Usability of smartphone apps as reading aids for low vision patients

PURPOSE

Reading is one of the main complaints of low vision patients referred for visual rehabilitation, since it is fundamental for full participation in modern society. The purpose of this study was to analyse the usability of free smartphone apps with magnification tools as digital aids for reading visual rehabilitation in low vision patients.

METHODS

Low vision adult patients were included regarding the following criteria: best-corrected visual acuity in the better-seeing eye from 0.6 to 1.3logMAR, previous habit of smartphone use, without former aid adaptation. Android system was used for the selection of three applications (apps) to be tested as digital reading aids. Visual acuity (VA) for near, reading acuity (RA) and reading speed (RS) using each app were measured. The participants were also asked about apps usability concerning accessibility, focus adjustment and text tracking.

RESULTS

Seventeen participants (10 females - 58.8%) with ages ranging from 26 to 73 years (mean = 45.2 ± 13.1 years) were included. Mean binocular VA, RA and RS without the apps were respectively 1.00 ± 0.22 logMAR, 1.01 ± 0.28 logMAR and 41.7 ± 28.6 words/minute. Statistically better visual and RA results through the apps were found with a mean ≥9-line gain for both, and no significant difference for RS was found. All apps achieved good usability scores (means > 7).

CONCLUSIONS

All tested apps provided improvement in VA and reading performance, with proven usability. Free smartphone apps for magnification should be considered in reading rehabilitation programmes for low vision patients.Implications for rehabilitationReading is essential for performing productive daily activities and for full participation in modern society, being a clinical indicator of visual function and quality of life.Difficulty in reading is one of the main complaints of low vision patients referred for visual rehabilitation.Smartphone apps for magnification and readability optimization of printed texts may provide improvement in visual acuity and reading performance of low vision patients.Digital technologies should be considered in the low vision reading rehabilitation programme since they provide additional advantages such as accessibility, cost, portability and social acceptance.Usability is the user's experience when interacting with a software application and associated with pleasantness, usefulness, ease of use, safety and efficiency. Low vision patient's feedback on the usability of assistive technologies is important for a successful visual rehabilitation which meets his/her needs and expectations.

A Low Vision Reading Comprehension Test

The Low Vision Reading Comprehension Assessment (LVRCA) uses an 18-sentence cloze format in two equivalent forms to measure understanding of print reading by persons with macular degeneration. It requires nine minutes to administer and thus can be used in clinical settings. This article describes its development and a study of the reliability and validity of the LVRCA tested on 50 persons with macular degeneration.

Reading Proficiency of Elderly Visually Impaired Persons after Rehabilitation

This article reports on the results of a study of the reading proficiency of 3,200 visually impaired persons in Sweden (86 percent of whom were elderly) following training in the use of optical devices and a follow-up study of 5 percent of the sample three years later. After training, 95 percent of the original sample used optical aids as their preferred reading medium, 71 percent could read newsprint, and 50 percent read fluently. Three years later, there was a substantial drop in the number of patients using reading aids, although those who used them had become more proficient readers.

Assessing Variability in Reading Performance with the New Greek Standardized Reading Speed Texts (IReST)

SIGNIFICANCE

This article evaluates the standardized Greek version of the International Reading Speed Texts (IReST) set, which enriches interlanguage comparisons and international clinical studies of reading performance. Moreover, it investigates how specific textual and subject-related characteristics modulate the variability of reading speed across texts and readers.

PURPOSE

The purpose of this study was to develop a standardized Greek version of the IReST set and investigate how specific textual and subject-related factors modulate the variability of reading speed across texts and readers.

METHODS

The English IReST texts were translated to Greek and matched for length, content, and linguistic difficulty. The Greek IReSTs were presented at a distance of 40 cm and size of 1 M to assess reading speeds of 25 normally sighted native speakers (age range, 18 to 35 years). The participants read the texts aloud while reading time was measured by stopwatch. Reading performance included measurement of reading speed in three units of analysis. Reading efficiency was assessed using a word-level oral reading task. Statistical analysis included evaluation of subject- and text-related variability, as well as correlations between reading speed and specific textual and subject-related factors.

