Visual requirements for reading

Evaluation of a Retinal Projection Laser Eyeware in Patients with Visual Impairment Caused by Corneal Diseases in a Randomized Trial

PURPOSE

Patients with incurable corneal diseases experience visual impairment (VI) despite having a healthy retina and optic pathway. Low-vision aids (LVAs) can optimize the use of remaining vision through magnification and contrast enhancement, but do not harness the full visual capacity because they rely on the optic media. Therefore, we investigated a novel laser eyewear (LEW) technology that bypasses the anterior segment of the eye. Images captured by an integrated camera are projected directly onto the retina using a low-energy laser. The patient is able to view a full-color video, realized as augmented reality. We aimed to evaluate the efficacy of the LEW to enhance the vision of individuals with corneal diseases.

DESIGN

Prospective, randomized, crossover clinical trial.

PARTICIPANTS

We examined the retinal projection glasses in 21 patients (25-69 years) with VI (0.7 logarithm of the minimum angle of resolution [logMAR] or worse) resulting from corneal diseases. Patients with comorbidities that impact vision, such as retinal disorders, were excluded.

METHODS

Standardized measurements of visual acuity (VA) for near vision (NV) and distance vision (DV) were conducted using ETDRS charts with the respective best correction (BC) and then with LEW. In addition reading speed, vision-related quality of life (QoL) and capacity to carry out daily tasks were assessed at an initial visit and at 2 subsequent visits after a home phase with and without the device. Six weeks after last use of the LEW, an ophthalmologic examination including spectral-domain-OCT or full-field-electroretinography was conducted and compared with baseline findings to evaluate the safety of the device. Four patients participated and completed a subsequent 12-month follow-up phase.

MAIN OUTCOME MEASURES

Improvement of VA using the LEW. Secondary objectives included safety, reading speed, QoL, and usability in daily activities.

RESULTS

The mean VA in patients with VI was improved by 0.43 logMAR in DV using the LEW compared with BC (P < 0.0001). Using the ×2 magnification mode of the LEW resulted in an average improvement of 0.66 logMAR compared with BC (P < 0.0001). In NV, an increase of 0.47 logMAR was achieved compared with BC (P < 0.0001). Although only 4 of 21 participants were able to read with BC, 17 of 21 participants were able to read with the LEW. Quality of life significantly improved in the 17 participants who completed all visits.

CONCLUSIONS

We demonstrated that the retinal projection glasses resulted in enhanced VA for all participants by directly projecting images onto the intact retina. In future, the LEW could represent a new option as an LVA for patients with corneal diseases. No pathological alterations were observed in the safety assessments.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Toward an internationally accepted standard for reading charts

Patients who suffer from sight-threatening eye diseases share a desire to regain a comfortable reading ability. In light of the modern advances achieved in ophthalmic diagnosis and therapy, and because a significant lack of comparability between reading charts still exists, there is an increasing need for a worldwide standard in the form of a norm for diagnostic reading charts. Already, applied advancements such as digital print, which allow a calibration of the print sizes of reading charts in correctly progressing geometric proportions by using the actual height of a lower case "x" in millimeters (x-height), and psychophysically standardizing reading charts and their test items by applying modern statistical methods have significantly contributed to establishing a norm for reading charts. In 2020, a proposal of the British delegation was accepted by the International Organization for Standardization (ISO) group "Visual Optics and Optical Instruments," and a working group was established. Bearing in mind the efforts of the ISO with regard to an international norm, this review article is intended to (a) give an overview of the historical background and related normative approaches for diagnostic reading tests used in ophthalmology and optometry, (b) explain psychophysical and technical concerns, and (c) discuss the possibilities and limits of concepts that seem relevant to developing a modern standard for reading charts.

A systematic review of the impact of childhood vision impairment on reading and literacy in education

PURPOSE

This systematic review evaluates current literature on the impact vision impairment has on reading and literacy levels within education.

METHODS

Six databases were searched with inclusion criteria of trials or studies involving children who are blind or vision impaired, and impact on academic or school performance - including reading and literacy. 1262 articles were identified, with 61 papers undergoing full screening. Quality appraisal was performed using Critical Appraisal Skills Program (CASP) and seven articles deemed eligible for inclusion.

RESULTS

Included articles achieved a quality score of over 70 % using the CASP checklists. Direct comparison of articles was not possible due to methodological differences in assessing reading and literacy levels. All seven studies investigated aspects of reading speed, with additional measures of reading performance, such as reading reserve, comprehension, and reading accuracy.

DISCUSSION

Underlying trends highlighted students with a vision impairment do not perform at same level as their normally sighted peers with respect to reading performance - in terms of speed, but not ability. Additionally, early intervention to enhance literacy skills may help improve educational outcomes. Future direction should be aimed at identifying specific obstacles to learning these students face and providing interventions to improve academic outcomes.

2022 Glenn A. Fry Award lecture: Enhancing clinical assessment for improved ophthalmic management

ABSTRACT

Detailed clinical assessment is critical to allow sensitive evaluation of the eye and its management. As technology advances, these assessment techniques can be adapted and refined to improve the detection of pathological changes of ocular tissue and their impact on visual function. Enhancements in optical medical devices including spectacle, contact, and intraocular lenses have allowed for a better understanding of the mechanism and amelioration of presbyopia and myopia control. Advancements in imaging technology have enabled improved quantification of the tear film and ocular surface, informing diagnosis and treatment strategies. Miniaturized electronics, large processing power, and in-built sensors in smartphones and tablets capacitate more portable assessment tools for clinicians, facilitate self-monitoring and treatment compliance, and aid communication with patients. This article gives an overview of how technology has been used in many areas of eye care to improve assessments and treatment and provides a snapshot of some of my studies validating and using technology to inform better evidence-based patient management.

MNREAD Reading Vision in Adults With Glaucoma Under Mesopic and Photopic Conditions

Purpose

Despite good photopic visual acuity, glaucoma patients report difficulty performing daily activities under dim light such as reading. Here we investigated the impact of mesopic lighting conditions on reading vision of glaucoma patients.

Methods

The study design included 39 patients with glaucoma and 40 healthy controls. Reading vision was assessed with MNREAD charts under mesopic (2 cd/m2) and photopic (220 cd/m2) conditions. Four reading indexes: maximum reading speed (MRS), critical print size (CPS), reading acuity (RA), and reading accessibility index (ACC) were obtained from the MNREAD test yielding a plot of reading speed versus print size.

Results

Compared to photopic conditions, reading vision of both healthy controls and glaucoma patients significantly decreased under mesopic conditions (P < 0.05). For glaucoma patients (85% with mild or moderate glaucoma), MRS and ACC decreased by six words per minute and 0.1, respectively under mesopic conditions; CPS and RA increased by 0.25 and 0.18 logMAR, respectively. Moreover, under both photopic and mesopic conditions, reading vision of glaucoma patients was significantly worse than that of healthy controls, but the difference was greater under mesopic conditions (P < 0.05) even after controlling for age and visual acuity.

Conclusions

Mesopic conditions make reading more challenging for both healthy controls and glaucoma patients. However, reading in dim light appears to be more burdensome for glaucoma patients. Mesopic reading tests mediated by both cone and rod photoreceptor systems likely provide a more sensitive and comprehensive assessment of a patient's reading impairment than testing under photopic conditions.

