Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ORTHOPTICS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,153 records · Page 64Linked to original sources
PubMed1992

Joint distribution of sphere, cylinder, and axis.

A mathematical expression for the joint probability density function of sphere, cylinder, and axis is presented for the first time. It holds under certain circumstances. A relation is derived which may be useful in obtaining the joint probability function when that expression does not hold. The joint probability density function is of fundamental importance in all quantitative studies of dioptric power in the form sphere, cylinder, and axis. Some of its properties are described. It represents a hypersurface in a four-dimensional space with a maximum, a saddle point, and variety of ridges.

Adult↗
PubMed1993

Persistent diplopia associated with strabismus surgery.

The primary therapeutic goal for patients with binocular vision problems is comfortable, single, clear, normal binocular vision at all distances and directions of gaze. Strabismus surgery is frequently used to assist in achieving this therapeutic goal. Strabismus surgery is also used for those patients who cannot achieve single normal binocular vision but who have a cosmetically noticeable ocular deviation. However, one of the complications of cosmetic strabismus surgery is persistent diplopia. This possibility must be considered seriously before any cosmetic strabismus surgery is performed. The purpose of this paper is to present a case report of a patient who had diplopia after cosmetic strabismus surgery to emphasize the need for careful consideration of the possibility of persistent diplopia after cosmetic strabismus surgery and how to avoid it.

Adult↗
PubMed1995

Predicting success with orthokeratology lens wear: a retrospective analysis of ocular characteristics.

PURPOSE: Orthokeratology procedures suffer from lack of predictability in the response of individuals. To identify factors contributing to this, we have retrospectively studied a range of ocular parameters in patients with varying outcomes from orthokeratology lens wear. EXPERIMENTAL DESIGN: Three groups were studied: an experimental group (9 subjects wearing Contex OK-3 design orthokeratology contact lenses), and 2 control groups [10 rigid gas permeable (RGP) contact lens wearers and 10 non-contact lens wearers]. Three categories were identified among the orthokeratology group: those responding well, moderately, or poorly to orthokeratology lens wear. Measurements included subjective refraction, intraocular distances, corneal thickness, ocular rigidity, and epithelial fragility. RESULTS: When comparing the three orthokeratology categories, there was no significant difference for central and peripheral epithelial fragility and ocular rigidity. There was also no significant difference for any of the biometric characteristics measured. The prefitting spherical equivalent power was found to be significantly different between categories of responders (p = 0.0228), with the poor responders having the highest initial level of myopia. None of the measured characteristics differed significantly among the orthokeratology group and the two control groups. CONCLUSIONS: In this pilot study, the success of orthokeratology lens wear was not related to ocular biomechanical or biometric attributes, but it was related to prefitting refractive error.

Adolescent↗
PubMed1996

Multifaceted treatment of congenital nystagmus: a report of 6 cases.

Patients with congenital nystagmus (CN) often have associated conditions (e.g., strabismus, high astigmatism, and binocular inefficiency) that also impair visual acuity. Unfortunately, individually used techniques directed at reducing nystagmus have generally produced only slight increases in Snellen acuity. We present case reports of six patients with nystagmus seen in our clinic (University of Houston, College of Optometry) to illustrate the use of problem-specific management to improve visual acuity and/or binocular function. The results suggest that a comprehensive management strategy should include treatment of all associated conditions as well as therapy to improve the characteristics of the nystagmus wave form.

Adolescent↗
PubMed1996

Effect of oculomotor and other visual skills on reading performance: a literature review.

The diagnosis and management of many oculomotor anomalies is within the domain of optometry. Thus, a thorough understanding of these systems and their relation to reading performance is vital. Efficient reading requires accurate eye movements and continuous integration of the information obtained from each fixation by the brain. A relation between oculomotor efficiency and reading skill has been shown in the literature. Frequently, these visual difficulties can be treated successfully with vision therapy.

Aptitude↗
PubMed1998

Vision therapy to reduce abnormal nearwork-induced transient myopia.

