Differences in reading performance of patients with Drusen maculopathy and subretinal fibrosis after CNV

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.

Possible limits of calibrating reading charts with the Landolt ring: a microscopic study

Purpose

To evaluate microscopically whether the print quality and accuracy of sizing of Landolt ring near vision charts are adequate for the calibration of reading charts.

Methods

Near vision charts with Landolt rings from Oculus GmbH (C-Test; Wetzlar, Germany), Precision Vision (Woodstock, IL) and the RADNER Charts were examined, as well as custom-made Landolt rings optimized for print quality. Microscopic investigations and measurements were performed by using a Huvitz HSZ 600 stereomicroscope (Nikon NIS Elements software) to evaluate the height of the Landolt rings, the thickness of the lines, and the width of the openings. The deviations from the mathematically correct values, which were calculated as given in the EN/ISO 8596 and by the International Council of Ophthalmology (ICO), were analyzed (calculated for a test distance of 40 cm).

Results

All the near vision charts showed notable deficiencies in print quality and aberrations from the nominal values in the height, thickness of the lines, and width of the openings. The openings were too narrow, whereas the height and thickness of the lines were larger than the nominal values. Even the openings of Landolt rings optimized for print quality were not always within an acceptable 5% tolerance and need further improvement.

Conclusion

This study reports inaccuracies in the heights, thicknesses of the lines, and widths of the openings of Landolt rings in all the near vision charts investigated. The extent of these inaccuracies excludes such near vision charts as reference tests for the calibration of reading charts. The x-height in relation to the visual angle still seems to be the most reliable method for standardizing the print sizes for reading charts.

Development and Validation of a Web-Based Reading Test for Normal and Low Vision Patients

Purpose

To develop and validate a web-based reading test for normal and low vision patients.

Methods

This is a prospective, comparative trial. The web-based Democritus Digital Acuity Reading Test (wDDART) was developed. wDDART introduces a series of advanced characteristics (advanced text calibration, computer-vision-based estimation of patient’s distance, and automatic calculation of patient’s reading times) that facilitate the overall examination procedure. wDDART’s reading parameters [reading acuity (RA), maximum reading speed (MRS), critical print size (CPS) and reading accessibility index (ACC)] were compared to the corresponding ones of its conventional Windows-based reading test (DDART) in a sample of normal and low vision participants. wDDART’s test–retest reliability for all reading parameters was evaluated in a 15-day time-window.

Results

One hundred patients (normal vision group-NVG: 70; low vision group-LVG: 30 patients) responded to DDART and wDDART. Non-significant differences between the two reading tests were found for all parameters in NVG and LVG. Intraclass correlation coefficients (ICCs) between the two tests demonstrated good or excellent correlation for RA, MRS, ACC and moderate correlation for CPS. Test–retest reliability was excellent for RA and ACC, while ICCs were 0.715–0.895 for MRS and CPS.

Conclusion

The wDDART demonstrated sufficient validity and repeatability making it suitable for clinical and research settings.

Clinicaltrials.gov Identifier

NCT04618224.

Luminance Contrast of Accessible Tactile Indicators for People With Visual Impairment

Australia is one of only two known countries with a safety standard specifying levels of contrast required to provide accessible environments for people with visual impairment. However, these requirements were not developed based on empirical research involving people with vision loss. We investigated whether the level of luminance contrast in Australian accessibility standards, 30%, is adequate for people with visual impairments to detect and identify discrete tactile ground surface indicators over a range of contrasts with the background flooring before contact. We found that the 30% luminance contrast is adequate for people with low vision, although they preferred higher contrast.

Reading Ability in Primary Open-angle Glaucoma: Evaluation with Radner Reading Charts

SIGNIFICANCE

This study determined the impact of visual disabilities caused by glaucoma on the patient's everyday life and emphasized the importance of developing strategies to improve reading ability in primary open-angle glaucoma (POAG) patients.

PURPOSE

The purposes of this study were to investigate the reading performances of patients affected by POAG using the Italian version of the Radner Reading Charts and to test the presence of correlation between visual field (VF) damage and reading parameters.

