Evaluating reading acuity and speed in children with microstrabismic amblyopia using a standardized reading chart system

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.

Reading Speed Using the International Reading Speed Texts in a Normal Canadian Cohort

Background The International Reading Speed Texts (IReST) are commonly used to measure reading speed, which may be affected in many eye conditions. They were originally tested in a younger British population. Our study evaluates IReST in a normal Canadian population. Methodology A normal Canadian cohort in Ontario was prospectively recruited with age >14 years, education >9 years, English as the primary language, and best-corrected visual acuity >20/25 distance and >N8 near in each eye. Participants with eye conditions and neurological/cognitive problems were excluded. Each participant consecutively read two IReST passages (passages 1 and 8). Reading speed in words per minute (WPM) was calculated. One-sample t-test was used to compare our cohort to published IReST standards. Results A total of 112 participants were included (35 male, 77 female). The mean age was 40 ± 17 years (14-18 years: 12; 18-35 years: 34; 35-60 years: 53; 60-75 years: 13). The mean reading speed for passage 1 was 211 ± 33 WPM compared to the published IReST standard of 236 ± 29 WPM (p < 0.0001). The mean reading speed for passage 8 was 218 ± 34 WPM compared to the IReST standard of 237 ± 24 WPM (p < 0.0001). Thus, our cohort read slower for both passages compared to IReST standards. The mean reading speed for passages 1 and 8 was the highest for the 14-18-year (231 and 239, respectively) and the lowest for the 60-75-year group (195 and 192, respectively). Conclusions Normal older populations have slower reading compared to younger populations. The slower reading in our cohort may also be because the passages were in British rather than in Canadian English. It is important that the IReST is evaluated in different populations to ensure reliable comparison standards for future research.

Amblyopia and the whole child

Amblyopia is a disorder of neurodevelopment that occurs when there is discordant binocular visual experience during the first years of life. While treatments are effective in improving visual acuity, there are significant individual differences in response to treatment that cannot be attributed solely to difference in adherence. In this considerable variability in response to treatment, we argue that treatment outcomes might be optimized by utilizing deep phenotyping of amblyopic deficits to guide alternative treatment choices. In addition, an understanding of the broader knock-on effects of amblyopia on developing visually-guided skills, self-perception, and quality of life will facilitate a whole person healthcare approach to amblyopia.

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.

Reading speed in school-age children with intermittent exotropia

Reading speed in intermittent exotropia (IXT) children has been minimally examined. This study assessed reading speed in school-age children with IXT and determined clinical characteristics of IXT that impacted their reading ability. We compared the reading speed of 63 school-age (10–14 years) children with IXT to 44 age-matched normal counterparts. In addition, the correlation between reading speed and clinical characteristics of IXT were evaluated. The reading speed in children with IXT was 231 ± 51 CPM, while reading speed in normal counterparts was 257 ± 33 CPM. Age, gender were found to be factors associated with reading speed in children with IXT. After adjusting for the age and gender, we found a significant correlation between the LogTNO and reading speed in IXT group based on a generalized linear model (p = 0.014). These data show that reading speed was slower in school-age children with IXT assessed with the International Reading Speed Texts. When age and gender were adjusted, poor stereo function at near was found to be related with a slower reading speed.

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

AIM

To investigate the effect of age on reading acuity and reading speed in attaining text information in healthy eyes.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Fellow Eye Deficits in Amblyopia

Amblyopia is a neurodevelopmental disorder of the visual system, as a result of discordant visual experience during infancy or early childhood. Because amblyopia is typically defined as monocularly reduced visual acuity accompanied by one or more known amblyogenic factors, it is often assumed that the fellow eye is normal and sufficient for tasks like reading and eye-hand coordination. Recent scientific evidence of ocular motor, visual, and visuomotor deficits that are present with fellow eye monocular viewing and with binocular viewing calls this assumption into question. This clinical update reviews the research that has revealed fellow ocular motor and visual deficits and the effect that these deficits have on an amblyopic child's visuomotor and visuocognitive skills. We need to understand how to prevent and rehabilitate the effects of amblyopia not only on the nonpreferred eye but also on the fellow eye.