After brief periods of nearwork, some younger patients complain of transient distance blur that is correlated with a transient pseudomyopic shift in their distance refraction. This phenomenon has recently been documented objectively. However, there is lack of objective documentation demonstrating the effects of conventional optometric vision therapy in symptomatic individuals manifesting this "abnormal nearwork-induced transient myopia" (ANITM). Five symptomatic subjects received 7 to 10 weeks (5 to 6 sessions) of accommodative facility vision therapy (i.e., lens flippers and Hart chart). Objective recording of their ANITM and its decay were taken before and after the vision therapy, using a Canon R-1 autorefractor. A daily log was maintained, describing qualitatively their nearwork-related symptomatology. After therapy, there was marked reduction of symptoms and considerable improvement in clinical accommodative facility measures, as well as improvement in the objective findings. These results demonstrate multi-faceted positive effects of optometric accommodative vision therapy in this diagnostic group of symptomatic individuals.

Accommodation, Ocular↗
PubMed2001

Preliminary investigation of the responsiveness of the Melbourne Low Vision ADL index to low-vision rehabilitation.

PURPOSE: To conduct a preliminary investigation on the ability of the Melbourne Low Vision ADL Index to detect changes in functional ability as a result of low-vision rehabilitation. METHODS: Twenty two subjects with age-related macular degeneration (ARMD) who were newly referred to the Kooyong Low Vision Clinic were recruited. The Melbourne Low Vision ADL Index was administered prerehabilitation and postrehabilitation. Changes in scores and effect size statistics were analyzed. RESULTS: The median total score for the subjects prerehabilitation was 67, and the median total score postrehabilitation was 76. The difference in prerehabilitation and postrehabilitation scores was statistically significant (Wilcoxon signed rank test = 248.5, p < 0.001). The mean change score for the total Melbourne Low Vision ADL Index was 9.3 (SD, 5.6). Thus the overall effect size statistic (mean change score divided by SD of prerehabilitation score) was 0.78. CONCLUSIONS: This preliminary investigation indicates that the Melbourne Low Vision ADL Index is responsive to a rehabilitation program for patients with ARMD. It has potential to be used as a measure of low-vision rehabilitation outcomes.

Activities of Daily Living↗
PubMed2002

A survey of treatment modalities for convergence insufficiency.

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 Cl. Possible treatment modalities include base-in prism, pencil pushup therapy (PPT), reading glasses, home-based vision therapy/orthoptics (HBVT), and office-based vision therapy/orthoptics (OBVT). The purpose of this study was to investigate the care process for Cl by surveying eyecare professionals regarding the most common treatment modalities used by both optometrists and ophthalmologists across the United States. METHODS: Surveys requesting doctors to indicate which treatment(s) they prescribed and believed to be most effective for symptomatic CI patients were mailed to 863 optometrists and 863 ophthalmologists in the United States. RESULTS: Fifty-eight percent of the optometrists responded to the survey; the most common treatment prescribed was PPT (36%) followed by HBVT (22%) and OBVT (16%). For the ophthalmologists (who had a 23% response rate), the most common treatment prescribed was PPT (50%) followed by HBVT (21 %) and base-in prism (10%). CONCLUSIONS: This survey suggests that most eyecare practitioners prescribe PPT as the initial treatment for CI.

Data Collection↗
PubMed2002

The effectiveness of pencil pushups treatment for convergence insufficiency: a pilot study.

PURPOSE: To study the effectiveness of pencil pushups treatment (PPT) for the treatment of convergence insufficiency in a clinical situation. METHODS: PPT was prescribed for use at home for 6 weeks for 25 subjects with convergence insufficiency. RESULTS: Twelve of the subjects returned for follow-up. Seven of 12 (58%) subjects showed a clinically significant improvement in nearpoint of convergence and positive fusional vergence, and 11 of 12 reported improvement in symptoms. Only one subject became asymptomatic. CONCLUSIONS: PPT resulted in some improvement in both objective findings and symptoms for some subjects. Compliance with the recommended home therapy protocol was poor.

Adolescent↗
PubMed2006

The attitudes to back pain scale in musculoskeletal practitioners (ABS-mp): the development and testing of a new questionnaire.

