- Forest Grove, Oregon, United States
Richard London
Pacific University, Optometry, Faculty Member
Background: The use of objective eye movement measuring devices, such as the Visagraph or ReadAlyzer, has gained popularity in patients with acquired brain injury (ABI) in order to address their common complaints of reading difficulty.... more
Background: The use of objective eye movement measuring devices, such as the Visagraph or ReadAlyzer, has gained popularity in patients with acquired brain injury (ABI) in order to address their common complaints of reading difficulty. Based on our clinical experience, we have found a specific recording pattern in these patients, where the duration of fixation is increased proportionally greater than other test findings. Methods: A retrospective research study was conducted to determine the characteristics of Visagraph/ReadAlyzer results in 36 patients with ABI. Results: Our results show that out of 36 patients, 75% showed a pattern where the duration of fixation was increased, and a reduction of at least two grade levels as compared to the second-lowest component of the recording was present. Conclusion: It is common to see increased duration of fixation in patients with a history of ABI. This may indicate a reduction in information processing. Tachistoscopic activities, as a part ...
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Our objective is to determine whether unilateral atropine as amblyopia therapy leads to an asymmetric change in refractive error compared to patching. Patients were enrolled in a clinical trial in which atropine 1% solution or occlusion... more
Our objective is to determine whether unilateral atropine as amblyopia therapy leads to an asymmetric change in refractive error compared to patching. Patients were enrolled in a clinical trial in which atropine 1% solution or occlusion with an adhesive patch was administered daily to the sound eye of children 3 to < 7 years of age for a period of at least 6 months to a maximum of 2 years. Refractive error at entry and at 2 years was determined with cycloplegic retinoscopy for 282 of 419 patients enrolled. The baseline mean refractive error was +3.13 Diopters (D) in eyes randomized to atropine and +2.58D in eyes randomized to patch. The mean change in refractive error of the sound eye was +0.10D in the atropine group (N=134) and +0.08D in the patching group (N=148). Patients also were subdivided into those treated with atropine only (n=41) and patching only (n=64). The mean change for the sound eye was -0.21 D for the patients receiving only atropine and -0.06 D for the patients receiving only patching. Unilateral atropine applied to the sound eye compared to occlusion was not associated with any adverse effect on refractive error following up to 2 years of treatment.
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Acquired involuntary eye movement disorders, including noncomitant strabismus, nystagmus, and saccadic dyskinesia, are common ocular manifestations of many neurodegenerative diseases. These patients may experience visual symptoms, such as... more
Acquired involuntary eye movement disorders, including noncomitant strabismus, nystagmus, and saccadic dyskinesia, are common ocular manifestations of many neurodegenerative diseases. These patients may experience visual symptoms, such as blurred vision, diplopia, and oscillopsia, which can significantly impact their use of vision. The goal of the management for these patients is to reduce the visual symptoms using any combination of available management strategies. This case report discusses the effective optical management using the combination of spectacle monovision correction and yoked prism to improve visual symptoms in a patient with olivopontocerebellar atrophy.
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The eye undergoes rapid growth during the first years of life. Using a mathematical model, we analyzed angle lambda from birth through adult life to determine what change in its magnitude occurs with growth of the eye. The effect of... more
The eye undergoes rapid growth during the first years of life. Using a mathematical model, we analyzed angle lambda from birth through adult life to determine what change in its magnitude occurs with growth of the eye. The effect of changes in angle lambda on measurement and correction of astigmatic errors and on the analysis of fixation patterns are discussed.
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Following a suggestion made by Percival in regard to dissociated phorias, we corrected vertical associated phoria in several patients who had disparities in both vertical and horizontal fixation. The principal objective result of this... more
Following a suggestion made by Percival in regard to dissociated phorias, we corrected vertical associated phoria in several patients who had disparities in both vertical and horizontal fixation. The principal objective result of this correction was a flattening of the slope of the type I horizontal forced-vergence curve. This result may be significant particularly because the slope has been identified as being a good prognosticator of patients likely to be symptomatic. Attention to a concurrent vertical component may offer a convenient way to normalize a steep slope on horizontal fixation disparity curves.
