Rehabilitation for Visual Disorders

Reading Difficulties in Individuals with Homonymous Visual Field Defects: A Systematic Review of Reported Interventions

Reading difficulties are amongst the most commonly reported problems in individuals with homonymous visual field defects (HVFDs). To be able to provide guidance for healthcare professionals considering offering reading training, researchers in this field and interested individuals with HVFDs, this systematic review aims to (1) provide an overview of the contextual and intervention characteristics of all published HVFD interventions and (2) generate insights into the different reading outcome measures that these studies adopted. A search on PsycINFO, MEDLINE and Web of Science was conducted up to February 2, 2023. All intervention studies for HVFD in which reading was measured were included. Data was collected about the intervention type, session duration, number of sessions, the intensity, duration, circumstance of the interventions, country in which the intervention was studied and reading measures. Sixty records are included, describing 70 interventions in total of which 21 are specifically reading interventions. Overall, adjusted saccadic behaviour interventions occur most in the literature. A wide range within all intervention characteristics was observed. Forty-nine records reported task-performance reading measures, and 33 records reported self-reported reading measures. The majority of task-performance measures are based on self-developed paragraph reading tasks with a time-based outcome measure (e.g. words per minute). Future research could benefit from making use of validated reading tests, approaching the measurement of reading mixed-methods and providing participants the possibility to supply outcomes relevant to them.

Rehabilitation of hemianopia and visuospatial hemineglect with a mixed intervention including adapted boxing therapy: An exploratory case study

Visual field loss and visuospatial neglect are frequent consequences of cerebral stroke. They often have a strong impact on independence in many daily activities. Rehabilitation aiming to decrease these disabilities is therefore important, and several techniques have been proposed to foster awareness, compensation, or restitution of the impaired visual field. We here describe a rehabilitation intervention using adapted boxing therapy that was part of a pluridisciplinary intervention tailored for a particular case. A 58-year-old man with left homonymous hemianopia (HH) and mild visuospatial hemineglect participated in 36 sessions of boxing therapy six months after a right temporo-occipital stroke. Repeated stimulation of his blind and neglected hemifield, and training to compensate for his deficits through improved use of his healthy hemifield were performed through boxing exercises. The patient showed a stable HH before the beginning of the training. After six months of boxing therapy, he reported improved awareness of his visual environment. Critically, his HH had evolved to a left superior quadrantanopia and spatial attention for left-sided stimuli had improved. Several cognitive functions and his mood also showed improvement. We conclude that boxing therapy has the potential to improve the compensation of visuospatial impairments in individual patients with visual field loss.

Vertical and horizontal reading training in patients with hemianopia and its effect on reading eye movements

Vertical reading training (VRTr) increases reading speed (RS) significantly in patients with hemianopic field defects (HFD). We ask, how eye movements (EM) contribute to this improvement and whether EM-behavior is affected by the side of HFD. Twenty-one patients, randomly assigned to VRTr or horizontal RTr, trained reading single lines from a screen at home, for 4 weeks. In the clinic, we recorded EM while reading short sentences aloud from a screen before training (T1), directly (T2) and 4 weeks afterwards (T3). RS-screen was correlated with RS during reading printed paragraphs (RS-print) to assess the transfer to everyday life. RS-screen and RS-print correlated positively (horizontal: r > 0.8, vertical: r > 0.9) at all times. Vertical RS did not exceed horizontal RS. We found significant negative correlations of EM-variables and RS-print: in right-HFD with the number of forward saccades (T1: r =  - 0.79, T2: r =  - 0.94), in left-HFD with the steps during return sweeps (T1: r =  - 0.83, T2: r =  - 0.56). Training effects remained stable at T3. EM-improvement was specific for the RTr and the side of the HFD: in right-HFD fewer forward saccades after VRTr, in left-HFD fewer steps during return sweeps after HRTr. RTr on a screen transfers to reading printed text in real-life situations.Trial registration: The study was retrospectively registered in the German Clinical Trials register: DRKS-ID: DRKS00018843, March 13th, 2020.

Compliance With the Use of Low-Vision Aids in a Greek Population: An Explorative Study

The aim of this study is to investigate the compliance with low-vision aids (LVAs) among patients with low vision (LV) in a Greek population. An explorative study was conducted in a sample of patients with LV attending our outpatient unit at the School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece. Patients' demographics and daily visual demands were recorded, and they were administered with the National Eye Institute Visual Function Questionnaire-25 (VFQ-25) at baseline. Participants were trained in the use of a wide range of LVAs before their prescription. Evaluation of the use of the LVAs was conducted at one year after the baseline using a structured phone survey. A total of 100 LV patients were included, with 68% of them being older than 65 years and 50 being males. The main cause of LV (57.0%) was age-related macular degeneration, and the mean VFQ-25 score at baseline was 49.2 (SD= 17.8). Overall, 75 patients had been prescribed LVAs, with 76.0% of these patients preferring an optical aid. The vast majority (98.7%) of these patients stated using the LVA one year after the baseline, and 62.1% of them reported using the aid often to very often. Significantly, 76% of these patients reported that their quality of life was positively affected by the use of the aid, and 97.3% would recommend the use of LVA to another individual with the same problem. Providing appropriate training before the prescription is of high significance to improve the rate of compliance with the use of LVAs. These results can be used to develop appropriate strategies in this field.

What are the reasons for abandonment of low vision devices prescribed in a large tertiary eye care centre?

PURPOSE

To investigate abandonment rates of near-vision low vision devices (LVDs) and factors that influence abandonment among patients attending a tertiary low vision rehabilitation centre in South India.

METHODS

Two hundred and eighty-six adults with low vision completed the modified device abandonment survey 1 year following device prescription. The survey included six questions: possession of device, timing of last use, reasons for abandonment, tasks for which the device was used, payment type and change in quality of life (QoL) from device use. The primary outcome measure was abandonment. Multivariate logistic regression analysis was used to investigate factors for abandonment.

RESULTS

Three hundred and twelve near-vision devices were prescribed (mean, 1.09 device per patient.) Stand magnifiers (35%) followed by hand-held magnifiers (24%) were most frequently prescribed. Mean logMAR visual acuity (Snellen) in the better-seeing eye was 0.80 (6/38). Of the prescribed near-vision devices, 22% (95% CI, 17 to 27) were abandoned. Patients who abandoned the device were significantly older than those who did not (49.3 ± 17.2 vs. 43.5 ± 18.1 years; p = 0.03). In multivariable analysis, patients reporting no change in their QoL from device use had higher odds of abandoning the device (OR: 63.97; 95% CI, 23.77 to 172.12). Device-related (31%) and psychological (30%) factors were the most frequent reasons for abandonment. Among device-related issues, the most frequent reason was that patients felt the device was too complex to use (50%) followed by being too cumbersome to use (25%).

