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1.
Transl Vis Sci Technol ; 13(5): 2, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38696181

ABSTRACT

Purpose: Currently, no solution exists to restore natural eyelid kinematics for patients with complete eyelid paralysis due to loss of function of both the levator palpebrae superioris and orbicularis oculi. These rare cases are prone to complications of chronic exposure keratopathy which may lead to corneal blindness. We hypothesized that magnetic force could be used to fully automate eyelid movement in these cases through the use of eyelid-attached magnets and a spectacle-mounted magnet driven by a programmable motor (motorized magnetic levator prosthesis [MMLP]). Methods: To test this hypothesis and establish proof of concept, we performed a finite element analysis (FEA) for a prototype MMLP to check the eyelid-opening force generated by the device and verified the results with experimental measurements in a volunteer with total bidirectional eyelid paralysis. The subject was then fitted with a prototype to check the performance of the device and its success. Results: With MMLP, eye opening was restored to near normal, and blinking was fully automated in close synchrony with the motor-driven polarity reversal, with full closure on the blink. The device was well tolerated, and the participant was pleased with the comfort and performance. Conclusions: FEA simulation results conformed to the experimentally observed trend, further supporting the proof of concept and design parameters. This is the first viable approach in human patients with proof of concept for complete reanimation of a bidirectionally paretic eyelid. Further study is warranted to refine the prototype and determine the feasibility and safety of prolonged use. Translational Relevance: This is first proof of concept for our device for total bidirectional eyelid paralysis.


Subject(s)
Blinking , Eyelids , Proof of Concept Study , Humans , Blinking/physiology , Eyelids/physiopathology , Eyelid Diseases/physiopathology , Eyelid Diseases/therapy , Oculomotor Muscles/physiopathology , Finite Element Analysis , Biomechanical Phenomena , Prostheses and Implants , Prosthesis Design , Magnets , Male
2.
Transl Vis Sci Technol ; 12(12): 1, 2023 12 01.
Article in English | MEDLINE | ID: mdl-38038607

ABSTRACT

Purpose: Examine the effect of force modulation via angular translation of a static magnetic field for customizable treatment of severe blepharoptosis. Methods: Prototype adjustable-force magnetic levator prostheses (aMLP) consisted of a spectacle-mounted magnet in rotatable housing and small eyelid-attached magnets embedded in a biocompatible polymer. Interpalpebral fissure (IPF) of 17 participants with severe blepharoptosis was continuously measured for one minute at five spectacle magnet angles, with order randomized and participant and data analyst masked. The hypothesis that angular position affected opening IPF (o-IPF), minimum blink IPF (m-IPF), and comfort ratings (1-10) was tested. Results: The aMLP improved o-IPF from 4.5 mm without the device to 6.2 mm on the lowest force setting (P < 0.001) and 7.1 mm on the highest setting (P < 0.001) and allowed for complete volitional blink regardless of setting (average m-IPF 0.4 mm and no change with aMLP; P = 0.76). Spontaneous blink without the device (2.0 mm) was affected on the highest force setting (m-IPF 3.9 mm; P < 0.001) but only marginally so on the lowest setting (3.0 mm; P = 0.06). Comfort (7.6/10) did not vary with the angle (P > 0.36). Profile analysis found substantial individual responses to angle (P < 0.001), confirming the value of customization. Conclusions: Angular translation provided adjustable force, which had a statistically and clinically meaningful impact on eye opening and the completeness of the spontaneous blink. This quantitative evidence supports continued use of the angular translation mechanism for force adjustment in the customizable magnetic correction of severe blepharoptosis. Translational Relevance: Evidence for the benefit of customizable magnetic force via angular translation in a larger sample of participants than reported previously.


