Frequency of convergence insufficiency among fifth and sixth graders. The Convergence Insufficiency and Reading Study (CIRS) group.

PURPOSE: To estimate the frequency of convergence insufficiency (CI) and its related clinical characteristics among 9- to 13-year-old children. METHODS: Fifth and sixth graders were screened in school settings at three different study sites. Eligible children with 20/30 or better visual acuity, minimal refractive error, no strabismus, and exophoria at near were evaluated according to a standardized protocol to determine the presence and severity of CI. These children were classified according to the presence and number of the following clinical signs: (1) exophoria at near > or =4delta than far, (2) insufficient fusional convergence, and (3) receded nearpoint of convergence. Also, children were classified as accommodative insufficient (AI) if they failed Hofstetter's minimum amplitude formula or had greater than a + 1.00 D lag on Monocular Estimate Method retinoscopy. RESULTS: Of 684 children screened, 468 (68%) were eligible for further evaluation. Of these, 453 had complete data on CI measurements and were classified as: no CI (nonexophoric at near or exophoric at near and < 4delta difference between near and far) (78.6%); low suspect CI (exophoric at near and one clinical sign: exophoria at near > or =4delta than far) (8.4%); high suspect CI (exophoric at near and two clinical signs) (8.8%); and definite CI (exophoric at near and three clinical signs) (4.2%). CI status varied according to ethnicity and study site (p < 0.0005), but not gender. The frequency of AI increased with the number of CI-related signs. For CI children with three signs, 78.9% were classified as also having AI. CONCLUSIONS: These findings suggest that CI (defined as high suspect and definite) is frequent (13%) among fifth and sixth grade children. In addition, there is a high percentage of CI children with an associated AI.

Prospective comparison of convergence insufficiency and normal binocular children on CIRS symptom surveys. Convergence Insufficiency and Reading Study (CIRS) group.

PURPOSE: To test the validity-related evidence of a child and a parent symptom survey developed by the Convergence Insufficiency and Reading Study (CIRS) group. METHODS: A case comparison method was used to measure differences in symptoms between 14 school-aged children (ages 8 to 13 years) with Convergence Insufficiency (CI) and 14 children with normal binocular vision (NBV). RESULTS: A pooled t-test indicated that CI children and their parents scored higher than the NBV children and their parents on the child's survey (p<0.001) and parent's survey (p<0.001), respectively. CI children also scored significantly higher (p<0.03) on the Conners' Rating Scale for Parents. CONCLUSIONS: The results suggest that the CIRS symptom survey is a valid instrument for differentiating CI children from those with normal binocular vision. Additionally, children in this age group were able to respond to a broad range of symptom questions associated with CI.

Normative values for the nearpoint of convergence of elementary schoolchildren.

BACKGROUND: Nearpoint of convergence (NPC) values of 8 to 10 cm are widely used to diagnose binocular dysfunctions such as convergence insufficiency. However, there are no published age-related normative values in the literature to substantiate these values. METHODS: Subjects were 297 schoolchildren in kindergarten, third grade, and sixth grade who had passed a school-based Modified Clinical Technique vision screening. Each child had the NPC break and recovery taken three times using a standardized protocol developed by the Convergence Insufficiency and Reading Study group. The examiners used an Astron International (ACR/21) Accommodative Rule with a movable column of 20/30 letters as the target. RESULTS: For each grade, the distribution of NPC break was right skewed, with a concentration of values between 1 and 6 cm. At least 85% of the subjects in each grade had an NPC break < or = 6 cm. NPC break values (mean +/- SD) were 3.3 +/- 2.6 cm for kindergartners, 4.1 +/- 2.4 cm for third graders, and 4.3 +/- 3.4 cm for sixth graders, and the means were found to be statistically different (analysis of variance, p = 0.031). NPC recoveries (mean +/- SD) for the three groups were 7.3 +/- 4.8 cm, 8.7 +/- 4.2 cm, and 7.2 +/- 3.9 cm, respectively, which were also significantly different (analysis of variance, p = 0.027). The recovery distributions were more symmetric and less skewed than those for break. For each grade level, there was a strong positive relationship between NPC recovery and NPC break, but the difference between NPC recovery and break had a low correlation with the NPC break. SUMMARY: Kindergartners had somewhat better NPC breaks than third or sixth graders, whereas no clear age trend was present for NPC recovery. A supporting study using a random sample of clinic patients (aged 10-12 years) suggests that patients with NPC breaks > 6 cm are more than twice as likely to be symptomatic than patients with NPC breaks < or = 6 cm. Based on these results and the NPC break distributions in this study, a clinical cutoff value of 6 cm is suggested for patients of elementary school age. A cutoff value in the 6- to 10-cm range is recommended for children of elementary school age in a screening context. The exact value within this range depends on the level of concern with identifying patients who have visual signs and symptoms associated with a receded NPC.