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Fixation disparity measurement as a tool for analyzing the binocular visual system has taken very different approaches in the United States and Central Europe. In the United States, testing has primarily followed a motor approach, and... more
Fixation disparity measurement as a tool for analyzing the binocular visual system has taken very different approaches in the United States and Central Europe. In the United States, testing has primarily followed a motor approach, and resulting management has followed parameters established by graphical analysis closely. In German-speaking countries, a strong sensory-based analysis has been popular for decades, utilizing equipment rarely seen in the United States. Management in these countries has been almost exclusively directed toward prismatic prescription. This report examines the instrumentation, underlying strategies, and management used in both the motor and sensory approaches to fixation disparity analysis. Testing protocols and management options are detailed for each approach. Although both approaches agree that fixation disparity has the potential to reveal a more realistic view of binocular system functioning under normal viewing conditions than other systems of analysis...
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Soft opaque contact lenses may be useful in certain recalcitrant vision problems. When the full central area is opaque, contact lenses eliminate the visual image, provide acceptable cosmesis, and may be useful in cases of intractable... more
Soft opaque contact lenses may be useful in certain recalcitrant vision problems. When the full central area is opaque, contact lenses eliminate the visual image, provide acceptable cosmesis, and may be useful in cases of intractable diplopia as well as in the treatment of amblyopia. Artificial iris contact lenses eliminate para-axial rays in monocular diplopia, aniridia, and albinism.
Research Interests: Binocular vision, Treatment, Amblyopia, Humans, Female, and 4 moreMale, Diplopia, Vision Disorders, and Aniridia
The eye undergoes rapid growth during the first years of life. Using a mathematical model, we analyzed angle lambda from birth through adult life to determine what change in its magnitude occurs with growth of the eye. The effect of... more
The eye undergoes rapid growth during the first years of life. Using a mathematical model, we analyzed angle lambda from birth through adult life to determine what change in its magnitude occurs with growth of the eye. The effect of changes in angle lambda on measurement and correction of astigmatic errors and on the analysis of fixation patterns are discussed.
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Unlike the typical manifestation of acquired strabismus, patients with sensory fusion disruption syndrome are unable to fuse targets even when bifoveally aligned under ideal clinical conditions. This condition usually follows trauma and a... more
Unlike the typical manifestation of acquired strabismus, patients with sensory fusion disruption syndrome are unable to fuse targets even when bifoveally aligned under ideal clinical conditions. This condition usually follows trauma and a period of coma. These patients suffer from chronic diplopia which is not relieved by optical or surgical means. Recognition of this entity may result in more effectual management. As a phenomenon, it serves as a potential clue to physiological composition of binocularity.
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Variations in anisocoria in light and dark conditions are used to help diagnose normal and pathologic conditions; however, there have been few observations of anisocoria in different lighting and accommodative conditions. The authors... more
Variations in anisocoria in light and dark conditions are used to help diagnose normal and pathologic conditions; however, there have been few observations of anisocoria in different lighting and accommodative conditions. The authors measured pupil size photographically in a group of normal subjects examined in six conditions that were controlled for illumination and accommodation. Greater variation and average extent of anisocoria were found in conditions that resulted in larger pupil size. A subset of subjects repeated several sessions. For this group, the average value of anisocoria and variability tended to be greater in dark conditions. These results show that the observation of anisocoria varies under different conditions, and they suggest careful consideration of conditions used clinically to assess pupil equality. Our analysis shows that for a given observation threshold, conditions that produce even modest changes in variability can cause dramatic changes in the probability...
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Alignment of the eyes during early years of life is critical for the development of normal binocu-lar vision and sensory fusion. Always determine alignment from the most natural condition to the less natural conditions. That is, start... more
Alignment of the eyes during early years of life is critical for the development of normal binocu-lar vision and sensory fusion. Always determine alignment from the most natural condition to the less natural conditions. That is, start with the normal, undisrupted viewing conditions some-times referred to associated viewing conditions, where both eyes are allowed to take their natural alignment in an attempt to view an object of re-gard. Examples of associated viewing conditions that detect the presence of an ocular deviation are observation, and the Hirschberg, B uckner, and unilateral cover tests. When possible, the magnitude of the deviation can be confirmed by dissociated viewing conditions such as the neu-tralization of the angle with an alternate cover test. These tests prevent the eyes from seeing si-multaneously and, thus, are less natural because this does not occur in the routine viewing of the world. Assessment of ocular alignment begins with the first observation of the p...