Reading ability of children treated for amblyopia

Previous studies have reported compromised reading ability in children with amblyopia. Standardized psychoeducational test norms have not been used; therefore, the practical consequences of poor reading ability, such as eligibility for reading supports at school, have not been assessed. Furthermore, several studies have used atypical reading conditions such as monocular or distant viewing. It is also not clear how amblyopia treatment impacts reading ability. Thus, the goal of this study was to use standardized tests to compare binocular reading performance in children treated for amblyopia to that of a large normative sample, as well as to the types of control groups used in previous studies. Children treated for strabismic or anisometropic amblyopia (N = 14) were compared to children treated for strabismus without amblyopia (N = 12) and to children with healthy vision (N = 39). Visual acuity, stereoacuity, interocular suppression, intellectual functioning, oral single-word reading (TOWRE-2), and oral paragraph reading (GORT-5) were assessed. The control group showed significantly higher single-word reading accuracy than the amblyopia and strabismus groups. However, mean performance for all groups was within the average range of the normative sample. While mean scores were in the average range, six children (four amblyopia, two strabismus) performed below average on the single-word reading task; four of these children also showed below average paragraph reading. Reading scores were not correlated with visual acuity in the patient groups. The results raise the possibility that both strabismus and amblyopia can disrupt reading ability, even following successful treatment, to an extent that might benefit from reading supports at school.

The Impact of Diplopia on Reading

Aim:

To compare the effect of induced vertical diplopia (small and large separation) on reading speed and accuracy.

Methods:

The Radner Reading Chart (RRC) was used to measure reading speed (correct words per minute (wpm)) and accuracy (percentage). Accuracy was measured using two different methods: ‘accuracy-omission’ where only the omission of a word reduced the score, and ‘accuracy-addition and omission’ where any error reduced the score. Three viewing conditions were created using Fresnel prisms on plano glasses: a control condition without diplopia (6 prism dioptres (Δ) base up (BU) over each eye), small separation vertical diplopia (3Δ BU right eye and 3Δ base down (BD) left eye) and large separation vertical diplopia (6Δ BU right eye and 6Δ BD left eye). Viewing conditions were counterbalanced to minimise order effects.

Results:

Twenty-four participants were included with a mean age of 20.1 years. The mean reading speed in the control condition was 156.90 wpm. Both diplopic conditions significantly reduced the reading speed compared to the control condition, small separation diplopia to 62.75 wpm (p < 0.001) and large separation diplopia to 105.71 wpm (p < 0.001). The mean reading speed with small separation diplopia was significantly slower than the mean reading speed with large separation diplopia (p < 0.01). Median accuracy scores in the control and the large separation diplopia conditions were 100% using both methods of measuring accuracy. The small separation diplopia condition significantly reduced accuracy to 92.86% (accuracy-omission method) and to 57.50% (accuracy-addition and omission method) compared to the control condition (p < 0.01) and the large separation diplopia condition (p < 0.05).

Conclusion:

When vertical diplopia was induced using Fresnel prisms, diplopia of smaller separation resulted in the greatest reduction in reading speed and accuracy, compared to without diplopia and large separation diplopia.

Pediatric ophthalmology and childhood reading difficulties: Amblyopia and slow reading

Reading is a major life activity, as recognized by the US Congress in the Americans with Disabilities Act Amendments Act of 2008, and the education code of most US states requires schools to evaluate reading and implement reading programs to addresses students' reading difficulties. Currently, such legislation is employed to identify accommodations needed for children with bilateral visual impairment and for children with dyslexia and/or related learning disabilities. Yet recent research has shown that children with the most common form of monocular visual impairment-amblyopia-read slowly. Slow reading can be detrimental to academic performance and learning, which in turn may affect self-esteem. Parents and educators can work together to implement accommodations (eg, extra time) to help amblyopic students succeed in their daily school tasks, and improve their performance on the timed, standardized tests that are critical for promotion and admission to magnet schools, TAG programs, high schools, and colleges. Children with other visual disorders that cause visual impairment in one eye (eg, glaucoma, cataract, trauma, etc) should also be considered for academic accommodations.