METHODS

In this cross-sectional observational study, all patients underwent a complete ophthalmic evaluation including VF testing and evaluation of reading performance using the Radner Reading Charts. The parameters for testing reading performance were reading acuity in logRAD, reading speed in words per minute, maximum reading speed, critical print size, and reading mistakes. Primary open-angle glaucoma and healthy groups were compared using the Mann-Whitney U test. The correlation between VF and reading parameters in glaucomatous eyes was assessed using Spearman correlation analysis. Based on VF mean deviation, each POAG patient had differences in reading performance between his/her best and worst eyes when compared using the paired Wilcoxon test. Statistical significance was set at P ≤ .05.

RESULTS

Eighty POAG patients and 60 healthy controls were enrolled. Glaucomatous subjects read slowly (166.63 ± 29.40 vs. 193.84 ± 26.20 words per minute, P < .0001) and made more mistakes than did healthy subjects. The critical print size for POAG patients was larger than the one for controls (0.52 ± 0.18 vs. 0.62 ± 0.16, P < .0001). Reading parameters showed a moderate correlation with VF mean deviation. The reading parameters were significantly impaired in the worst eye, and this result confirms the impact of VF loss on reading ability.

CONCLUSIONS

This study demonstrated that glaucomatous patients read slowly and with more errors. Reading performances showed a good correlation with VF defect.

Assessing reading performance in the periphery with a Bayesian adaptive approach: The qReading method

Reading is a crucial visual activity and a fundamental skill in daily life. Rapid Serial Visual Presentation (RSVP) is a text-presentation paradigm that has been extensively used in the laboratory to study basic characteristics of reading performance. However, measuring reading function (reading speed vs. print size) is time-consuming for RSVP reading using conventional testing procedures. In this study, we develop a novel method, qReading, utilizing the Bayesian adaptive testing framework to measure reading function in the periphery. We perform both a psychophysical experiment and computer simulations to validate the qReading method. In the experiment, words are presented using an RSVP paradigm at 10° in the lower visual field. The reading function obtained from the qReading method with 50 trials exhibits good agreement (i.e., high accuracy) with the reading function obtained from a conventional method (method of constant stimuli [MCS]) with 186 trials (mean root mean square error: 0.12 log10 units). Simulations further confirm that the qReading method provides an unbiased measure. The qReading procedure also demonstrates excellent precision (half width of 68.2% credible interval: 0.02 log10 units with 50 trials) compared to the MCS method (0.03 log10 units with 186 trials). This investigation establishes that the qReading method can adequately measure the reading function in the normal periphery with high accuracy, precision, and efficiency, and is a potentially valuable tool for both research and clinical assessments.

Bayesian adaptive assessment of the reading function for vision: The qReading method

Reading is a fundamental skill that can be significantly affected by visual disabilities. Reading performance, which typically is measured as reading speed with a reading chart, is a key endpoint for quantifying normal or abnormal vision. Despite its importance for clinical vision, existing reading tests for vision are time consuming and difficult to administer. Here, we propose a Bayesian adaptive method, the qReading method, for automated assessment of the reading speed versus print size function. We implemented the qReading method with a word/nonword lexical decision task and validated the method with computer simulations and a psychophysical experiment. Computer simulations showed that both the interrun standard deviation and intrarun half width of the 68.2% credible interval of the estimated reading speeds from the qReading method were less than 0.1 log10 units after 150 trials, with a bias of 0.05 log10 units. In the psychophysical experiment, reading functions measured by the qReading and Psi methods (Kontsevich & Tyler, 1999) in a word/nonword lexical decision task were compared. The estimated reading functions obtained with the qReading and Psi methods were highly correlated (r = 0.966 ± 0.004, p < 0.01). The precision of the qReading method with 225 trials was comparable to that of the Psi method with 450 trials. We conclude that the qReading method can precisely and accurately assess the reading function in much reduced time, with great promise in both basic research and clinical applications.