Efficacy οf Wet Age-related Macular Degeneration Treatment οn Reading: A Pilot Study Using Eye-movement Analysis

SIGNIFICANCE

Functional vision, as evaluated with silent passage reading speed, improves after anti-vascular endothelial growth factor (anti-VEGF) treatment in patients with wet age-related macular antidegeneration (wAMD), reflecting primarily a concomitant reduction in the number of fixations. Implementing eye movement analysis when reading may better characterize the effectiveness of therapeutic approaches in wAMD.

PURPOSE

This study aimed to evaluate silent reading performance by means of eye fixation analysis before and after anti-VEGF treatment in wAMD patients.

METHODS

Sixteen wAMD patients who underwent anti-VEGF treatment in one eye and visual acuity (VA) better than 0.5 logMAR served as the AMD group. Twenty adults without ocular pathology served as the control group. Central retinal thickness and near VA were assessed at baseline and 3 to 4 months after their first visit. Reading performance was evaluated using short passages of 0.4-logMAR print size. Eye movements were recorded using EyeLink II video eye tracker. Data analysis included computation of reading speed, fixation duration, number of fixations, and percentage of regressions. Frequency distributions of fixation durations were analyzed with ex-Gaussian fittings.

RESULTS

In the AMD group, silent reading speed in the treated eye correlated well with central retinal thickness reduction and improved significantly by an average of 15.9 ± 28.5 words per minute (P = .04). This improvement was accompanied by an average reduction of 0.24 ± 0.38 in fixations per word (P = .03). The corresponding improvement in monocular VA was not statistically significant. Other eye fixation parameters did not change significantly after treatment. No statistically significant differences were found in the control group.

CONCLUSIONS

Visual acuity tests may underestimate the potential therapeutic effects after anti-VEGF treatment in patients with relatively good acuity who are being treated for wAMD. Evaluating silent reading performance and eye fixation parameters may better characterize the effectiveness of therapeutic approaches in wAMD patients.

Reading Vision in Adults With Early and Intermediate Age-Related Macular Degeneration Under Mesopic and Photopic Conditions

Purpose

Reading is involved in various daily activities that operate under a wide range of luminance levels. Rod- and cone-mediated mesopic visual function is known to be impaired even in early/intermediate age-related macular degeneration (AMD). It remains unclear whether and to what extent mesopic reading is impaired in early/intermediate AMD. Here, we assessed differences in reading vision between photopic and mesopic conditions in early/intermediate AMD and compared their performance to those in older adults with normal macular health.

Methods

The study included 30 patients with early/intermediate AMD and 30 healthy controls. Reading performance was tested on the MNREAD iPad app under mesopic (2 cd/m2 with a neural-density filter) and photopic (220 cd/m2) conditions. Four reading indices-maximum reading speed (MRS), critical print size (CPS), reading acuity (RA), and reading accessibility index (ACC)-were obtained from the MNREAD test, yielding a function representing reading speed versus print size.

Results

Compared to photopic conditions, patients with AMD and healthy controls both exhibited noticeable decreases in reading vision under mesopic conditions (P < 0.001) despite normal photopic visual acuity. This decrease was more pronounced in AMD even after adjusting for age (P < 0.001): Under mesopic conditions, MRS and ACC decreased by 8 words per minute and 0.1, respectively; CPS and RA were enlarged by 0.27 and 0.24 logMAR, respectively.

Conclusions

Reading vision deteriorates under mesopic conditions compared to photopic conditions in early/intermediate AMD and is accentuated compared to this difference in healthy controls.

Translational Relevance

A mesopic reading test may provide a more sensitive and comprehensive assessment of a patient's reading impairment.

Approaching rehabilitation in patients with advanced glaucoma

Vision loss from advanced glaucoma is currently irreversible and impairs functional visual ability to effectively perform everyday tasks in a number of distinct functional domains. Vision rehabilitation strategies have been demonstrated to be effective in low vision populations and should be utilized in persons with advanced glaucoma to reduce disability and improve quality of life. Initial challenges to rehabilitation include an incomplete understanding of vision rehabilitation by the physician and patient, motivation to integrate rehabilitation into the plan of care, and availability of suitable providers to deliver this care. Physicians, working with well-trained vision rehabilitation providers can maximize function in important visual domains customized to the patient based on their needs, specific complaints, severity/pattern of visual damage, and comorbidities. Potential rehabilitative strategies to be considered for reading impairment include spectacle correction, visual assistive equipment, and sensory substitution, while potential strategies to facilitate driving in those deemed safe to do so include refractive correction, lens design, building confidence, restriction of driving to safer conditions, and avoiding situations where cognitive load is high. Mobility is frequently disrupted in advanced glaucoma, and can be addressed through careful distance refraction, behavior modification, home modification, mobility aids, walking assistance (i.e., sighted guide techniques), and smartphone/wearable technologies. Visual motor complaints are best addressed through optimization of lighting/contrast, sensory substitution, IADL training, and education. Special rehabilitative concerns may arise in children, where plans must be coordinated with schools, and working adults, where patients should be aware of their rights to accommodations to facilitate specific job tasks.

Collective endpoint of visual acuity and contrast sensitivity function from hierarchical Bayesian joint modeling

Clinical trials typically analyze multiple endpoints for signals of efficacy. To improve signal detection for treatment effects using the high-dimensional data collected in trials, we developed a hierarchical Bayesian joint model (HBJM) to compute a five-dimensional collective endpoint (CE5D) of contrast sensitivity function (CSF) and visual acuity (VA). The HBJM analyzes row-by-row CSF and VA data across multiple conditions, and describes visual functions across a hierarchy of population, individuals, and tests. It generates joint posterior distributions of CE5D that combines CSF (peak gain, peak frequency, and bandwidth) and VA (threshold and range) parameters. The HBJM was applied to an existing dataset of 14 eyes, each tested with the quantitative VA and quantitative CSF procedures in four Bangerter foil conditions. The HBJM recovered strong correlations among CE5D components at all levels. With 15 qVA and 25 qCSF rows, it reduced the variance of the estimated components by 72% on average. Combining signals from VA and CSF and reducing noises, CE5D exhibited significantly higher sensitivity and accuracy in discriminating performance differences between foil conditions at both the group and test levels than the original tests. The HBJM extracts valuable information about covariance of CSF and VA parameters, improves precision of the estimated parameters, and increases the statistical power in detecting vision changes. By combining signals and reducing noise from multiple tests for detecting vision changes, the HBJM framework exhibits potential to increase statistical power for combining multi-modality data in ophthalmic trials.

Comparison of visual performance and quality of life with a new nondiffractive EDOF intraocular lens and a trifocal intraocular lens

PURPOSE

To compare visual performance and quality of life (QoL) following bilateral implantation of a new nondiffractive extended depth-of-focus (EDOF) intraocular lens (IOL) and a trifocal IOL.

SETTING

Department of Ophthalmology, Baskent University Faculty of Medicine, Ankara, Turkey.

DESIGN

Prospective comparative interventional case series.

METHODS

104 eyes of 52 patients with cataract, bilaterally implanted with a nondiffractive EDOF IOL or a trifocal IOL, were included. Outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), distance corrected intermediate visual acuity and distance corrected near visual acuity, defocus curves, QoL (Visual Function Index 14), quality of vision (Quality of Vision [QoV] index), contrast sensitivity (Pelli-Robson chart), and binocular reading speed.