Sports fixed and variable tranaglyphs 2. Variable and fixed sports tranaglyphs with look-aways, and using red/green flippers for vergence facility, clown vectogram, VTS 3. Cheiroscope, stereoscope, continue tranaglyphs with look-aways 4.... more
Sports fixed and variable tranaglyphs 2. Variable and fixed sports tranaglyphs with look-aways, and using red/green flippers for vergence facility, clown vectogram, VTS 3. Cheiroscope, stereoscope, continue tranaglyphs with look-aways 4. GTVT chart walk-aways with prism flips, distance stereo trainer, VTS computer vergence program, continue tranaglyphs and stereoscope 5. Aperture Rule Trainer, continue stereoscope 6. HTS computer software for home training, aperture rule with added minus lenses, tranaglyph with added minus lenses, continue stereoscope 7. Lifesaver Cards, Binocular Accommodative Rock above bifcoal, GTVT walk aways with prism flips, continue aperture rule with added minus lenses and HTS
Quantification and retrieval of data in vision therapy is a difficult task for both the private practitioner and optometric educator. The problem-oriented record provides an organizational approach that readily identifies... more
Quantification and retrieval of data in vision therapy is a difficult task for both the private practitioner and optometric educator. The problem-oriented record provides an organizational approach that readily identifies patient&#39;s problems, therapeutic objectives, and the results of administered therapy. A minimum data base and the resultant problem list for vision therapy has been designed by us. By combining these two through a system of coding, a ready computer data retrieval system was devised. This system provides a method to clearly define terms, objectives, and results. Utilization of this record system by optometric schools and practitioners should reduce much of the confusion existing in the specialty field of vision therapy.
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: The purpose of this article is to compare vision therapy/orthoptics, pencil pushups, and placebo vision therapy/orthoptics as treatments for symptomatic convergence insufficiency in adults 19 to 30 years of age. : In a randomized,... more
: The purpose of this article is to compare vision therapy/orthoptics, pencil pushups, and placebo vision therapy/orthoptics as treatments for symptomatic convergence insufficiency in adults 19 to 30 years of age. : In a randomized, multicenter clinical trial, 46 adults 19 to 30 years of age with symptomatic convergence insufficiency were randomly assigned to receive 12 weeks of office-based vision therapy/orthoptics, office-based placebo vision therapy/orthoptics, or home-based pencil pushups. The primary outcome measure was the symptom score on the Convergence Insufficiency Symptom Survey. Secondary outcome measures were the near point of convergence and positive fusional vergence at near. : Only patients in the vision therapy/orthoptics group demonstrated statistically and clinically significant changes in the near point of convergence (12.8 cm to 5.3 cm, p = 0.002) and positive fusional vergence at near (11.3Delta to 29.7Delta, p = 0.001). Patients in all three treatment arms demonstrated statistically significant improvement in symptoms with 42% in office-based vision therapy/orthoptics, 31% in office-based placebo vision therapy/orthoptics, and 20% in home-based pencil pushups achieving a score &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;21 (our predetermined criteria for elimination of symptoms) at the 12-week visit. : In this study, vision therapy/orthoptics was the only treatment that produced clinically significant improvements in the near point of convergence and positive fusional vergence. However, over half of the patients in this group (58%) were still symptomatic at the end of treatment, although their symptoms were significantly reduced. All three groups demonstrated statistically significant changes in symptoms with 42% in office-based vision therapy/orthoptics, 31% in office-based placebo vision therapy/orthoptics, and 20% in home-based pencil push-ups meeting our criteria for elimination of symptoms.
