Critical Print Size Research Articles

Near visual function measured with a novel tablet application in patients with astigmatism

ABSTRACT Clinical relevance While the clinical focus of performance metrics is traditionally based on visual acuity, research from the field of visual impairment has demonstrated that metrics such as reading speed and critical print size correlate much more strongly with subjective patient reported outcomes and assessed ability in real‐world tasks. Background More recently, digital device use has increasingly replaced many paper‐based tasks. Therefore, this study aimed to assess the correlation between standard acuity/contrast metrics and functional reading ability compared to real‐world performance on an iPad‐based reading task with astigmatic patients corrected wearing toric and mean spherical equivalent contact lenses. Methods Thirty‐four adult participants, with −0.75 to −1.50-D of refractive astigmatism, were enrolled in a double‐masked cross‐over study and fitted with toric and spherical equivalent contact lenses, in random order. A digital application was developed to assess zoom, contrast modifications, the distance at which the tablet was held, blink rate, and time to complete the reading task. High and low contrast near logMAR visual acuity were measured along with reading performance (critical print size and optimal reading speed). Results The amount participants chose to increase tablet font size (zoom) was correlated with their high‐contrast visual acuity with toric correction (r = 0.434, p = 0.010). With best sphere correction, zoom was associated with reading speed (r = −0.450, p = 0.008) and working distance (r = 0.522, p = 0.002). Text zoom was also associated with horizontal (toric: r = 0.898, p < 0.001; sphere: r = 0.880, p < 0.001) and vertical scrolling (toric: r = 0.857, p < 0.001; sphere: r = 0.846, p < 0.001). There was a significant negative association between the selection of text contrast and zoom (toric: r = −0.417, p = 0.0141; sphere: r = −0.385, p = 0.025). Conclusion Real‐world task performance allows more robust assessment of visual function than standard visual metrics alone. Digital technology offers the opportunity to better understand the impact of different vision correction options on real‐world task performance.

Evaluating Reading Performance in Different Preferred Retinal Loci in Persian-Speaking Patients with Age-Related Macular Degeneration.

Purpose:To evaluate reading performance in different preferred retinal loci (PRLs) using a Persian version of a Minnesota Low Vision Reading (MNREAD) chart in Persian-speaking patients with age-related macular degeneration (AMD).Methods:In this cross-sectional study, 35 patients with AMD were assessed. The reading performance was investigated by the MNREAD chart without using low vision aids. The location of PRL was determined monocularly using an MP1 microperimeter (Nidek Technologies, Padua, Italy). The anatomical location of the fovea was determined using optical coherence tomography (OCT). Images were taken with the MP1 microperimeter, and Spectralis HRA-OCT device was processed using graphic software to determine the location of the PRL on the retina.Results:Thirty-five patients (51 eyes) with a mean age of 73.8 ± 7.7 years (range, 54–88 years) were assessed. Mean best corrected distance visual acuity (logMAR) was 0.65 ± 0.35 (range, 0.2–1.3). Mean levels of reading acuity (RA) (P = 0.009) and critical print size (CPS) (P = 0.015) were significantly different in different locations of PRL. Average scores of maximum reading speed (MRS) (P = 0.058) and reading accessibility index (ACC) (P = 0.058) were not statistically significant in different locations of PRL. There was a positive correlation between PRL-fovea distance and RA (P < 0.001, r = 0.591) and CPS (P < 0.001, r = 0.614). Significant negative correlations were observed between PRL-fovea distance and MRS (P < 0.001, r = −0.519) and ACC (P < 0.001, r = −0.545).Conclusions:This study provides evidence for differences in the reading performance of Persian-speaking patients with AMD in different PRL locations. The average scores of all reading indices obtained in the right-field PRL are lower than those in other areas and are highly correlated with the PRL-fovea distance.

Repeatability and Validity of MNREAD Test in Children With Vision Impairment.

