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PubMed2004

[Ocular changes in Down syndrome].

BACKGROUND, MATERIAL AND METHODS: Down's syndrome is the most common cause of mental retardation with an incidence of about 1.5/1000 live births. Life expectancy and quality of life have improved substantially for this group over the last decades. The aim of this paper is to give an updated short survey of ocular changes present in Down's syndrome based on current international literature and the clinical experience of the authors. RESULTS AND INTERPRETATION: Ocular problems are common, mostly refractive errors, poor accommodation, strabismus, cataract, and keratoconus. Accommodation deficit is present in a majority of individuals with Down's syndrome, also in children and young people. Bifocal or progressive glasses should therefore be prescribed liberally. Because of the high frequency of ocular pathology, all individuals with Down's syndrome should be enrolled in a continuous visual screening programme from birth. We suggest the following screening guidelines: first examination at one month of age, then at one year of age, at 2-3 years of age, at 5-6 years of age (school start), and thereafter every five years. In case of positive findings (e.g. refractive errors, poor accommodation, strabismus) the frequency of examination should be increased and determined individually by the responsible ophthalmologist.

Accommodation, Ocular↗
PubMed1994

[Influence of refraction on the visual field defects in normal tension glaucoma and primary open angle glaucoma eyes].

The prevalence of normal tension glaucoma (NTG) or primary open angle glaucoma (POAG) is higher in myopic populations and the prevalence of myopia and NTG is relatively high in the Japanese. To evaluate the influence of myopic refractive error on the central visual field defect in NTG eyes, the data obtained from NTG eyes with the Humphrey Visual Field Analyser were analysed in comparison with those from POAG eyes. One hundred and twenty NTG eyes and one hundred and ninety-seven POAG eyes were included. All of them had clear ocular media, but no myopic degeneration in the fundus. Multiple linear regression analysis was performed with a dependent variable of the deviation of the measured threshold value from normal reference value (total deviation, STATPAC) and independent variables of refractive error and mean deviation (STATPAC). Myopic power was found to be positively correlated with the depression in the lower papillo-macular area in both NTG and POAG eyes, and it was negatively correlated with the depression in an upper arcuate area extending just nasal to the fixation only in NTG eyes.

Adult↗
PubMed2005

The Pakistan national blindness and visual impairment survey--research design, eye examination methodology and results of the pilot study.

PURPOSE: To establish age- and sex-specific prevalence rates and causes of blindness and low vision in children aged 10 to 15 years and adults aged 30 years and older in Pakistan. METHODS: Multi-stage, stratified (rural/urban), cluster random sampling, with probability proportional-to-size procedures, was utilised to select a cross-sectional, nationally representative sample of adults (16,600 subjects) and children (6,000 subjects). Each subject underwent: interview, visual acuity (logMAR), autorefraction and optic disc examination. Those that saw < 6/12 in either eye underwent corrected visual acuity and dilated posterior segment examination. RESULTS: The results of a pilot survey are reported in this paper. In the two rural pilot sites, 159 subjects (including 47 children) were examined; 50% were male. Thirty seven adults (23.3%) but no children saw worse than 6/12 in either eye. Two subjects were blind (corrected visual acuity) in the better eye, and 11 were visually impaired. Refractive error was the main cause (in 22 eyes (39% of the total of 56 eyes)) of < 6/12 visual acuity, followed by cataract (12 eyes), uncorrected aphakia (6 eyes) and age-related macular disease (3 eyes). CONCLUSIONS: The pilot survey demonstrated that the proposed examination process for the main survey is feasible. Particular strengths of this survey include the use of logMAR visual acuity testing and autorefraction of all subjects, a dilated posterior segment examination, and the use of a 'less than 6/12' threshold for further examination. This lower threshold addresses the burden of refractive error, which, with cataract, are two of the diseases specifically targeted by Vision 2020.

Adolescent↗
PubMed1988

Can the accuracy of intraocular lens calculations be improved?

Regression analysis of data from 222 extracapsular cataract extractions was performed to determine if the accuracy of IOL prediction in cataract surgery can be improved. Polynomial and piecewise regression of large, medium, and short eyes were used to calculate new formulas for IOL prediction. The Taylor series representation of the theoretical lens power formula was calculated to determine what combination of the variables for IOL power prediction are reasonable to consider in constructing a polynomial regression model. The formulas calculated from the data in this study were compared with other published methods of IOL calculation. In this study, the difference between the postoperative refraction error and emmetropia was independent of the formula used. The exception was the modified Binkhorst formula, which caused greater error. Inclusion of higher order terms in the regression formula or piecewise regression did not reduce the postoperative refractive error.