Reading charts in ophthalmology

A new generation of logarithmic reading charts has sparked interest in standardized reading performance analyses. Such reading charts have been developed according to the standards of the International Council of Ophthalmology. The print size progression in these calibrated charts is in accordance with the mathematical background of EN ISO 8596. These reading charts are: the Bailey–Lovie Word Reading Chart, the Colenbrander English Continuous Text Near Vision Cards, the Oculus Reading Probe II, the MNREAD Charts, the SKread Charts, and the RADNER Reading Charts. The test items used for these reading charts differ among the charts and are standardized to various extents. The Bailey–Lovie Charts, MNREAD Charts, SKread Charts, and RADNER Charts are also meant to measure reading speed and allow determination of further reading parameters such as reading acuity, reading speed based on reading acuity, critical print size, reading score, and logMAR/logRAD ratio. Such calibrated reading charts have already provided valuable insights into the reading performance of patients in many research studies. They are available in many languages and thus facilitate international communication about near visual performance. In the present review article, the backgrounds of these modern reading charts are presented, and their different levels of test-item standardization are discussed. Clinical research studies are mentioned, and a discussion about the immoderately high number of reading acuity notations is included. Using the logReading Acuity Determination ([logRAD] = reading acuity equivalent of logMAR) measure for research purposes would give reading acuity its own identity as a standardized reading parameter in ophthalmology.

Toward developing a standardized Arabic continuous text reading chart

PURPOSE

Near visual acuity is an essential measurement during an oculo-visual assessment. Short duration continuous text reading charts measure reading acuity and other aspects of reading performance. There is no standardized version of such chart in Arabic. The aim of this study is to create sentences of equal readability to use in the development of a standardized Arabic continuous text reading chart.

METHODS

Initially, 109 Arabic pairs of sentences were created for use in constructing a chart with similar layout to the Colenbrander chart. They were created to have the same grade level of difficulty and physical length. Fifty-three adults and sixteen children were recruited to validate the sentences. Reading speed in correct words per minute (CWPM) and standard length words per minute (SLWPM) was measured and errors were counted. Criteria based on reading speed and errors made in each sentence pair were used to exclude sentence pairs with more outlying characteristics, and to select the final group of sentence pairs.

RESULTS

Forty-five sentence pairs were selected according to the elimination criteria. For adults, the average reading speed for the final sentences was 166 CWPM and 187 SLWPM and the average number of errors per sentence pair was 0.21. Childrens' average reading speed for the final group of sentences was 61 CWPM and 72 SLWPM. Their average error rate was 1.71.

CONCLUSIONS

The reliability analysis showed that the final 45 sentence pairs are highly comparable. They will be used in constructing an Arabic short duration continuous text reading chart.

The accuracy of reading speed measurement by stopwatch versus measurement with an automated computer program (rad-rd©)

PURPOSE

To compare the reading time and reading speed measurements obtained with a stopwatch with those of an automated computer program for measuring reading speed and acuity (rad-rd^© ; patent: AT 504635B1/10-2006).

METHODS

The rad-rd^© was used (in conjunction with a PC and microphone) for the computer-based measurements. In rotation, each of four examiners took a turn reading the 12 sentences from one of the four RADNER Reading Charts to three other examiners, who served as stoppers. The stoppers simultaneously measured the reading time with a stopwatch while a fifth investigator used the rad-rd^© to obtain computerized measurements. The stopwatch measurements were then statistically compared with the rad-rd^© measurements.

RESULTS

The mean reading time obtained with the stopwatch measurements was 4.34 ± 0.57 seconds (196.21 ± 21.79 wpm), versus 4.44 ± 0.59 seconds (192.24 ± 22.20 wpm) by computer measurement (r = 0.84). Of the 144 stopwatch measurements, 97 (67.36%) were shorter, and 47 (32.64%) were equal to (n = 5) or longer than the computer measurements. The mean difference for the shorter measurements was -0.17 ± 0.1 seconds (3.91% of the mean reading time), and the mean difference for the longer measurements was 0.11 ± 0.1 seconds (2.53% of the mean reading time). Most differences ranged from -0.1 to 0.1 seconds (42.36%). The results did not differ significantly among the four stoppers.

CONCLUSION

The rad-rd^© is an accurate, automated computer program for measuring reading time. Stopwatch measurements, although subject to inaccuracy from several sources, remain a reliable and simple method for analysis of reading performance.