PurposeTo evaluate the test–retest reliability and validity of the MNREAD test for use in children with vision impairment (VI) and to compare their performance on the test to that of normally sighted children.MethodsChildren with VI (n = 62) and without VI (n = 40) were administered the MNREAD test and the Basic Reading Inventory (BRI) on two study visits, 1 to 3 weeks apart. The maximum reading rate, critical print size, and reading acuity were determined for the MNREAD test, and test–retest reliability was evaluated. The reading rate for the MNREAD test was compared to the BRI results.ResultsStrong correlations between visits were found for all MNREAD parameters (0.68–0.99). Older, but not younger, children with VI read significantly more slowly on both the MNREAD and the BRI than children with normal vision (P < 0.05). Reading rates between the two tests were strongly correlated (r = 0.88). For the MNREAD test, the reading rate increased 4.4 words per minute (wpm) per year for VI and 10.6 wpm/y for those with normal vision. For the BRI, the reading rate increased by 5.9 wpm/y for VI and 9.7 wpm/y for those with normal vision. Poorer visual acuity was associated with slower reading rates on the MNREAD test but not on the BRI, as the MNREAD relies largely on visual factors but the BRI also relies on linguistic and grammar skills.ConclusionsThe MNREAD test are reliable and valid for use in children with vision impairment.Translational RelevanceThe MNREAD test can be utilized by clinicians, as they are a quick, easy-to-administer method for evaluating reading vision in children with VI.

Comparison of Post-Cataract Surgery Visual Outcomes and Quality of Life in Patients Bilaterally Implanted with Multifocal Intraocular Lenses.

IntroductionThe present study compared visual outcomes in eyes with bilateral implantation of two multifocal intraocular lenses (MFIOLs)—the Eyecryl™ ACTV diffractive multifocal IOL (group 1) and AcrySof® IQ ReSTOR® multifocal IOL (group 2).MethodsThis was a prospective, two-group observational longitudinal study of 118 eyes from 59 patients conducted at Laxmi Eye Institute, Panvel, India. We evaluated the patients at 1, 3, and 6 months. We assessed visual acuity, contrast sensitivity, higher-order aberrations, reading speed, defocus curve, stereopsis, quality of life (QOL), and adverse events in these participants.ResultsThe median (interquartile range) best-corrected distance visual acuity was 0.18 (0, 0.18) in group 1 and 0.18 (0, 0.18) in group 2 at 1, 3, and 6 months; the difference was not statistically significant (p = 0.48). The binocular defocus curve in both groups showed two peaks at 0.0 to −0.5 D and at −2.5 D. The mean (95% confidence interval) critical print size was significantly different between groups 1 and 2 at low illumination (0.918 [0.905, 0.931] vs 1.154 [1.128, 1.180]; p = 0.004). Contrast sensitivity was significantly better in group 1 under mesopic conditions but not under scotopic conditions. Though total QOL did not differ significantly between groups, the psychosocial quality of life was significantly better in group 1. About 23% of patients in group 2 reported unwanted images, compared with 0% in group 1 (p = 0.01).ConclusionWe found that the Eyecryl and AcrySof groups were comparable for best-corrected visual acuity, photopic contrast sensitivity, defocus curve, reading parameters, stereopsis, and quality of vision. However, the Eyecryl group had better mesopic contrast and a lower proportion of unwanted images. Psychosocial quality of life was significantly better in the Eyecryl group; however, satisfaction was similar between groups. The cost of one of the lenses is less than the other. Thus, individuals with limited resources may opt for the Eyecryl™ ACTV, with similar visual outcomes.

Introduction of a digital near-vision reading test for normal and low vision adults: development and validation

BackgroundMNREAD is an advanced near-vision acuity chart that has already been translated and validated in Greek language. Considering that no validated Greek digital near-vision test exists, our primary objective was to develop and validate a digital near-vision reading test based on the fundamental properties of the Greek printed MNREAD (MNREAD-GR).MethodsThis is a prospective, comparative study. A digital near-vision chart was developed (Democritus Digital Acuity Reading Test – DDART) with text size calibration, audio recording for automatic reading timing, as well as automatic calculation of reading acuity (RA), maximum reading speed (MRS), critical print size (CPS) and reading accessibility index (ACC). Normal and low vision subjects participated in the validation process, responding to MNREAD-GR and DDART at the same day, at a 40 cm viewing distance. Differences in all parameters between the charts were compared with t-test and intraclass correlation coefficients (ICCs). Within 15 days, all participants responded again to DDART in a different set of sentences to assess its test-retest reliability.ResultsOne hundred patients (normal vision group - NVG: 70 patients; low vision group - LVG: 30 patients) responded to both reading tests. Non-significant differences were detected for all parameters between DDART and MNREAD-GR except for MRS and ACC that were significantly higher in MNREAD-GR in NVG (p < 0.01). NVG participants demonstrated sufficient ICCs that ranged from 0.854 to 0.963, while LVG demonstrated ICCs for RA, ACC, MRS and CPS equal to 0.986, 0.894, 0.794 and 0.723, respectively. All parameters calculated with DDART demonstrated excellent test-retest reliability (ICCs: 0.903 – 0.956).ConclusionsThe proposed reading test presented comparable validity and repeatability to MNREAD-GR suggesting that it can be used both in normal and low vision Greek patients.Trial registrationClinicalTrials.gov, NCT04242836. Registered 24 January 2020 – Retrospectively registered.

