Individual differences in stereo acuity (original) (raw)

Normative Values for Near and Distance Clinical Tests of Stereoacuity

Strabismus, 2016

Extensive literature exists on normative stereoacuity values for younger children, but there is less information about normative stereoacuity in older children/adults. Individual stereotests cannot be used interchangeably-knowing the upper limit of normality for each test is important. This report details normative stereoacuity values for 5 near/distance stereotests drawn from a large sample of participants aged 16-40 years, across 3 studies. Participants (n=206, mean age 22.18±5.31 years) were administered the following stereotests: TNO, Preschool Randot, Frisby, Distance Randot, and Frisby-Davis 2. Medians and upper limits were calculated for each test. Upper limits for each stereotest were as follows: TNO (n=127, upper limit=120" arc), Preschool Randot (PSR, n=206, upper limit=70" arc), Frisby (n=206, upper limit=40" arc), Distance Randot (n=127, upper limit=160" arc), and Frisby-Davis 2 (n=109, upper limit=25" arc). Normative values for each stereotest a...

Stereoacuity norms for school-age children using the Frisby stereotest

Journal of American Association for Pediatric Ophthalmology and Strabismus, 2013

BACKGROUND The Frisby stereotest and the TNO test for stereoscopic vision are popular clinical tests for assessing stereoacuity: however, reference data for school-age children for the Frisby stereotest are limited. This study compared stereoacuity results of both tests in a large sample of typically developing school-age children. METHODS Primary (elementary school grades 1-6) and post-primary (high school grades 7-11) students aged 6-16 years were recruited and assessed in schools. Stereoacuity thresholds were measured using the Frisby and TNO stereotests. Children with ocular pathology, anisometropia of 1.00D,interoculardifferenceofvisualacuity1.00 D, interocular difference of visual acuity 1.00D,interoculardifferenceofvisualacuity0.2 logMAR, or strabismus were excluded. RESULTS A total of 212 children were recruited; data for 186 subjects were analyzed. Median Frisby stereoacuity scores were, for crossed disparity, 20 arcsec for primary and 10 arcsec for post-primary children and, for uncrossed disparity, 25 arcsec (primary) and 10 arcsec (post-primary). TNO stereoacuity was 60 arcsec for both age groups. For Frisby stereoacuity, scores of 85 arcsec (crossed) and 170 arcsec (uncrossed) or better were achieved by 95% of primary school children; scores of 85 arcsec (crossed and uncrossed) or better were achieved by 95% of post-primary subjects. A statistically significant difference in median stereoacuity scores was noted across age groups for the Frisby stereotest (crossed: z 5 4.67, P \ 0.0001; uncrossed: z 5 4.67, P \ 0.0001). No statistically significant difference in stereoacuity scores was noted with the TNO stereotest (z 5 1.35, P 5 0.18). A significant weak correlation was found between the Frisby and TNO stereotests (Frisby [crossed], r 5 0.21 P \ 0.005). CONCLUSIONS These data describe normative values for the Frisby stereotest for children aged 6-16 years. Participants recorded significantly better stereoacuity scores with the Frisby stereotest than the TNO stereotest. The Frisby stereotest values are weakly correlated with the TNO stereoacuity test.

Stereoacuity in Varying Degrees of Myopia Before and After Correction

Background: Stereoacuity is measure of three-dimensional perception due to binocular disparity, helps in recognizing depth while perceiving distance, along supporting in recognition of solid objects. Objective: To compare the stereoacuity among varying degrees of uncorrected myopia and after its correction. Secondly, to compare stereoacuity before and after correcting myopia. Study Design: Comparative cross-sectional study.

Evaluation of Change in Stereopsis with Age in Normal Eyes

Journal of Evidence Based Medicine and Healthcare, 2020

BACKGROUND Stereopsis is the ability to perceive the depth of field based on the disparity of the images formed by the two eyes; in other words, the fusion of the separated images on the Panum's area in order to form binocular single vision. Depth perception is very important in everyday life tasks such as driving, orientation in space while moving (e.g. descending a flight of stairs) and for fine-motor tasks involving hand eye coordination such as threading a needle. By reducing the amount of scanning necessary to extract spatial information, stereopsis facilitates comprehension of complex visual experiences. While stereopsis is a uniquely binocular phenomenon, there are many monocular clues which can provide information on depth including linear perceptive, shadows, texture and gradients. We wanted to study the change and variation of stereopsis with age in normal eyes. METHODS This prospective study was conducted on the participants attending the Outpatient Department of the Department of Ophthalmology of our hospital. A total of 80 subjects (patients/ their relatives) aged between 7 and 80 years, were included in the study. Informed consent was taken from all the participants. Subjects with strabismus, amblyopia, anisometropia (difference of ≥ 2.5D between both eyes), glaucoma, cataract and with age related macular degeneration and patients with history of eye surgery were excluded from the study. Stereopsis was assessed by TNO random dot stereotest (TNO Test). The participants read the test plates at a distance of 40 cm, wearing polaroid spectacles or red-green goggles, under proper illumination and after correction for any refractive error. RESULTS Data was entered in EpiData entry and analysed using EpiData analysis software v. 3.0. Significance was set at p<0.05. It was observed that the stereopsis remained stable till the age of 30 years. Thereafter there was a decline in the median values of stereopsis with increasing age and this decline became statistically significant after the age of 50 years (p<0.0001). CONCLUSIONS In our study, we found that the stereoacuity decreased as the age increased when assessed by TNO test. Stereopsis has an impact on vision related quality of life. Thus knowledge of the underlying population prevalence of physiological reduction of stereopsis with age can help in assessing its contribution to already reducing quality of life with increasing age.

Stereo tests as a screening tool for strabismus: which is the best choice?

Clinical Ophthalmology, 2014

University Vita-salute, scientific institute san raffaele, Milano, italy Purpose: To compare four stereo tests (Lang I, Lang II, Titmus, and TNO) and assess their effectiveness. The main focus of this study is to identify the most useful stereo test as a challenging tool in the screening of strabismus. Patients and methods: A total of 143 Caucasian subjects, 74 males (52%) and 69 females (48%), aged between 4 years and 78 years (mean age 19.09±15.12 years) were examined at our Strabismus Service (Scientific Institute San Raffaele Hospital, Milan, Italy) and included in this observational cross-sectional study. Subjects recruited in this study were either affected by strabismus, including microstrabismic patients, or healthy volunteers. Subjects affected by ophthalmological diseases, other than strabismus, were excluded. All patients underwent both ophthalmological and orthoptic examination, including stereo tests, Hirschberg Corneal Light Reflex Test, Worth Four-Dot Test, the 4 Prism Diopter Base-Out Test, Cover Testing, Bruckner Test, visual acuity, automated refraction under 1% tropicamide cycloplegia and thereafter, posterior pole evaluation. Results: All data were processed using the IBM SPSS Statistics, Version 2.0, to perform all statistical calculations. The main finding of this study is that Lang I stereo test achieved the highest sensitivity (89.8%) and specificity (95.2%) in detecting strabismus, including microstrabismus as well, compared to all the other stereoacuity tests. Furthermore, Lang I is the stereo test with the highest positive predictive value and negative predictive value, both greater than 90%.