Assessment of stereopsis in pediatric and adolescent spectacle-corrected refractive error – A cross-sectional study

Purpose: To assess the level of stereopsis in school children with spectacle?corrected refractive errors using Titmus fly and Randot stereo tests, evaluate the factors associated with the level of stereopsis, and determine the level of agreement between the two tests. Methods: A cross?sectional study was done on 5? to 18?year?old school?children wearing spectacles for at least 1?month duration. Visual acuity was assessed using Snellen’s visual acuity chart, and their spectacle correction being used currently was measured using an auto lensmeter. The level of stereopsis was assessed using Randot and Titmus fly stereo tests. Data were entered using Microsoft Excel and analyzed using IBM?SPSS version 20, Chicago, IL. The associations between stereopsis and type of refractive error, visual acuity, age, and gender were analyzed. An agreement between Randot and Titmus fly test was done using Kappa statistics. Results: A total of 222 children (101 boys and 121 girls; mean age 13 years) were assessed. Astigmatism was the most prevalent refractive error (60.4%), followed by myopia (24.8%) and hypermetropia (1.4%). Thirty children (13.5%) had anisometropia. All hyperopes had normal stereopsis. Children with spherical myopia had better stereopsis, followed by astigmatism and anisometropia in the same order (P = 0.036). Children with anisometropia ?1.5 D had better stereopsis than anisometropia more than 1.5 D. Stereopsis was also found to have no correlation with the age and visual acuity at the time of testing or the age at which the child first started wearing spectacles. Stereopsis values obtained from Randot and Titmus fly stereo tests showed moderate agreement with Kappa value 0.581. Conclusion: Anisometropia and astigmatism are the most critical factors determining the level of stereopsis in refractive errors

Study on stereoacuity and associated factors in school children aged 7 to 14 years

Purpose: The study aimed to estimate the prevalence of subnormal stereoacuity in school children and to assess the factors associated with it. Methods: In this prospective cross?sectional study, a total of 2,376 school children without amblyopia and manifest squint were screened by the titmus fly test, Snellen chart, tests for heterophoria, anterior segment examination, and fundoscopy. Children with a manifest squint, amblyopia (best?corrected visual acuity [BCVA] <6/18), and history of ocular trauma or surgery, and one?eyed children were excluded. Cycloplegic refraction was done in children with uncorrected or undercorrected refractive errors, and stereoacuity was assessed again with spectacle correction. Results: The prevalence of normal stereoacuity by titmus fly test was 93.18% with correction of refractive errors. Girls had slightly better stereopsis compared with boys. The subnormal stereoacuity was significantly associated with refractive error (P < 0.00001, significant at P < 0.05), unilateral refractive error (P < 0.00001, significant at P < 0.05), bilateral refractive error (P < 0.00001, significant at P < 0.05), anisometropia (P < 0.00001, significant at P < 0.05), ametropia (P < 0.00001, significant at P < 0.05), lower BCVA (P < 0.00001, significant at P < 0.05), hyperopia (P < 0.05, significant at P < 0.05), and heterophoria (P = 0.014, significant at P < 0.05). The subnormal stereoacuity was positively correlated with the magnitude of refractive error of the eyes. Conclusion: This study underlines the significant impact of identification and correction of refractive errors and squints in school children. The measurement of stereoacuity will be of immense importance and must be included in the screening programs for children

Evaluation of Criteria of Stereoacuity for Titmus, Randot & TNO Stereotests

The commonly used tests for stereopsis are Titmus-fly, Randot, and TNO tests. In this study, 50 normal subjects were tested with these tests in order to set a criterion for normal stereopsis. The value of mean, mode and 75% point of these three tests were derived and compared.These three tests were also performed in 23 intermittent exotropes and 32 accommodative esotropes who showed gross stereopsis in the range of 60 to 400 seconds of arc by Titmus-fly testing. The aim was to obtain standards for clinical applicability and accuracy of these tests.This study cincludes that the appropriate criteria for normal stereopsis are less than 60 seconds of arc for Titmus-fly or Randot test, and 120 seconds of arc fot TNO test. Accurate testing for stereopsis in patients with gross stereopsis requires both Titmus-fly and Randot tests together. TNO test was inferior to the other two tests in terms of the accuracy and clinical applicability.