CONCLUSION

The abandonment rate for near-vision LVDs in South India was comparable with that reported in high-income countries. Patients reporting no change in their QoL had a higher likelihood of abandoning the device compared with those who reported some change. Device-related and psychological factors were the most frequent reasons for abandonment. These results can be used to develop strategies to improve compliance with use of devices.

Perceptual restoration fails to recover unconscious processing for smooth eye movements after occipital stroke

The visual pathways that guide actions do not necessarily mediate conscious perception. Patients with primary visual cortex (V1) damage lose conscious perception but often retain unconscious abilities (e.g. blindsight). Here, we asked if saccade accuracy and post-saccadic following responses (PFRs) that automatically track target motion upon saccade landing are retained when conscious perception is lost. We contrasted these behaviors in the blind and intact fields of 11 chronic V1-stroke patients, and in 8 visually intact controls. Saccade accuracy was relatively normal in all cases. Stroke patients also had normal PFR in their intact fields, but no PFR in their blind fields. Thus, V1 damage did not spare the unconscious visual processing necessary for automatic, post-saccadic smooth eye movements. Importantly, visual training that recovered motion perception in the blind field did not restore the PFR, suggesting a clear dissociation between pathways mediating perceptual restoration and automatic actions in the V1-damaged visual system.

Rehabilitation of visual perception in cortical blindness

Blindness is a common sequela after stroke affecting the primary visual cortex, presenting as a contralesional, homonymous, visual field cut. This can occur unilaterally or, less commonly, bilaterally. While it has been widely assumed that after a brief period of spontaneous improvement, vision loss becomes stable and permanent, accumulating data show that visual training can recover some of the vision loss, even long after the stroke. Here, we review the different approaches to rehabilitation employed in adult-onset cortical blindness (CB), focusing on visual restoration methods. Most of this work was conducted in chronic stroke patients, partially restoring visual discrimination and luminance detection. However, to achieve this, patients had to train for extended periods (usually many months), and the vision restored was not entirely normal. Several adjuvants to training such as noninvasive, transcranial brain stimulation, and pharmacology are starting to be investigated for their potential to increase the efficacy of training in CB patients. However, these approaches are still exploratory and require considerably more research before being adopted. Nonetheless, having established that the adult visual system retains the capacity for restorative plasticity, attention recently turned toward the subacute poststroke period. Drawing inspiration from sensorimotor stroke rehabilitation, visual training was recently attempted for the first time in subacute poststroke patients. It improved vision faster, over larger portions of the blind field, and for a larger number of visual discrimination abilities than identical training initiated more than 6 months poststroke (i.e., in the chronic period). In conclusion, evidence now suggests that visual neuroplasticity after occipital stroke can be reliably recruited by a range of visual training approaches. In addition, it appears that poststroke visual plasticity is dynamic, with a critical window of opportunity in the early postdamage period to attain more rapid, more extensive recovery of a larger set of visual perceptual abilities.

Vision Evaluation Tools for Adults With Acquired Brain Injury: A Scoping Review

Background. Unrecognized visual deficits (VDs) following an acquired brain injury (ABI) may impact clients’ rehabilitation. Little is known about evaluation tools used in vision rehabilitation. Purpose. To systematically explore the literature describing evaluation tools used for VD on adults with ABI. Method. Using a scoping review methodology, we searched in MEDLINE(Ovid), Embase, CINAHL, PsycINFO, and the grey literature from inception to 2020. Quantitative and thematic analyses were performed. Findings. Of the 83 studies reporting on 86 evaluation tools, 47% used multiple tools to assess VD. Tools were mostly used by occupational therapists and psychologists to evaluate intermediate, intermediate to high, and high-level visual skills. Clinicians tend to select specific tools that focus on different levels of the hierarchy of visual skills. Implications. Future research should investigate the optimal timeframe for assessment of VD and the psychometric properties of tools to ensure comprehensive VD evaluation.

Head-mounted Visual Assistive Technology-related Quality of Life Changes after Telerehabilitation

SIGNIFICANCE

Head-mounted low vision devices have become a viable alternative to enhance residual vision. This study supports the use of a head-mounted display to improve aspects of functional vision and quality of life. Much is still unknown regarding the required frequency, duration, or potential effectiveness of this telerehabilitation training protocol or what characteristics best identify optimal users.

PURPOSE

A randomized study explored the effect of telerehabilitation on quality of life and functional vision in individuals with low vision using a head-mounted display.

METHODS

We recruited 57 participants (age, 21 to 82 years; mean, 54.5 years) among new prospective eSight Eyewear users, randomized 1:1 into two parallel groups; the experimental group received the telerehabilitation training provided by a low vision therapist, whereas the control group received the self-training standard offered by the device manufacturer and without involvement of a low vision therapist. The primary outcome measures were the impact of telerehabilitation on validated measures of assistive technology-related quality of life: the Psychosocial Impact of Assistive Devices Scale and the Quebec User Evaluation of Satisfaction with Assistive Technology scale. Exploratory outcomes were the assessment of self-reported functional vision using the Veterans Affairs Low Vision Visual Functioning Questionnaire-48 and cybersickness associated with head-mounted display use with the Simulator Sickness Questionnaire.

RESULTS

Assistive technology-related quality of life was improved when measured by the satisfaction scale but not the psychosocial scale within the first 3 months, independently of training type. Overall, functional vision improvement was observed within the first 2 weeks of device use and maintained during the 6-month study, independently of group type. Cybersickness outcomes were similar between training groups and did not change significantly for 6 months.

CONCLUSIONS

eSight Eyewear, either with telerehabilitation or with the manufacturer self-training comparison, improved functional vision and increased users' quality of life within the initial 3 months of device training and practice.

Personalized Telerehabilitation for a Head-mounted Low Vision Aid: A Randomized Feasibility Study

SIGNIFICANCE

A recent trend in low vision rehabilitation has been the use of portable head-mounted displays to enhance residual vision. Our study confirms the feasibility of telerehabilitation and informs the development of evidence-based recommendations to improve telerehabilitation interventions to reduce device abandonment.

PURPOSE

To develop evidence-based recommendations for telerehabilitation, we conducted a feasibility study in preparation for a future randomized trial on the use of head-mounted displays.

METHODS

We recruited novice eSight Eyewear users, randomized 1:1: the experimental group received telerehabilitation by a low vision therapist using video conferencing; the control group completed at home self-training provided by the device manufacturer. The primary feasibility outcomes were whether the recruitment goal of 60 participants (30/group) was attainable within 1 year and how participants judged the accessibility and acceptability of the telerehabilitation. An exploratory outcome was the impact of telerehabilitation on eSight Eyewear use behavior.

RESULTS

Among 333 eSight users, 57 participants were enrolled, of which 35% withdrew from the study, whereas the remainder completed the 6-month follow-up. The withdrawal rate was higher in the control group but did not differ significantly from the experimental group. High accessibility (93% of participants accessed the platform) and global acceptability (100% overall satisfaction) were reported among those who completed the telerehabilitation protocol. The therapist had no difficulty judging the participants' reading performances qualitatively while participants used their device to read their eSkills and VisExc guides. Most participants improved their daily activities, based on qualitative reports of the attained goals. Seventy-nine percent of individuals declined to participate, whereas 16% of participants decided not to use eSight Eyewear anymore.