RESULTS

The average reading speed between texts was 208 ± 24 words/min, 450 ± 24 syllables/min, and 1049 ± 105 characters/min. Differences between readers accounted for the 76.6%, whereas differences across texts accounted for the 23.4% of the total variability of reading speed. Word length (in syllables per word) and median word frequency showed a statistically significant contribution to the variability of reading speed (r = 0.95 and 0.70, respectively). Reading speed was also statistically correlated with word reading efficiency (r = 0.68).

CONCLUSIONS

The addition of the Greek version in the IReST language pack is expected to be a valuable tool for clinical practice and research, enriching interlanguage comparisons and international studies of reading performance.

Ergonomic Enhancement for Older Readers with Low Vision

This study found that the provision of ergonomic workstations for 12 older persons with age-related macular degeneration who used low vision devices significantly increased the participants’ reading speed and decreased their discomfort when reading.

Increasing Reading Fluency in Elementary Students with Low Vision through Repeated Readings

The purpose of this study was to explore a user-friendly method to increase the reading fluency of four elementary students with low vision. An analysis of the effects of repeated readings on the students’ reading rates, error rates, and comprehension found that the intervention was successful in improving all four students’ reading fluency and did not adversely affect their error rates or comprehension. The results from generalized readings indicated that the students’ improved reading rates were generalized to classroom reading.

Rehabilitation of reading skills in patients with age-related macular degeneration

Reading is the most frequent clinical complaint and the primary goal for patients with macular degeneration seeking vision rehabilitation. The current prevalent methods for reading skills training across the globe are still magnification and basic scotoma awareness training. More recent studies showed that specific eccentric training, comprehension ability training, and specific oculomotor training are all beneficial to reading skills rehabilitation. In clinical practice, ophthalmologists should strive to implement reading skills methods that include assessment of cognitive skills, optimal eyewear, optimal reading material, PRL assessment, training of better oculomotor control, and efficient perceptual training.

Rehabilitation Approaches in Macular Degeneration Patients

Age related macular degeneration (AMD) is a visual disease that affects elderly population. It entails a progressive loss of central vision whose consequences are dramatic for the patient's quality of life. Current rehabilitation programs are restricted to technical aids based on visual devices. They only temporarily improve specific visual functions such as reading skills. Considering the rapid increase of the aging population worldwide, it is crucial to intensify clinical research on AMD in order to develop simple and efficient methods that improve the patient's visual performances in many different contexts. One very promising approach to face this challenge is based on perceptual learning (PL). Through intensive practice, PL can induce neural plasticity in sensory cortices and result in long-lasting enhancements for various perceptual tasks in both normal and visually impaired populations. A growing number of studies showed how appropriate PL protocols improve visual functions in visual disorders, namely amblyopia, presbyopia or myopia. In order to successfully apply these approaches to more severe conditions such as AMD, numerous challenges have to be overcome. Indeed, the overall elderly age of patients and the reduced cortical surface that is devoted to peripheral vision potentially limit neural plasticity in this population. In addition, ocular fixation becomes much less stable because patients have to rely on peripheral fixation spots outside the scotoma whose size keeps on evolving. The aim of this review article is to discuss the recent literature on this topic and to offer a unified approach for developing new rehabilitation programs of AMD using PL. We argue that with an appropriate experimental and training protocol that is adapted to each patient needs, PL can offer fascinating opportunities for the development of simple, non-expensive rehabilitation approaches a large spectrum of visual functions in AMD patients.

Safety and efficacy of an intraocular Fresnel prism intraocular lens in patients with advanced macular disease: initial clinical experience

PURPOSE

To perform a pilot study of a new in-the-bag Fresnel prism intraocular lens (IOL) designed to deviate the image from diseased to healthy retina in eyes with bilateral age-related macular degeneration (AMD).

SETTING

Anterior segment subspeciality practice, Pretoria, South Africa.

DESIGN

Prospective nonmasked trial.

METHOD

Cataract surgery and unilateral implantation of the prismatic IOL were performed in patients with bilateral AMD and cataract. Outcomes were surgical complications, subjective and objective visual improvement, and undesirable optical effects.