Subject(s)
Blepharoptosis , Humans , Blepharoptosis/surgery , Eyelids , Prostheses and Implants , Magnetic Phenomena
3.
Invest Ophthalmol Vis Sci ; 64(14): 26, 2023 Nov 01.
Article in English | MEDLINE | ID: mdl-37975848

ABSTRACT

Purpose: To investigate compensatory gaze-scanning behaviors during street crossings by pedestrians with homonymous hemianopia (HH) and hemispatial neglect (HSN). Methods: Pedestrians with right homonymous hemianopia (RHH) and left homonymous hemianopia without (LHH) and with left spatial-neglect (LHSN) walked on city streets wearing a gaze-tracking system that also captured scene videos. Street-crossing instances were manually annotated, and horizontal gaze scan of magnitude ≥20° and scanning rates were compared within-subject, between the side of the hemifield loss (BlindSide) and the other side (SeeingSide). Proportion of instances with scans to both the left and the right side at nonsignalized crossings (indicative of safe scanning behavior) were compared among the three subject groups. Results: Data from 19 participants (6 LHH, 7 RHH, and 6 with mild [4] or moderate [2] LHSN), consisting of 521 street-crossing instances of a total duration of 201 minutes and 5375 gaze scans, were analyzed. The overall gaze magnitude (mean [95% confidence interval (CI)]) was significantly larger toward the BlindSide (40.4° [39.1°-41.9°]) than the SeeingSide (36° [34.8°-37.3°]; P < 0.001). The scanning rate (mean [95% CI] scans/min) toward the BlindSide (14 [12.5-15.6]) was significantly higher than the SeeingSide (11.5 [10.3°-12.9°]; P < 0.001). The scanning rate in the LHSN group (10.7 [8.9-12.8]) was significantly lower than the LHH group (14 [11.6-17.0]; P = 0.045). The proportion of nonsignalized crossings with scans to both sides was significantly lower in LHSN (58%; P = 0.039) and RHH (51%; P = 0.003) than LHH (75%) participants. Conclusions: All groups demonstrated compensatory scanning, making more gaze scans with larger magnitudes to the blind side. Mild to moderate LHSN adversely impacted the scanning rate.


Subject(s)
Pedestrians , Perceptual Disorders , Humans , Hemianopsia/diagnosis , Visual Fields
4.
Optom Vis Sci ; 100(11): 794-798, 2023 Nov 01.
Article in English | MEDLINE | ID: mdl-37889985

ABSTRACT

SIGNIFICANCE: Stakeholder engagement has been identified by national health organizations as a crucial step to successful translation of new health care treatments. In this clinical report, clinician-stakeholder feedback is presented for the magnetic levator prosthesis (MLP), a promising noninvasive spectacle device that restores eyelid motility with magnetic force. PURPOSE: This study aimed to evaluate MLP clinical need and translational barriers. METHODS: Ten vision rehabilitation optometrists who attended an educational presentation on the MLP and participated in a hands-on workshop in the fitting of a patient were invited to complete an anonymous online survey. Ten multiple-choice items gathered data on estimated patient need, current approaches, main barriers to MLP, temporary versus chronic use, cost barriers, and need for insurance coverage. Open fields allowed for additional comments. RESULTS: Nine of 10 specialists completed the survey. Of those, seven answered that they could potentially see at least 1 to 5 patients for ptosis management within a year. The most common ptosis management options reported were the ptosis crutch, taping the eyelid open, and oxymetazoline drops, all with six responses each. Seven clinicians indicated that cost was a main concern. If cost to patient was not a barrier, all indicated they would be at least somewhat likely to try the MLP (1) for temporary management of ptosis, (2) as a pre-surgical trial, and (3) for long-term management of ptosis, with more selecting extremely likely and very likely than somewhat likely. Main comments were expressing enthusiasm for the technology and that it would be more appealing for patients if covered by insurance. CONCLUSIONS: This clinical report suggests that the main barriers to clinical success of the MLP may be cost and insurance coverage, appearance of the device, and self-application. Possible solutions are cost-benefit analysis research, engineering efforts to reduce spectacle magnet size and improve the ease of eyelid magnet application.


Subject(s)
Blepharoptosis , Humans , Feedback , Blepharoptosis/surgery , Eyelids , Prostheses and Implants , Magnetic Phenomena
5.
Transl Vis Sci Technol ; 12(8): 11, 2023 08 01.
Article in English | MEDLINE | ID: mdl-37566397