CONCLUSIONS

The data demonstrated the feasibility of a randomized controlled telerehabilitation study for people with low vision using a head-mounted display. Positive feedback from the participants and the therapist suggests the potential value of this modality for low vision services.

How Much Do Clinical and Microperimetric Findings Affect Reading Speed in Low Vision Patients with Age-related Macular Degeneration?

Purpose: To investigate the factors affecting the reading speed of patients with central scotoma due to age-related macular degeneration (AMD).Materials and Methods: We included 63 eyes of 63 patients with AMD who applied to our low vision clinic between August 2018 and September 2019 in this prospective study. We evaluated socio-demographic characteristics, eye examination findings and Minnesota Low Vision Reading Test (MNREAD) results. We used the MAIA microperimeter device to evaluate the properties of the preferred retinal locus for fixation (PRL) of the patients. Evaluations included the assessment of the effects of all parameters on reading speed.Results: The PRL was most commonly in the nasal (31%) and superior (26%) quadrants. Twenty-nine percent of the cases preferred the left visual field. PRL localization had no effect on reading speed, whereas, fixation stability, educational status, presence of foveal absolute scotoma, reading acuity and duration of reading interruption were found to have the most significant effects. Multiple regression analysis showed that reading speed decreased by 67 units in the presence of unstable fixation, by 17 units in the presence of foveal absolute scotoma, by 3 units with every 0.1 increase in logMAR value, and by 1.7 units with every 1-year increase in reading interruption. Additionally, being a university graduate was associated with an increased reading speed (by 18 units)Conclusion: Increased reading performance is one of the factors that can improve quality of life. The factors found to affect the reading speed in the current study may guide the rehabilitation process in low vision patients.

Training of vertical versus horizontal reading in patients with hemianopia - a randomized and controlled study

HYPOTHESIS

Patients with hemianopic field defects (HFD) might benefit from reading text in vertical orientation if they place the text in the seeing hemifield along the vertical midline.

METHODS

We assigned 21 patients with HFD randomly to either vertical or horizontal reading training. They trained reading single lines of texts from a computer screen at home for 2 × 30 min/day, 5 days/week, for 4 weeks. The main outcome variable was reading speed (RS) during reading standardized paragraphs of printed text (IReST) aloud. RS was assessed before training (T1), directly after training (T2) and 4 weeks later (T3). Quality of life (QoL) was assessed by Impact of Visual Impairment (IVI) questionnaire.

RESULTS

Vertical training improved RS in the vertical direction significantly. Only patients with right HFD benefited. Horizontal training improved RS in horizontal diection significantly, but much more in patients with left than in those with right HFD. Both effects remained stable at T3. RS during training at the computer improved highly significantly and correlated strongly with RS of printed text (Pearson r= > 0.9). QoL: Vertical training showed a statistically significant improvement in the complete IVI-score, patients with right HFD in the emotional IVI-score.

CONCLUSIONS

The improvements of RS were specific for the training. The stable effect indicates that the patients can apply the newly learned strategies to everyday life. The side of the HFD plays an essential role: Left-HFD patients benefitted from horizontal training, right-HFD patients from vertical training. However, the vertical RS did not reach the level of horizontal RS. The study was registered in the German Clinical Trials register (DRKS-ID: DRKS00018843).

Validation of the International Reading Speed Texts in a Canadian Sample

SIGNIFICANCE

The International Reading Speed Texts (IReST) is a valid measure of reading speed in a Canadian sample. However, if clinicians desire to assess reading comprehension using the IReST, this will significantly reduce reading speeds of individuals with normal vision or reduced visual acuity and therefore should use the values presented here.

PURPOSE

The purposes of this study are (1) to validate the IReST in an English-speaking Canadian sample and (2) to examine how reading comprehension questions and reduced visual acuity affect reading speed on the IReST.

METHODS

For study 1, Canadian English speakers (n = 25) read all 10 IReST following the procedures used in the original IReST validation. For study 2, Canadian English speakers (n = 50) read all 10 IReST, half with normal/corrected-to-normal vision and half with reduced visual acuity, and were asked reading comprehension questions.

RESULTS

No significant differences were found between Canadian sample and the published IReST values (in all cases, P > .05; mean difference [Mdiff] = -5.30 to +11.43; Cohen d = -0.15 to +0.27; Bayes factors = 0.41, 0.09). Assessing reading comprehension with multiple-choice questions on the IReST significantly reduced reading speeds in the normal vision condition (Mdiff = 25.3; 95% confidence interval, -16.7 to -34.1) and in the simulated impairment condition (Mdiff = 59.3; 95% confidence interval, -47.7 to -71).

CONCLUSIONS

The IReST is a valid measure that can be used to assess reading speed in a Canadian English-speaking sample. If researchers/clinicians wish to assess both reading speed and comprehension, using multiple-choice reading comprehension questions, then the values provided by the IReST will likely underestimate an individual's true reading speed in individuals with normal/corrected-to-normal vision or reduced visual acuity.

Evolution and visual outcomes of outer foveolar lucency after surgery for large idiopathic macular hole

PURPOSE

To explore the evolution of outer foveolar lucency (OFL) after vitrectomy and the correlation between OFL and visual acuity (VA) outcome in eyes with large idiopathic macular hole (IMH).

METHODS

In this retrospective study, 244 eyes of 233 subjects with large IMH (diameter > 400 μm), who underwent vitrectomy, were included. Preoperative clinical data, postoperative optical coherence tomography (OCT) images, and VA at 1-, 4-, and 10-month visits were documented. The prevalence, incidence, and width of OFL and their correlation with postoperative VA were analyzed.

RESULTS

The prevalence of OFL was 10.4% (24/231) at 1 month and significantly increased to 30.4% (55/181) at 4 months (P < 0.001) and 34.2% (25/73) at 10 months (P < 0.001). The incidence was 26.1% (40/153) and 22.0% (9/41) at 4 and 10 months, respectively. OFL appeared at 1 month while disappeared at 4 or 10 months in 8 eyes (50.0%). The presence of OFL at 1 month was negatively associated with IMH diameter (Nagelkerke R² = 0.06; P = 0.02). Eyes with OFL at 4 months had better VA at their 4-month visit than eyes without OFL (P = 0.02). Eyes with early-developed OFLs had better VA at 10 months than those with later-developed ones (P = 0.02). Width of OFL was not associated with postoperative VA at any point.

CONCLUSIONS

OFL is not rare in eyes with large IMH after surgery. It can occur gradually and remain during the 10-month follow-up. The presence of OFL appears to have no negative impact on the postoperative VA and it may represent the remodeling of foveal photoreceptors.