RESULTS

Twenty-six patients were included in each group. The UDVA and CDVA were better in the EDOF group (0.05 ± 0.04 and 0.01 ± 0.04) than the trifocal group (0.13 ± 0.06 and 0.11 ± 0.07) ( P = .02 and .01). Defocus curves showed that visual acuity was better with the EDOF IOL for vergences at 0.00, -0.50, and -1.00 and better with the trifocal IOL for vergences at -2.50, -3.00, -3.50, and -4.00. Contrast sensitivity scores were similar with both IOLs ( P = .12). The overall mean QoL scores were lower in the EDOF group, indicating a better QoL ( P = .04). The QoV was better in the EDOF group with significantly less glare, halos, and blurry vision ( P < .01).

CONCLUSIONS

The EDOF IOL performed better at distance, and the trifocal IOL performed better at near. Overall QoL and quality of vision were better with the EDOF IOL.

Luciole, a new font for people with low vision

Low vision affects the ability to read and can be a major barrier to educational success and insertion into the workplace. We designed a new font (Luciole) to improve the readability and comfort for people with low vision. In this study, we analyze the effect of the font type on readability. Luciole was compared to five other fonts (Arial, OpenDyslexic, Verdana, Eido and Frutiger) in 145 French readers (73 with low vision, and 72 normal sighted), aged 6 to 35 years old and divided into four reading expertise groups. Participants completed two tasks, first reading texts on paper and then reading false-words on screen using eye tracking. About half of the participants with low vision had a subjective preference for Luciole when reading on paper and on the screen; lower preference is noted for participants with normal vision. Other readability criteria show a slight advantage of the Luciole font over some fonts (e.g., Eido and OpenDyslexic) in both groups. The results obtained when taking into consideration the level of reading expertise confirm this trend.

A gaze-contingent saccadic re-referencing training with simulated central vision loss

Patients with central vision loss (CVL) adopt an eccentric retinal location for fixation, a preferred retinal location (PRL), to compensate for vision loss at the fovea. Although most patients with CVL are able to rapidly use a PRL instead of the fovea, saccadic re-referencing to a PRL develops slowly. Without re-referencing, saccades land the saccade target in the scotoma. This results in corrective saccades and leads to inefficient visual exploration. Here, we tested a new method to train saccadic re-referencing. Healthy participants performed gaze-contingent visual search tasks with simulated central scotoma in which participants had to fixate targets with an experimenter-defined forced retinal location (FRL). In experiment 1, we compared single-target search and foraging search tasks in the course of five training sessions. Results showed that both tasks improved the efficiency of gaze sequences and led to saccadic re-referencing to the FRL. In experiment 2, we trained participants extensively for 25 sessions, both with and without a gaze-contingent FRL-marker visible during training. After extensive training, observers' performance approached that of foveal vision. Thus, gaze-contingent FRL-fixation may become an efficient tool for saccadic re-referencing training in patients with central vision loss.

Habitual visual acuity and visual acuity threshold demands in Nigerian school classrooms

This study was designed to estimate the burden of blindness and vision impairment in school children, and to determine the proportion of students meeting the visual acuity (VA) demand for their classrooms. From 148 primary and secondary school classrooms in Edo State, Nigeria, the habitual distance and near VA of over 2000 students were measured. Values obtained were compared with the calculated distance VA demand and actual near VA demand for their classrooms. Measures used to calculate the VA demand were working distance and smallest text size on learning materials, at both distance and near. We also determined the relationship between age and calculated VA demand and the effect of factors such as school ownership and school type on the VA  demand. Habitual distance vision impairment was found in 0.8% of pupils, including 2 (0.10%) who met the WHO criteria for blindness. The average VA demand at the furthest and nearest sitting position to the board was 0.21 ± 0.23 and 0.65 ± 0.33LogMAR, respectively. Near working distance of students ranged from 15.00 to 37.20 cm, and the near VA demand as well as actual near VA demand (using a 2.5 times acuity reserve) was 0.60 ± 0.17 and 0.20 ± 1.7LogMAR, respectively. LogMAR VA demand increased (size of print decreases) with increasing age, at both distance (r =  - 0.549, p = 0.070) and near (r =  - 0.921, p < 0.0001). The VA demand at maximum distance and the actual near VA demand differed significantly by school ownership and between primary and secondary schools. Most students had VA better, but up to 11% of students per class had VA poorer than their classroom demands. Although the majority of students had better VA than their classroom demands, for students with reduced vision, learning could be negatively impacted. It is important to continually screen students for vision impairment and ensure prompt referral and treatment. These findings have implications for managing vision problems in children, as well as enabling appropriate classroom arrangements for those with vision impairment.

Digital Reading with Low Vision: Principles for Selecting Display Size

SIGNIFICANCE

Digital reading devices have become increasingly popular among people with low vision. Because displays come in many sizes ranging from smart watches to large desktop computer displays, it is important to have principles to guide people with low vision in selecting suitable displays for reading.

PURPOSE

The selection of effective digital displays for reading by people with low vision focuses attention on the interacting effects of print size, display size, font, visual acuity, and reading distance. This technical report aims to provide principles for identifying the minimum size of digital displays required for fluent reading by people with low vision.

METHODS

We emphasize two critical factors in selecting an appropriate reading display: angular print size, which should exceed the individual's critical print size, and display size, which should allow at least 13 characters to be presented on each line. Our approach considers a low-vision individual's acuity and preferences for viewing distance and fonts.

RESULTS

Through an illustrative example, we demonstrate how our approach can be used to determine display size for a low-vision individual with 20/200 acuity and central field loss who wants to read at 30-cm viewing distance with the Times Roman font. We have developed a web application based on our recommended approach to provide easy access to our algorithm.

CONCLUSIONS

We provide a procedure to guide the selection of appropriate displays for a wide range of acuities. Our approach can help clinicians in making recommendations for their patients, digital product designers in developing more accessible devices, and low-vision individuals in selecting digital displays for reading.

Can listening provide a useful clinical estimate of low vision reading parameters?

PURPOSE

The purpose of this study was to determine whether a clinician can assess critical print size (CPS) and/or reading fluency by listening to a visually impaired patient reading aloud across a range of print sizes on an MNREAD chart, rather than needing to plot and analyse reading speed data as a function of print size.

METHODS

Fifty-six low vision participants were audio-recorded reading an MNREAD chart under standard conditions. Two experienced raters listened to the recordings and made judgments of the CPS (logMAR), and of the level of reading fluency achieved at large print sizes on a 4-point rating scale. Reading times were plotted as a function of print size to determine the CPS as the smallest print size that supported the participant's maximum reading speed (MRS) by inspection, and the MRS as the mean reading speed across print sizes including, and larger than, the CPS.

RESULTS

Listened CPS judgments made for each rater were slightly larger than the CPS values obtained by inspection (mean differences 0.04logMAR (p = 0.06), 0.08logMAR (p < 0.01); limits of agreement (LoA) ±0.28logMAR, ±0.39logMAR, respectively). CPS judgments were consistent both between raters (mean difference 0.04logMAR [p = 0.18]; LoA ±0.42logMAR) and between two judgments made by each rater (mean differences 0.00logMAR (p = 1.0), 0.03logMAR (p < 0.05); LoA ±0.23logMAR, ±0.17logMAR). Reading fluency could be categorised as 'functional' (MRS > 80 wpm) or 'non-functional' (MRS < 80 wpm) with a sensitivity of 88%-90% and a specificity of 100%.