RESULTS

Three eyes of 3 patients were evaluated. All patients reported displacement of the scotoma, and no patient reported diplopia. The only complication was posterior capsule opacification (1 eye).

CONCLUSIONS

Patients noted improved vision and no diplopia. This pilot was performed using a prototype IOL with single power and single angle of deviation; however, there is scope for individual patient optimization. This new technology merits further research and development because it may benefit large numbers of patients with stable end-stage AMD.

FINANCIAL DISCLOSURE

Dr. Claoué has a financial interest in the patent controlling the Fresnel prism IOL. Dr. Potgieter has no financial or proprietary interest in any material or method mentioned.

Measuring reading performance

Despite significant changes in the treatment of common eye conditions like cataract and age-related macular degeneration, reading difficulty remains the most common complaint of patients referred for low vision services. Clinical reading tests have been widely used since Jaeger introduced his test types in 1854. A brief review of the major developments in clinical reading tests is provided, followed by a discussion of some of the main controversies in clinical reading assessment. Data for the Salisbury Eye Evaluation (SEE) study demonstrate that standardised clinical reading tests are highly predictive of reading performance under natural, real world conditions, and that discrepancies between self-reported reading ability and measured reading performance may be indicative of people who are at a pre-clinical stage of disability, but are at risk for progression to clinical disability. If measured reading performance is to continue to increase in importance as a clinical outcome measure, there must be agreement on what should be measured (e.g. speed or comprehension) and how it should be measured (e.g. reading silently or aloud). Perhaps most important, the methods for assessing reading performance and the algorithms for scoring reading tests need to be optimised so that the reliability and responsiveness of reading tests can be improved.

Quality of vision: A consensus building initiative for a new ophthalmologic concept

PURPOSE

Many studies have addressed the quantification of visual acuity, and the conventional method of measuring it has so far demonstrated serious limitations. Vision testing requires new methods that can more precisely express the quality of vision as perceived by the patient.

METHODS

This study employed the Delphi method of consensus building. Concepts associated with quality of vision (QoV) were identified by a board of experts and proposed to participating specialists in two subsequent questionnaires. Upon receipt of the completed questionnaires, the replies were classified to determine the building blocks of a consensus.

RESULTS

By analyzing the replies to the two questionnaires, the authors determined the key elements of QoV on which a consensus was found among the respondents.

CONCLUSIONS

A consensus was reached on the opinion that the quantification of visual acuity by traditional means is inadequate for investigating QoV. Although visual acuity is still a basic element for testing, the experts believe that contrast sensitivity, reading speed, and microperimetry are additional parameters necessary for quantifying QoV. The use of a psychometric questionnaire on visual function could allow a better interpretation of visual impairment.

Occupational therapy interventions in low vision rehabilitation

Low vision can significantly decrease a person's functional ability and independence. With the continuing rise in age of our population, the number of people with low vision will increase substantially. Restoring and maintaining their ability to function independently through the use of specific interventions is an intricate process that calls for the collaboration of various health care professionals. Occupational therapists (OTs) and occupational therapy assistants are essential members of the multidisciplinary rehabilitation team providing such interventions. OTs in low vision rehabilitation enhance performance for specific activities of daily living by training skills that are dependent on residual vision, such as reading and writing. OTs also conduct environmental assessments in the home and in the workplace or school to improve and promote a safe environment for patients with low vision. OTs may also assist in developing rehabilitation programs for orientation and mobility, driving, and vision rehabilitation therapy. To prepare for the future needs of the ageing Canadian population, more low vision rehabilitation practitioners and more funding for multidisciplinary rehabilitation programs are required.

Image relocation with prisms in patients with age-related macular degeneration

BACKGROUND

To determine the benefits of image relocation (IR) with prisms in patients with age-related macular degeneration (AMD).

METHODS

This was a retrospective comparative interventional case series of 100 patients with AMD and 5 years of available follow-up records. Participants underwent complete low vision (LV) assessments, including identification of preferred retinal locus (PRL). Prisms were added to prescription glasses to produce IR to the presumed PRL. Main outcome measures were best-corrected visual acuity (BCVA), location of the PRL preferred by the patient for rehabilitation, use of glasses prescribed, and number of prism diopters prescribed.