Slow reading in children with anisometropic amblyopia is associated with fixation instability and increased saccades

BACKGROUND

Previous studies show slow reading in strabismic amblyopia. We recently identified amblyopia, not strabismus, as the key factor in slow reading in children. No studies have focused on reading in amblyopic children without strabismus. We examined reading in anisometropic children and evaluated whether slow reading was associated with ocular motor dysfunction in children with amblyopia.

METHODS

Anisometropic children (7-12 years) with or without amblyopia were compared to age-similar normal controls. Children silently read a grade-appropriate paragraph during binocular viewing. Reading rate (words/min), number of forward and regressive saccades (per 100 words) and fixation duration were recorded with the ReadAlyzer. Binocular fixation instability was also evaluated (EyeLink 1000).

RESULTS

Amblyopic anisometropic children read more slowly (n = 25; mean with standard deviation, 149 ± 42 words/min) than nonamblyopic anisometropic children (n = 15; 196 ± 80 words/min; P = 0.024) and controls (n = 25; 191 ± 65 words/min; P = 0.020). Nonamblyopic anisometropic children read at a comparable rate to controls (P = 0.81). Slow reading in amblyopic anisometropic children was correlated with increased forward saccades (r = -0.84, P < 0.001), increased regressive saccades (r = -0.85, P < 0.001), and fellow eye instability during binocular viewing (r = -0.52, P = 0.019).

CONCLUSIONS

Slow reading in school-age children with anisometropic amblyopia is related to increased frequency of saccades and fixation instability of the fellow eye. Further research should consider the effects of slower reading on academic performance.

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.

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.

[Strabismus and reading: Effect of strabismus on reading tests in children from 8 to 11 years]

PURPOSE

We try to show a relationship between strabismus and changes in reading skills.

MATERIAL AND METHODS

We have carried out a prospective study including 135 children from 8 to 11 years (French level CE2 to CM2). They were given an ophthalmologic and orthoptic examination and then divided into 4 groups: strabismus with vertical deviation without binocular vision, accommodative strabismus with binocular vision, accommodative strabismus without binocular vision and control group (children without strabismus). Each child took 4 validated reading tests: reading fluency, uncommon words reading, comparison of letters sequences without signification, searching "verbal index".

RESULTS

Results are significantly lower in children with accommodative strabismus without binocular vision for two tests (reading fluency and uncommon words reading). In contrast, results for the two other tests do not differ significantly between the 4 groups.

CONCLUSION

Our study demonstrated lowered reading skills in tests of reading fluency in children with accommodative strabismus without binocular vision.

Reading Fluency in School-Aged Children with Bilateral Astigmatism

PURPOSE

To compare oral reading fluency (ORF) in students with no/low astigmatism and moderate/high astigmatism and to assess the impact of spectacle correction on ORF in moderate and high astigmats.

METHODS

Subjects were third- to eighth-grade students from a highly astigmatic population. Refractive error was determined through subjectively refined cycloplegic autorefraction. Data from students with ocular abnormalities, anisometropia, symptomatic binocular vision disorders, or refractive error that did not meet study criteria (no/low [cylinder < 1.00 both eyes, no significant myopia/hyperopia], moderate [cylinder ≥ 1.00 D both eyes, mean ≥ 1.00 D and < 3.00 D], or high astigmatism group [cylinder ≥ 1.00 D both eyes, mean ≥ 3.00 D]) were excluded. Oral reading fluency was tested with a modified version of the Dynamic Indicators of Basic Early Literacy Skills (DIBELS) Next test of ORF. No/low astigmats were tested without spectacles; astigmats were tested with and without spectacles. Mean ORF was compared in no/low astigmats and astigmats (with and without correction). Improvement in ORF with spectacles was compared between moderate and high astigmats.

RESULTS

The sample included 130 no/low, 67 moderate, and 76 high astigmats. ORF was lower in uncorrected astigmats than in no/low astigmats (p = 0.011). ORF did not significantly differ in no/low astigmats and corrected astigmats (p = 0.10). ORF significantly improved with spectacle correction in high astigmats (p = 0.001; mean improvement, 6.55 words per minute) but not in moderate astigmats (p = 0.193; mean improvement, 1.87 words per minute). Effects of spectacle wear were observed in students who read smaller text stimuli (older grades).