ABSTRACT

Purpose: Blepharoptosis is a common oculoplastic condition causing incomplete opening of the upper eyelid. Surgical approaches, the mainstay for correction, often fail to improve blink function. The purpose of this study was to develop a nonsurgical treatment option for severe ptosis that allows blink re-animation. Methods: Magnetic force required to perform blink re-animation was characterized by evaluation of eye-opening and closing using inter-palpebral fissure (IPF) outcomes with various combinations of eyelid array and box magnets. Optimal size of the spectacle magnet that achieved forces required for optimal blink dynamics was selected using simulation. The adjustable magnetic levator prosthesis (aMLP) included an eyelid array magnet and an adjustable rotating spectacle magnet that allowed change in the magnetic direction, thus changing the net magnetic interactive force between the magnets. The clinical feasibility of aMLP in improving eye opening without limiting eye closing was evaluated in patients with ptosis through a proof-of-concept study using IPF and comfort outcomes. Results: Optimal eye opening and closing was achieved by a magnet-array combination providing 45 grams of surface force (gF) in the tested ptosis population. The aMLP was able to modulate eye opening and closing with change in rotation of the spectacle magnet in two patients with ptotis. The best fitting of an aMLP improved IPF opening without limiting eye closing and with good comfort reported. Conclusions: Preliminary results suggest that the an aMLP can correct ptosis without adversely affecting blink function. Further evaluation in a larger patient population is warranted. Translational Relevance: A nonsurgical, proof of concept, adjustable magnetic treatment option for blink re-animation in patients with severe ptosis is presented.


Subject(s)
Blepharoptosis , Humans , Blepharoptosis/surgery , Eyelids/surgery , Prostheses and Implants , Magnetic Phenomena
6.
Arch Rehabil Res Clin Transl ; 5(1): 100246, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36968165

ABSTRACT

Objective: To provide a retrospective evaluation of a new eye and vision rehabilitation care pathway in a U.S. multi-site inpatient rehabilitation network involving the occupational therapy (OT) staff and a consulting doctor of optometry (OD) specializing in vision rehabilitation. Design: Retrospective study. Setting: Two Inpatient Rehabilitation Facilities (IRFs) and 1 Long Term Acute Care Hospital (LTACH). Participants: There were 2083 records reviewed (44% women, avg. age 59 years). The most common diagnoses were hemispatial neglect (19.2%), homonymous field defects (18.5%), and oculomotor cranial nerve palsies (16.7%) (N=2083). Interventions: Clinical care was reviewed where diagnosis-specific protocols were developed and training was provided to OTs in order to reinforce OD-prescribed interventions during daily treatment sessions, including (1) third, fourth, and sixth ocular cranial nerve palsies (OCNPs) with prisms fitted for full time, postural adaptation training, and oculomotor re-education using pursuits, saccades, head-rotations, and binocular vision exercises including alternate cover and vergence; (2) homonymous hemianopia with training awareness of field loss, eccentric viewing, and fitting of Peli lens for optical field expansion; and (3) prism adaptation therapy (PAT) for left hemispatial neglect. Main Outcome Measures: Frequency of diagnoses. Hypothesis: Diagnoses with developed protocols were most common. Secondarily, feasibility and efficacy by anonymous OT survey. Results: 2083 vision consults were performed over 5 years. The most common diagnoses were hemispatial neglect (n=399, 19.2%), homonymous field defects (n=386, 18.5%), and OCNPs (n=347, 16.7%). None of the OTs reported the protocols were infeasible and 63% (IQR 38%-69%) reported their patients benefited from the interventions. The survey suggested prism for OCNPs helped in 42%, and Peli lens and PAT both helped in 38%. Conclusions: Data support the feasibility of this inpatient eye and vision rehabilitation care pathway which may be used as a foundation for creating or refining similar programs elsewhere. Uniform administration of IRF-based visual neuro-rehabilitation care could provide a substrate for future clinical trials to evaluate efficacy.