CONCLUSIONS

Experienced raters listening to a patient reading an MNREAD chart can determine a clinically useful estimate of critical print size and can discriminate maximum reading speeds that are above and below that likely to provide sustained reading ability. Listening to a patient reading an MNREAD chart is an option for the low vision clinician's armoury of assessments.

Multicountry clinical outcomes of a new nondiffractive presbyopia-correcting IOL

PURPOSE

To evaluate the effectiveness and safety of a new presbyopia-correcting intraocular lens (IOL) with a nondiffractive design, DFT015, compared with an aspheric monofocal IOL, SN60WF.

SETTING

19 investigational sites in 4 countries: Australia, Canada, Spain, and the United Kingdom.

DESIGN

Prospective, randomized, parallel-group, controlled, assessor- and patient-masked clinical study.

METHODS

Participants aged ≥22 years with bilateral cataracts were randomized to DFT015 or SN60WF in a 5:4 ratio and masked until final postoperative follow-up at month 6. The primary effectiveness objective was superiority of DFT015 over SN60WF in mean monocular photopic distance-corrected intermediate visual acuity (DCIVA) at month 3. Secondary effectiveness objectives included noninferiority of DFT015 to SN60WF in mean monocular photopic corrected distance visual acuity (CDVA) and superiority in the mean monocular photopic distance-corrected near visual acuity (DCNVA) at month 3. Visual disturbances were assessed at month 6.

RESULTS

282 patients were randomized to DFT015 (n = 159) or SN60WF (n = 123). All effectiveness objectives were achieved at month 3 in first eyes. For monocular photopic results in first eyes, DFT015 demonstrated superior mean DCIVA (least squares means of -0.139 logMAR in favor of DFT015, P < .001), noninferior mean CDVA (97.5% upper confidence limit [UCL] of the difference was <0.1 logMAR) and superior mean DCNVA (95% UCL of the difference was <0.0 logMAR) compared with SN60WF at month 6. DFT015 exhibited a similar visual disturbance profile to that of SN60WF.

CONCLUSIONS

DFT015 provided superior intermediate and near vision and a similar visual disturbance profile compared with an aspheric monofocal IOL.

The Effect of Diquafosol Ophthalmic Solution on Clinical Parameters and Visual Function in Soft Contact Lens-Related Dry Eye

INTRODUCTION

This study evaluated the efficacy and safety of diquafosol ophthalmic solution (DQS) in soft contact lens (SCL)-related dry eye using artificial tear as a control.

METHODS

This study enrolled 26 patients with SCL-related dry eye. DQS and artificial tears (AT) were instilled into the right and left eyes, respectively, with their SCLs on. Dry eye examinations (including tear film breakup time, tear volume, and staining score) were performed and visual function (including contrast sensitivity) was also evaluated before (at baseline) and after treatment (at 4- and 8-week examinations). Subjective symptoms were assessed separately in each eye using a questionnaire on dry eye in contact lens wearers. The results were compared before and after treatment, and between the right eyes treated with DQS (the DQS eye) and the left eyes treated with AT (the AT eye) using the mixed effect model.

RESULTS

Corneal and conjunctival staining scores at 8-week examination were significantly lower than those at baseline in the DQS eye (p = 0.03; p < 0.001, respectively), but no significant changes were observed in the AT eye. Most subjective symptoms improved significantly in both the DQS and AT eyes. However, major subjective symptoms (dryness and blurry vision) improved significantly only in the DQS eye at 8-week examination. Contrast sensitivity at 8-week examination in the DQS eye improved significantly at 12 cycles/degree compared to baseline (p = 0.001) and was significantly better than that in the AT eye (p = 0.03). There were no adverse events related to DQS or AT.

CONCLUSIONS

DQS was effective and safe for SCL-related dry eye. DQS also improved contrast sensitivity.

TRIAL REGISTRATION

University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR), Identification No. UMIN000024064.

Clinical Outcomes, Contrast Sensitivity, Reading Performance and Patient Satisfaction Following Bilateral Implantation of AT LARA 829MP EDoF IOLs

Purpose

To evaluate the visual outcomes, contrast sensitivity, reading performance and patient satisfaction after bilateral implantation of AT LARA extended depth of focus (EDoF) intraocular lenses (IOLs).

Methods

Patients undergoing phacoemulsification for age-related cataract and satisfying the eligibility criteria underwent bilateral implantation with AT LARA EDoF IOLs (Carl Zeiss Meditec, Jena, Germany). At follow-up visits of 1, 3, 6 and 12 months, binocular uncorrected and corrected distance, intermediate and near visual acuity, reading performance, defocus curve, contrast sensitivity and patient satisfaction for dysphotopsia and spectacle independence were evaluated.

Results

A total of 60 eyes from 30 patients with a mean age of 65.40±7.71 years were included in the study. At 12 months, 83% of patients (n=25) had binocular cumulative uncorrected distance visual acuity (UDVA) of 20/20 or better. Postoperative spherical equivalent refraction accuracy was within ±0.50 D for 95% of eyes (n=57) and refractive cylinder accuracy was within ≤0.50 D in 95% of eyes (n=57). The mean binocular uncorrected near visual acuity (UNVA) was 0.16±0.09 logMAR, and the mean uncorrected intermediate visual acuity (UIVA) at 60 and 80 cm was 0.01±0.09 and 0.03±0.08 logMAR, respectively, at 12 months. Reading speeds at 40, 60 and 80 cm showed improvement over time. No patient had complaints of severe dysphotopsia and none of the patients required glasses for any activity. No eye underwent YAG-laser capsulotomy for significant posterior capsule opacification at the end of mean follow-up.

Conclusion

In our limited experience of 30 patients at 12 months, AT LARA EDoF IOLs resulted in excellent visual outcomes for uncorrected distance, intermediate and near visual acuity. The incidence of dysphotopsia and spectacle dependence was low, resulting in good patient satisfaction.

Trial Registry

CTRI/2020/08/027105 (www.ctri.nic.in).

Evaluation of vision-related quality of life in retinitis pigmentosa patients with low vision

PURPOSE

To investigate the effect of sociodemographic and clinical characteristics on vision-related quality of life (QoL) in retinitis pigmentosa (RP) patients with low vision.

STUDY DESIGN

Retrospective.

PATIENTS AND METHODS

Thirty-three RP patients with low vision who had tunnel vision due to RP and 27 volunteers with healthy vision (controls) were included in the study. Visual loss was classified according to the International Classification of Diseases (ICD-10). The National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25) was used to determine vision-related QoL. Static automated perimetry (Central 30-2 threshold program) was used for visual field testing, and the degree of the central visual field was calculated. Reading speed was calculated using the Minnesota Low-Vision Reading Acuity Chart (MNREAD) with best near correction.

RESULTS

The mean total scores from the NEI VFQ-25 were 47.8 ± 15.8 in the RP group and 94.8 ± 4.3 in the control group (P < .001 for total and subscale scores). The mean total score and the social functioning and dependency scores were higher in the men than in the women (P = .016). The NEI VFQ-25 scores increased when reading speed was above 80 words per minute (wpm). Positive correlations were found between the degree of the central visual field and the mean total score and the general vision, near, and distance activities; social functioning; mental health; role difficulties; dependency; and color vision scores. The factors that affected the NEI-VFQ-25 score the most were male sex and degree of the central visual field in the RP group, whilst education level and the presence of systemic disease were the most effective factors in the controls.