Comparing Reading Speeds for Reading Standardized Single Sentences and Paragraphs in Patients with Maculopathy

INTRODUCTION

The purpose of this study was to compare reading speeds (RS) of either paragraphs of text or single sentences in patients with maculopathy by investigating the repeatability of RS to decide which text type to use in studies on patients with maculopathy.

METHODS

RS was measured for standardized texts in 25 participants with a central scotoma due to maculopathy (mean age 77.8 years ± 9.9 SD, mean binocular visual acuity 0.65 logMAR (±0.85 SD), median magnification requirement 3-fold). Reading 3 single sentences taken from the Radner reading charts (sample #1, #2, and #3) of 14 words and reading 3 paragraphs of International Reading Speed Texts (IReST, sample # 3, #6, and #10) with a mean of 132 (±3.2 SD) words, each in German, were compared. The 6 texts were read aloud in random order from a closed-circuit TV system, with size adjusted according to the individual magnification requirement. Reading time was measured by stopwatch, and speed was calculated in correctly read words per minute (wpm). Differences in RS depending on text length (single sentence vs. paragraph) and text sample were calculated by the Bland-Altman analysis.

RESULTS

The mean RS showed no significant difference between 2 charts of the same kind (sentences: 93 wpm ± 37 SD; paragraphs: 95 wpm ± 38 SD). RS differences between 2 charts were lower in paragraphs than in single sentences. Highest correlations of RS between all 6 texts existed between the 3 IReST text samples (r = 0.98, 0.98, and 0.98) compared with the 3 Radner sentences (r = 0.89, 0.81, and 0.90). The inter-chart reliability (coefficient of repeatability) was smaller for the paragraphs (12.9 wpm) than for the single sentences (36.4 wpm).

CONCLUSION

In patients with maculopathy, single sentences are well suited for single measurement of RS. For repeated measurements (e.g., monitoring the course of a reading disorder or assessing effects of interventions), paragraphs are preferable because of their lower variability of RS between the paragraphs.

Interventions Addressing Vision, Visual-perceptual Impairments Following Acquired Brain Injury: A Cross-sectional Survey

BACKGROUND.

The existing literature on the effectiveness of interventions targeting vision, visual-perceptual impairments following acquired brain injury (ABI) is scarce and unlinked to occupational performance.

PURPOSE.

To explore current occupational therapy practice in vision-rehabilitation among adults with ABI in Canada, and to determine the evidence-practice gaps.

METHODS.

An online survey was made available through the Canadian Association of Occupational Therapists (CAOT) website, and disseminated to seven public healthcare institutions in Quebec. The survey collected respondent demographic information, and the types and frequency of treatments delivered. Descriptive statistics were conducted to determine interventions' frequency. Participant comments were collected and grouped into recurring themes.

FINDINGS.

Over half (55%) of respondents regularly use evidence-based interventions when addressing visual acuity (VA) and visual field (VF) deficits, but only very few (3%) use it when dealing with oculomotor function and visual stress impairments.

IMPLICATIONS.

Results gave a glimpse of interventions used and suggested the need for further research in vision rehabilitation.

Measuring changes in device use of a head-mounted low vision aid after personalised telerehabilitation: protocol for a feasibility study

INTRODUCTION

A recent trend in low vision (LV) has been towards the use of portable head-mounted displays (HMDs) to enhance residual vision. The decision process around the (non-)use of such devices have been identified as multifactorial. Among important barriers identified in the context of magnifying LV aids were transportation issues and insufficient training. In recent years, telerehabilitation has become of growing interest in healthcare because it allows individuals to remain at home while receiving rehabilitation services. A recent pilot study indicated encouraging outcomes; however, very few applications of telerehabilitation for LV have been tested systematically.

METHODS AND ANALYSIS

To help guide evidence-based practice recommendations for this modality, we will carry out a feasibility study to assess the recruitment, retention, accessibility and acceptability of an eventual fully randomised trial of telerehabilitation for people with LV using HMDs. We will recruit 60 participants aged 18+ years among prospective eSight Eyewear owners, randomised 1:1 into two parallel groups. The active intervention will be the telerehabilitation operated by a LV therapist; the control arm will be the current self-training standard provided by the device vendor. The primary feasibility outcome measures will be: time to recruit participants, loss to follow-up, accessibility and acceptability of the telerehabilitation (satisfaction of the users and LV therapist). Exploratory outcomes will be the impact of telerehabilitation on eSight Eyewear use behaviour (discontinuance rate), and validated measures of assistive-technology-related quality of life.

ETHICS AND DISSEMINATION

The study was approved by the Ethics Review Board of the Centre de Recherche Interdisciplinaire en Réadaptation de Montréal métropolitain (CRIR# 1286-1217). Dissemination is planned via local, national and international healthcare conferences and peer-reviewed journal publications.

VeRSE: Vertical Reading Strategy Efficacy for Homonymous Hemianopia after Stroke: A Feasibility Study

Aim:

To conduct a feasibility study using vertical reading for stroke survivors with homonymous hemianopia. Feasibility objectives included assessing the appropriateness of testing methods, outcomes and amount of recruitment possible. Vertical reading has yet no empirical evidence for its use in homonymous hemianopia.

Method:

A cross-over design was used involving stroke survivors with homonymous hemianopia. Three reading directions (horizontal; 90° clockwise rotation; 90° anti-clockwise rotation) were assessed in a randomised order whilst measuring reading speed.

Results:

Seven participants with stroke-induced homonymous hemianopia were recruited (25.9% recruitment rate). The mean horizontal reading speed was 120.3 (SD 33.9) words per minute. When reading vertically (downwards) at 90° clockwise rotation the mean reading speed was 62.7 (SD 43.4) words per minute. When reading vertically (upwards) at 90° anti-clockwise rotation the mean reading speed was 74.6 (SD 53.5) words per minute.

Conclusions:

This feasibility study has informed and provided vital information for planning and developing future studies for vertical reading. The primary outcome measure for future studies should be reading acuity, taking account of both speed and errors. Further preliminary studies are required which incorporate a practice element to assess for any improvement over time.

Determinants of Reading Performance in Eyes with Foveal-Sparing Geographic Atrophy

PURPOSE

To identify anatomic determinants of reading performance in eyes with foveal-sparing geographic atrophy (GA).

DESIGN

Prospectively recruited, cross-sectional study, SIGHT (clinicaltrials.gov identifier, NCT02332343).

PARTICIPANTS

Patients with foveal-sparing GA secondary to age-related macular degeneration (AMD).

METHODS

Monocular best-corrected visual acuity and reading acuity together with reading speed were assessed using Radner charts. Fundus autofluorescence, near-infrared reflectance, and spectral-domain OCT images were acquired using a Spectralis device. The minimal required reading rectangle (M3R), 19 letters × 2.4 lines in the smallest readable print size of an individual eye, was computed. The status of the M3R was determined as either free of atrophy or involved in the atrophic process, and the impact on reading was assessed.

MAIN OUTCOME MEASURES

Radner reading score (logRAD) and reading speed (words per minute [wpm]).