7.
Transl Vis Sci Technol ; 11(10): 34, 2022 10 03.
Article in English | MEDLINE | ID: mdl-36269183

ABSTRACT

Purpose: To determine the feasibility of a custom frame generation approach for nonsurgical management of severe blepharoptosis with the magnetic levator prosthesis (MLP). Methods: Participants (n = 8) with severe blepharoptosis (obscuring the visual axis) in one or both eyes who had previously been using a non-custom MLP had a craniofacial scan with a smartphone app to generate a custom MLP frame. A magnetic adhesive was attached to the affected eyelid. The custom MLP frame held a cylindrical magnet near the eyebrow above the affected eyelid, suspending it in the magnetic field while still allowing blinking. The spectacle magnet could be rotated manually, providing adjustable force via angular translation of the magnetic field. Fitting success and comfort were recorded, and interpalpebral fissure (IPF) was measured from video frames after 20 minutes in-office and one-week at-home use. Preference was documented, custom versus non-custom. Results: Overall, 88% of patients (7/8) were successfully fitted with a median 9/10 comfort (interquartile 7-10) and median ptosis improvement of 2.3 mm (1.3-5.0); P = 0.01). Exact binomial testing suggested, with 80% power, that the true population success rate was significantly greater than 45% (P = 0.05). Five participants took the custom MLP home for one week, with only one case of mild conjunctival redness which resolved without treatment. Highest to lowest force modulation resulted in a marginally significant median IPF adjustment of 1.5 mm (0.8 to 2.7; P = 0.06). All preferred the custom frame. Conclusions: The three-dimensional custom MLP frame generation approach using a smartphone app-based craniofacial scan is a feasible approach for clinical deployment of the MLP. Translational Relevance: First demonstration of customized frame generation for the MLP.


Subject(s)
Artificial Limbs , Blepharoptosis , Humans , Blepharoptosis/surgery , Oculomotor Muscles/diagnostic imaging , Oculomotor Muscles/surgery , Feasibility Studies , Printing, Three-Dimensional , Magnetic Phenomena
8.
Optom Vis Sci ; 98(12): 1387-1393, 2021 12 01.
Article in English | MEDLINE | ID: mdl-34905525

ABSTRACT

SIGNIFICANCE: This is the first report recording an accommodative disorder after concussion characterized by periodic moderately sized myopic refractive error fluctuations without measurable other features of spasm of the near reflex. PURPOSE: Objectively document a class of accommodative dysfunction that may be related to concussion. CASE REPORTS: Case 1 involved two sports-related concussions 2 months apart with symptoms of headache and variable blur. Refractive stability was measured 28 months after injury with a binocular open-field refractometer documenting fluctuations from -0.25 to -1.75 D occurring 10 times during 4.2 seconds of recording with no evident miosis or convergent strabismus. The symptoms resolved with 1% atropine × 3 weeks. Case 2 involved a concussive blast injury (improvised explosive device) 7 years prior with symptoms of headache behind the eyes and occasional variable blur and reduced tolerance of electronic displays and other visually intensive tasks. Refractive fluctuations from +0.50 to -2.00 D occurred seven times over 44 seconds of recording with no appreciable miosis or change of interpalpebral fissure. The signs and symptoms were unresponsive to seven occupational therapy sessions involving task modifications and accommodative vision therapy activities. CONCLUSIONS: In patients complaining of blurry vision, a careful evaluation of the stability of accommodation is indicated.


Subject(s)
Myopia , Refractive Errors , Accommodation, Ocular , Humans , Refraction, Ocular , Vision, Binocular
9.
Arch Rehabil Res Clin Transl ; 3(1): 100100, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33363279

ABSTRACT

OBJECTIVE: To describe and evaluate a secure video call system combined with a suite of iPad vision testing apps to improve access to vision rehabilitation assessment for inpatients. DESIGN: Retrospective. SETTING: Two acute care inpatient rehabilitation hospitals and 1 long-term acute care (LTAC) hospital. PARTICIPANTS: Records of inpatients seen by the vision service. INTERVENTIONS: Records from a 1-year telemedicine pilot performed at acute rehabilitation (AR) hospital 1 and then expanded to AR hospital 2 and LTAC hospital during coronavirus disease 2019 (COVID-19) were reviewed. In the virtual visits, an occupational therapist measured the patients' vision with the iPad applications and forwarded results to the off-site Doctor of Optometry (OD) for review prior to a video visit. The OD provided diagnosis and education, press-on prism application supervision, strategies and modifications, and follow-up recommendations. Providers completed the telehealth usability questionnaire (10-point scale). MAIN OUTCOME MEASURES: Vision examinations per month at AR hospital 1 before and with telemedicine. RESULTS: With telemedicine at AR hospital 1, mean visits per month significantly increased from 10.7±5 to 14.9±5 (P=.002). Prism was trialed in 40% of cases of which 83% were successful, similar to previously reported in-person success rates. COVID-19 caused only a marginal decrease in visits per month (P=.08) at AR1, whereas the site without an established program (AR hospital 2) had a 3-4 week gap in care while the program was initiated. Cases at the LTAC hospital tended to be more complex and difficult to manage virtually. The telehealth usability questionnaire median category scores were 7 for Ease of Use, 8 for Interface Quality, 6 for Reliability, and 9 for Satisfaction and Future Use. CONCLUSIONS: The virtual vision clinic process improved inpatient access to eye and visual neurorehabilitation assessment before and during the COVID-19 quarantine and was well accepted by providers and patients.