CONCLUSION

The only modifiable factor affecting vision-related QoL in patients with RP was reading speed; thus, QoL could improve if reading speed is increased in patients with RP.

Assessing optimal colour and illumination to facilitate reading: an analysis of print size

PURPOSE

This study examined how optimal colour/illumination conditions and the efficacy of the iPad, LuxIQ and Smart Bulb varied as a function of print size in younger, older and visually impaired adults.

METHODS

Participants with visual impairments and simulated low vision (SLV) read the MNRead using the iPad, LuxIQ and Smart Bulb.

RESULTS

In the impairment condition at 1.20 logMAR, the iPad (M = 9.49, 95% CI [3.18, 19.42]) and LuxIQ (M = 15.95, 95% CI [9.54, 24.86]) improved the reading speeds. At 0.80 logMAR (SLV), all devices improved reading speeds of older adults (iPad (M = 28.70, 95% CI [14.65, 42.51]); LuxIQ (M = 49.63, 95% CI [30.04, 69.68]); Smart Bulb (M = 23.11, 95% CI [3.33, 42.11])), but in younger adults only the LuxIQ (M = 13.04, 95% CI [3.21, 21.27]) did so. In the impairment condition, the iPad (M = 5.54, 95% CI [0.31, 12.13]) and LuxIQ (M = 13.90, 95% CI [7.88, 23.49]) improved reading speeds. In the SLV condition, age was a significant predictor of reading speed at 1.20 logMAR (F_3,164  = 10.74, p < 0.001, Adj. R²  = 0.16). At 0.80 logMAR, age and luminance, but not colour, were significant predictors (F_3,164  = 52.52, p < 0.001, Adj. R²  = 0.49). In the impairment condition, both age and lux were significant predictors of reading speed at 1.20 (F_3,85  = 7.14, p < 0.001, Adj. R²  = 0.20) and 0.80 logMAR (F_3,85  = 7.97, p < 0.001, Adj. R²  = 0.22), but colour was not.

CONCLUSIONS

Light source effectiveness and optimal colour/illumination vary as a function of print size. It appears that print size is the most important factor for improving reading speed. As print size decreases, luminance becomes crucial, and only at the smallest print sizes does the effect of colour become useful.

The impact of low vision on activities, participation, and goals among older adults: a scoping review

PURPOSE

Participation is a key outcome of rehabilitation. However, no reviews have investigated the impact of low vision on the activities, participation, and goals of older adults. This paper aims to review and synthesize available literature on how low vision impacts the activity and participation of older adults.

METHOD

A scoping review was conducted. The key findings were extracted from 30 full-text articles that met the selection criteria. The International Classification of Functioning, Disability and Health was used to frame the findings at the activity and participation levels.

RESULTS

At the activity level, the categories of Walking, Moving around in different locations, and Reading were commonly impacted by low vision. The main domains impacted at the participation level were Community, social and civic life and Interpersonal interaction and relationships. Only one study addressed the goals of older adults with low vision.

CONCLUSION

Low vision impacts reading, walking, and moving around in different locations. Rehabilitation therapists should be aware of and consider assessing these activities. Further research is needed on the impact of low vision on other functional activities, participation, and self-identified goals of older adults to guide clinical practice.Implications for rehabilitationLow vision has an impact on the activity level of older adults, consistently identified in the areas of walking and moving around in different locations and reading for knowledge and leisure.At the participation level, the impact of low vision is less frequently identified compared to the areas identified at the activity level, in the areas of leisure, social interactions and basic and instrumental ADL.Rehabilitation therapists working with older adults with low vision should assess clients' performance of moving around in different locations, in addition to walking, and include screening questions on the impact of low vision on driving.Rehabilitation therapists working with older adults with low vision should determine clients' reading needs and acquire competence in assessing clients' reading ability and providing intervention for different types of reading to enable them to continue participating in various life situations that require the performance of reading.

New methodology for measuring intraocular lens performance using acuity reserve

PURPOSE

To validate a new methodology of intraocular lens (IOL) assessment using acuity reserve analysis via area under the curve (AUC) to assess intermediate vision.

SETTING

Study 1 was conducted at 17 sites in Australia, Chile, and Europe. Study 2 was conducted at 15 sites in Australia, Brazil, and Europe.

DESIGN

Post hoc analyses of defocus curve results from 2 clinical trials (study 1: single-arm investigation of the AcrySof IQ PanOptix Trifocal IOL [model TFNT00; Alcon Research LLC]; study 2: comparative investigation of AcrySof PanOptix Trifocal IOL vs the AT LISA Trifocal IOL [model 839MP; Carl Zeiss Meditec AG]).

METHODS

Acuity reserve was calculated using AUC compared with visual demand (logMAR) at various distances. Study 1 validated the model; study 2 compared acuity reserve, for a range of defocus levels, for the 2 IOLs.

RESULTS

The defocus curve (study 1 [149 patients; 298 eyes]) showed good visual acuity (ie, >20/25) at all defocus levels; the AUC estimate showed 2 lines or more of reserve at -2.50 diopters. Comparative post hoc analysis (study 2 [182 patients]) demonstrated significantly improved acuity reserve with PanOptix IOL vs AT LISA IOL at 20 to 40 days postoperatively (P < .001) and 120 to 180 days postoperatively (P < .001).

CONCLUSIONS

Acuity reserve analysis using AUC represents a new methodology for comparative IOL assessment, providing additional detail beyond defocus curve analysis. This method demonstrated that the PanOptix Trifocal IOL was superior to the AT LISA Trifocal IOL (model 839MP) for visual acuity at near to intermediate distances with visual acuity reserve analysis.

Immersive reading in virtual and augmented reality environment

Purpose

This study aims to investigate “immersive reading,” which occurs when individuals read text while in a virtual reality (VR) or augmented reality (AR) environment.

Design/methodology/approach

In Experiment 1, 64 participants read text passages and answered multiple-choice questions in VR and AR head-mounted displays (HMDs) compared with doing the same task on liquid crystal display (LCD). In Experiment 2, 31 participants performed the same reading tasks but with two VR HMDs of different display quality.

Findings

Compared with reading on LCD as the baseline, participants reading in VR and AR HMDs got 82% (VR) and 88% (AR) of the information accurately. Participants tended to respond more accurately and faster, though not statistically significant, with the VR HMD of higher pixel density in the speed-reading task.

Originality/value

The authors observed the speed and accuracy of reading in VR and AR environments, compared with the reading speed and accuracy on an LCD monitor. The authors also compared the reading performance on two VR HMDs that differed in display quality but were otherwise similar in every way.

Availability of low vision services and barriers to their provision and uptake in Ghana: practitioners' perspectives

Background

Provision and uptake of low vision services are essential.

Objective

To assess the availability of low vision services and barriers to their provision and uptake in the Ashanti and Brong Ahafo regions of Ghana from the perspective of eye care practitioners.

Methods

A descriptive, quantitative, cross-sectional study design using semi-structured questionnaires was used to collect information from eye care practitioners selected from 58 eye care facilities in the Ashanti and Brong Ahafo regions of Ghana.

Results

Forty-four eye care practitioners from Ashanti region and 10 from Brong Ahafo region responded to the questionnaire. Seventeen (34%) of the 50 eye care facilities who reported having patients seeking low vision services in their facilities provided such services. Lack of low vision devices (94.4%) and equipment (87%) were reported to be the main barriers to the provision of low vision services. Major barriers to low vision services uptake were lack of awareness (88.7%), high cost (70.4%) and social unacceptability of low vision assistive devices (59.3%).