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

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. In this prospective study, patients were randomized into two groups: the diffractive multifocal Tecnis + 2.75D (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 40cm, and preferred reading distances and spectacle independence for near activities were assessed preoperatively and at the postoperative 1st, 3rd, and 6th months. 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 ± 4.67cm; 45.87 ± 5.32cm, 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). 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.

Effect of illumination on reading performance in Japanese patients with age-related macular degeneration.

Several studies of Western patients with age-related macular degeneration (AMD) have investigated reading performance that improved at high levels of illumination; however, the relation between reading performance and macular function has not been evaluated in detail in Japan. The goals of this study were to evaluate the effect of different levels of illumination on reading performance in Japanese patients with AMD and determine the factors, such as macular function, that affect these results. Cross-sectional study. We prospectively included 39 patients with bilateral AMD or maculopathy. We evaluated reading performance; reading acuity (RA), critical print size (CPS), and maximal reading speed (MRS) using charts with Japanese sentences based on the MNREAD-J in 500-7500lx. Patients were classified into two groups based on the presence of a central scotoma (CS) or no CS (NCS) diagnosed by microperimetry. The RA improved significantly in 500-7500lx in both groups (NCS, p = 0.001; CS, p = 0.046). The RA improvement differed significantly (2000lx, p = 0.021; 5,000lx; p = 0.021; 7500lx, p = 0.047) between 500lx and other illumination levels only in the NCS group and then plateaued over 2000lx. The CPS and MRS did not improve significantly at any illumination level. These results suggest that the difference in macular function was related to improvement in the RA with increased illumination in Japanese patients with AMD.

Reading with central vision loss: binocular summation and inhibition.

PurposeThere are conflicting reports as to whether there is a binocular advantage or disadvantage when reading with central vision loss. This study examined binocular reading summation in patients with macular degeneration.MethodsSeventy‐one patients with bilateral central vision loss [mean age: 63 (S.D. = 21) years] participated. Reading performances during binocular and monocular viewing with the better eye (i.e., the eye with the best monocular visual acuity) were evaluated using different versions of the Italian MNREAD reading chart (www.precision‐vision.com). Fixation stability and preferred retinal loci (PRLs) were recorded monocularly for each eye. The overall sample was split into inhibition, equality, and summation groups based on the binocular ratio (i.e., binocular/monocular) of the maximum reading speed.Results41% of patients experienced binocular inhibition, 42% summation, and 17% equality. Binocular reading speed of the inhibition group was approximately 30 words per minute slower than those of the equality and summation groups, although the inhibition group had the best visual acuity. These patients generally had monocular PRLs in non‐corresponding locations temporal or nasal to the scotoma, had the largest interocular acuity difference and lacked residual stereopsis. The three groups did not differ in fixational control, contrast sensitivity or critical print size.ConclusionsEqual proportions of patients with central vision loss show binocular reading summation and inhibition. Patients with binocular reading inhibition have poorer reading performance and different clinical characteristics than those with binocular reading summation and equality.

Visual Acuity, Defocus Curve, Reading Speed and Patient Satisfaction with a Combined Extended Depth of Focus Intraocular Lens and Multifocal Intraocular Lens Modality.