Evaluation Studies as Topic↗
PubMed2006

Visual and binocular status of Down syndrome children in Malaysia.

BACKGROUND: Down syndrome is a common chromosomal anomaly. Few reported studies make reference to the ocular status in Asian children with Down syndrome. The purpose of this study was to determine the visual and binocular status of a sample of Down syndrome children in Malaysia. METHODS: A total of 73 Malaysian children with Down syndrome (38 boys and 35 girls) in the Kuala Lumpur area aged one to 12 years were examined. Cycloplegic refraction was performed on each eye and binocular visual acuity was assessed using the Cardiff acuity card or the LogMAR chart. Binocular functions were assessed using the cover test and Lang's stereo acuity test. RESULTS: The mean age of the subjects was 6.01 +/- 3.41 years. Refraction of the right eye showed that 10 per cent of the subjects were myopic, 20 per cent were hyperopic and 70 per cent had no significant refractive error. The mean spherical equivalent was +0.92 +/- 2.32 DS for the right eye and +0.99 +/- 2.21 DS for the left. The mean of binocular LogMAR VA was 0.36 +/- 0.22 (6/12). Cover test revealed that 21 subjects had strabismus (of those, 33 per cent had unilateral esotropia, 52 per cent had alternating esotropia, nine per cent had unilateral exotropia and five per cent had alternating exotropia). Only 22 subjects gave clear positive response to the stereotest. Other ocular findings included ptosis (one per cent), abnormal head posture (seven per cent) and nystagmus (six per cent). CONCLUSION: Malaysian children with Down syndrome have a high incidence of refractive error and strabismus. Regular visual examination is important so that corrective lenses can be prescribed to improve vision and to enhance the quality of life of these children in Malaysia.

Child↗
PubMed1980

Risk factors for genetic typing and detection in retinitis pigmentosa.

An outpatient population with retinitis pigmentosa was evaluated with respect to best corrected visual acuity, cycloplegic refractive error, appearance of the lenses, presence or absence of bone spicule pigmentation, age of onset of night blindness by history, and presence or absence of a history of parental consanguinity. The population included 489 affected patients subdivided into the four following groups: 69 (14.1%) dominant, 67 (13.7%) autosomal recessive, 34 (7.0%) X-chromosome-linked, and 319 (65.2%) isolate. Contingency table and life table analyses showed that significant differences existed for these criteria among the various groups. An analysis based on data from 35 families showed significant differences with respect to best corrected visual acuity and cylindrical refractive error when comparing affected patients with their age-matched normal relatives. These findings support the idea that observations in a routine ocular examination can aid in genetic classification of affected patients and in selection of relatives of affected patients who are at higher risk for having early stages of retinitis pigmentosa.

Adolescent↗
PubMedDate not supplied

An assessment of recycled spectacles donated to a developing country.

BACKGROUND: A rapid assessment methodology was used to determine the suitability of donated recycled spectacles for the Pacific nation of Tuvalu. METHODS: Spectacles (102) from a donated cache were examined. Those with astigmatism of > 1.00 D, anisometropia of > 0.50 D, significant central lens scratches, broken frame, poor cosmetic fit and comfort, or unsuitable frame appearance were excluded. The refractive errors (> or = +/-0.50 D distance or near) of 320 Tuvaluans were determined. RESULTS: Of the spectacles, 62.7% had > 1.00 DC and/or > 0.50 D anisometropia, 30% were broken and/or scratched and 50% were uncomfortable or cosmetically unacceptable. Only 13% were optically satisfactory, physically intact, and cosmetically appropriate. Of the people, 8.8% had > 1.00 DC and/or > 0.50 D anisometropia, requiring custom-made spectacles. A further 8.1% needed a -0.50 to -2.00 DS correction, for which there were no spectacles in this cache. For the other 83.1% (266), if the cache contained at least 5538 spectacles, each would eventually find a suitable pair. CONCLUSION: If the scheme to Tuvalu is typical, refractive error will remain largely uncorrected if only donated recycled spectacles are available. No amount of efficiency and effectiveness in the delivery chain can justify the output and outcome of this recycling scheme.

Aged↗
PubMed2001

Influence of scan radius correction for ocular magnification and relationship between scan radius with retinal nerve fiber layer thickness measured by optical coherence tomography.