RESULTS

A total of 45 eyes of 31 patients (30 women; mean age, 76.14 years [range, 64.17-89.22 years]) were included. Median best-corrected visual acuity was 0.20 logarithm of the minimum angle of resolution (logMAR; Snellen equivalent, 20/32). Reading score was 0.52 logRAD (IQR, 0.30-1.4 logRAD) and maximum reading speed was 141.19 wpm (IQR, 105.52-164.62 wpm). In 27 eyes, the M3R was involved in the atrophic process. This was associated with a significant worsening in Radner score (1.21 logRAD [IQR, 0.46-1.40 logRAD] vs. 0.31 logRAD [IQR, 0.20-0.51 logRAD]; P < 0.001) and reading speed (110.84 wpm [IQR, 90.0-131.92 wpm] vs. 162.34 wpm [IQR, 137.51-176.66 wpm]; P = 0.002). Eyes in which the M3R was nonatrophic additionally showed an increase in reading speed with decreasing print size (peak increase, +73.08 wpm [IQR, 27.43-86.64 wpm] compared with the largest test sentence).

CONCLUSIONS

The results indicate that a defined area on the retina that can be assessed by retinal imaging is required for unhindered reading in patients with foveal-sparing GA. The findings highlight that smaller test sentences can be read faster by patients with this AMD subphenotype. Our results allow prediction of reading impairment based on imaging parameters in clinical routine and may support establishing anatomic surrogate end points in clinical trials. Furthermore, the findings could be used to facilitate the adjustment of magnifying reading aids.

Scotoma Simulation in Healthy Subjects

SIGNIFICANCE

This article shows a successful concept for simulating central scotoma, which is associated with age-related macular degeneration (AMD), in healthy subjects by an induced dark spot at the retina using occlusive contact lenses. The new concept includes a control mechanism to adjust the scotoma size through controlling pupil size without medication. Therefore, a miniaturized full-field adaptation device was used.

PURPOSE

The aim of this study was to design a novel concept to simulate AMD scotoma in healthy subjects using occlusive contact lenses.

METHODS

To define an optimal set of lens parameters, we constructed an optical model and considered both the anatomical pupil diameter and the opaque central zone diameter of the contact lens. To adjust the scotoma size, we built a miniaturized full-field adaptation device. We demonstrate the validity of this novel concept by functional measurements of visual fields using automated threshold perimetry. Finally, we conducted a perception study including two tasks, consisting of pictograms and letters. The stimuli were presented at different eccentricities and magnifications.

RESULTS

The visual fields of all 10 volunteers exhibited absolute scotomas. The loss of contrast sensitivity ranged within 27 and 36 dB (P < .05), and the scotoma localizations were nearly centered to the macula (mean variation, 2.0 ± 4.8° horizontally; 3.5 ± 4.7° vertically). The eccentric perception of letters showed the largest numbers of correctly identified stimuli. The perception of pictograms showed significantly reduced numbers (P < .0001) and revealed a dependency on magnification. The results suggest that best perception is possible for magnified stimuli near the scotoma.

Conclusions

We demonstrated that the creation of an absolute simulated AMD scotoma is possible using occlusive contact lenses combined with a miniaturized full-field adaptation device.

Effects of visual search training in children with hemianopia

BACKGROUND

This study investigates the effect of a new computer-based visual search training (VST) that was adapted for children with homonymous hemianopia (HH).

METHODS

22 children with HH (median age 11 years, 8 months: 6y6m-19y2m) trained at home for 15 minutes twice/day, 5 days/week, for 6 weeks. To assess performance before training (T1), directly after training (T2) and 6 weeks after the end of training (T3), we measured search times (STs) during on-screen search (with eye tracking), and in a real life search task. Additional variables analyzed during on-screen search were numbers, amplitudes, and durations of saccades, their directional patterns and the proportional number of saccades into the non-seeing field. The latter was the main variable during free viewing. Sixteen healthy age-matched children, who did not undergo the training, served as comparison group. Quality of Life (QoL)-questionnaires were also applied.

RESULTS

STs of the patients decreased significantly during the training and all search performance tests. This improvement persisted 6 weeks after the end of the training. Saccade amplitudes increased, total number of saccades to find the target decreased, and the proportional number of saccades to the non-seeing side increased. These changes were maintained at T3. Saccade durations did not change. During free viewing, saccades were equally distributed to both sides before and after training. Patients reported improvements in QoL and activities of daily living. Performance in the healthy children did not change by simply repeating the visual search test.

CONCLUSIONS

The improvement in STs in all search tasks, larger and fewer saccades, and an improved search strategy after VST suggests that the children with HH benefited from the training. The maintained improvement at T3 and the improvement in the real life search task indicate that the newly developed search strategy persists and can be applied to everyday life.

The anatomy of the foveola reinvestigated

Objective

In the foveola of the eye, photoreceptors and Müller cells with a unique morphology have been described, but little is known about their 3D structure and orientation. Considering that there is an angle-dependent change in the foveolar photoreceptor response for the same light beam, known as the Stiles Crawford Effect of the first kind (SCE I), which is still not fully understood, a detailed analysis of the anatomy of the foveolar cells might help to clarify this phenomenon.

Methods

Serial semithin and ultrathin sections, and focused ion beam (FIB) tomography were prepared from 32 foveolae from monkeys (Macaca fascicularis) and humans. Foveolae were also analyzed under the electron microscope. Serial sections and FIB analysis were then used to construct 3D models of central Müller and photoreceptor cells. In addition, we measured the transmission of collimated light under the light microscope at different angles after it had passed through human foveae from flat mounted isolated retinae.

Results

In monkeys, outer segments of central foveolar cones are twice as long as those from parafoveal cones and do not run completely parallel to the incident light. Unique Müller cells are present in the central foveolae (area of 200 µm in diameter) of humans and monkeys. Light entering the fovea center, which is composed only of cones and Müller cells, at an angle of 0° causes a very bright spot after passing through this area. However, when the angle of the light beam is changed to 10°, less light is measured after transpasssing through the retina, the foveolar center becomes darker and the SCE-like phenomenon is directly visible. Measurements of the intensities of light transmission through the central foveola for the incident angles 0 and 10° resemble the relative luminance efficiency for narrow light bundles as a function of the location where the beam enters the pupil as reported by Stiles and Crawford. The effect persisted after carefully brushing away the outer segments.

Conclusion

We show that unique cones and Müller cells with light fibre-like properties are present in the center of the fovea. These unique Müller cells cause an angle dependent, SCE-like drop in the intensity of light guided through the foveola. Outer segments from the foveolar cones of monkeys are not straight.

Revisiting Vision Rehabilitation

Low vision is a condition caused by eye or brain disease, in which visual acuity is 20/70 (3/10 or 6/18) or poorer in the better-seeing eye and cannot be corrected or improved with regular eyeglasses. It impacts personal ability to perform vision-dependent tasks as activities of daily living, walking, reading or using a computer. Rehabilitation is a multidisciplinary training dedicated to improve patients’ functional abilities and quality of life. It has to be personalized to every individual situation, whatever the underlying pathology.