10.
Optom Vis Sci ; 95(9): 795-804, 2018 09.
Article in English | MEDLINE | ID: mdl-30169355

ABSTRACT

SIGNIFICANCE: The first report on the use of peripheral prisms (p-prisms) for patients with left neglect and homonymous visual field defects (HVFDs). PURPOSE: The purpose of this study was to investigate if patients with left hemispatial neglect and HVFDs benefit from p-prisms to expand the visual field and improve obstacle detection. METHODS: Patients (24 with HVFDs, 10 of whom had left neglect) viewed an animated, virtual, shopping mall corridor and reported if they would have collided with a human obstacle that appeared at various offsets up to 13.5° from their simulated walking path. There were 40 obstacle presentations on each side, with and without p-prisms. No training with p-prisms was provided, and gaze was fixed at the center of expansion. RESULTS: Detection on the side of the HVFD improved significantly with p-prisms in both groups, from 26 to 92% in the left-neglect group and 43 to 98% in the non-neglect group (both P < .001). There was a tendency for greater improvement in the neglect patients with p-prisms. For collision judgments, both groups exhibited a large increase in perceived collisions on the side of the HVFD with the prisms (P < .001), with no difference between the groups (P = .93). Increased perceived collisions represent a wider perceived safety margin on the side of the HVFD. CONCLUSIONS: Within the controlled conditions of this simulated, collision judgment task, patients with left neglect responded well to initial application of p-prisms exhibiting improved detection and wider safety margins on the side of the HVFD that did not differ from non-neglect patients. Further study of p-prisms for neglect patients in free-gaze conditions after extended wear and in real-world mobility tasks is clearly warranted.


Subject(s)
Eyeglasses , Hemianopsia/physiopathology , Perceptual Disorders/physiopathology , Vision, Low/physiopathology , Visual Perception/physiology , Adult , Aged , Aged, 80 and over , Female , Humans , Judgment , Male , Middle Aged , Visual Field Tests , Visual Fields/physiology , Young Adult
11.
Transl Vis Sci Technol ; 7(1): 5, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29359111

ABSTRACT

PURPOSE: Drivers with homonymous hemianopia (HH) were previously found to have impaired detection of blind-side hazards, yet in many jurisdictions they may obtain a license. We evaluated whether oblique 57Δ peripheral prisms (p-prisms) and perceptual-motor training improved blind-side detection rates. METHODS: Patients with HH (n = 11) wore p-prisms for 2 weeks and then received perceptual-motor training (six visits) detecting and touching stimuli in the prism-expanded vision. In a driving simulator, patients drove and pressed the horn upon detection of pedestrians who ran toward the roadway (26 from each side): (1) without p-prisms at baseline; (2) with p-prisms after 2 weeks acclimation but before training; (3) with p-prisms after training; and (4) 3 months later. RESULTS: P-prisms improved blind-side detection from 42% to 56%, which further improved after training to 72% (all P < 0.001). Blind-side timely responses (adequate time to have stopped) improved from 31% without to 44% with p-prisms (P < 0.001) and further improved with training to 55% (P = 0.02). At the 3-month follow-up, improvements from training were maintained for detection (65%; P = 0.02) but not timely responses (P = 0.725). There was wide between-subject variability in baseline detection performance and response to p-prisms. There were no negative effects of p-prisms on vehicle control or seeing-side performance. CONCLUSIONS: P-prisms improved detection with no negative effects, and training may provide additional benefit. TRANSLATIONAL RELEVANCE: In jurisdictions where people with HH are legally driving, these data aid in clinical decision making by providing evidence that p-prisms improve performance without negative effects.