PURPOSE: To investigate how optical coherence tomography (OCT) modifies the preset scan parameters to correct the errors resulting from ocular magnification, the influence of examiner's final correction of those already modified parameters on retinal nerve fiber layer (RNFL) thickness measurements, the induced change on RNFL thickness measurements and RNFL estimated integrals (RNFL(estimated integrals)) by adjusting the actual scan radius during RNFL examinations performed by OCT. METHODS: Thirty-five healthy patients underwent an RNFL examination by OCT four times using different scan radii. The first scan was performed with the preset circular scan diameter of 3.46 mm; the actual scan diameter was different, however, because it was modified by the OCT instrument. The second, third, and fourth scans were generated after readjusting the already modified scan diameter by the examiner to 3.46, 3.20, and 3.60 mm. The relationship of axial length and refractive error with the actual scan radius (with ocular magnification calculated by OCT), with the influence of the examiner's final correction on RNFL thickness measurements, with the relationship between scan radius with RNFL thickness measurements, and with RNFL(estimated integrals) were investigated. RESULTS: The actual scan diameter was found to be primarily determined by axial length (R = 0.97, P < 0.0001), but the influence of refractive error was small (R = -0.26, P = 0.067). Final correction of the actual scan radius by the examiner had a significant influence on RNFL thickness measurements (P = 0.025). RNFL thickness measurements obtained without correction of the actual scan radius for magnification were found to be inversely correlated with axial length (R = -0.54, P = 0.001), whereas no similar relationship was found when RNFL thickness measurements were obtained with correction (R = 0.21, P = 0.11). A reciprocal relationship between 1/scan radius with RNFL thickness measurements (they tended to be thinner as scan radii were increased) was found (R = 0.41, P = 0.169), but RNFL(estimated integrals) areas were found to be independent of the scan radius (P = 0.521). CONCLUSION: To increase the accuracy of RNFL thickness measurements, it will be appropriate for the examiner to manually correct the actual scan parameters to the desired or preset ones after their automatic modification performed by the OCT instrument. Keeping the actual scan radius constant for repeated exams is also recommended because RNFL thickness measurements were found to depend on scan size. Alternatively, RNFL(estimated integrals) could be used because they were found to be independent of the scan size.

Adolescent↗
PubMed2004

Refractive astigmatism and the toricity of ocular components in human infants.

PURPOSE: Many studies have characterized astigmatism in infancy, but few have been longitudinal or contained ocular component data. This study characterized the frequency, orientation, and longitudinal change with age of infant astigmatism. Additional factors investigated were the influence of early astigmatism on emmetropization and its relation to corneal and lenticular toricity. METHODS: Three hundred two infants were enrolled in the study. Of these, 298 provided data for at least one visit at 3 +/- 1 months, 9 +/- 1 months, 18 +/- 2 months, and 36 +/- 3 months. Testing included cycloplegic retinoscopy (cyclopentolate 1%), video-based keratophakometry, and ultrasonography over the closed eyelid. RESULTS: Astigmatism > or =1.00 DC was common at 3 months of age (41.6%) but decreased in prevalence to 4.1% by 36 months (p < 0.0001). The most common orientation was with-the-rule at 3 months (37.0% compared with 2.7% for against-the-rule) but against-the-rule at 36 months (3.2% compared with 0.9% for with-the-rule). Most of the change in the average value of the horizontal/vertical component of astigmatism (J0) occurred between 3 and 9 months (-0.26 +/- 0.36 D; p < 0.0001) with no significant change between 9 and 36 months (-0.05 +/- 0.36 D; p=0.09). Spherical equivalent refractive error was not correlated with J0 at 3 and 9 months (R=0.002, p=0.48 and R=0.001, p=0.56, respectively). The two were only weakly correlated at 18 and 36 months (R=0.06 for each age, p <0.0001, p=0.0002, respectively). Changes in spherical equivalent between 3 and 9 months were unrelated to either the initial value of J0 (partial R for J0=0.0001; p=0.85) or the change in J0 (partial R for change in J0=0.0031; p=0.31). Across all the ages, corneal toricity was with-the-rule, and lenticular toricity was against-the-rule (produced by the toricity of the posterior lens surface). The cornea and anterior lens surface became more spherical with age, contributing to the shift away from with-the-rule refractive astigmatism. Toricity of all the refractive surfaces became less variable with age. CONCLUSIONS: Consistent with many reports, astigmatism was common in early infancy but decreased in prevalence with age, particularly when with-the-rule in orientation. The reduction in percentage of infants with astigmatism appeared to be caused by decreases in the toricity of the cornea and the anterior lens combined with decreases in the variability of corneal and lenticular surfaces. Astigmatism in infancy appeared to be unrelated to emmetropization of spherical equivalent refractive error.