Conclusion

Lack of adequate low vision services and barriers to their provision and uptake impact negatively on efforts to prevent visual impairment and blindness in Ghana.

European, Multicenter, Prospective, Non-comparative Clinical Evaluation of an Extended Depth of Focus Intraocular Lens

PURPOSE

To evaluate clinical and safety results obtained with an extended depth of focus (EDOF) intraocular lens (IOL).

METHODS

In this European, multicenter, prospective, uncontrolled, interventional study, 77 patients were enrolled in the study, 71 patients received bilateral implantation of the Mini Well Ready EDOF IOL (SIFI S.p.A.), and 68 patients completed the study and were evaluated 2 to 4 months postoperatively. Each clinical examination recorded uncorrected (UDVA) and corrected (CDVA) distance visual acuity, uncorrected (UIVA) and distance-corrected (DCIVA) intermediate visual acuity, and uncorrected (UNVA), distance-corrected (DCNVA), and corrected (CNVA) near visual acuity. A defocus curve from +2.00 to -5.00 diopters (D) was obtained, contrast sensitivity and reading ability were assessed, and the perception of dysphotopsia was evaluated.

RESULTS

Mean binocular visual results showed UDVA, UIVA, and UNVA values of -0.01 ± 0.15, 0.03 ± 0.10, and 0.10 ± 0.11 logMAR, respectively. Mean binocular defocus curve demonstrated a visual acuity of 0.30 logMAR or better from +2.00 to -3.00 D. Mean photopic contrast sensitivity values were 1.86, 2.18, 1,97, 1.51, and 1.17 at 1.5, 3.0, 6.0, 12.0, and 18.0 cycles per degree, respectively. A fluent reading speed of 80 words per minute was reached at 0.5 logRAD by 95.31% of patients without distance correction. The mean halo size was 33.06 ± 14.25, mean halo intensity was 38.00 ± 18.51, mean glare size was 23.85 ± 10.43, and mean glare intensity was 42.23 ± 13.22. One postoperative complication, a moderate photophobia, was observed and classified as related to the lens.

CONCLUSIONS

The Mini Well Ready EDOF IOL provides good visual acuity across various distances and functional reading ability provided at a near range, and delivers an enhanced contrast sensitivity while causing a low incidence of photic phenomena. [J Refract Surg. 2020;36(7):426-434.].

Measurement properties of reading tests in subjects with maculopathy

PURPOSE

A reliable reading test provides a standardized measure of the visual component of reading performance. This study evaluated reproducibility, agreement and feasibility of five Dutch language continuous text reading tests used in clinical practice and research in visually impaired participants.

METHODS

In 42 participants with macular pathologies (mean age 77 years), the Colenbrander Reading Card (Colenbrander), International Reading Speed Texts (IReST), Laboratory of Experimental Ophthalmology (LEO) charts, 'de Nederlanders' (NED) and the Radner Reading Charts (Radner) were evaluated. The coefficient of repeatability was calculated for different reading parameters, and agreement between the reading tests was determined.

RESULTS

Between the reading tests, the differences found in repeatability for reading performance were mainly within the limit of one line (0.1 logMAR). Exceptions were the inter-session repeatability for critical print size: Colenbrander (0.35 logMAR), LEO (0.34), Radner (0.23). The highest agreement was found between the LEO and Radner; Reading acuity bias 0.03 logMAR (SD 0.10), CPS 0.03 (0.12).

CONCLUSION

This study shows that reading performance results obtained with reading tests are not always reliable and reading parameters could not always be properly assessed in participants with maculopathies. Therefore, choices regarding which reading test to use especially for research purposes should be based on both the feasibility and reliability of the reading test. The NED (a historical test) was the least feasible, and it is recommend that this test is no longer used. To allow standardized and comparable analysis of reading performance a highly standardized reading test, like the Radner is recommended.

Assessment of age‐related maculopathy using subjective vision tests

This paper reviews non-standard, clinical vision tests that may be used to detect the earliest visual loss in age-related maculopathy (ARM), before fundus changes are detected. We recommend a clinical test battery for all patients aged 60 years and older, comprising low luminance/low contrast (SKILL) VA or low contrast VA, desaturated D-15 colour vision assessment, flicker perimetry, glare recovery and dark adaptation if possible, together with conventional assessments of case history, ophthalmoscopy and high contrast visual acuity (VA) for the detection and diagnosis of ARM. Reading rate is also discussed as a potential indicator of early visual loss. For monitoring the progressive visual loss in age-related macular degeneration (AMD) and determining the requirements for optometric vision rehabilitation, we recommend more conventional clinical vision tests of distance and near visual acuity, reading rate, the effects of varying illumination and a functional central visual field assessment.

Visual function: the problem with eccentricity

Age-related macular degeneration (AMD) is the leading cause of blindness in developed countries. With an ageing population, the prevalence of such a condition has resulted in a large proportion of the population relying on peripheral vision to undertake activities of daily living. Peripheral vision is not a scaled-down version of the fovea, simply requiring larger print or increased contrast for detection of objects or reading text. Even when print size is scaled and eye movements are minimised, the peripheral retina cannot perform at the level of the foveal region. Understanding how and why reading performance is limited as a function of eccentricity has important implications for how we approach rehabilitation of patients with central visual loss. This brief review of the extensive literature on reading with peripheral vision and the research aimed at better reading rehabilitation for low vision patients focuses on why many of the problems associated with the reduced reading capability of peripheral vision cannot be completely solved with magnification, reducing eye movements or modifying print.

Do visual fields need to be considered in classification criteria within visually impaired shooting?

Classification within the sport of vision impairment (VI) shooting is based upon the athlete's visual function. This study aimed to determine whether more than one class of competition is needed within VI shooting on the basis of visual field loss. Qualification scores of 23 elite athletes were obtained at World Championship events in prone and standing shooting disciplines. Visual field data were obtained from classification data and from assessment at events. A standardized scoring protocol determined whether athletes had function (≥10 dB) or no function (<10 dB) at locations between 0-60 degrees eccentricity along 10 meridia. Visual field function was not associated with shooting performance in prone or standing disciplines (p > 0.05). Having measurable visual field function beyond 30 degrees made no difference to athletes' ability to shoot competitively in prone (p = 0.65) or standing disciplines (p = 0.47), although a potential impact on qualification was observed in the standing discipline. There was no evidence that loss of visual field function at any specific location adversely affected ability to shoot competitively. There is currently no evidence to consider visual fields in classification within prone or standing VI shooting, although further research is needed as the sport grows.

The effect of font size and type on reading performance with Arabic words in normally sighted and simulated cataract subjects

BACKGROUND

Previous investigations have shown that reading is the most common functional problem reported by patients at a low vision practice. While there have been studies investigating effect of fonts in normal and low vision patients in English, no study has been carried out in Arabic. Additionally, there has been no investigation into the use of optimum print sizes or fonts that should be used in Arabic books and leaflets for low vision patients.

METHODS

Arabic sentences were read by 100 normally sighted volunteers with and without simulated cataract. Subjects read two font types (Times New Roman and Courier) in three different sizes (N8, N10 and N12). The subjects were asked to read the sentences aloud. The reading speed was calculated as number of words read divided by the time taken, while reading rate was calculated as the number of words read correctly divided by the time taken.