Integrating a novel concept of sentence optotypes into the RADNER Reading Charts

PURPOSE

To add a new set of 24 sentence optotypes to the German version of the RADNER reading charts and to investigate whether sentences constructed based upon an optimised concept of sentence optotypes can be used together with the original 38 sentences.

METHODS

Twenty-eight optimised sentence optotypes were constructed based upon the concept of sentence optotypes as established for the RADNER Reading Charts, with words having the same number of characters and syllables being placed in the same positions. The best comparable sentences were statistically selected in 30 volunteers. Reading speed and the number of errors were determined. Validity was analysed in comparison to a 111-word long standardised paragraph and 7 of the 38 original sentence optotypes.

RESULTS

The mean reading speed obtained with the 28 sentences was 192.30±26.69 words per minute (wpm), as compared with 192.47±25.32 wpm for the 7 original sentence optotypes and 165.28±20.82 wpm for the long paragraph; 24 of the 28 optimised sentences met our selection criteria for reading speed/time (mean reading speed: 192.41±26.58). The mean number of reading errors was 0.10±0.30. The correlation between the 24 optimised sentence optotypes and the long paragraph was r=0.90. Reliability analyses yielded an overall Cronbach's α coefficient of 0.992.

CONCLUSION

The 24 new sentence optotypes can be integrated into the existing set of 38 original sentences. Since all the statistical results obtained were similar to those of the original sentences, the best possible reliability had apparently already been achieved with the original sentence optotypes.

Near vision examination in presbyopia patients: Do we need good homologated near vision charts?

Presbyopia correction is mainly concerned with the goal of regaining an uncorrected reading performance. Since historic reading charts do not provide a unique standard that is applicable for the analysis of clinical and scientific reading performance, new standardized reading charts have been developed, in order to provide reading performance analyses analogous to modern single-optotype distance acuity measurements: the Bailey-Lovie Word Reading Chart, the Colenbrander English Continuous Text Near Vision Cards, the MNREAD Charts, and the RADNER Reading Charts. The last three are also meant to measure reading speed, thus allowing detailed analysis of the reading capabilities of the patient’s functional vision. Furthermore, these reading charts can be declared homologated, based on the standards that were published for reading charts by the Visual Function Committee of the International Council of Ophthalmology (ICO) in 1988. Many research studies have shown that by analyzing the reading performance with homologated reading charts, valuable insight into the reading performance of patients suffering from various diseases can be obtained. These reading charts have also been successfully used in presbyopia research. It therefore seems evident that homologated, standardized reading charts facilitate not only research concerning functional vision in many fields of ophthalmology but also international communication about near visual performance. Homologated reading charts are available in almost all languages and have become a valuable tool in analyzing reading performance. We argue in this review that homologated reading charts are clearly a necessity for presbyopia research.

Mining for genes related to choroidal neovascularization based on the shortest path algorithm and protein interaction information

BACKGROUND

Choroidal neovascularization (CNV) is a serious eye disease that may cause visual loss, especially for older people. Many factors have been proven to induce this disease including age, gender, obesity, and so on. However, until now, we have had limited knowledge on CNV's pathogenic mechanism. Discovering the genes that underlie this disease and performing extensive studies on them can help us to understand how CNV occurs and design effective treatments.

METHODS

In this study, we designed a computational method to identify novel CNV-related genes in a large protein network constructed using the protein-protein interaction information in STRING. The candidate genes were first extracted from the shortest paths connecting any two known CNV-related genes and then filtered by a permutation test and using knowledge of their linkages to known CNV-related genes.

RESULTS

A list of putative CNV-related candidate genes was accessed by our method. These genes are deemed to have strong relationships with CNV.

CONCLUSIONS

Extensive analyses of several of the putative genes such as ANK1, ITGA4, CD44 and others indicate that they are related to specific biological processes involved in CNV, implying they may be novel CNV-related genes.

GENERAL SIGNIFICANCE

The newfound putative CNV-related genes may provide new insights into CNV and help design more effective treatments. This article is part of a Special Issue entitled "System Genetics" Guest Editor: Dr. Yudong Cai and Dr. Tao Huang.