Age Distribution↗
PubMedDate not supplied

[A survey of the prevalence and causes of eye disorders in primary school children in Antananarivo].

To assess the prevalence and causes of ocular abnormalities in children, we performed a cross-sectional survey with cluster sampling in Madagascar in Antananarivo primary schools in October 1994. Our other aim was to sensitize the sanitary authorities and the students of ophthalmology to the notion of public health ophthalmology in a country where a national blindness prevention program is being established. 1,081 children aged from 8 to 14 years (mean age 10.6 years) were examined. 51, or 4.7%, were diagnosed as having ocular abnormalities. These abnormalities were distributed as follows: 22 cases or 2% of the sample had refractive errors including 0.74% with myopia of less than 6 dioptrics, 0.18% with myopia of more than 6 dioptrics, 0.83% with hypermetropia of less than 6 dioptrics, and 0.28% with hypermetropia of more than 6 dioptrics; 15 cases or 1.4% of the sample had unilateral amblyopia including 0.9% with anisometropia, 0.37% with strabismus, and 0.09% with macular pathology; 8 cases or 0.74% of the sample had strabismus without amblyopia; and 6 cases or 0.57% of the sample had simple medical pathology. The results showed that 29 children were supposed to have an optic correction, including surgical treatment for 12 and medical treatment for 6. The same low frequencies of ocular abnormalities, mainly concerning refractive errors, were found in the literature. However, children suffering from important visual impairment do not attend school, and we cannot generalize the above results for the whole population.

Adolescent↗
PubMed1999

Measurement of the validity of a preschool vision screening program.

OBJECTIVES: The validity (sensitivity and specificity) of a preschool vision screening program was measured over a 3-year period to determine how well strabismus and significant refractive errors could be detected. METHODS: Public health nurses were trained to administer tests of visual acuity, stereoacuity, and ocular alignment. Failure on any test, visual acuity of 6/9 or less, stereoacuity of less than 100 seconds of arc, or an apparent misalignment of the eyes resulted in referral to an eye care practitioner. An age-matched control was also referred. Analysis of practitioner reports used predefined study-based criteria for ocular abnormalities. RESULTS: More than 1100 children were screened each year. The annually calculated prevalence of vision problems ranged between 10.5% and 13.8%. The estimated sensitivity varied from 60.4% to 70.9% (specificity, 69.6% to 79.9%). The yield indicated that a very high percentage of children with vision problems were identified for the first time. CONCLUSIONS: The validity of this screening is comparable to that of other school screenings. The limitations are predictable. Consideration should be given to replacing visual acuity tests with a rapid, objective measure of refractive error and ocular alignment.

Age Factors↗
PubMed2000

Factors affecting pupil size after dilatation: the Twin Eye Study.

BACKGROUND/AIMS: Well dilated pupils make eye surgery easier. A classic twin study was established to examine the relative importance of genes and environment in the variance of pupil size after mydriasis, and to examine the effects of other factors such as age, iris colour, and refractive error. METHODS: 506 twin pairs, 226 monozygotic (MZ) and 280 dizygotic (DZ), aged 49-79 (mean age 62.2 years, SD 5.7) were examined. Dilated pupil size was measured using a standardised grid superimposed over digital retroillumination images taken 50-70 minutes after mydriasis using tropicamide 1% and phenylephrine 10%. Univariate maximum likelihood model fitting was used to estimate genetic and environmental variance components. RESULTS: Dilated pupil size was more highly correlated in MZ compared with DZ twins (intraclass correlation coefficients 0.82 and 0.39 respectively). A model specifying additive genetic and unique environmental factors showed the best fit to the data, yielding a heritability of 78-80%. Individual environmental factors explained 18-19% of the variance in this population. Age only accounted for 2-3% of the variance and refractive error and iris colour did not significantly contribute to the variance. CONCLUSIONS: Pupil size after mydriasis is largely genetically determined, with a heritability of up to 80%.

Aged↗
PubMed1999

Foveal retinoschisis and retinal detachment in severely myopic eyes with posterior staphyloma.