CONCLUSIONS

ORF is significantly reduced in students with bilateral astigmatism (≥1.00D) when uncorrected but not when best-corrected compared with their nonastigmatic peers. Improvement in ORF with spectacle correction is seen in high astigmats but not in moderate astigmats. These data support the recommendation for full-time spectacle wear in astigmatic students, particularly those with high astigmatism.

The Danish version of the Radner Reading Chart: design and empirical testing of sentence optotypes in subjects of varying educational background

PURPOSE

To develop 28 short texts to be used as sentence optotypes in a Danish version of the Radner Reading Chart for the measurement of reading acuity and speed.

METHOD

Forty-six short texts of comparable lexical and grammatical difficulty were constructed. The short texts were tested together with two longer reference texts in 100 persons with visual acuity 6/6, of which 50 were university students (age: 24.7 ± 3.1 years, 36% males) and 50 were blue-collar workers (37.2 ± 13.4 years, 54% males). Study parameters were mean reading speed and error rate per participant, and mean reading time, variance and number of errors per short text.

RESULTS

The students read the short texts faster than the blue-collar workers (184 ± 21.4 words per minute (wpm) versus 163 ± 26.3 wpm, p < 0.0001). There was a high correlation between the reference texts and the short texts [Pearson's correlation coefficient = 0.89 (95% CI 0.83-0.92)]. The mean reading time for each of the short texts ranged from 4.4 s to 5.8 s with a mean of 4.96 ± 0.35 s, and the median number of errors was eight. Twenty-eight short texts were selected for sentence optotypes with mean reading times between 4.6 s and 5.2 s, a mean standard deviation of 1.2 s or less and a number of errors of 17 per 100 persons or less.

CONCLUSION

Reading time uniformity in the Danish version of the Radner Reading Chart was comparable to that of the original German version. Education had an influence on reading performance that may warrant stratification for this parameter when reading tests are used in clinical trials.

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.

Effect of strabismus surgery on the reading ability of school-age children

AIM

To evaluate if strabismus surgery on children between the ages 5 and 14 years leads to an improvement in reading ability by comparing reading performance of patients before and after surgery.

METHODS

Pre- and postoperatively, the visual acuity, ocular alignment, and stereoacuity of 15 children with horizontal strabismus was recorded. The "3-Minute Reading Assessments: Word Recognition, Fluency, and Comprehension" for the appropriate age-group were used to assess children between the ages of 5 and 14 years. Thirteen of the 15 children presented with esotropic deviation, and the remaining 2 were exotropic.

RESULTS

Postoperatively, 12 patients were orthophoric and 3 had significant residual esotropia. The 15 patients had an average improvement in reading speed (10.3 words per minute), accuracy (4%), and fluency (2 points). For the 12 orthophoric patients, reading speed increased by 12.2 (P = .003), accuracy by 3% (P = .064), and fluency by 1.33 (P = .006).

CONCLUSION

Corrective strabismus surgery in school-age children showed an early improvement in reading ability that could translate into better academic performance. Our results suggest that reading ability could be an important factor when considering corrective surgery for children with strabismus.

Review of guidelines for children's vision screenings

The aim of children's vision screenings is to detect visual problems that are common in this age category through valid and reliable tests. Nevertheless, the cost effectiveness of paediatric vision screenings, the nature of the tests included in the screening batteries and the ideal screening age has been the cause of much debate in Australia and worldwide. Therefore, the purpose of this review is to report on the current practice of children's vision screenings in Australia and other countries, as well as to evaluate the evidence for and against the provision of such screenings. This was undertaken through a detailed investigation of peer-reviewed publications on this topic. The current review demonstrates that there is no agreed vision screening protocol for children in Australia. This appears to be a result of the lack of strong evidence supporting the benefit of such screenings. While amblyopia, strabismus and, to a lesser extent refractive error, are targeted by many screening programs during pre-school and at school entry, there is less agreement regarding the value of screening for other visual conditions, such as binocular vision disorders, ocular health problems and refractive errors that are less likely to reduce distance visual acuity. In addition, in Australia, little agreement exists in the frequency and coverage of screening programs between states and territories and the screening programs that are offered are ad hoc and poorly documented. Australian children stand to benefit from improved cohesion and communication between jurisdictions and health professionals to enable an equitable provision of validated vision screening services that have the best chance of early detection and intervention for a range of paediatric visual problems.