Frequency of convergence insufficiency in optometry clinic settings. Convergence Insufficiency and Reading Study (CIRS) Group.

PURPOSE: To estimate the frequency of convergence insufficiency (Cl) and its related characteristics among 8- to 12-year-old children randomly selected from 2 optometry clinic populations. METHODS: Clinic records of 620 children were randomly selected and reviewed according to a standard protocol, using a systematic sampling method based on the total number of 8- to 12-year-old children seen over a 1-year period at 2 optometry clinics. Records were reviewed for demographic and clinical data. Data on Cl-related symptoms were obtained at one of the sites. Records that met the eligibility criteria of: good visual acuity (20/30 or better in both eyes); minimal refractive error (-0.50 to +1.00 D and < or = 1.00 D of astigmatism in either eye, and < or = 1.00 D of anisometropia); and no strabismus were evaluated for Cl-related characteristics. Eligible children were classified according to the direction of their near heterophoria and the number of the following clinical signs present: (1) exophoria at near > or = 4 delta than at far; (2) insufficient fusional convergence [i.e., failing Sheard's criterion or minimum normative positive fusional vergence (PFV) of 12 delta base-out (BO) blur/15 delta BO break]; and (3) receded nearpoint of convergence (NPC) of > or = 7.5 cm break or > or = 10.5 cm recovery. Children were then classified as: no Cl (nonexophoric at near or < 4 delta difference between far and near); low suspect (exophoric at near and 1 sign); high suspect (exophoric at near and 2 signs); or definite Cl (exophoric at near and 3 signs). RESULTS: Sixty-seven percent (415/620) of the records met the eligibility criteria and had complete data on phoria, NPC, and PFV. The age (mean +/- SD) of the study population was 10.2 +/- 1.2 years. Ethnicity data were available for 85% of those eligible; the ethnic distribution was 36% African American, 29% Caucasian, 19% Hispanic, and 1% Asian. About one-half of the 415 children were classified as either low suspect (33%); high suspect (12%); or definite Cl (6%). Clinically significant Cl (high suspect and definite categories) was identified in 17.6% of the children. The percentage of children rated as symptomatic increased with the number of Cl-related clinical signs present. CONCLUSIONS: These findings suggest a high frequency of Cl in optometry clinic populations and a potential correlation between patient symptoms and the number of Cl signs present.

Role of optometric vision therapy for surgically treated strabismus patients.

BACKGROUND: Occasionally, co-management involving both optometry and ophthalmology is needed to optimize treatment outcome for the strabismic patient. METHODS: JB, a 47-month-old consecutive esotrope presented to our clinic. Two previous attempts to surgically correct her exotropia had failed and the parents sought another treatment approach. We recommended optometric vision therapy (VT) to improve sensorimotor fusion before any further surgery. After 31 VT sessions (bi-weekly for a time, then weekly), before a third scheduled surgery, sensorimotor fusion was good in the amblyoscope, but unstable with neutralizing prism in free-space. We recommended surgery be postponed, but the family proceeded. Esotropia recurred with constant suppression. After additional VT, JB developed stable sensorimotor fusion and random dot stereopsis in free-space with neutralizing prism. A fourth surgery was then performed resulting in esophoria at all distances with good sensory fusion. RESULTS: Twenty-one months postoperatively, JB remains nonstrabismic with good sensory fusion. CONCLUSIONS: Clinicians should understand the roles and limitations of available treatment options. Surgery reduces the magnitude of the deviation, whereas optometric VT provides the unique role of establishing normal sensory processing.

Quality of life: a review.