Transcranial direct current stimulation (tDCS) combined with blindsight rehabilitation for the treatment of homonymous hemianopia: a report of two-cases

[Purpose] Homonymous hemianopia is one of the most common symptoms following neurologic damage leading to impairments of functional abilities and activities of daily living. There are two main types of restorative rehabilitation in hemianopia: "border training" which involves exercising vision at the edge of the damaged visual field, and "blindsight training," which is based on exercising the unconscious perceptual functions deep inside the blind hemifield. Only border effects have been shown to be facilitated by transcranial direct current stimulation (tDCS). This pilot study represents the first attempt to associate the modulatory effects of tDCS over the parieto-occipital cortex to blindsight treatment in the rehabilitation of the homonymous hemianopia. [Subjects and Methods] Patients TA and MR both had chronic hemianopia. TA underwent blindsight treatment which was combined with tDCS followed by blindsight training alone. MR underwent the two training rounds in reverse order. [Results] The patients showed better scores in clinical-instrumental, functional, and ecological assessments after tDCS combined with blindsight rehabilitation rather than rehabilitation alone. [Conclusion] In this two-case report parietal-occipital tDCS modulate the effects induced by blindsight treatment on hemianopia.

The treatment methods for post-stroke visual impairment: A systematic review

AIM

To provide a systematic overview of interventions for stroke related visual impairments.

METHOD

A systematic review of the literature was conducted including randomized controlled trials, controlled trials, cohort studies, observational studies, systematic reviews, and retrospective medical note reviews. All languages were included and translation obtained. This review covers adult participants (aged 18 years or over) diagnosed with a visual impairment as a direct cause of a stroke. Studies which included mixed populations were included if over 50% of the participants had a diagnosis of stroke and were discussed separately. We searched scholarly online resources and hand searched articles and registers of published, unpublished, and ongoing trials. Search terms included a variety of MESH terms and alternatives in relation to stroke and visual conditions. Article selection was performed by two authors independently. Data were extracted by one author and verified by a second. The quality of the evidence and risk of bias was assessed using appropriate tools dependant on the type of article.

RESULTS

Forty-nine articles (4142 subjects) were included in the review, including an overview of four Cochrane systematic reviews. Interventions appraised included those for visual field loss, ocular motility deficits, reduced central vision, and visual perceptual deficits.

CONCLUSION

Further high quality randomized controlled trials are required to determine the effectiveness of interventions for treating post-stroke visual impairments. For interventions which are used in practice but do not yet have an evidence base in the literature, it is imperative that these treatments be addressed and evaluated in future studies.

Adaptation, perceptual learning, and plasticity of brain functions

The capacity for functional restitution after brain damage is quite different in the sensory and motor systems. This series of presentations highlights the potential for adaptation, plasticity, and perceptual learning from an interdisciplinary perspective. The chances for restitution in the primary visual cortex are limited. Some patterns of visual field loss and recovery after stroke are common, whereas others are impossible, which can be explained by the arrangement and plasticity of the cortical map. On the other hand, compensatory mechanisms are effective, can occur spontaneously, and can be enhanced by training. In contrast to the human visual system, the motor system is highly flexible. This is based on special relationships between perception and action and between cognition and action. In addition, the healthy adult brain can learn new functions, e.g. increasing resolution above the retinal one. The significance of these studies for rehabilitation after brain damage will be discussed.

Vision Rehabilitation in Patients with Age-related Macular Degeneration

Background

The aim of this study was to investigate the rehabilitative process and visual rehabilitation outcomes in patients with central vision loss due to age-related macular degeneration (AMD).

Methods

Ninety-five subjects with AMD selected from the attendees of the National Centre of Services and Research for the Prevention of Blindness and Rehabilitation of Low Vision Patients—International Agency for Prevention of Blindness—IAPB Italia Onlus, were evaluated for this retrospective study. Low vision examination included psychological counseling, best corrected visual acuity (BCVA), near visual acuity, Pelli-Robson contrast sensitivity, and fixation stability analysis. Once the clinical assessment was completed, patients attended a low-vision rehabilitative pathway based on visual stimulation, devices training and, if needed, psychological support. Required magnification and reading speed were also evaluated.

Results

For the whole sample, the mean BCVA of the better eye was 0.7 (±0.2) LogMAR and of the worse eye was 1 (±0.2) LogMAR. Restoring reading ability was the most important focus for the patients examined as it was requested by 85% of the whole sample. Mean power of optical magnifying aids for near activities was 10.6 (±9.1) positive spherical diopters. Mean reading speed for the whole sample was 33.1 (±18.2) words per minute (wpm) before visual rehabilitation sessions and increased to 55.2 (±33.1) wpm after visual rehabilitation path. To cope with distance difficulties, 78 distance refractive correction, 10 Galilean telescopes, and 7 Keplerian telescopes were prescribed. For intermediate distance activities, 22 compensation lenses and 10 Galilean telescopes were suggested. Moreover, PC magnifier softwares were prescribed to nine patients. Sixty-five polarized medical filters were prescribed to reduce glare of sunlight. Because of unstable fixation in their better eye (32.3% (±19.7) within 2° circle and 54.8% (±22.9) within 4° circle) and visual acuity < 1.2 LogMAR in the fellow eye, 38 subjects, before starting the devices training sessions, attended a bio-feedback rehabilitation session with flickering pattern stimulus. In these subjects, fixation stability increased significantly to 75.6 (±14.9) within 2° and 89.4 (±19.5) within 4° ( P < 0.05), respectively.

Conclusions

Attending a customized low-vision intervention based on a multidisciplinary approach seems to be effective for improving visual functions in AMD. Both optical/electronic magnifiers and specific visual stimulation program can enhance visual performances.

Biofeedback stimulation in patients with age-related macular degeneration: comparison between 2 different methods

OBJECTIVE

To evaluate changes in patient's visual performance after rehabilitation training with 2 different biofeedback training programs offered by the MP-1 microperimeter. Spontaneous retinal location of preferred retinal loci (PRLs) and fixation stability are not always optimal for best visual performances. MP-1 microperimeter biofeedback techniques have been suggested as modalities for training for better fixation stability and to find a better location of the new PRL in a more useful area of the retina in nonoptimal cases. The MP-1 microperimeter offers different biofeedback strategies, such as acoustic biofeedback and structured light stimulus plus acoustic biofeedback.

DESIGN

Retrospective study.

PARTICIPANTS

Thirty subjects affected by age-related macular degeneration with absolute central scotoma.

METHODS

A standard protocol of examination before and after visual rehabilitation training was performed on all study subjects. Assessment included demographics data, visual acuity, fixation stability, retinal sensitivity, and reading speed. Rehabilitation training was performed with standard and structured stimulus biofeedback. The whole sample was divided into 2 groups of 15 patients attending the 2 different stimulation training biofeedback.

