Able to speak English",[64,65,66],"Any physical or mental impairments, including cognitive dysfunction, balance problems or other deficits that could impair the ability to walk or use the prism spectacles","A history of seizures in the last 6 months","Hemispatial neglect (subjects with hemianopic field loss only)","Inclusion Criteria:\n\n* Visual field loss, either peripheral field loss or hemianopic field loss\n* Visual acuity of at least 20\u002F50 in the better eye\n* In sufficiently good health to be able to complete sessions lasting 2-4 hours\n* Able to independently walk short distances\n* Able to give voluntary, informed consent\n* Able to speak English\n\nExclusion Criteria:\n\n* Any physical or mental impairments, including cognitive dysfunction, balance problems or other deficits that could impair the ability to walk or use the prism spectacles\n* A history of seizures in the last 6 months\n* Hemispatial neglect (subjects with hemianopic field loss only)",[69,70,71],"CHILD","ADULT","OLDER_ADULT",[73],{"facility":74,"status":8,"city":75,"state":76,"zip":77,"country":78,"geoPoint":79},"Schepens Eye Research Institute","Boston","Massachusetts","02114","United States",{"lat":80,"lon":81},42.35843,-71.05977,[83],{"name":84,"role":85,"phone":86,"email":87},"Alex Bowers","CONTACT","617 912 2512","alex_bowers@meei.harvard.edu",[89],{"name":90,"affiliation":91,"role":92},"Eliezer Peli, MSc, OD","Schepens Eye Research Institute of Massachusetts Eye and Ear","STUDY_DIRECTOR",[94],{"pmid":95,"type":96,"citation":97},"38990239","DERIVED","Bowers AR, Manda S, Shekar S, Hwang AD, Jung JH, Peli E. Pilot study of a pedestrian collision detection test for a multisite trial of field expansion devices for hemianopia. Optom Vis Sci. 2024 Jun 1;101(6):408-416. doi: 10.1097\u002FOPX.0000000000002152.",[],{"nct_id":4,"conditions":100,"biomarkers":102},[101],"Visual Field Defect",[],{"nct_id":4,"found":104,"summary":105,"prompt_version":114},true,{"design":106,"status":107,"heading":6,"summary":108,"follow_up":109,"word_count":110,"commitments":111,"compensation":112,"drugs_mentioned":113},"This is an interventional study involving about 20 participants. It is testing different high-power prism configurations.","completed","This study is testing different types of high-power prisms. These prisms are designed to help people with visual field loss (hemianopia, tunnel vision, or other visual field defects) see better by shifting images from blind spots into areas where they can still see. The goal is to help you detect obstacles more easily when walking. Researchers want to find the best prism designs and how to fit them for future studies. You might be able to join if you are between 7 and 80 years old, have visual field loss, and your vision in your better eye is at least 20\u002F50. You also need to be healthy enough for 2-4 hour sessions, able to walk short distances, and speak English. The study aims to enroll 20 participants, but its current recruitment status is unclear. Success will be measured by how much your field of vision expands over about four months.","Your field of view expansion will be measured through study completion, which is an average of four months.",150,"You would have multiple visits, typically four, to Schepens Eye Research Institute for fitting and testing with the prism glasses. Each session would last 2-4 hours.","Not stated in the trial record.",[],"v2"]