RESULTS

There was an improvement in reading performance of normally sighted and simulated visually impaired subjects when the print size increased. There was no significant difference in reading performance between the two types of font used at small print size, however the reading rate improved as print size increased with Times New Roman.

CONCLUSION

The results suggest that the use of N12 print in Times New Roman enhanced reading performance in normally sighted and simulated cataract subjects.

Simple Vision Function Tests that Distinguish Eyes with Early to Intermediate Age-related Macular Degeneration

PURPOSE

To present and compare baseline vision findings in eyes with early age-related macular degeneration (E-AMD), intermediate AMD (I-AMD), and age-similar participants with normal aging changes to the retina (No-AMD).

METHODS

Two hundred and thirty-seven eyes of 125 individuals (66.4% female, mean age 75.3 years) were tested monocularly using several simple, rapid psychophysical tests: high contrast visual acuity, low contrast visual acuity at reduced luminance, contrast sensitivity, shape discrimination hyperacuity, colour vision, reading rate, and glare recovery. Retinal status was determined using colour fundus photographs that were graded according to the Beckman Initiative for Macular Research Classification Committee scale. Logistic regression analyses with generalized estimating equations were used to assess the association between each vision variable and AMD category, while taking into account the correlation between the two eyes.

RESULTS

Three vision measures (contrast sensitivity [CS], shape discrimination hyperacuity [SDH], and colour discrimination [DesatCCS]) were significantly and independently associated with intermediate AMD. Relative Risk Ratios (RRR), 95% Confidence Intervals (in parentheses), beta coefficients, and significance (p) for the I-AMD vs. No-AMD model are: CS: RRR = 6.5 (1.91-22.0), beta = 1.87, p < .01; SDH: RRR = 2.34 (1.24-4.44), beta = 0.85, p < .001; DesatCCS: RRR = 1.43 (1.22-1.68), beta = 0.36, p < .001. Performance on these measures was significantly poorer for participants with I-AMD vs. No-AMD.

CONCLUSIONS

Simple screening tests distinguish eyes with intermediate AMD from eyes with less severe AMD or normal aging changes. This suggests that these vision measures may be significant predictors of which participants will go on to develop advanced AMD.

Biofeedback stimulation in the visually impaired: a systematic review of literature

BACKGROUND

It is estimated that approximately 1.3 billion people live with some form of distance or near visual impairment. Numerous studies have been carried out to evaluate the effects of biofeedback (BF) and establish if it could be a useful tool in vision rehabilitation for various eye diseases.

OBJECTIVE

This systematic review aimed: 1) to examine the current evidence of BF efficacy for the rehabilitation of the visually impaired and 2) to describe methodological variations used in previous BF studies to provide recommendations for vision rehabilitation interventions.

METHODS

A systematic review was conducted in the Medline, PubMed, Cochrane Library and Web of Science databases to collect documents published between January 2000 and May 2020. Of the 1,960 studies identified, 43 met the criteria for inclusion. The following information was collected from each study: sample size, control group, any eye disease, apparatus used, frequency and number of sessions of BF, main outcomes of training and whether a follow-up was conducted. The first group included studies published as scientific articles in peer-reviewed journals. The second group included abstracts of studies presented at peer-reviewed conferences. Publications were also grouped according to the eye disease treated.

RESULTS

25 articles and 18 peer-reviewed conference abstracts (PRCAs) were included in this review. BF stimulation is a commonly used technique for the treatment of visual impairment caused by macular disease. Most BF studies evaluate the effect of training on the preferred retinal locus (PRL), particularly with regard to fixation location and stability. Across these studies, participants who received BF intervention improved fixation stability and reading speed. High variability in the number of sessions and the duration of BF training was found. Most studies did not use a control group.

CONCLUSIONS

The findings of this review present evidence for biofeedback treatment in vision rehabilitation, with improved oculomotor abilities. Currently, it is not possible to formulate evidence-based recommendations for a standard training procedure due to the poor quality of existing randomised controlled trials. High-quality studies are needed to develop standard protocols for a range of eye diseases.

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.

Reduced visual acuity is mirrored in low vision imagery

Research has examined the nature of visual imagery in normally sighted and blind subjects, but not in those with low vision. Findings with normally sighted subjects suggest that imagery involves primary visual areas of the brain. Since the plasticity of visual cortex appears to be limited in adulthood, we might expect imagery of those with adult-onset low vision to be relatively unaffected by these losses. But if visual imagery is based on recent and current experience, we would expect images of those with low vision to share some properties of impaired visual perception. We examined key parameters of mental images reported by normally sighted subjects, compared to those with early- and late-onset low vision, and with a group of subjects with restricted visual fields using an imagery questionnaire. We found evidence that those with reduced visual acuity report the imagery distances of objects to be closer than those with normal acuity and also depict objects in imagery with lower resolution than those with normal visual acuity. We also found that all low vision groups, like the normally sighted, image objects at a substantially greater distance than when asked to place them at a distance that 'just fits' their imagery field (overflow distance). All low vision groups, like the normally sighted, showed evidence of a limited visual field for imagery, but our group with restricted visual fields did not differ from the other groups in this respect. We conclude that imagery of those with low vision is similar to that of those with normal vision in being dependent on the size of objects or features being imaged, but that it also reflects their reduced visual acuity. We found no evidence for a dependence on imagery of age of onset or number of years of vision impairment.

Visual Demand and Acuity Reserve of Chinese versus English Newspapers

SIGNIFICANCE

This study suggests that Chinese newspaper characters are more legible than English newspaper letters. Characters in Chinese newspapers have higher acuity reserve than English newspapers.

PURPOSE

The purpose of this study was to evaluate visual demand and acuity reserve for Chinese newspapers in comparison with published data on U.S. newspapers.

METHODS

The test distances for visual acuity in Chinese clinical studies were reviewed systematically. Characters from different sections of newspapers printed in simplified Chinese were evaluated. The character height, frequency, and visual demand and acuity reserve of each newspaper section were determined for Chinese characters of the six different levels of complexity.

RESULTS

More than 70% of Chinese clinical studies measure near visual acuity at either 33 or 40 cm. The height of Chinese characters ranged from 1.95 to 3.28 mm across different sections of five newspapers compared with 1.0 to 2.0 mm for English letters. The frequency of Chinese characters from least to most complex ranged from 7 to 34% across 12 sections of one Chinese newspaper. The angular threshold across the six complexity levels of Chinese characters ranged from 4.62 to 5.93 arcmin (0.54 to 0.69 mm at 40-cm reading distance) with a weighted angular threshold of 5.18 arcmin compared with 3.37 arcmin (0.39 mm) for the English letters. For Chinese newspapers, at 40-cm reading distance, the acuity reserve for the smallest and largest median size was 3.55 and 4.61, respectively.

CONCLUSIONS

Chinese characters are larger than English characters in all newspaper sections newspapers by a factor of 1.60 to 2.34. Given that Chinese characters need to be 1.54 times larger than English letters to provide the same acuity reserve, on average, Chinese newspapers are more legible than U.S. English newspapers.

Long-Term Outcomes of Descemet Membrane Endothelial Keratoplasty in Eyes with Prior Glaucoma Surgery

PURPOSE

The purpose of this study was to evaluate the long-term outcomes of Descemet membrane endothelial keratoplasty (DMEK) in eyes that had previously undergone trabeculectomy and/or drainage device implantation.