Research Interests: Ophthalmology, Clinical Trial, Randomization, Treatment, Placebo Effect, and 15 moreTreatment Outcome, Comparative Study, Visual acuity, Vision, Humans, Placebo, Female, Orthoptics, Male, Statistical Significance, Adult, Randomized Clinical Trial, Severity of Illness Index, Outcome measure, and Medical and Health Sciences
The refractive changes of pediatric patients who were prescribed overminus lenses for exotropia were evaluated. Overminus lenses means additional minus power over the lenses required to correct the refractive error at distance. Forty... more
The refractive changes of pediatric patients who were prescribed overminus lenses for exotropia were evaluated. Overminus lenses means additional minus power over the lenses required to correct the refractive error at distance. Forty exotropic patients, ages 1 to 15 years, were prescribed overminus lenses (-0.50 D to -3.75 D) for a period of 9 to 86 months. A small but significant correlation was found between the initial refractive error and the mean annual change toward myopia. Other factors such as age when treatment was given, duration of therapy, amount of overminus, and the amount of the exodeviation had little effect on the rate of myopic change. The mean annual changes in refractive error for hyperopes (-0.13 +/- 0.44 D, N = 15), emmetropes (-0.26 +/- 0.37 D, N = 17), and myopes (-0.75 +/- 0.77 D, N = 18) were similar to values reported in the literature for nonexotropic children.
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The Convergence Insufficiency Treatment Trial (CITT) Investigator Group conducted a preliminary study assessing the effectiveness of home-based push-up therapy and office-based vision therapy/orthoptics for the treatment of convergence... more
The Convergence Insufficiency Treatment Trial (CITT) Investigator Group conducted a preliminary study assessing the effectiveness of home-based push-up therapy and office-based vision therapy/orthoptics for the treatment of convergence insufficiency (CI). The CITT group developed a placebo therapy program that was designed to simulate real vision therapy/orthoptics. The purpose of this paper is to evaluate the effectiveness of this placebo therapy program in maintaining masking of subjects randomized to the office-based treatment arms (real or placebo). Subjects (ages 9 to 30 years) were enrolled, stratified into two groups by age, and then randomly assigned to one of three treatment groups: pencil push-up therapy, office-based vision therapy/orthoptics, or office-based placebo vision therapy/orthoptics. At the end of treatment, subjects in the two office-based therapy groups (placebo and real) were asked: (1) which treatment do you think you received? and (2) how sure are you about your answer? Ninety-five percent of subjects assigned to real therapy and 83% assigned to placebo therapy thought they were in the real therapy group. Of the subjects who thought they received real therapy, 90% assigned to real therapy and 89% assigned to placebo therapy were &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;somewhat sure,&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;pretty sure,&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; or &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;very sure&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; of their answer. Those assigned to real therapy had more responses in the &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;very sure&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; category. The CITT placebo therapy program was effective in maintaining subject masking in this multicenter clinical trial.
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Accommodation and vergence have a complex relation which occasionally breaks down, resulting in a loss of visual efficiency along with symptoms of discomfort associated with use of the eyes. Studies of accommodation/vergence interactions... more
Accommodation and vergence have a complex relation which occasionally breaks down, resulting in a loss of visual efficiency along with symptoms of discomfort associated with use of the eyes. Studies of accommodation/vergence interactions and tonic vergence disorders indicate that, using classical analysis techniques, separate methods are frequently necessary to determine whether existing binocular deficiencies are causing reported symptoms. The problem with current systems of binocular visual function analysis is that the vergence error which exists under binocular conditions is often not the same as that which is measured under monocular conditions. A rationale for, and technique of, analyzing binocular function using results of tests made under binocular conditions is described. This analysis incorporates the concepts of CA/C, proximal vergence (PV), and fixation disparity along with several accommodative measures (facility, lag, sustaining ability, and accuracy). By identifying relevant binocular components and the interrelations, the clinician should be better able to assess the contribution of each and examine which may be modified most easily by vision therapy, lenses, and/or prism intervention.