Oral reading after treatment of dense congenital unilateral cataract

BACKGROUND

Good long-term visual acuity outcomes for children with dense congenital unilateral cataracts have been reported after early surgery and good compliance with postoperative amblyopia therapy. However, treated eyes rarely achieve normal visual acuity, and there has been no formal evaluation of the utility of the treated eye for reading.

METHODS

Eighteen children previously treated for dense congenital unilateral cataract were tested monocularly with the Gray Oral Reading Test, 4th edition (GORT-4) at 7 to 13 years of age with the use of 2 passages for each eye, one at grade level and one at +1 above grade level. In addition, right eyes of 55 normal children age 7 to 13 served as a control group. The GORT-4 assesses reading rate, accuracy, fluency, and comprehension.

RESULTS

Visual acuity of treated eyes ranged from 0.1 to 2.0 logMAR and of fellow eyes from -0.1 to 0.3 logMAR. Treated eyes scored significantly lower than fellow and normal control eyes on all scales at grade level and at +1 above grade level. Monocular reading rate, accuracy, fluency, and comprehension were correlated with visual acuity of treated eyes (r(s) = -0.575 to -0.875, p < 0.005). Treated eyes with 0.1-0.3 logMAR visual acuity did not differ from fellow or normal control eyes in rate, accuracy, fluency, or comprehension when reading at grade level or at +1 above grade level. Fellow eyes did not differ from normal controls on any reading scale.

CONCLUSIONS

Excellent visual acuity outcomes after treatment of dense congenital unilateral cataracts are associated with normal reading ability of the treated eye in school-age children.

Monocular oral reading performance after amblyopia treatment in children

PURPOSE

To evaluate the monocular oral reading rate, accuracy, fluency, and comprehension in 10-year-old children previously treated for amblyopia.

DESIGN

Prospective, observational case series.

METHODS

Seventy-nine children (mean age, 10.3 years) previously treated in a multicenter randomized trial comparing patching and atropine were tested at seven sites using a modification of the Gray Oral Reading Test, Fourth Edition (GORT-4).

RESULTS

The mean visual acuities (VA) in the amblyopic and fellow eyes at the time of the reading assessment were 0.17 logarithm of the minimum angle of resolution (logMAR) units (approximately 20/32) and -0.03 logMAR units (approximately 20/20), respectively. Compared with the sound eye, amblyopic eye performance was worse when reading orally with respect to rate (P < .001), accuracy (P = .03), and fluency (P < .001). Reading comprehension scores were similar with the amblyopic and fellow eyes (P = .45). Similar results were found with respect to original treatment group assignment (atropine or patching). There was a modest correlation between interocular difference (IOD) of VA at age 10 years and IOD in reading rate (r = 0.37; 95% confidence interval [CI], 0.18 to 0.56) and fluency (r = 0.28; 95% CI, 0.08 to 0.49). There was no correlation between the IOD in VA and IOD in accuracy (r = 0.08; 95% CI, -0.14 to 0.30) or comprehension (r = 0.16; 95% CI, -0.05 to 0.37).

CONCLUSIONS

The monocular oral reading ability when measured with the GORT-4 was slightly worse when reading with previously treated amblyopic eyes compared with fellow eyes in terms of rate, accuracy, and fluency, but reading comprehension testing was similar.

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.

Fixation patterns evaluation by means of MP-1 microperimeter in microstrabismic children treated for unilateral amblyopia

PURPOSE

The aim of the study was to evaluate the fixation patterns of microstrabismic children previously treated for unilateral amblyopia.

METHODS

Thirty-three children (mean age 7.3+/-1.5 years) were included in the study. Visual acuity (VA) was measured using the Early Treatment of Diabetic Retinopathy Study charts. Fixationwas assessed by MP-1 microperimeter. Differences in position and stability of fixation between the fellow and the microstrabismic eyes were calculated by using the percentage of the preferred fixation points within central fixation and the percentage of the fixation points within target fixation, respectively. For statistical analysis Mann-Whitney test was used. To evaluate the influence of age and duration of anti-amblyopic treatment on microstrabismic eyes fixation, linear regression analysis was performed.