12.
Transl Vis Sci Technol ; 7(1): 7, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29367892

ABSTRACT

PURPOSE: We further optimized and evaluated the safety of the magnetic levator prosthesis (MLP) for temporary management of severe blepharoptosis, and compared efficacy and comfort against the ptosis crutch. METHODS: The interpalpebral fissure (IPF) of participants (n = 12) with ptosis was measured during attempted eyelid opening, volitional closing, and spontaneous closing with no device, ptosis crutch, or the MLP. A 10-point scale documented comfort. Additionally, a 20 minute and then 1 week trial of the MLP was offered. Safety measures were skin erythema rating, change in visual acuity, and change in corneal staining. RESULTS: The MLP and crutch opened the eye (IPF 11.2 and 9.3 mm), but the MLP allowed better volitional closure (IPF 1.0 vs. 4.9 mm, P = 0.009), but was no better in allowing spontaneous blink (IPF 7.5 vs. 7.7 mm, P = 0.722). Both devices were equally comfortable (both median 8/10 comfort, P = 0.46). With extended use, opening with the MLP showed IPF 9.24 mm at 20 minutes and 9.46 mm at 1 week, and volitional closure was IPF 0.95 and 0.52 mm, respectively. Closure on spontaneous blink improved with extended wear to IPF 5.14 and 5.18 mm, respectively (P = 0.002). Two participants exhibited moderate skin erythema and one had increased corneal staining without change in acuity. CONCLUSIONS: The MLP is safe and feasible for temporary correction of severe ptosis. TRANSLATIONAL RELEVANCE: First group data in patients showing successful reanimation of the eyelid with magnetic force.

13.
Optom Vis Sci ; 94(1): 120-124, 2017 01.
Article in English | MEDLINE | ID: mdl-27575993

ABSTRACT

PURPOSE: Patching for double vision is a common palliative treatment for head-trauma patients with acquired strabismus when prisms are not feasible. METHODS: We review literature on spatial neglect and discuss possible effects of monocular occlusion on spatial attention. RESULTS: Patching the left eye has been shown to worsen spatial judgments in some brain-injured patients with left neglect by inhibiting the right superior colliculus further impairing contralateral leftward orienting (the Sprague Effect). CONCLUSIONS: Because more peripheral parts of the visual field increasingly project to the contralateral superior colliculus with the temporal crescent being entirely contralateral, avoiding patching of the temporal crescent was advised, and in most cases can be achieved by taping off the spectacle lens and avoiding an elastic eye patch.


Subject(s)
Bandages , Brain Injuries/therapy , Diplopia/therapy , Palliative Care , Adult , Brain Injuries/physiopathology , Contraindications , Diplopia/physiopathology , Female , Humans , Male , Middle Aged , Sensory Deprivation , Spatial Processing/physiology , Strabismus/physiopathology , Visual Fields/physiology , Young Adult
14.
Am J Phys Med Rehabil ; 96(4): e70-e74, 2017 Apr.
Article in English | MEDLINE | ID: mdl-27552350

ABSTRACT

Visual impairments are common after traumatic brain injury (TBI) and negatively affect quality of life. We describe a 39-year-old woman with a severe TBI who was evaluated by the inpatient optometry and vision rehabilitation service with findings of complete right homonymous hemianopia and right cranial nerve III palsy with 30-degree right exotropia (eye turn out) and complete right ptosis (eyelid will not open). The 30-degree exotropia advantageously generated 30 degrees of right visual field expansion when the right ptosis was treated with a magnetic levator prosthesis, which restores eyelid opening. Once opened, the patient used visual field expansion derived from a right exotropia to overcome functional impairments caused by right hemianopia. Field expansion improved the patient's wheelchair mobility and reaching tasks during inpatient therapy. This is the first report of visual field expansion by strabismus facilitated by correction of ptosis. Strabismus should be considered for its potential field expansion benefits when homonymous visual deficits are present, before considering patching. A multidisciplinary vision rehabilitation team is well suited to make this determination.


Subject(s)
Brain Injuries, Traumatic/complications , Hemianopsia/therapy , Magnetic Field Therapy , Adult , Blepharoptosis/etiology , Blepharoptosis/therapy , Exotropia/etiology , Female , Hemianopsia/etiology , Humans , Oculomotor Nerve Diseases/etiology
15.
Transl Vis Sci Technol ; 5(1): 9, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26933522

