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Fulltext The screening of visual impairment among preschool children in an urban population in Malaysia; the Kuching pediatric eye study: a cross sectional study

Premsenthil M, Manju R, Thanaraj A, Rahman SA, Kah TA

BMC Ophthalmol, 2013 Apr 19;13:16.
PMID: 23601160 DOI: 10.1186/1471-2415-13-16

BACKGROUND: To screen for visual impairment in Malaysian preschool children.
METHODS: Visual screening was conducted in 400 preschool children aged 4 to 6 years. The screening involved two basic procedures; the distant visual acuity test using the Sheridan Gardiner chart and the depth perception test using the Langs stereoacuity test. Criteria for referral were a visual acuity of 6/12 or less in the better eye or a fail in the depth perception test.
RESULTS: The prevalence of visual impairment was 5% (95% confidence interval [CI] = 3.3, 7.6). Of the 400 preschool children screened, 20 of them failed the distant visual acuity test or the stereopsis test. Refractive errors were the most common cause of visual impairment (95%, 95% CI = 76.2, 98.8); myopic astigmatism was the commonest type of refractive error (63.2%, 95% CI = 40.8, 80.9).
CONCLUSION: The study is a small but important step in the effort to understand the problem of visual impairment among our preschool children. Our study showed that it is feasible to measure distant visual acuity and stereopsis in this age group.

Matched MeSH terms: Depth Perception/physiology
Visual outcomes following bilateral implantation of a non-diffractive extended depth of focus toric intraocular lens using a mini-monovision approach

Lee MW

Int Ophthalmol, 2024 Jul 24;44(1):334.
PMID: 39046597 DOI: 10.1007/s10792-024-03247-x

PURPOSE: To evaluate the clinical outcomes following bilateral implantation of the AcrySof™ IQ Vivity™ toric extended depth of focus (EDOF) intraocular lens (IOL).
DESIGN: Prospective interventional case series.
METHODS: Patients with bilateral significant cataracts and pre-existing corneal astigmatism underwent cataract surgery and implantation with the AcrySof™ IQ Vivity™ toric IOL. Dominant eyes were targeted at emmetropia and non-dominant eyes at -0.50D. Primary endpoints were binocular uncorrected distance (UDVA), intermediate (UIVA at 66 cm) and near (UNVA at 40 cm) acuities at 3 months. Secondary outcomes were corrected distance (CDVA), distance corrected intermediate (DCIVA) and distance corrected near (DCNVA), refractive predictability, rotational stability, binocular defocus curve, contrast sensitivity, Questionnaire for Visual Disturbances (QUVID) and Visual Function Index (VF-14) questionnaire scores. All visual acuities were converted to logarithm of minimum angle of resolution (logMAR) for analysis.
RESULTS: 30 patients underwent uneventful phacoemulsification. The mean binocular UDVA, UIVA and UNVA were 0.06 ± 0.12, 0.11 ± 0.10 and 0.26 ± 0.10 respectively. The mean refractive spherical equivalent (MRSE) for dominant and non-dominant eyes were - 0.07D ± 0.27 and - 0.12D ± 0.54 respectively. 92.4% of dominant eyes and 84.6% of non-dominant eyes within 0.50D of target. The mean IOL rotation was 3.85° ± 5.09 with 86.7% of eyes with less than 5° of rotation. 26.7%, 20% and 36.7% of patients reported starbursts, haloes and glare respectively. The mean VF-14 score was 91.77.
CONCLUSION: Bilateral implantation of the AcrySof™ IQ Vivity™ Toric IOL resulted in very good unaided visual acuities for far and intermediate distance with functional near vision. Dysphotopsias were reported but despite this, a high level of visual function was achieved.

Matched MeSH terms: Depth Perception/physiology
Stereopsis in end-stage renal disease (ESRD)

Jones DJW, Harris JP, Butler LT, Vaux EC

Physiol Behav, 2017 03 15;171:1-6.
PMID: 28025091 DOI: 10.1016/j.physbeh.2016.12.029

We investigated an effect of end-stage renal disease (ESRD) on the visual system by measuring the ability of 21 patients to perceive depth in the random dot stereograms and circles of the Randot Test. To control for other factors which might influence performance on the tests of stereopsis, patients were compared with healthy controls matched for age, years of education, IQ, and general cognitive ability. Vernier acuity (thought to reflect mainly central processing) and Landolt acuity (more sensitive to retinal and optical abnormalities) were also measured, but the study did not include a formal ophthalmological examination. All controls could perceive depth in random dot stereograms, whereas 9/21 patients could not. Patients who could perceive depth had worse stereoacuity than did their matched controls. The patient group as a whole had worse Vernier and Landolt acuities than the controls. The stereoblind patient subgroup had similar Vernier acuity to the stereoscopic subgroup, but worse Landolt acuity, and was more likely to have peripheral vascular disease. We conclude that ESRD had affected structures both within the eye, and within the visual brain. However, the similarity of Vernier acuity and difference of Landolt acuity in the stereoblind and stereoscopic patient subgroups suggest that the differences in stereoscopic ability arise from abnormalities in the eyes rather than in the brain.

Matched MeSH terms: Depth Perception/physiology*
Fulltext EEG based evaluation of stereoscopic 3D displays for viewer discomfort

Malik AS, Khairuddin RN, Amin HU, Smith ML, Kamel N, Abdullah JM, et al.

Biomed Eng Online, 2015;14:21.
PMID: 25886584 DOI: 10.1186/s12938-015-0006-8

Consumer preference is rapidly changing from 2D to 3D movies due to the sensational effects of 3D scenes, like those in Avatar and The Hobbit. Two 3D viewing technologies are available: active shutter glasses and passive polarized glasses. However, there are consistent reports of discomfort while viewing in 3D mode where the discomfort may refer to dizziness, headaches, nausea or simply not being able to see in 3D continuously.

Matched MeSH terms: Depth Perception/physiology*