Measurement properties of continuous text reading performance tests

PURPOSE

Measurement properties of tests to assess reading acuity or reading performance have not been extensively evaluated. This study aims to provide an overview of the literature on available continuous text reading tests and their measurement properties.

METHODS

A literature search was performed in PubMed, Embase and PsycInfo. Subsequently, information on design and content of reading tests, study design and measurement properties were extracted using consensus-based standards for selection of health measurement instruments. Quality of studies, reading tests and measurement properties were systematically assessed using pre-specified criteria.

RESULTS

From 2334 identified articles, 20 relevant articles were found on measurement properties of three reading tests in various languages: IReST, MNread Reading Test and Radner Reading Charts. All three reading tests scored high on content validity. Reproducibility studies (repeated measurements between different testing sessions) of the IReST and MNread of commercially available reading tests in different languages were missing. The IReST scored best on inter-language comparison, the MNread scored well in repeatability studies (repeated measurements under the same conditions) and the Radner showed good reproducibility in studies.

CONCLUSIONS

Although in daily practice there are other continuous text reading tests available meeting the criteria of this review, measurement properties were described in scientific studies for only three of them. Of the few available studies, the quality and content of study design and methodology used varied. For testing existing reading tests and the development of new ones, for example in other languages, we make several recommendations, including careful description of patient characteristics, use of objective and subjective lighting levels, good control of working distance, documentation of the number of raters and their training, careful documentation of scoring rules and the use of Bland-Altman analyses or similar for reproducibility and repeatability studies.

English sentence optotypes for measuring reading acuity and speed--the English version of the Radner Reading Charts

PURPOSE

To develop 28 short sentence optotypes for the English version of the Radner Reading Charts that are as comparable as possible in number and length of words, as well as in difficulty and syntactical construction.

METHODS

Thirty-four English sentences were constructed following the method used for other Radner Reading Charts to obtain "sentence optotypes" with comparable structure and the same lexical and grammatical difficulty. Best comparable sentences were statistically selected and standardized in 50 volunteers. Reading speed and the number of errors were determined. Validity was analyzed with a 124-word long 4th-grade paragraph of the Florida Comprehensive Assessment Test®. Computerized measurements of reading parameters were performed with the RADNER Reading Device (RAD-RD©; in conjunction with a PC and microphone).

RESULTS

The mean reading speed obtained with the 28 selected short sentences was 201.53 ± 35.88 words per minute (wpm), as compared to 215.01 ± 30.37 wpm for the long paragraph. The mean reading times were 4.30 ± 0.79 s and 35.26 ± 4.85 s, respectively. The mean number of reading errors was 0.11 ± 0.34. The correlation between the short sentences and the long paragraph was high (r = 0.76; p < 0.05; n = 50). Reliability analyses yielded an overall Cronbach's alpha coefficient of 0.9743.

CONCLUSION

The present study indicates that the 28 selected English sentence optotypes are comparable in terms of both lexical difficulty as well as in reading length, and it demonstrates the validity and reliability of such sentences as test items for determining reading parameters such as reading acuity and speed.

Foveal morphology affects self-perceived visual function and treatment response in neovascular age-related macular degeneration: a cohort study

Objectives

To investigate the relationship between foveal morphology and self-perceived visual function in patients with neovascular age-related macular degeneration (AMD) and whether foveal characteristics are associated with Ranibizumab treatment response on the self-perceived visual function.

Methods

This prospective cohort study included patients with newly diagnosed neovascular AMD found eligible for treatment with Ranibizumab. Foveal morphology of both eyes was assessed using spectral-domain optical coherence tomography and all patients were interviewed using the 39-item National Eye Institute Visual Function Questionnaire (VFQ). Patients were re-interviewed 3 and 12 months after initiation of treatment with Ranibizumab. We evaluated foveal morphology at baseline in relation to VFQ scores at baseline and clinically meaningful changes in VFQ after 3 and 12 months.