PurposeTo evaluate the vision, defocus curve, reading speed and patient satisfaction after implantation of an extended depth of focus (EDOF) IOL in one eye and a diffractive multifocal in the fellow eye.SettingOne clinical practice in the USA.DesignProspective unmasked non-randomized clinical trial.MethodsSubjects presenting for routine cataract surgery interested in reducing their dependence on spectacles were enrolled. Study endpoints included uncorrected and distance-corrected binocular distance (4 m), intermediate (66 cm) and near (40 cm) visual acuity at 3 months. Additional endpoints included the residual refraction, spectacle independence, overall satisfaction with vision, visual symptoms, reading speed and defocus curve.ResultsWith a best distance correction, 77% (30/39) of subjects had 20/25 or better VA at distance, intermediate and near and nearly all subjects had 20/32 or better VA at all three distances. Defocus curve results showed mean continuous vision of 20/25 or better from plano to −2.50 D. Nearly 80% (31/39) of subjects had 20/25 visual acuity from 0.00 D to −2.50 D. The critical print size was between 0.3 and 0.4 logMAR (20/40 to 20/50 Snellen Equivalent). Spectacle independence was 100% at distance, 95% at intermediate and approximately 70% at near. The percentage of subjects who were “not at all” or “slightly” bothered by visual disturbances ranged from 64% (16/25) for Halos to 88% (22/25) for Starbursts.ConclusionsEDOF/bifocal IOL blended implantation results in at least 20/25 mean visual acuity from distance to near with good spectacle independence and low reports of severe visual disturbances.

Effects of Task on Reading Performance Estimates.

Reading is a primary problem for low vision patients and a common functional endpoint for eye disease. However, there is limited agreement on reading assessment methods for clinical outcomes. Many clinical reading tests lack standardized materials for repeated testing and cannot be self-administered, which limit their use for vision rehabilitation monitoring and remote assessment. We compared three different reading assessment methods to address these limitations. Normally sighted participants (N = 12) completed MNREAD, and two forced-choice reading tests at multiple font sizes in counterbalanced order. In a word identification task, participants indicated whether 5-letter pentagrams, syntactically matched to English, were words or non-words. In a true/false reading task, participants indicated whether four-word sentences presented in RSVP were logically true or false. The reading speed vs. print size data from each experiment were fit by an exponential function with parameters for reading acuity, critical print size and maximum reading speed. In all cases, reading speed increased quickly as an exponential function of text size. Reading speed and critical print size significantly differed across tasks, but not reading acuity. Reading speeds were faster for word/non-word and true/false reading tasks, consistent with the elimination of eye movement load in RSVP but required larger text sizes to achieve those faster reading speeds. These different reading tasks quantify distinct aspects of reading behavior and the preferred assessment method may depend on the goal of intervention. Reading performance is an important clinical endpoint and a key quality of life indicator, however, differences across methods complicate direct comparisons across studies.

Potential roles of MNREAD acuity charts and contrast/glare sensitivity in Ranibizumab treatment of branch retinal vein occlusion.

Background/ObjectivesTo investigate the potential utility of MNREAD acuity charts and contrast/glare sensitivity (CGS) assessment for evaluating the efficacy of an initial treatment with ranibizumab (Lucentis®) for branch retinal vein occlusion (BRVO).MethodsIntravitreal injections of ranibizumab were administered in 43 eyes of 43 treatment-naïve patients with BRVO. Efficacy was assessed 1 month later. Best-corrected far/near visual acuity (BCFVA/BCNVA), MNREAD parameters (reading acuity [RA], maximum reading speed [MRS], critical print size [CPS]), CGS (CS/GS), and central macular thickness (CMT) in optical coherence tomography (OCT) before and after treatment were evaluated. The area (superior/inferior) affected by BRVO was determined by fluorescein angiography.ResultsAll parameters improved significantly following treatment (p < 0.05), and all MNREAD and CGS parameters were significantly correlated with BCVA in the treated eye before and after treatment (p < 0.01). The changes in BCFVA, BCNVA, MRS, and CS were significantly correlated with the amount of change in CMT (p < 0.007; r = 0.415, 0.528, -0.465, and -0.508, respectively). MRS exhibited a percentage change that was significantly correlated with that in CMT (p < 0.007; r = -0.511). Additionally, MRS exhibited the lowest threshold CMT (397 μm) at which the most significant change in improvement was observed. CMT was less likely to improve if BRVO occurred at a superior site than if it occurred at an inferior site (0.05 < p = 0.07 < 0.1).ConclusionsMNREAD and CGS testing were useful for evaluating BRVO treatment efficacy. MRS might be a valuable index for evaluating treatment success and making treatment decisions.

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.