PURPOSE: To evaluate the tomographic features of the retina in patients with severe myopia and posterior staphyloma. METHODS: In a prospective study of 32 eyes of 19 consecutive patients with severe myopia and posterior staphyloma, we performed complete ophthalmic examinations and studied cross-sectional images of the macula with optical coherence tomography. Patients' age ranged from 41 to 83 years (average, 62.7 years). Best-corrected visual acuity ranged from 20/500 to 20/40 (average, 20/120). The study included 26 phakic and six pseudophakic eyes. The refractive errors of 26 phakic eyes ranged from -8 to -31 diopters (average, -16.7 diopters). Although refractive errors were within -8 diopters in six pseudophakic eyes, the eyes had apparent posterior staphyloma. The axial lengths measured by A-mode ultrasonography ranged from 25.7 to 32.7 mm (average, 29.2 mm). Slit-lamp examination with contact lens showed that none of the eyes had a macular hole. RESULTS: In nine eyes with shallow retinal elevation on slit-lamp examination, optical coherence tomography disclosed a foveal retinal detachment with retinoschisis in eight eyes and a foveal retinal detachment in one eye. Two of the remaining 23 eyes had retinoschisis. CONCLUSIONS: Foveal retinal detachment and retinoschisis are common features in severely myopic eyes with posterior staphyloma. Retinal detachment may precede the formation of a macular hole in severely myopic eyes.

Adult↗
PubMed1999

Comparison of objective and subjective refraction before and after laser in situ keratomileusis.

PURPOSE: To compare the accuracy and reliability of objective and subjective refractions before and after laser in situ keratomileusis (LASIK) for myopia, hyperopia, and astigmatism. SETTING: Augenchirurgie und Laserzentrum Hochrum, Innsbruck, Austria. METHODS: In this prospective study, the objective refraction obtained with the Nidek AR-K 900 autorefractor was compared with the subjective refraction in 159 eyes (125 with myopia and 34 with hyperopia) operated on with 2 different lasers. Refractions were done before and 6 months after LASIK. RESULTS: Preoperatively, the objective and subjective refractions correlated better in eyes with low myopia than in those with high myopia (P < .01). Postoperatively, objective refraction was less accurate and reliable than preoperatively. The difference between the objective and subjective spherical refractions was statistically significant (P < .0001) after LASIK in eyes with hyperopia. The correlation between the objective and subjective cylindrical refractions was stronger preoperatively. Especially after LASIK for hyperopia, the objective refraction did not reliably assess the magnitude and axis of the cylinder. The preoperative refractive error did not significantly affect the preoperative and postoperative difference between the objective and subjective refractions or the change between the preoperative and postoperative mean differences. The type of excimer laser used significantly affected the difference between the objective and subjective refractions. CONCLUSIONS: Especially after LASIK for hyperopia, the objective refraction determined with the Nidek AR-K 900 autorefractor delivered erroneous results, which have implications for postoperative care and preoperative measurements for ocular surgery such as enhancement procedures or cataract surgery.

Adult↗
PubMed1991

Autosomal recessive inheritance of myopia in Hong Kong Chinese infants.

Hong Kong Chinese infants were refracted by retinoscopy at regular intervals between the age of approximately 10 and 40 weeks. Cyclopentolate 1% was used to obtain cycloplegia. The spherical equivalent of the refractive error was calculated for each child and analysis of variance carried out according to the refractive status of the parents. From approximately 20 weeks of age a significant difference was found between the mean spherical equivalent of the refractive error of infants of parents both of whom were myopic and that of infants of parents neither of whom was myopic. At 40 weeks of age a good fit with an autosomal recessive probability model was obtained.

Adult↗
PubMed2005

Sensitivity of screening tests for detecting vision in preschoolers-targeted vision disorders when specificity is 94%.

PURPOSE: To compare the sensitivity of 11 preschool vision screening tests administered by licensed eye care professionals for the detection of the 4 Vision in Preschoolers (VIP)-targeted vision disorders when specificity is 94%. METHODS: This study consisted of a sample (n = 2588) of 3- to 5-year-old children enrolled in Head Start programs, 57% of whom had failed an initial Head Start vision screening. Screening results from 11 tests were compared with results from a standardized comprehensive eye examination that was used to classify children with respect to the four VIP-targeted vision disorders: amblyopia, strabismus, significant refractive error, and unexplained reduced visual acuity (VA). With overall specificity set to 94%, we calculated the sensitivity for the detection of each targeted vision disorder. RESULTS: With the overall specificity set to 94%, the most accurate tests for detection of amblyopia were noncycloplegic retinoscopy (NCR) (88% sensitivity), the SureSight Vision Screener (80%), and the Retinomax Autorefractor (78%). For detection of strabismus, the most accurate tests were the MTI Photoscreener (65%), the cover-uncover test (60%), the Stereo Smile II stereoacuity test (58%), the SureSight Vision Screener (54%), and the Retinomax Autorefractor (54% in year 1, 53% in year 2). The most accurate tests for detection of significant refractive error were NCR (74%), the Retinomax Autorefractor (66%), the SureSight Vision Screener (63%), and the Lea Symbols VA test (58%). For detection of reduced VA, the most accurate tests were the Lea Symbols Distance VA test (48%), the Retinomax Autorefractor (39%), and NCR (38%). CONCLUSIONS: Similar to the previously reported results at 90% specificity, the screening tests vary widely in sensitivity with specificity set at 94%. The rankings of the sensitivities for detection of the 4 VIP-targeted vision disorders are similar to those with specificity set to 90%.