RESULTS

Mean reading speed was found to be significantly increased for both groups (p < 0.05 and p < 0.01). Also, a statistically significant improvement of fixation stability was registered for both groups (p < 0.01). Only patients trained with the flickering pattern biofeedback stimulation increased retinal sensitivity (p < 0.01).

CONCLUSIONS

Both regular biofeedback and flickering pattern biofeedback training seem to improve visual functions. More benefits seem to be accrued, however, with flickering pattern biofeedback training.

Characterization of field loss based on microperimetry is predictive of face recognition difficulties

PURPOSE

To determine how visual field loss as assessed by microperimetry is correlated with deficits in face recognition.

METHODS

Twelve patients (age range, 26-70 years) with impaired visual sensitivity in the central visual field caused by a variety of pathologies and 12 normally sighted controls (control subject [CS] group; age range, 20-68 years) performed a face recognition task for blurred and unblurred faces. For patients, we assessed central visual field loss using microperimetry, fixation stability, Pelli-Robson contrast sensitivity, and letter acuity.

RESULTS

Patients were divided into two groups by microperimetry: a low vision (LV) group (n = 8) had impaired sensitivity at the anatomical fovea and/or poor fixation stability, whereas a low vision that excluded the fovea (LV:F) group (n = 4) was characterized by at least some residual foveal sensitivity but insensitivity in other retinal regions. The LV group performed worse than the other groups at all blur levels, whereas the performance of the LV:F group was not credibly different from that of the CS group. The performance of the CS and LV:F groups deteriorated as blur increased, whereas the LV group showed consistently poor performance regardless of blur. Visual acuity and fixation stability were correlated with face recognition performance.

CONCLUSIONS

Persons diagnosed as having disease affecting the central visual field can recognize faces as well as persons with no visual disease provided that they have residual sensitivity in the anatomical fovea and show stable fixation patterns. Performance in this task is limited by the upper resolution of nonfoveal vision or image blur, whichever is worse.

Psychological and educational recommendations for working with young people with Retinitis Pigmentosa

This article reviews the consequences of Retinitis Pigmentosa, a retinal degenerative disease with progressive reduction of the visual field, visual acuity, contrast sensitivity, and night blindness. Retinitis Pigmentosa is addressed from both a psychological and an educational standpoint, focusing on the impact on learning, emotional well-being, and the social relationships of young people and adolescents. We examine problems affected people have to face and offer suggestions and strategies to professionals working with individuals and family members.

Vision and night driving abilities of elderly drivers

OBJECTIVE

In this article, we review the impact of vision on older people's night driving abilities. Driving is the preferred and primary mode of transport for older people. It is a complex activity where intact vision is seminal for road safety. Night driving requires mesopic rather than scotopic vision, because there is always some light available when driving at night. Scotopic refers to night vision, photopic refers to vision under well-lit conditions, and mesopic vision is a combination of photopic and scotopic vision in low but not quite dark lighting situations. With increasing age, mesopic vision decreases and glare sensitivity increases, even in the absence of ocular diseases. Because of the increasing number of elderly drivers, more drivers are affected by night vision difficulties. Vision tests, which accurately predict night driving ability, are therefore of great interest.

METHODS

We reviewed existing literature on age-related influences on vision and vision tests that correlate or predict night driving ability.

RESULTS

We identified several studies that investigated the relationship between vision tests and night driving. These studies found correlations between impaired mesopic vision or increased glare sensitivity and impaired night driving, but no correlation was found among other tests; for example, useful field of view or visual field. The correlation between photopic visual acuity, the most commonly used test when assessing elderly drivers, and night driving ability has not yet been fully clarified.

CONCLUSIONS

Photopic visual acuity alone is not a good predictor of night driving ability. Mesopic visual acuity and glare sensitivity seem relevant for night driving. Due to the small number of studies evaluating predictors for night driving ability, further research is needed.

Radiologic presentation of pituitary adenoma

PURPOSE

This case report aims to educate the importance of ordering radiographic studies when suspicion arises: visual field defects and optic nerve appearance may lead to the discovery of otherwise asymptomatic central nervous system disease.

CASE REPORT

We describe a patient who was previously diagnosed and successfully treated for a pituitary adenoma but who presents with worsening visual acuity and visual field defects.

CONCLUSIONS

Pituitary tumors are the most common of all tumors arising from the sellar and parasellar region. Owing to the high prevalence and proximity of these tumors to the optic nerve, chiasm, and tract, it is especially important to incorporate an appropriate history, examination, and radiographic workup in patients with suspicious visual field or optic nerve appearances. It is also critical to have anatomic and physiologic familiarity with the sellar and parasellar region. This case report explores the clinical presentation, test results, anatomy and physiology, interdisciplinary co-management, and current and future treatments of pituitary adenomas.

Abandonment of low-vision devices in an outpatient population

PURPOSE

To investigate abandonment rate of prescribed low-vision devices for near tasks and factors associated with abandonment in a U.S. outpatient population.

METHODS

A telephone survey was administered to 88 patients with low vision from four clinical sites about 1 year after examination and prescription of devices. Patients were surveyed on timing and frequency of use and reasons for abandonment of devices. The main outcome measure (abandonment) was defined as patient report of no use of prescribed device in the previous 3 months. Multivariate logistic regression was used to investigate significant vision and demographic factors related to abandonment.

RESULTS

Of 119 prescribed devices, 19% (95% CI, 12 to 26) had not been used within the previous 3 months. Mean (±SD) better eye visual acuity at examination was 0.61 ± 0.29 logMAR, and mean age was 77 ± 17 years. Mean time between device prescription and survey was 11 ± 3 months. Device abandonment was not associated with age (p = 0.863), time since prescription (p = 0.125), visual acuity (p = 0.804), or category of magnification device (spectacle, handheld, stand, or video) (p = 0.412). There was a significant association between documented non-central visual field loss and abandonment of magnification device (p = 0.046). Repeat administration of the survey resulted in the same abandonment classification in 15 of 15 patients (100%).

CONCLUSIONS

Abandonment rate was similar for this outpatient population to those previously reported in the U.S. veteran inpatient population and in other countries. Patients with visual field loss may be more likely to abandon prescribed devices.

Comparison of visual field training for hemianopia with active versus sham transcranial direct cortical stimulation

BACKGROUND

Vision Restoration Therapy (VRT) aims to improve visual field function by systematically training regions of residual vision associated with the activity of suboptimal firing neurons within the occipital cortex. Transcranial direct current stimulation (tDCS) has been shown to modulate cortical excitability.

OBJECTIVE

Assess the possible efficacy of tDCS combined with VRT.

METHODS

The authors conducted a randomized, double-blind, demonstration-of-concept pilot study where participants were assigned to either VRT and tDCS or VRT and sham. The anode was placed over the occipital pole to target both affected and unaffected lobes. One hour training sessions were carried out 3 times per week for 3 months in a laboratory. Outcome measures included objective and subjective changes in visual field, recording of visual fixation performance, and vision-related activities of daily living (ADLs) and quality of life (QOL).