Evaluation of pre- and post-surgery reading ability in patients with epiretinal membrane: a prospective observational study

BackgroundThis study aimed to investigate the pre- and post-surgery reading ability in patients with idiopathic epiretinal membrane (ERM) to evaluate whether measurement of reading performance is a helpful test in addition to visual acuity (VA) as an assessment measure.MethodsThis prospective observational study involved 42 eyes of 40 patients with idiopathic ERM. Best-corrected visual acuity (BCVA), reading ability, and metamorphopsia score were evaluated at baseline and at 3, 6, and 12 months post-surgery. As the outcome measure, the reading ability of each patient (i.e., overall performance) was examined with MNREAD-J, the Japanese version of the MNREAD reading acuity (RA) charts, to determine RA, critical print size (CPS), and maximum reading speed (MRS). Generally, a difference of 0.2 logMAR or more is considered a significant change in BCVA. Thus, as a subgroup analysis, we additionally evaluated the BCVA and reading ability of the patients with a BCVA difference of 0.1 logMAR or less between at baseline and at 12 months post-surgery.ResultsRelative to their values at baseline, the subjects exhibited significantly improved BCVA, RA, and CPS throughout the post-surgery examination period (P < 0.001) and significantly improved MRS at 12 months post-surgery (P = 0.04). No significant change in the vertical metamorphopsia score was observed throughout the post-surgery follow-up period. However, and compared to the value at baseline, significant improvements in the horizontal metamorphopsia score were observed at 3, 6 (P < 0.05), and 12 months (P < 0.001) post-surgery. In the subgroup analysis of the 23 eyes that exhibited a BCVA improvement of 0.1 logMAR or less, the median BCVA did not change, but the median RA and CPS improved by 0.2 logMAR.ConclusionsOur findings showed that the surgical removal of ERM improves reading ability, even when the BCVA score does not improve. The measurement of reading performance appears to be a helpful test in addition to VA as a measure for assessing the surgical removal of ERM.

Effects of luminance contrast and character size on reading speed

Both luminance contrast and character size are critical factors affecting reading performance. Previous studies reported on the effect of luminance contrast on the reading-speed function, that is, the relationship between reading speed and character size. In particular, when contrast was reduced, the critical print size (CPS) was found to shift to a larger character size even though the maximum reading speed and function shape did not change [Japanese Journal of Ophthalmology 52(1) (2008) 44–47]. In the present study, the effect of luminance contrast on the reading function was quantitatively examined. Japanese phrases with a luminance contrast of 0.03–0.99 were prepared as stimuli. Observers with normal vision were asked to read aloud phrases with several character sizes. Then, the reading functions were obtained for each luminance contrast. CPS was found to increase as the luminance contrast decreased. The relationship between contrast and CPS was linear in log–log coordinates, that is, log–CPS increased as the log-contrast of the characters decreased. It was found that the contrast of the stimulus systematically affects the location of the reading function.

Benefit of an electronic head-mounted low vision aid.

To evaluate the efficacy of electronic head-mounted low vision aid (e-LVA) SightPlus (GiveVision, UK, givevision.net) and to determine which people with low vision would see themselves likely using an e-LVA like this. Sixty participants with low vision aged 18 to 93 used SightPlus during an in-clinic study session based ona mixed methods design. Visual acuity (ETDRS), contrast sensitivity (Pelli-Robson) and reading performance (MNREAD) were measured binocularly at baseline (no device), with the device in 'normal' mode (zoom only), and with preferred enhanced mode (zoom and oneof four digital image enhancements). At the end of the session, a short questionnaire recorded willingness to use an e-LVA like SightPlus, potential use cases, positive/negative comments and adverse effects. Binocular distance visual acuity improved significantly by 0.63 logMAR on average (p<0.0001) to 0.20 logMAR. Contrast sensitivity improved significantly by 0.22 log units (p<0.0001) to 1.21 log units with zoom only and by 0.40 log units to 1.37 log units with zoom and preferred image enhancement. Reading performance improved significantly for near visual acuity and critical print size (p<0.015), although reading speed significantly decreased (p<0.0001). Nearly half (47%) of the participants indicated they would use an e-LVA like SightPlus, especially for television, reading and entertainment (e.g. theatre). Multivariate logistic regression showed that proportion of lifetime affectedby sight loss, baseline contrast sensitivity and use of electronic LVAs explained 41% of the variation in willingness to use. SightPlus improves visual function in people with low vision and would be used in its current form by one half of the people who tried it. Adverse effects were infrequentand resolved when the device was removed. Future work should focus on comparing e-LVAs through repeatable real-world tasks and impact on quality of life.