RESULTS

Patients wearing prescribed glasses for distance with prisms for IR showed improved BCVA (t(63) = 9.5, p = 0.001) as did those patients wearing prescribed glasses for distance without prisms for IR (t(14) = 2.25, p = 0.04). Patients wearing prescribed glasses for distance with prisms for IR achieved better BCVA than those patients wearing prescribed glasses for distance without prisms for IR (t(77) = 2.0, p = 0.05). Patients reported using distance glasses with prisms for 3 to 48 months (mean [SD], 8.4 [11.7] mo). Number of prism diopters used (mean [SD], 5.8 [1.9] D) was well tolerated by all patients. PRL preferred by patients was on the upper retina in 98.5% of cases.

INTERPRETATION

IR with prisms to PRL in patients with AMD results in a significant and sizable improvement in BCVA. This effect is probably created by facilitation of oculomotor functions resulting from direct reduction of fixation instability.

Short-Term In-Office Practice Improves Reading Performance with Stand Magnifiers for People with AMD

PURPOSE

People with low vision often use optical low vision aids to assist reading. There have been numerous training programs recommended to train people using magnifiers for reading. However, most of the programs are time consuming and labor intensive. In this study, we investigated the effects of home-based large print reading practice on reading performance when stand magnifiers (STM's) are first prescribed.

METHODS

Thirty-two subjects with age-related macular degeneration (AMD) and with minimal experience in using magnifiers for reading were recruited. They were divided into three groups: control, practice 1 (P1), and practice 2 (P2). Before the prescription of STM's, all the subjects were given the same amount of in-office practice with the STM (weeks 0 to 2). In addition, in these 2 weeks, P1 and P2 subjects were given large print books to read daily at home. P2 subjects were required to read the large print books through a reduced field of view. The control group subjects received no additional reading practice. Reading rates with and without STM's on passages of text were assessed for all the subjects regularly for 20 weeks.

RESULTS

There were no significant differences between the control, P1, and P2 groups in the increase in reading rate with STM (p = 0.29). At week 0, reading rate for small print with STM was significantly slower than reading rate on the equivalent-sized large print (p = 0.004); however, as time went on, reading rate with STM's increased significantly (p = 0.02). After 2 weeks of in-office magnifier practice and repeated measures of reading rate with STM, reading rate with STM had improved such that it was not significantly different from reading rate on large print (p = 0.11).

CONCLUSION

Supervised, short-term, in-office practice with the magnifier was effective in improving magnifier reading performance to achieve maximum reading rate. Additional large print reading practice did not result in any greater improvement in reading rate than in-office magnifier practice alone.

Determining magnification for reading with low vision

BACKGROUND

In the past, practitioners have used distance and/or near visual acuity (VA) to calculate required magnification for low vision aids. Magnification was usually under-estimated when compared with the final magnification prescribed. Recent studies have emphasised the importance of acuity reserve in determining the required magnification for optimum reading rate. Two different approaches have been proposed for the appropriate acuity reserve to use in calculating magnification. These are a fixed acuity reserve of 0.3 log unit or an individual determination of optimum acuity reserve. The aim of this study was to investigate the magnification and reading rates with low vision aids selected by the two methods.

METHODS

Nineteen low vision subjects with age-related macular degeneration (AMD) who were experienced magnifier-users were recruited. Reading rates and near VA with low vision aids determined by the fixed and individual acuity reserve methods were compared with the same measures made with the subjects' own magnifiers.

RESULTS

There were no significant differences in reading rate and near VA measured with low vision aids selected by either the fixed or individual acuity reserve methods or the subjects' own magnifiers. Reading rate with low vision aids was not significantly different from reading rate for large print with conventional near additions. Thus, for experienced users, magnifiers do not cause reduced reading rate.

CONCLUSIONS

The fixed acuity reserve method is simple to apply as only near VA and print size of the target reading task are required. For the individual acuity reserve method, reading rates at different print sizes need to be measured. We recommend the use of a fixed acuity reserve (0.3 log unit) for the calculation of required magnification for low vision patients. If near VA or reading rate are not satisfactory with the magnification calculated by this method, individual assessment of required acuity reserve is necessary.