ABSTRACT

PURPOSE: Peripheral prisms (p-prisms) shift peripheral portions of the visual field of one eye, providing visual field expansion for patients with hemianopia. However, patients rarely show adaption to the shift, incorrectly localizing objects viewed within the p-prisms. A pilot evaluation of a novel computerized perceptual-motor training program aiming to promote p-prism adaption was conducted. METHODS: Thirteen patients with hemianopia fitted with 57Δ oblique p-prisms completed the training protocol. They attended six 1-hour visits reaching and touching peripheral checkerboard stimuli presented over videos of driving scenes while fixating a central target. Performance was measured at each visit and after 3 months. RESULTS: There was a significant reduction in touch error (P = 0.01) for p-prism zone stimuli from pretraining median of 16.6° (IQR 12.1°-19.6°) to 2.7° ( IQR 1.0°-8.5°) at the end of training. P-prism zone reaction times did not change significantly with training (P > 0.05). P-prism zone detection improved significantly (P = 0.01) from a pretraining median 70% (IQR 50%-88%) to 95% at the end of training (IQR 73%-98%). Three months after training improvements had regressed but performance was still better than pretraining. CONCLUSIONS: Improved pointing accuracy for stimuli detected in prism-expanded vision of patients with hemianopia wearing 57Δ oblique p-prisms is possible and training appears to further improve detection. TRANSLATIONAL RELEVANCE: This is the first use of this novel software to train adaptation of visual direction in patients with hemianopia wearing peripheral prisms.

16.
Invest Ophthalmol Vis Sci ; 56(6): 4135-42, 2015 Jun.
Article in English | MEDLINE | ID: mdl-26120818

ABSTRACT

PURPOSE: Although the impact of homonymous visual field defects (HFDs) on mobility has been investigated previously, the emphasis has been on obstacle detection. Relatively little is known about HFD patients' ability to judge collisions once an obstacle is detected. We investigated this using a walking simulator. METHODS: Patients with HFDs (n = 29) and subjects with normal vision (NV; n = 21) were seated in front of a large screen on which a visual simulation of walking was displayed. They made collision judgments for a human figure that appeared for 1 second at lateral offsets from the virtual walking path. A perceived-collision threshold was calculated for right and left sides. RESULTS: Symmetrical collision thresholds (same on left and right sides) were measured for participants with NV (n = 21), and right (n = 9) and left (n = 7) HFD without hemispatial neglect. Participants with left neglect (n = 10) showed significant asymmetry with thresholds smaller (compared to the NV group and other HFD groups) on the blind (P < 0.001) and larger on the seeing (P = 0.05) sides. Despite the asymmetry, the overall width of the zone of perceived collision risk was not different, suggesting a relatively uniform rightward deviation in judgments of the left neglect group. CONCLUSIONS: Left neglect was associated with rightward asymmetry in collision judgments, which may cause collisions on the left side even when an obstacle is detected. These behaviors may represent the spatial misperceptions in body midline described previously in patients with left neglect.


Subject(s)
Hemianopsia/physiopathology , Judgment/physiology , Motion Perception/physiology , Perceptual Disorders/physiopathology , Visual Fields/physiology , Adult , Case-Control Studies , Female , Humans , Logistic Models , Male , Middle Aged , Sensory Thresholds/physiology , Walking
17.
Transl Vis Sci Technol ; 3(6): 9, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25674358

ABSTRACT

PURPOSE: To test a prototype magnet system (magnetic levator prosthesis) for the ability to comfortably and non-invasively provide eye opening with maintenance of the blink in people with paralytic ptosis and determine preliminary efficacy for short-term clinical application. METHODS: The prototype device consisted of a magnet on a spectacle frame and a micro-magnet array mounted externally on the eyelid. Participants with unilateral CN III palsy (n=3) trialed the predicate (ptosis crutch) and magnet device. Video analysis was used to quantify changes in eyelid opening and subjective responses were documented with a rating scale. A 20-minute and then a 1-week trial were offered. RESULTS: The magnetic levator prosthesis device was effective to provide eye opening while allowing, at minimum, a volitional blink without ill effects on the eyelid skin or ocular surface. Comfort scores ranged from 6 to 9 out of 10 over 3 evaluations. All patients chose an extended trial of the magnet device and reported continued 8-9/10 comfort and efficacy after the extended 1-week trial. CONCLUSIONS: Comfortable and effective restoration of eye opening with maintenance of the blink is feasible using external static magnets and warrants further study. TRANSLATIONAL RELEVANCE: This is the first careful documentation of the successful use of an externally mounted static magnet system to treat paralytic ptosis.

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