Results

VFQ scores correlated with central foveal thickness, central foveal thickness of neuroretina (CFN), foveal RPE elevation, foveal integrity of the photoreceptor inner segment/outer segment junction (IS/OS), and external limiting membrane. In a multiple linear regression model, only best-corrected visual acuity of the better eye (p<0.001) and the IS/OS status in the better eye (p = 0.012) remained significant (Adjusted R² = 0.418). Lower baseline VFQ and a baseline CFN within 170–270 µm in the better eye were both associated with a clinically meaningful increase in the VFQ scores after 3 and 12 months. An absent foveal IS/OS band in the better eye was associated with a clinically meaningful decrease in the VFQ scores at 12 months.

Conclusions

Foveal morphology in the better eye influences the self-perceived visual function in patients with neovascular AMD and possesses a predictive value for change in the self-perceived visual function at 3 and 12 months after initiation of treatment. These findings may help clinicians provide patients more individualized information of their disease and treatment prognosis from a patient-perceived point-of-view.

One year follow-up of functional recovery in neovascular AMD during monthly anti-VEGF treatment

PURPOSE

To identify neurosensory recovery, testing different functional variables during monthly intravitreal standard anti-vascular endothelial growth factor (VEGF) therapy in neovascular age-related macular degeneration (AMD).

DESIGN

Prospective interventional cohort study.

METHODS

Sixty-four treatment-naïve neovascular AMD patients with subfoveal lesions were treated and examined monthly for distance visual acuity, reading acuity, maximum reading speed, and contrast sensitivity and with microperimetry evaluating the percentage of absolute and relative scotoma and mean central retinal sensitivity weighted by area. Improvements in reading acuity, distance acuity, reading speed, contrast sensitivity, mean central retinal sensitivity, and scotoma area in dependence of age, lesion type, lesion size, and mean central retinal sensitivity were evaluated by a random-slope and random-intercept model. Recovery pattern of parameters was compared by correlating the individual slopes of each variable.

RESULTS

Initially, a rapid short-term effect of anti-VEGF treatment was documented throughout all functional variables. Progressive functional gain over 1 year was observed for distance visual acuity (P = .011), contrast sensitivity (P ≤ .0001), and mean central retinal sensitivity (P ≤ .0001), but not for reading acuity (P = .31) and maximum reading speed (P = .94). Decrease of absolute scotoma area missed statistical significance over time (P = .053) and also fixation stability did not improve (P = .08). However, lesion size influenced the course of absolute scotoma area (P = .0015), while lesion type had no effect on any visual function variable evaluated. The individual slopes of reading acuity and distance visual acuity showed a moderate correlation; however, all other variables showed only a weak or no significant correlation among each other.

CONCLUSION

Visual recovery in anti-VEGF therapy is reflected in a characteristic pattern of functional changes over time, whereas distance visual acuity does not seem to comprehensively reflect overall visual function gain.

Visual Function Endpoints to Enable Dry AMD Clinical Trials

The slow progression of non-exudative age-related macular degeneration (dry AMD) presents challenges for drug discovery. The standard endpoint used for ophthalmic clinical trials, best-corrected visual acuity, is insensitive to the early stages and slow progression of dry AMD. Effective drug discovery for dry AMD treatments will therefore require novel applications of more effective visual function endpoints. This review will present candidates for visual function endpoints for dry AMD clinical trials. The promising visual assessments include contrast sensitivity, reading speed, microperimetry, and dark adaptation. Their adoption as exploratory endpoints in future trials will be critical for determining their accuracy, precision, and applicability, and ultimately determine their value for drug discovery.

Reading performance in infantile nystagmus

OBJECTIVE

To characterize reading deficits in infantile nystagmus (IN), to determine optimal font sizes for reading in IN, and to investigate whether visual acuity (VA) and severity of nystagmus are good indicators of reading performance in IN.

DESIGN

Prospective cross-sectional study.

PARTICIPANTS AND CONTROLS

Seventy-one participants with IN (37 idiopathic, 34 with albinism) and 20 age-matched controls.

METHODS

Reading performance was assessed using Radner reading charts and was compared with near logarithm of the minimum angle of resolution (logMAR) VA, nystagmus intensity, and foveation characteristics as quantified using eye movement recordings.

MAIN OUTCOME MEASURES

Reading acuity (smallest readable font size), maximum reading speed, critical print size (font size below which reading is suboptimal), near logMAR VA, nystagmus intensity, and foveation characteristics (using the eXpanded Nystagmus Acuity Function).