Age factor affects reading acuity and reading speed in attaining text information.

To investigate the effect of age on reading acuity and reading speed in attaining text information in healthy eyes. Reading acuity, critical print size, reading speed and maximum reading speed were measured in groups of 40 children (8 to 12 years old), 40 teenagers (13 to 19 years old), 40 young adults (20 to 39 years old), and 40 adults (40 years old and above) using the Buari-Chen Malay Reading Chart [contextual sentences (CS) set and random words (RW) set] in a cross-sectional study design. Reading acuity was significantly improved by 0.04 logMAR for both CS set and RW set from children to teenagers, then gradually worsened from young adults to adults (CS set: 0.06 logMAR; RW set: 0.08 logMAR). Critical print size for children showed a significant improvement in teenagers (CS set: 0.14 logMAR; RW set: 0.07 logMAR), then deteriorated from young adults to adults by 0.09 logMAR only for CS set. Reading speed significantly increased from children to teenagers, [CS set: 46.20 words per minute (wpm); RW set: 42.06 wpm], then stabilized from teenagers to young adults, and significantly reduced from young adults to adults (CS set: 28.58 wpm; RW set: 24.44 wpm). Increment and decrement in maximum reading speed measurement were revealed from children to teenagers (CS set: 39.38 wpm; RW set: 43.38 wpm) and from young adults to adults (CS set: 22.26 wpm; RW set: 26.31 wpm) respectively. The reference of age-related findings in term of acuity and speed of reading should be incorporated in clinical practice to enhance reading assessment among healthy eyes population.

Scoring reading parameters: An inter-rater reliability study using the MNREAD chart.

PurposeFirst, to evaluate inter-rater reliability when human raters estimate the reading performance of visually impaired individuals using the MNREAD acuity chart. Second, to evaluate the agreement between computer-based scoring algorithms and compare them with human rating.MethodsReading performance was measured for 101 individuals with low vision, using the Portuguese version of the MNREAD test. Seven raters estimated the maximum reading speed (MRS) and critical print size (CPS) of each individual MNREAD curve. MRS and CPS were also calculated automatically for each curve using two different algorithms: the original standard deviation method (SDev) and a non-linear mixed effects (NLME) modeling. Intra-class correlation coefficients (ICC) were used to estimate absolute agreement between raters and/or algorithms.ResultsAbsolute agreement between raters was ‘excellent’ for MRS (ICC = 0.97; 95%CI [0.96, 0.98]) and ‘moderate’ to ‘good’ for CPS (ICC = 0.77; 95%CI [0.69, 0.83]). For CPS, inter-rater reliability was poorer among less experienced raters (ICC = 0.70; 95%CI [0.57, 0.80]) when compared to experienced ones (ICC = 0.82; 95%CI [0.76, 0.88]). Absolute agreement between the two algorithms was ‘excellent’ for MRS (ICC = 0.96; 95%CI [0.91, 0.98]). For CPS, the best possible agreement was found for CPS defined as the print size sustaining 80% of MRS (ICC = 0.77; 95%CI [0.68, 0.84]). Absolute agreement between raters and automated methods was ‘excellent’ for MRS (ICC = 0.96; 95% CI [0.88, 0.98] for SDev; ICC = 0.97; 95% CI [0.95, 0.98] for NLME). For CPS, absolute agreement between raters and SDev ranged from ‘poor’ to ‘good’ (ICC = 0.66; 95% CI [0.3, 0.80]), while agreement between raters and NLME was ‘good’ (ICC = 0.83; 95% CI [0.76, 0.88]).ConclusionFor MRS, inter-rater reliability is excellent, even considering the possibility of noisy and/or incomplete data collected in low-vision individuals. For CPS, inter-rater reliability is lower. This may be problematic, for instance in the context of multisite investigations or follow-up examinations. The NLME method showed better agreement with the raters than the SDev method for both reading parameters. Setting up consensual guidelines to deal with ambiguous curves may help improve reliability. While the exact definition of CPS should be chosen on a case-by-case basis depending on the clinician or researcher’s motivations, evidence suggests that estimating CPS as the smallest print size sustaining about 80% of MRS would increase inter-rater reliability.