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Monocular Estimate Method (MEM) dynamic retinoscopy is an objective clinical method for determining the accommodative response to a fixed accommodative stimulus. Although MEM has been used in many clinical investigations, it has never... more
Monocular Estimate Method (MEM) dynamic retinoscopy is an objective clinical method for determining the accommodative response to a fixed accommodative stimulus. Although MEM has been used in many clinical investigations, it has never been compared with the measurement of accommodative response by the haploscope. This report compares the accommodative responses obtained by MEM and by a haploscopic instrument, the phoroaccommodometer. Linear regression analysis indicates that MEM consistently provides a close approximation to the phoroaccommodometer finding (r = 0.975, p less than 0.001). A conversion table has been generated so MEM findings may be adjusted to correspond with the phoroaccommodometer at higher stimulus values.
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Accommodative insufficiency (AI) and convergence insufficiency (CI) have been associated with similar symptomology and frequently present at the same time. The severity of symptomology in CI has been linked to the severity of the CI,... more
Accommodative insufficiency (AI) and convergence insufficiency (CI) have been associated with similar symptomology and frequently present at the same time. The severity of symptomology in CI has been linked to the severity of the CI, suggesting a dose-dependent relationship. However, with increasing severity of CI also comes increased comorbidity of AI. AI alone has been shown to cause significant symptomology. We hypothesize that AI drives the symptoms in CI with a comorbid AI condition (CIwAI) and that it is the increased coincidence of AI, rather than increased severity of CI, which causes additional symptomology. Elementary school children (n = 299) participated in a vision screening that included tests for CI and AI and the CISS-V15 symptom survey. They were categorized into four groups:1) normal binocular vision (NBV); 2) AI-only; 3) CI-only; and 4) CIwAI. One hundred seventy elementary school children fell into the categories of interest. Pairwise comparison of the group means on the symptom survey showed: 1) children with AI-only (mean = 19.7, p = 0.006) and children with CIwAI (mean = 22.8, p = 0.001) had significantly higher symptom scores than children with NBV (mean = 10.3); and 2) children with CI-only (mean = 12.9, p = 0.54) had a similar symptom score to children with NBV. Using a two-factor analysis of variance (AI and CI), the AI effect was significant (AI mean = 21.56; no AI mean = 11.56, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001), whereas neither the CI effect (p = 0.16) nor the CI by AI interaction effect (p = 0.66) were significant. CI is a separate and unique clinical condition and can occur without a comorbid AI condition, our CI-only group. Past reports of high symptom scores for children with CI are the result of the presence of AI, a common comorbid condition. When AI is factored out, and children with CI only are evaluated, they are not significantly more symptomatic than children with NBV.
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ABSTRACT Previous controlled reliability studies of cup to disc (C/D) ratio estimations may have been biased by lack of criteria for cup determination, small sample size; and/or large interval grouping of collected data. In our study four... more
ABSTRACT Previous controlled reliability studies of cup to disc (C/D) ratio estimations may have been biased by lack of criteria for cup determination, small sample size; and/or large interval grouping of collected data. In our study four examiners independently estimated the C/D ratios of 40 patients by direct ophthalmoscopy using a contour criterion for cup determination. Results indicated that 75% of the estimate pairs differed by 0.10 or less. Fewer than 14% of the estimate pairs differed by 0.2 or greater. The results of the study suggest that when examiners use a specified criterion of contour cupping, interexaminer assessment of the C/D ratio estimation is clinically and statistically reliable.
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Research Interests: Binocular vision, Adolescent, Ophthalmic, Strabismus, Humans, and 14 moreChild, Female, Male, Clinical Sciences, Optometry and Vision Science, Questionnaires, Optometry and Ophthalmology, Vision screening, Adult, Vision Disorders, Reproducibility of Results, Sensitivity and Specificity, Medical and Health Sciences, and Population surveillance
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Background. Convergence insufficiency (CI) is a common and distinct binocular vision disorder. However, there is a lack of consensus regarding the treatment most appropriate for CI. Possible treatment modalities include base-in prism,... more
Background. Convergence insufficiency (CI) is a common and distinct binocular vision disorder. However, there is a lack of consensus regarding the treatment most appropriate for CI. Possible treatment modalities include base-in prism, pencil pushup therapy (PPT), ...