OBJECTIVES: Little is known about practitioners' beliefs and attitudes to the treatment of low back pain, and whether these influence their clinical decisions, intervention strategies, and patient-centered outcomes. This study aimed to develop, test, and explore the underlying dimensions of a new questionnaire, the Attitudes to Back Pain Scale (ABS), in a specific group of clinicians, practitioners who specialize in musculoskeletal therapy. METHODS: Items for the draft questionnaire were derived from interviews with practitioners (chiropractors, osteopaths, and physiotherapists). The draft questionnaire (52 items) sought to assess practitioners' attitudes concerning role and self-image plus their beliefs about treatment goals and prognosis of low back pain. The questionnaire was sent to a random selection of 300 practitioners from each professional group, and 546 (61%) responded. Split-sample analyses were performed using exploratory and confirmatory factor analysis. RESULTS: Separate exploratory analyses were done for attitudes concerned with personal interaction (34 items) and attitudes about treatment orientation (18 items), producing six domains: limitations on sessions, psychologic, connection to health care system, confidence and concern, reactivation, and biomedical. Confirmatory analyses indicated that the model tested presented a good fit. Validity interviews revealed high agreement of categorization and low levels of difficulty in categorizing the items. CONCLUSIONS: The internal structure of the new questionnaire not only shows excellent psychometric properties and good face validity, but also has the added advantage of being developed with a specific clinical context in mind. Additional evaluation is required to fully describe the psychometric integrity of this instrument.

Adult↗
PubMed2004

Corneal iron ring formation associated with overnight orthokeratology.

PURPOSE: To describe a case of iron deposition in both eyes after overnight orthokeratology. METHODS: This is a case report of a 31-year-old man who underwent overnight orthokeratology. The subject was fitted with rigid gas-permeable contact lenses of reverse-geometry design to correct myopia. RESULTS: The prefitting manifest refraction was -4.75 -0.25 x 175 in the right eye and -4.50 -0.25 x 175 in the left eye. There was no corneal abnormality until 9 months after treatment, but development of corneal arcuate lines in both eyes was observed at the 1-year follow-up visit. Visual acuity was not affected. The deposition pattern corresponded to the outside border of central flatter zone, as shown on the corneal topography map. CONCLUSION: The current findings suggest that tear pooling between the corneal surface and the back surface of the contact lens plays a role in the development of corneal iron ring after orthokeratology with reverse-geometry contact lenses.

Adult↗
PubMed2004

Influence of overnight orthokeratology on corneal endothelium.

PURPOSE: To evaluate the influence of overnight orthokeratology on the corneal endothelium. METHODS: Fifty-two eyes of 31 patients undergoing overnight orthokeratology for myopia were examined. They wore the lens every night and were followed up for at least 1 year. The corneal endothelium was examined with specular microscopy to calculate mean endothelial cell density, coefficient of variation of cell area, and percentage of hexagonal cells. Data obtained at 1-year follow-up examinations were compared with those at the baseline examinations using a paired t test. RESULTS: Orthokeratology significantly reduced manifest refraction from -2.32 +/- 1.18 D (mean +/- standard deviation) to -0.16 +/- 0.33 D (P < 0.0001) and improved uncorrected visual acuity from 0.77 +/- 0.29 to -0.07 +/- 0.10 logMAR (P < 0.0001). The endothelial cell density did not change significantly (2879 +/- 231 cells/mm before and 2864 +/- 260 cells/mm after treatment, P = 0.252). The coefficient of variation of cell area was 22.3 +/- 2.7 at baseline and 22.1 +/- 2.4 at 1-year posttreatment, which did not change significantly (P = 0.537). The percentage of hexagonal cells was 72.8 +/- 10.2% pretreatment and 72.5 +/- 10.9% posttreatment (P = 0.800). CONCLUSIONS: Overnight orthokeratology for 1 year did not influence the density or morphology of corneal endothelial cells.

Adolescent↗
PubMed2006

Optical quality of the cornea after overnight orthokeratology.