RESULTS

In the microstrabismic eyes VA was significantly reduced when compared to the fellow eyes (0.1236+/-0.0204 vs 0.0042+/-0.0032 logMAR; p<0.001). Position and stability of fixation were significantly better in the fellow eyes (93.21+/-0.65% vs 70.91+/-4.80%; p=0.002, and 89.88+/-0.94% vs 71.73+/-2.94%; p<0.001, respectively). A significant correlation was found between fixation stability and both the duration of anti-amblyopic treatment and pretreatment VA (p=0.024 and p=0.009, respectively) and between fixation centrality and pretreatment VA (p<0.001).

CONCLUSIONS

VA, centrality, and stability of fixation were significantly impaired in the microstrabismic eyes. Pretreatment VA was a risk factor for fixation impairment. The severity of fixation stability impairment was linked to the duration of anti-amblyopic treatment.

Crowding--an essential bottleneck for object recognition: a mini-review

Crowding, generally defined as the deleterious influence of nearby contours on visual discrimination, is ubiquitous in spatial vision. Crowding impairs the ability to recognize objects in clutter. It has been extensively studied over the last 80 years or so, and much of the renewed interest is the hope that studying crowding may lead to a better understanding of the processes involved in object recognition. Crowding also has important clinical implications for patients with macular degeneration, amblyopia and dyslexia. There is no shortage of theories for crowding-from low-level receptive field models to high-level attention. The current picture is that crowding represents an essential bottleneck for object perception, impairing object perception in peripheral, amblyopic and possibly developing vision. Crowding is neither masking nor surround suppression. We can localize crowding to the cortex, perhaps as early as V1; however, there is a growing consensus for a two-stage model of crowding in which the first stage involves the detection of simple features (perhaps in V1), and a second stage is required for the integration or interpretation of the features as an object beyond V1. There is evidence for top-down effects in crowding, but the role of attention in this process remains unclear. The strong effect of learning in shrinking the spatial extent of crowding places strong constraints on possible models for crowding and for object recognition. The goal of this review is to try to provide a broad, balanced and succinct review that organizes and summarizes the diverse and scattered studies of crowding, and also helps to explain it to the non-specialist. A full understanding of crowding may allow us to understand this bottleneck to object recognition and the rules that govern the integration of features into objects.

Monocular and binocular reading performance in children with microstrabismic amblyopia

AIM

To evaluate if functionally relevant deficits in reading performance exist in children with essential microstrabismic amblyopia by comparing the monocular and binocular reading performance with the reading performance of normal sighted children with full visual acuity in both eyes.

METHODS

The reading performance of 40 children (mean age 11.6 (SD 1.4) years) was evaluated monocularly and binocularly in randomised order, using standardised reading charts for the simultaneous determination of reading acuity and speed. 20 of the tested children were under treatment for unilateral microstrabismic amblyopia (visual acuity in the amblyopic eyes: logMAR 0.19 (0.15); fellow eyes -0.1 (0.07)); the others were normal sighted controls (visual acuity in the right eyes -0.04 (0.15); left eyes -0.08 (0.07)).

RESULTS

In respect of the binocular maximum reading speed (MRS), significant differences were found between the children with microstrabismic amblyopia and the normal controls (p = 0.03): whereas the controls achieved a binocular MRS of 200.4 (11) wpm (words per minute), the children with unilateral amblyopia achieved only a binocular MRS of 172.9 (43.9) wpm. No significant differences between the two groups were found in respect of the binocular logMAR visual acuity and reading acuity (p>0.05). For the monocular reading performance, significant impairment was found in the amblyopic eyes, whereas no significant differences were found between the sound fellow eyes of the amblyopic children and the control group.

CONCLUSION

In binocular MRS, significant differences could be found between children with microstrabismic amblyopia and normal controls. This result indicates the presence of a functionally relevant reading impairment, even though the binocular visual acuity and reading acuity were both comparable with the control group.