RESULTS

Although 12 participants were enrolled, only 8 could be analyzed. The VRT and tDCS group demonstrated significantly greater expansion in visual field and improvement on ADLs compared with the VRT and sham group. Contrary to expectations, subjective perception of visual field change was greater in the VRT and sham group. QOL did not change for either group. The observed changes in visual field were unrelated to compensatory eye movements, as shown with fixation monitoring.

CONCLUSIONS

The combination of occipital cortical tDCS with visual field rehabilitation appears to enhance visual functional outcomes compared with visual rehabilitation alone. TDCS may enhance inherent mechanisms of plasticity associated with training.

Treatment of homonymous visual field defects

OPINION STATEMENT

A clinical presentation of a retrochiasmal or homonymous visual field defect (HVFD) usually represents a permanent visual impairment. The visual and functional ramifications of HVFD will vary by patient. Comprehensive care-the clinical evaluation and consideration for treatment of HVFD-includes vision rehabilitation provided by optometrists, occupational therapists, or ophthalmologists. On the basis of individual patient needs, the eye care practitioner typically uses one or both of the following approaches to treat the HVFD: (1) field enhancement (also referred to in the literature as "field expansion"), in which optical systems incorporating prism are prescribed to optimize the use of the remaining vision, and (2) rehabilitative techniques including saccadic training ("compensation training") or vision restorative therapy ("restitution training"). Although lacking in strength, the evidence does support benefits from field enhancement and saccadic training for patients with HVFD, but vision restorative therapy has not been shown to be an effective option.

A randomized controlled trial comparing 2 interventions for visual field loss with standard occupational therapy during inpatient stroke rehabilitation

BACKGROUND AND PURPOSE

Compensatory and restorative treatments have been developed to improve visual field defects after stroke. However, no controlled trials have compared these interventions with standard occupational therapy (OT).

METHODS

A total of 45 stroke participants with visual field defect admitted for inpatient rehabilitation were randomized to restorative computerized training (RT) using computer-based stimulation of border areas of their visual field defects or to a computer-based compensatory therapy (CT) teaching a visual search strategy. OT, in which different compensation strategies were used to train for activities of daily living, served as standard treatment for the active control group. Each treatment group received 15 single sessions of 30 minutes distributed over 3 weeks. The primary outcome measures were visual field expansion for RT, visual search performance for CT, and reading performance for both treatments. Visual conjunction search, alertness, and the Barthel Index were secondary outcomes.

RESULTS

Compared with OT, CT resulted in a better visual search performance, and RT did not result in a larger expansion of the visual field. Intragroup pre-post comparisons demonstrated that CT improved all defined outcome parameters and RT several, whereas OT only improved one.

CONCLUSIONS

CT improved functional deficits after visual field loss compared with standard OT and may be the intervention of choice during inpatient rehabilitation. A larger trial that includes lesion location in the analysis is recommended.

Current methods of visual rehabilitation

BACKGROUND

Despite therapeutic progress, many diseases of the eyes and visual pathways still cause persistent visual deficits that make everyday life more difficult in many ways. Rehabilitation aims to compensate for these limitations by optimizing residual vision. The demand for visual rehabilitation will increase markedly in the near future.

METHODS

We summarize the state of the art in visual rehabilitation on the basis of a selective review of the literature, including randomized, controlled trials (RCTs) in the Cochrane and PubMed databases as well as Cochrane reviews. We also pay particular attention to studies illustrating an important principle or a clinically established method.

RESULTS

Central visual field defects impair reading. Persons with an absolute central scotoma can regain reading ability by eccentric fixation and text magnification. Many kinds of magnifying visual aids are available. Specific reading training can further improve reading speed. Peripheral field defects impair orientation. Persons with a concentric field defect can be helped by tactile aids, such as a cane, and with orientation and mobility training. Persons with hemianopia can benefit from compensatory saccadic training.

CONCLUSION

Suitable rehabilitative measures chosen after the thorough diagnostic evaluation of a visual impairment and analysis of its effects can usually restore reading ability, improve orientation, and thereby enhance the patient's independence and quality of life. As the demand for visual rehabilitation is increasing, steps will need to be taken to make it more widely available. Furthermore, as the scientific basis for visual rehabilitation is currently inadequate in some areas, more research in the field will be needed.

Rehabilitative techniques

This chapter deals with neuro-ophthalmological diseases at different levels of the afferent visual pathways with special regard to visual field defects, their functional impact, and their rehabilitation. The nature of these impairments and their significance for activities of daily living can be quite varied; an exact assessment of the residual function is required to determine specific rehabilitation approaches. Rehabilitation aims to compensate for the visual deficits by means of specific training and visual aids. Visual field defects in the center cause reading disability. Preconditions for reading are a sufficient size of the reading visual field or perceptual span and sufficient resolution of the retinal area used for reading. In central scotoma, as in macular or optic nerve disease, reading ability can be regained by eccentric fixation plus text magnification. In hemianopia, reading depends on the amount of sparing in the center, the side of the defect, and adaptive strategies. Field defects in the periphery cause orientation and mobility problems. In constricted fields, tactile training with a cane is indicated; in hemianopia, explorative saccadic training is effective. With the appropriate technique, rehabilitation can be very successful, and quality of life can be regained in most patients.

Reading Difficulty after Stroke: Ocular and non Ocular Causes

Background

Ocular causes of reading impairment following stroke include visual field loss, eye movement impairment and poor central vision. Non ocular causes may include cognitive errors or language impairment.

Aim

The purpose of this study was to identify all patients referred with suspected visual impairment who had reported reading difficulty to establish the prevalence of ocular and non ocular causes.

Methods

Prospective, multicentre, observation study with standardised referral and assessment forms across 21 sites. Visual assessment included visual acuity measurement, visual field assessment, ocular alignment, and movement and visual inattention assessment. Multicentre ethical approval and informed patient consent were obtained.

Results

A total of 915 patients were recruited, with a mean age of 69·18 years (standard deviation 14·19). Reading difficulties were reported by 177 patients (19·3%), with reading difficulty as the only symptom in 39 patients. Fifteen patients had normal visual assessment but with a diagnosis of expressive or receptive aphasia. Eight patients had alexia. One hundred and nine patients had visual field loss, 85 with eye movement abnormality, 27 with low vision and 39 patients with visual perceptual impairment. Eighty-seven patients had multiple ocular diagnoses with combined visual field, eye movement, low vision or inattention problems. All patients with visual impairment were given targeted treatment and/or advice including prisms, occlusion, refraction, low vision aids and scanning exercises.

Conclusions

Patients complaining of reading difficulty were mostly found to have visual impairment relating to low vision, eye movement or visual field loss. A small number were found to have non ocular causes of reading difficulty. Treatment or advice was possible for all patients with visual impairment.