PURPOSE: To review changes in the optical quality of the cornea induced by overnight orthokeratology for myopia. METHODS: Sixty-four eyes of 39 patients who underwent overnight orthokeratology for myopia were prospectively examined. Inclusion criteria were uncorrected visual acuity of 20/20 or better after treatment and a minimum follow-up of 3 months. To quantitatively assess changes in corneal regular and irregular astigmatism, videokeratography data were decomposed into spherical component, regular astigmatism, asymmetry, and higher-order irregularity using Fourier analysis. In addition, corneal wavefront aberrations were calculated by expanding anterior corneal height data from videokeratography into a set of orthogonal Zernike polynomials. RESULTS: Although orthokeratology significantly reduced manifest refraction and improved uncorrected visual acuity, the asymmetry component, which is one of the features of irregular astigmatism, increased significantly from 0.35 +/- 0.22 to 0.64 +/- 0.40 D after treatment (P < 0.0001, paired t test). The increases in the asymmetry component significantly correlated with the amount of myopic correction (Pearson correlation coefficient, R = 0.40, P = 0.0009). Furthermore, the root-mean-square of third-order (coma-like) and fourth-order (spherical-like) aberrations significantly increased after orthokeratology (P < 0.0001, paired t test), and these increases showed significant positive correlations with the amount of myopic correction (Pearson correlation coefficient, R = 0.452, P = 0.0001 and R = 0.381, P = 0.0017, respectively). CONCLUSION: Corneal irregular astigmatism and higher-order aberrations significantly increased even in clinically successful orthokeratology, and the increases correlated with the magnitude of myopic correction. A large myopic correction by orthokeratology should be avoided to not decrease corneal optical quality.

Adolescent↗
PubMed2005

A randomized clinical trial of vision therapy/orthoptics versus pencil pushups for the treatment of convergence insufficiency in young adults.

PURPOSE: : 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. METHODS: : 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. RESULTS: : 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 <21 (our predetermined criteria for elimination of symptoms) at the 12-week visit. DISCUSSION: : 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.

Adult↗
PubMed1987

Identification of factors limiting the action of the horizontal recti muscles. A guide to the avoidance of gross limitation of adduction or abduction after squint surgery.

Limitation of the action of the medial rectus muscle will cause limitation of adduction of the eye just as limitation of the lateral rectus will cause limitation of abduction. Factors limiting the action of the medial rectus are: (i) loss of ability of the muscle to contract beyond a certain proportion of its length; (ii) limitation of relaxation of the antagonist lateral rectus and fascial connections; (iii) innervational factors seen most obviously in Duane's syndrome, but also possibly active with various vertical anomalies; and (iv) loss of mechanical advantage or torque as the eye rotates inward. Using A scan the last factor may be assessed for a particular eye. There will be no loss of torque until the muscle passes a tangential point where its line of action is tangential to the globe, but torque will then be lost progressively until it becomes negligible as the null point is approached. At the null point the muscle has no torque, being perpendicular to the globe, and it marks the point where the oculomotor axis joining the centre of rotation of the eye and the apex of the orbit intersects the globe. The first three factors may be assessed clinically by measuring the adduction of the eye in degrees, and for 50 normal patients (100 eyes) the mean was 44 degrees, standard deviation 3 degrees. The tangential point for an average eye lies 54 degrees behind the medial rectus muscle so for normal adduction there is no loss of torque in full adduction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed2006

Intermittent exotropia: comparison of treatments.

PURPOSE: To identify the best treatment option for intermittent exotropia. METHODS: A retrospective analysis of the progress of 150 treated intermittent exotropia patients was performed. Treatment forms considered are: (i) surgery combined with orthoptic/occlusion therapy; (ii) surgery; (iii) orthoptic/occlusion therapy; and (iv) observation. Pearson's chi(2)-analysis of association of therapy form with success was performed. Reduction of exodeviation in prism dioptres between groups and subgroups were compared at 6 months, 1, 2 and 5 years follow up and the "within group" variations were compared. Exodeviation reduction in prism dioptres per millimetre of horizontal rectus surgery performed in the "surgery with orthoptic/occlusion therapy" and "surgery only" groups were compared. RESULTS: Chi(2)-analysis revealed a significantly highest (P < 0.001) association with success in the "surgery with orthoptic/occlusion therapy" group at follow up. ANOVA analysis revealed that surgery with orthoptic/occlusion therapy resulted significantly (P < 0.001) in the highest reduction of exodeviation as compared with the other three treatment modalities at each follow up. Reduction of exodeviation in prism dioptres per millimetre of horizontal rectus surgery performed was significantly higher (P < 0.05) in the surgery with orthoptic/occlusion therapy group as compared with surgery only at all follow ups. Chi(2)-test revealed no significant association of success with the magnitude of initial exodeviation (P > 0.05). CONCLUSION: Surgery with preoperative orthoptic/occlusion therapy had the highest success rates. Surgery with orthoptic/occlusion therapy was more effective in reducing exodeviation (prism dioptres per millimetre of horizontal rectus surgery), compared with surgery only.

Child↗