Amblyopia↗
PubMed2002

Moderate visual impairment in India: the Andhra Pradesh Eye Disease Study.

AIM: To assess the prevalence and demographic associations of moderate visual impairment in the population of the southern Indian state of Andhra Pradesh. METHODS: From 94 clusters in one urban and three rural areas of Andhra Pradesh, 11 786 people of all ages were sampled using a stratified, random, cluster, systematic sampling strategy. The eligible people were invited for interview and detailed dilated eye examination by trained professionals. Moderate visual impairment was defined as presenting distance visual acuity less than 6/18 to 6/60 or equivalent visual field loss in the better eye. RESULTS: Of those sampled, 10,293 (87.3%) people participated in the study. In addition to the previously reported 1.84% prevalence of blindness (presenting distance visual acuity less than 6/60 or central visual field less than 20 degrees in the better eye) in this sample, 1237 people had moderate visual impairment, an adjusted prevalence of 8.09% (95% CI 6.89 to 9.30%). The majority of this moderate visual impairment was caused by refractive error (45.8%) and cataract (39.9%). Increasing age, female sex, decreasing socioeconomic status, and rural area of residence had significantly higher odds of being associated with moderate visual impairment. CONCLUSIONS: These data suggest that there is a significant burden of moderate visual impairment in this population in addition to blindness. Extrapolation of these data to the population of India suggests that there were 82 million people with moderate visual impairment in the year 2000, and this number is likely to be 139 million by the year 2020 if the current trend continues. This impending large burden of moderate visual impairment, the majority of which is due to the relatively easily treatable refractive error and cataract, would have to be taken into account while estimating the eye care needs in India, in addition to dealing with blindness. Specific strategies targeting the elderly population, people with low socioeconomic status, those living in the rural areas, and females would have to be implemented in the long term to reduce moderate visual impairment.

Adolescent↗
PubMed2004

Comparison of the amblyopia treatment study HOTV and electronic-early treatment of diabetic retinopathy study visual acuity protocols in children aged 5 to 12 years.

PURPOSE: To compare two established visual acuity protocols: the Amblyopia Treatment Study HOTV (ATS HOTV) visual acuity protocol and the Electronic-Early Treatment of Diabetic Retinopathy Study (E-ETDRS) protocol, in children aged 5 to 12 years. DESIGN: Prospective cohort study. METHODS: Crowded HOTV optotypes and crowded ETDRS optotypes were presented to 236 consecutive children aged 5 to 12 years using an electronic visual acuity tester (Palm handheld, personal computer, and monitor). Twenty-three percent of the children were classified as amblyopic, 35% as having uncorrected refractive error, 36% as normal, and 6% as other. Visual acuity test results were converted to logarithm of minimal angle of resolution (logMAR) units for analysis. RESULTS: In developmentally normal children (n = 230), testability was 100% for HOTV in 5- to 12-year-olds and 100% for E-ETDRS in 7- to 12-year-olds. The E-ETDRS testing could be completed in 52% of 5-year-olds and in 87% of 6-year-olds. Visual acuity performance was better when measured by HOTV compared with E-ETDRS (median difference 0.06 logMAR [three letters on a chart with five letters/line], P =.0001), and the difference was found in normal eyes, eyes with refractive error, and amblyopic eyes. CONCLUSIONS: The ATS HOTV protocol yields slightly better visual acuity performance compared with E-ETDRS in 5- to 12-year-olds, but on average by less than a logMAR level. This systematic difference is important when a physician changes testing modality as a child matures and should be considered when interpreting the results of recent and ongoing clinical trials in amblyopia.

Amblyopia↗