RESULTS

Using optimal reading conditions, maximum reading speeds were 18.8% slower in albinism and 14.7% slower in idiopathic IN patients compared with controls. Reading acuities were significantly worse (P<0.001) in IN patients compared with controls. Also, the range of font sizes over which reading speeds were less than the optimum were much larger in IN patients compared with controls (P<0.001). Reading acuity was correlated strongly to near VA (r(2) = 0.74 albinism, r(2) = 0.55 idiopathic), but was better than near VA in participants with poor VA. Near VA was a poor predictor of maximum reading speed. Nystagmus intensity and foveation were poor indicators of both reading acuity and maximum reading speed.

CONCLUSIONS

Maximum reading speeds can be near normal in IN when optimal font sizes are provided, even in individuals with poor VA or intense nystagmus. However, reading performance in IN is acutely sensitive to font size limitations. Font sizes for optimal reading speeds in IN may be as much as 6 logMAR lines worse than the near VA.

FINANCIAL DISCLOSURE(S)

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

Reliability testing of the Dutch version of the Radner Reading Charts

PURPOSE

To statistically analyze the test-retest and inter-chart reliability of the newly developed actual logarithmically scaled Dutch Radner Reading Charts in an older population affected by macular disease. These Dutch Radner Reading Charts are developed according to the strict principles of sentence construction of the originally German language Radner Reading Charts.

METHODS

Thirty-six subjects aged 50 years or older and affected with a macular disease monocularly read the three charts of the Radner Reading Charts in a randomized order twice with 1 month in between. The subjects were divided into three groups according to their distance logMAR visual acuity (group 1, > or =0.1; group 2, 0.12 to 0.4; and group 3, 0.42 to 0.8). Reading acuity (logRAD, the reading equivalent of logMAR), logRAD score, maximum reading speed, critical print size, and logRAD/logMAR ratio were measured. Variance component analysis was used to determine the sources of variability.

RESULTS

The test-retest and inter-chart reliability was high for all visual acuity groups and variables. For all groups together the chart accounted for maximal 5% of the total variability for all measurements. The individual subject did have the largest influence on the measurements (88 to 98% of the variability).

CONCLUSIONS

The Dutch version of the Radner Reading Charts provided high reliable test-retest and inter-chart measurements of reading performance in a heterogeneous group of subjects with subnormal to low vision. This study also showed that the strict principles of sentence construction of the originally German Radner Reading Charts may also be successfully used for other languages.

Reading performance of patients with uveitis-associated cystoid macular edema

PURPOSE

To evaluate the extent of the visual impairment caused by uveitis-associated cystoid macular edema (CME) and compare the results with lesion size.

DESIGN

Observational case series.

METHODS

setting: Uveitis outpatient clinic of the Department of Ophthalmology and Optometry, Medical University of Vienna. patient population: CME was verified in 30 eyes of 30 consecutive uveitis patients with optical coherence tomography and lesion size was assessed with retinal thickness analyzer. main outcome measures: Distance visual acuity (VA) (measured with Early Treatment Diabetic Retinopathy Study charts), reading acuity, and reading speed (tested with Radner Reading Charts). Results were compared with nonaffected partner eyes.

RESULTS

Distance VA was logMAR 0.22 +/- 0.15 in CME eyes vs -0.02 +/- 0.17 in healthy controls. Reading acuity was 75% of logMAR in CME eyes vs 92% of logMAR in control eyes (P = .01). The mean reading speed was 148.4 +/- 36.6 words per minute in patients with CME vs 168.9 +/- 36.3 in patients without CME (P = .04). Reading acuity correlated with both lesion size and distance VA (r = 0.61; P = .01 and r = 0.53; P = .028, respectively). Neither anatomical classification of uveitis nor gender or age had a significant influence on the evaluated parameters.

CONCLUSIONS

Reading acuity and reading speed were considerably more impaired than distance visual acuity. The assessed parameters showed a better correlation to lesion size and seem to be a better reflection of macular dysfunction. Analyzing reading function is an important factor when following patients with CME and evaluating success of treatment modalities.