Frequency of Convergence Insufficiency and treatment it with vision exercise in Optometry Clinic

Abstract

Introduction: Convergence insufficiency (CI) is a common binocular vision disorder characterized by difficulty in establishing near motor fusion. A common characteristic of CI is that patients have more symptoms, such as eyestrain and headache, after close work.

Purposes: The purpose of this study was to determine the frequency of insufficiency convergence (Cl) in optometry clinic for one year for cases with age 5 to 20 years in Erbil Medical Technical Institute. Also, the aim of this study was to determine the prevalence cases with convergence insufficiency with gender and age in a sample of age between 5 to 20 years, also do vision exercise to them.

Material and methods: In the present study optometric and ophthalmologic examinations were performed on all participants. Clinic records of 735 children were randomly selected and reviewed according to a standard protocol, Subject age was 5 to 20 years at year 1 of follow-up at 1 optometry clinic. Measurements included refractive error, distance and near phoria, interpupillary distance (IPD), prism bar fusional vergence ranges, and near point of convergence (NPC). Records were reviewed for demographic and clinical data. Data on Cl-related symptoms were obtained at one of the sites. 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. Records that met the eligibility criteria of: good visual acuity (20/30 or better in both eyes), 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 prism than at far; (2)  receded near point of convergence (NPC) of > or = 6 cm break or > or = 10.5 cm recovery. near break point of convergence (NPC) ≥ 6 cm. Children were then classified as: no Cl (no exophoric at near or < 4 prism difference between far and near); or NPC little than 6 cm.

Results: Ninety-six percent (706/735) of the records met the eligibility criteria and had complete data on phoria, NPC. The age (mean age +/- SD) of the study population was (12 +/- 1.3) years. The percentage of children rated as symptomatic increased with the number of Cl-related clinical signs present. A total of 706 participants' records were evaluated. Of those, 421 (59.7%) cases were female and 285 (40.3%) case were male. The prevalence of CI (177 cases) 25 % of patients were insufficiency convergence eye. In the present study, from eye cases with CI (177) cases from 706 cases, 40 normal eye cases (5.6%) had CI, 137 cases of cases with refractive errors had CI, 13 cases with mixed astigmatism  from 149 cases (9%) had CI, 4 cases with CHA from 149 cases ( 3%) had CI, 7 cases with SHA from 149 cases  (5%) had CI,  6 cases with SH from 149 cases  (4%) had CI,   64 cases with CMA from 149 cases  (43 %) had CI,  23 cases with SMA from 149 cases  ( 15%) had CI and ,  20 cases with SM from 149 cases  ( 13%) had CI. The more CI prevalence there were in CMA. According to the results, 60 cases (60%) from 95 cases of myopic eyes that they had all types of myopia refractive errors had CI, 17 cases (43%) with all types of hypermetropic eyes from 39 cases with hypermetropic eyes had CI. It shows the cases with myopic eyes more than hypermetropic eyes.

Conclusions: The prevalence of clinically significant convergence insufficiency in this sample. CI is a separate and unique clinical condition and can occur without a combined condition. 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 person. These results suggest that for myopic children convergence ranges decrease for both distance and near viewing during the school years as near phoria becomes more exophoric.