Reading deficits in diabetic patients treated with panretinal photocoagulation and good visual acuity.

Patients with proliferative diabetic retinopathy (PDR) treated with panretinal photocoagulation (PRP) can have abnormal visual functioning that may be missed by Snellen visual acuity alone. We investigated reading deficits in patients treated with PRP for PDR using the Minnesota reading (MNREAD) test. Thirty patients treated with PRP and 15 controls underwent best-corrected visual acuity (BCVA), the MNREAD, frequency doubling perimetry (FDP), and fundus photography. Panretinal photocoagulation (PRP)-treated subjects were compared to controls on MNREAD results by two-sample t-tests and Wilcoxon tests and Pearson correlations were used to assess the association between performance on MNREAD and other central visual function tests within PRP subjects. Panretinal photocoagulation (PRP)-treated patients had reduced MNREAD acuity (p<0.0001) and increased critical print size (p=0.01) compared to controls but not a significantly reduced maximum reading speed (p=0.06). Logmar MNREAD acuity was strongly positive correlated with logMAR BCVA (r=0.58, p=0.0098) and strongly negatively correlated with FDP foveal threshold (r=-0.63, p=0.0030). Maximum reading speed was positively correlated with FDP foveal threshold (r=0.57, p=0.0143) and FDP mean deviation (r=0.51, p=0.0432). Visual acuity did not correlate with the sensitivities on the FDP. The MNREAD test reveals that PRP reduces reading ability and other aspects of macular function, and thus provides new understanding of how vision-related quality of life is impaired. These findings may lead to improved means to evaluate and enhance vision following treatment for PDR.

Rehabilitation with biofeedback training in age-related macular degeneration for improving distance vision

Biofeedback training (BT) is a modern method for enhancing the use of preferred retinal loci (PRL) retraining for new retinal loci (TRL), hence improving far and near vision. This article attempts to clarify the optimal methodology for BT and the types of patients who can benefit most from BT. This is a retrospective review of cases who received BT with the macular integrity assessment (MAIA) microperimetre. Outcome measures selected for analysis were visual acuity, PRL location, fixation stability, fixation pattern orientation, reading acuity, critical print size, and reading speed. Out of 30 cases who received BT, only those with age-related macular degeneration and visual acuity of logMAR 0.8 (20/126) or poorer showed a visual acuity gain (statistically significant of 12 letters) after BT. Those with other diagnoses and those with residual Early Treatment Diabetic Retinopathy Study best-corrected visual acuity of logMAR of 0.7 (20/100) or better showed only positive trends for visual acuity and a negative trend for fixation stability. All subjects showed a shift in PRL location toward the superior quadrant of the retina (p < 0.02) in those who received BT. BT seems to offer patients a unique and efficient modality to improve distance vision outside of using optical devices.

Extending the MNREAD sentence corpus: Computer-generated sentences for measuring visual performance in reading

The MNREAD chart consists of standardized sentences printed at 19 sizes in 0.1 logMAR steps. There are 95 sentences distributed across the five English versions of the chart. However, there is a demand for a much larger number of sentences: for clinical research requiring repeated measures, and for new vision tests that use multiple trials at each print size. This paper describes a new sentence generator that has produced over nine million sentences that fit the MNREAD constraints, and demonstrates that reading performance with these new sentences is comparable to that obtained with the original MNREAD sentences. We measured reading performance with the original MNREAD sentences, two sets of our new sentences, and sentences with shuffled word order. Reading-speed versus print-size curves were obtained for each sentence set from 14 readers with normal vision at two levels of blur (intended to simulate acuity loss in low vision) and with unblurred text. We found no significant differences between the new and original sentences in reading acuity and critical print size across all levels of blur. Maximum reading speed was 7% slower with the new sentences than with the original sentences. Shuffled sentences yielded slower maximum reading speeds and larger reading acuities than the other sentences. Overall, measures of reading performance with the new sentences are similar to those obtained with the original MNREAD sentences. Our sentence generator substantially expands the reading materials for clinical research on reading vision using the MNREAD test, and opens up new possibilities for measuring how text parameters affect reading.