BACKGROUND: Quality of life has become an important issue in evaluating clinical research outcomes, and in relationship to cost containment and managed care issues. METHODS: The literature on quality of life was reviewed to give the practicing optometrist an overview of the issue. RESULTS: Quality of life embraces a wide range of physical and psychological characteristics that describe a person's functional ability. There is no agreed upon definition of quality of life. This lack of agreement has led most researchers to adopt a multidimensional approach toward assessing quality of life since no single parameter has ever proven to be adequate. CONCLUSION: Quality of life measurement is an important issue in health care research and policy. In the future, awareness of quality of life issues will be of increasing importance for the optometrist.

Detecting learning-related visual problems in the primary care setting.

BACKGROUND: School-aged children with learning problems are frequently encountered by optometrists. Current research indicates a link between learning problems and certain visual factors that are referred to as learning-related visual problems. As a result, the primary care vision doctor should identify children with learning-related visual problems within the context of a primary care examination. We will present a diagnostic strategy for identifying children with learning-related visual problems. The use of appropriate case history questions and a few additional tests will allow the primary care vision doctor to detect or diagnose the majority of learning-related visual problems within the context of a primary care examination.

A comparison of drop instillation and spray application of 1% cyclopentolate hydrochloride.

We compared the objective cycloplegic refractive error of 37 hyperopic children (ages 18 months to 6 years). Cycloplegia was by spray application to the closed eye, or by a one-drop instillation to the open eye. Patients were initially screened for hyperopia using a masked noncycloplegic retinoscopy with loose trial lenses. Spray and drop cycloplegias (1% cyclopentolate hydrochloride; 1% Spectro Pentolate) were administered to each patient in random order within a 2-week period. A masked cycloplegic retinoscopy was performed 20 min after drug administration for patients with "light" iris coloration and after 40 min for those with "dark" irides. One examiner conducted all cyclopentolate administrations; a separate examiner (masked to application method) conducted all refractive testing. For right eyes, the mean spherical equivalent refractive error after spray application was 1.76 D (SD = 1.63 D) and after drop instillation 1.78 D (SD = 1.85 D). Results were similar for the left eyes. These small differences were not statistically significant (ANOVA, F = 0.05, p = 0.82). The absolute difference in spherical equivalent was 0.50 D or less in 93% of all subject eyes. A scaling system was used to rate the ease of administration and the patient's response to each method. Using an exact test of marginal homogeneity, the response rating for the spray method was significantly better (p = 0.038). The spray application of cyclopentolate hydrochloride is easier to administer and is an effective alternative to traditional drop instillation.

Differential diagnosis of an isolated inferior oblique paresis vs. Brown's syndrome: a case report.

The primary care optometrist is often faced with evaluating and diagnosing oculomotor anomalies. Non-concomitant deviations can be especially challenging because of the additional skill and knowledge needed for differential diagnosis. The following case illustrates the diagnostic process involved in differentiating inferior oblique paresis from Brown's syndrome. The clinical features, incidence, etiology and management considerations of each condition are discussed.

Binocular accommodative facility testing reliability.

This study evaluated the reliability of the 1-min binocular accommodative facility test by extending the testing period for 2 additional minutes. Subjects, ages 8 to 12 years, were tested for an initial 1-min period, to identify 2 groups, high fail (greater than 3, but less than 8 cpm, N = 30) and low fail (less than 3 cpm, N = 30), and then tested for an additional 2 min. The low fail group had greater test-retest reliability in both minutes 2 and 3. Both groups improved (high fails mean = 0.93 cpm, low fails mean = 0.37 cpm), but no clear statistical difference was found between groups. When diagnostic classification was monitored over the 3 min, 40% of high fails passed, whereas no low fails passed. The 1-min testing method appears reliable if the initial rate is less than 3 cpm. For patients whose initial rate is between 3 and 8 cpm, extended testing (1 to 2 additional minutes) may be needed to arrive at an accurate diagnosis, especially if presenting symptoms are absent.

Comparative study of computer-based and standard clinical accommodative facility testing methods.