DESIGN

Retrospective, noncomparative case series.

METHODS

Medical records of 251 consecutive DMEK procedures performed by 1 surgeon (S.X.D.) from 2013 to 2017 were reviewed. Patients with ≥2 years of follow-up were divided into 3 groups: eyes with prior glaucoma surgery (ST), eyes with medically treated glaucoma (MT), and eyes without glaucoma (NG). Main outcomes measured were visual acuity, endothelial cell count (ECC), rates of secondary graft failure (SGF), and postoperative complications.

RESULTS

Ninety procedures (87 eyes) met inclusion criteria. The mean follow-up period of all eyes was 38.4 ± 11.2 months (range, 24.2-64.4 months). At last follow-up, the proportion of eyes reaching a vision of ≥20/40 was higher than that before the DMEK procedure in each group (all P < .05). The rate of ECC loss was the highest in the ST group compared to that in the MT and NG groups (63.8% vs 47.6% vs 44.0%, respectively; P < .05) as well as the rate of SGF (41.6% vs 0% vs 2.4%, respectively; P < .05). The rate of SGF of repeat DMEK was higher than that of primary DMEK (P < .05). The rates of postoperative complications were similar among all groups (all P > .05).

CONCLUSIONS

In eyes with prior glaucoma surgery, DMEK achieved good long-term visual outcomes but experienced a higher rate of SGF than eyes without such comorbidity.

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.

Comparison of two extended depth of focus intraocular lenses with a monofocal lens: a multi-centre randomised trial

Purpose

The AT LARA 829MP is a next-generation extended depth of focus (EDOF) intraocular lens (IOL) providing continuous vision over a range of distances. The aim of this prospective multi-centre randomised trial was to compare two EDOF IOLs and one monofocal IOL.

Methods

Cataract patients between 50 and 80 years were randomised for bilateral implantation with either the AT LARA 829MP (EDOF), the TECNIS Symfony (EDOF) or the CT ASPHINA 409MP (monofocal). Follow-up was at 1 to 2 weeks, 1 month and 4 to 6 months.

Results

A total of 211 patients were randomised and included in the final analysis. Monocular depth of focus was significantly better for AT LARA 829MP eyes compared with that for TECNIS Symfony at all thresholds (p = 0.024, 0.001 and 0.006, for 0.1, 0.2 and 0.3 logMAR respectively) with no significant difference for binocular depth of focus. LARA eyes had significantly better monocular depth of focus at all levels compared with ASPHINA eyes (all p < 0.0001), while there was no significant difference between Symfony and ASPHINA eyes at 0.1 logMAR and 0.2 logMAR. Both EDOF IOLs were significantly better than the monofocal ASPHINA at all levels for binocular depth of focus (LARA: all p < 0.0001; Symfony: all p = 0.002). Distance visual acuity was similar for all IOLs at 6 months; intermediate and near visual acuity were significantly better for the EDOF IOLs than for the monofocal (p < 0.0001). Refraction improved in all groups relative to baseline. Contrast sensitivity was higher with the CT ASPHINA 409MP but both EDOF lenses had a better spectacle independence rate. At 6 months, all IOLs were well centred with no cases of tilt. No general safety issues were raised for any of the groups.

Conclusion

The two EDOF intraocular lenses investigated provided good visual outcomes with comparable visual acuity at all distances. The AT LARA 829MP provided the widest monocular depth of focus at 0.1 and 0.2 logMAR, with a clear superiority compared with the monofocal IOL. TECNIS Symfony was superior to the monofocal control at 0.3 logMAR. Spectacle independence and patient satisfaction were comparable.

Trial registration

Trial registered on https://clinicaltrials.gov/ under the identification NCT03172351 (date of registration 1 June May 2017).

Comparison of reading performance with low add bifocal and extended depth of focus intraocular lenses implanted with mini-monovision

PURPOSE

To evaluate reading performance, preferred reading distance, and spectacle independence in patients implanted with a low add multifocal or an extended depth of focus (EDOF) intraocular lens (IOL) after phacoemulsification.

METHODS

In this prospective study, patients were randomized into two groups: the diffractive multifocal Tecnis + 2.75 D (ZKB00) IOL (Tecnis + 2.75 group; 15 patients) or the EDOF Tecnis Symfony (ZXR00) IOL (Symfony group; 14 patients) for bilateral implantation with mini-monovision. Reading performance parameters (reading acuity [RA], critical print size [CPS], and maximum reading speed [MRS]) were evaluated with MNREAD acuity charts at 40 cm, and preferred reading distances and spectacle independence for near activities were assessed preoperatively and at the postoperative 1st, 3rd, and 6th months.

RESULTS

At the postoperative 6th month, binocular logMAR UNVA and DCNVA were significantly better in the Symfony group than in the Tecnis + 2.75 group (UNVA: 0.15 ± 0.07 vs. 0.22 ± 0.08, p = 0.046; DCNVA: 0.21 ± 0.05 vs. 0.28 ± 0.07, p = 0.043; respectively). There was no significant difference in reading performance parameters between the groups; however, the Symfony group preferred significantly closer reading distance than the Tecnis + 2.75 group (42.00 ± 4.67 cm; 45.87 ± 5.32 cm, respectively, p = 0.030). At the postoperative 6th month, 14.3% and 26.7% of patients reported that they needed spectacles, rarely or occasionally, for near activities in the Symfony and Tecnis + 2.75 groups, respectively (p > 0.05).

CONCLUSIONS

When implanted with mini-monovision, although functional near visual acuity and a high degree of spectacle independence at near distances were achieved with both IOLs, patients implanted with the EDOF IOL preferred closer reading distance than those implanted with the low add diffractive multifocal IOL.

Development and Validation of the Persian Version of the MNREAD Acuity Chart

Purpose:

To develop the Persian version of MNREAD acuity charts and test their repeatability in a normal adult population.

Methods:

Two hundred sentences were constructed using the most frequent words of 8-year-olds schoolbooks. The number of characters and sentence length were adjusted based on the design principles of the Minnesota Low Vision Reading Test. Two Persian language teachers checked the sentences for syntax and meaning. The accepted sentences were read by 20 adults and then by 20 children. Using RADNER charts method, the sentences with inappropriate reading time and repeated errors were excluded. Thirty-eight sentences were approved to create charts. To check the charts' validity and repeatability, 20 adults read both charts and a paragraph of a daily newspaper. Reading acuity, critical print size, and maximum reading speed were calculated. The measured reading speeds were compared to the readers' reading speeds for a paragraph of a daily newspaper. Bland-Altman plots were used to evaluate the agreement between the two charts.

Results:

Thirty-eight selected sentences were used in the final printed charts. There were significant correlations between maximum reading speed for Charts 1 and 2 (r = 0.87, P < 0.0001), Chart 1 and newspaper paragraph (r = 0.73, P = 0.001), and Chart 2 and newspaper paragraph (r = 0.83, P = 0.0001). Correlations were observed between reading acuities and critical print sizes of two charts (r = 0.72, P < 0.002 and r = 0.77, P = 0.00). The 95% limits of agreement in reading acuity, critical print size, and reading speed between Charts 1 and 2 were ± 0.034 logMAR, ±0.11 logMAR, and ±8.00 words per minute, respectively.

Conclusion:

The designed Persian MNREAD charts are repeatable and could be used reliably to calculate near acuity, reading speed, and critical print size in Persian-speaking people.