Two methods for assessing accommodative facility were compared: the Computer Orthoptics Diagnostic Program and the standard Lens Flipper Method. In random fashion, 40 visually normal [modified clinical technique (MCT) screening] subjects, ages 10 to 18 years, were tested monocularly and binocularly on both methods. Scatter-plot comparisons of the data showed no apparent relation between the two methods, with correlation coefficients close to zero for both monocular (r = 0.0205) and binocular (r = 0.1180) results. In addition, the subject's diagnostic classification (pass or fail) was compared between the two methods. The kappa statistic indicated a low level of agreement between the two methods both monocularly and binocularly. These results suggest that the Computer Orthoptics' diagnostic test is not a valid method for diagnosing accommodative facility deficiencies.

Management of infantile-onset esotropia.

Background information on the prevalence, clinical characteristics, and differential diagnosis of infantile-onset esotropia is presented. A brief overview of early development of binocularity is also presented to set the stage for management, as well as a sequential treatment plan for two age groups of infantile esotropes: 1) infants and toddlers, and 2) preschool and "older" patients. Flowcharts and case examples are included to highlight the management principles for attaining maximum binocular function.

Stereoscopic depth perception by static stereo-deficient observers in dynamic displays with constant and changing disparity.

The performance of 11 static stereo-deficient subjects and 11 static stereo-normal subjects was compared on two types of dynamic stereo displays--one where disparities were constant during motion and one where disparities changed continuously. Computer-generated displays simulating horizontal motion of figures at different depths or rotation of figures about a vertical axis were viewed through a Brewster stereoscope. About one-half of the subjects in our static stereo-deficient sample were able to make depth judgments on the basis of disparity in both types of dynamic displays. The clinical feature which appeared to distinguish those static stereo-deficient subjects who could use disparity information in dynamic displays from those who could not was early onset constant strabismus. These results indicate that a complete evaluation of stereo ability should include tests with dynamic displays, possibly including both constant and changing disparities.

Monocular accommodative facility testing reliability.

Recently, concern has been expressed about accommodative facility testing reliability, especially for subjects rated initially as failing. Our study evaluated an extended testing period's effect on reliability. Subjects, ages 8 to 12 years, were tested for an initial 1-min period; to identify two groups; high fails (greater than 6, but less than 11 cpm, N = 30) and low fails (less than 6 cpm, N = 30), and then for an additional 2 min. Mean rate change analysis showed both high and low fail groups improved their accommodative facility over extended testing (1.29 and 0.87 cpm, respectively), although no significant difference was found between the groups. In contrast, test-retest correlations indicate a higher reliability for the baseline rates among low fail (r = 0.720) as compared to high fail (r = 0.402) subjects. The difference between groups became more evident when diagnostic classification was monitored over the 3-min testing period, with 73.3% of the low fails remaining low fails, and 43.4% of the high fails reached the pass criterion. The 1-min testing method appears more reliable if the initial rate is less than 6 cpm. For patients whose initial rate is between 6 and 11 cpm, extended testing (1 additional min) may be needed to arrive at an accurate diagnosis, especially if presenting symptoms are absent.

A comparison study of dynamic visual acuity between athletes and nonathletes.

A comparison study of dynamic visual acuity (DVA) was conducted using samples of nonathletic college students and college baseball players. The experimental population consisted of 17 male baseball players ranging in age from 19-24 years. The control population was made up of 25 male graduate students ranging in age from 23-29 years. Subjects reported the direction of a 20/25 "Landolt C" target exhibiting uniform angular motion produced by a projection system. Angular target velocities between 10 deg/sec and 110 deg/sec with an exposure time of 400 ms were used. The results showed a statistically significant difference between the two groups' DVA. The mean DVA for the baseball players was 82.35 deg/sec and 69.90 deg/sec for the control group.

Management of a young esotrope using vision therapy and prismatic prescription.

This case report illustrates the important issues concerning optometric management of the pediatric patient presenting with esotropia. Appropriate treatment options and prognostic factors are covered. The case demonstrates the successful, sequential treatment of a young, early-onset, esotropic patient through vision therapy and prismatic lens prescription.

Management of binocular anomalies: efficacy of vision therapy in the treatment of accommodative deficiencies.

This paper is a review of the literature supporting vision therapy as an effective treatment mode for accommodative deficiencies. Vision therapy procedures have been shown to improve accommodative function effectively and eliminate or reduce associated symptoms. In addition, the actual physiological accommodative response variables modified by the therapy have been identified, eliminating the possibility of Hawthorne or placebo effects accounting for treatment success. Finally, the improved accommodative function appears to be fairly durable after treatment.