Biomedical subjects

E E Birch

Publications and source records attributed to E E Birch.

At least 19 recordsLinked to original sources

PubMed2001

The amblyopia treatment study visual acuity testing protocol.

OBJECTIVE: To evaluate the reliability of a new visual acuity testing protocol for children using isolated surrounded HOTV optotypes. METHODS: After initial pilot testing and modification, the protocol was evaluated using the Baylor-Video Acuity Tester (BVAT) to present isolated surrounded HOTV optotypes. At 6 sites, the protocol was evaluated for testability in 178 children aged 2 to 7 years and for reliability in a subset of 88 children. Twenty-eight percent of the 178 children were classified as having amblyopia. RESULTS: Using the modified protocol, testability ranged from 24% in 2-year-olds to 96% in 5- to 7-year-olds. Test-retest reliability was high (r = 0.82), with 93% of retest scores within 0.1 logMAR unit of the initial test score. The 95% confidence interval for an acuity score was calculated to be the score +/-0.125 logMAR unit. For a change between 2 acuity scores, the 95% confidence interval was the difference +/-0.18 logMAR unit. CONCLUSIONS: The visual acuity protocol had a high level of testability in 3- to 7-year-olds and excellent test-retest reliability. The protocol has been incorporated into the multicenter Amblyopia Treatment Study and has wide potential application for standardizing visual acuity testing in children.

Amblyopia↗

PubMed2001

Essential fatty acids in visual and brain development.

Essential fatty acids are structural components of all tissues and are indispensable for cell membrane synthesis; the brain, retina and other neural tissues are particularly rich in long-chain polyunsaturated fatty acids (LC-PUFA). These fatty acids serve as specific precursors for eicosanoids, which regulate numerous cell and organ functions. Recent human studies support the essential nature of n-3 fatty acids in addition to the well-established role of n-6 essential fatty acids in humans, particularly in early life. The main findings are that light sensitivity of retinal rod photoreceptors is significantly reduced in newborns with n-3 fatty acid deficiency, and that docosahexaenoic acid (DHA) significantly enhances visual acuity maturation and cognitive functions. DHA is a conditionally essential nutrient for adequate neurodevelopment in humans. Comprehensive clinical studies have shown that dietary supplementation with marine oil or single-cell oil sources of LC-PUFA results in increased blood levels of DHA and arachidonic acid, as well as an associated improvement in visual function in formula-fed infants matching that of human breast-fed infants. The effect is mediated not only by the known effects on membrane biophysical properties, neurotransmitter content, and the corresponding electrophysiological correlates but also by a modulating gene expression of the developing retina and brain. Intracellular fatty acids or their metabolites regulate transcriptional activation of gene expression during adipocyte differentiation and retinal and nervous system development. Regulation of gene expression by LC-PUFA occurs at the transcriptional level and may be mediated by nuclear transcription factors activated by fatty acids. These nuclear receptors are part of the family of steroid hormone receptors. DHA also has significant effects on photoreceptor membranes and neurotransmitters involved in the signal transduction process; rhodopsin activation, rod and cone development, neuronal dendritic connectivity, and functional maturation of the central nervous system.

Brain↗

PubMed2001

Computerized method of visual acuity testing: adaptation of the amblyopia treatment study visual acuity testing protocol.

PURPOSE: To report a computerized method for determining visual acuity in children using the Amblyopia Treatment Study visual acuity testing protocol. METHODS: A computerized visual acuity tester was developed that uses a programmed handheld device that uses the Palm operating system (Palm, Inc, Santa Clara, California). The handheld device communicates with a personal computer running a Linux operating system and 17-inch monitor. At a test distance of 3 m, single letters can be displayed from 20/800 to 20/12. A C program on the handheld device runs the Amblyopia Treatment Study visual acuity testing protocol. Using this method, visual acuity was tested in both the right and left eyes, and then the testing was repeated in 156 children age 3 to 7 years at four clinical sites. RESULTS: Test-retest reliability was high (r =.92 and 0.95 for and right and left eyes, respectively), with 88% of right eye retests and 94% of left eye retests within 0.1 logarithm of minimal angle of resolution (logMAR) units of the initial test. The 95% confidence interval for an acuity score was calculated to be the score +/- 0.13 logMAR units. For a change between two acuity scores, the 95% confidence interval was the difference +/- 0.19 logMAR units. CONCLUSIONS: We have developed a computerized method for measurement of visual acuity. Automation of the Amblyopia Treatment Study visual acuity testing protocol is an effective method of testing visual acuity in children 3 to 7 years of age.

Amblyopia↗

PubMed2001

Preterm birth and visual development.

Visual impairment, oculomotor abnormalities, and refractive error are prevalent among children with a history of preterm birth. These conditions may result from exposure of the immature visual system to early visual stimulation, from nutritional deficits that occur following the abrupt loss of placental maternal-to-fetal transfer of essential nutrients, and as secondary effects of systemic disease or complications associated with preterm birth. This chapter provides an overview of the structural and functional maturation of the visual system of the healthy preterm infant and of several forms of visual impairment that are prevalent in the low birth weight population.

Electroretinography↗

PubMed2001

Early binocular visual experience may improve binocular sensory outcomes in children after surgery for congenital unilateral cataract.

PURPOSE: To compare the effect of intensive and reduced occlusion therapy regimens on binocular sensory outcomes, visual acuity, and the prevalence of strabismus in children after surgery for congenital unilateral cataract. METHODS: Two nonrandomized groups of patients were studied prospectively: (1) an intensive occlusion group (n = 29) patched 80% of waking hours were followed for a median 6.9 years and (2) a reduced occlusion group (n = 8) patched 25% to 50% of waking hours were followed for a median 4.3 years. Six subjects in the intensive group and 4 in the reduced occlusion group had secondary intraocular lenses. Two subjects in the intensive group had epikeratophakia surgery. Binocular sensory function was assessed with random dot and contour stereoacuity tests and the Worth 4-dot test. The prevalence and age at onset of strabismus were determined from the patients' charts. RESULTS: A higher proportion of subjects in the reduced occlusion group (50%) had stereoacuity or fusion compared with the intensive occlusion group (14%), a borderline significant difference (P =.08). No significant difference (P =.55) was found in median visual acuity between the intensive (20/50) and the reduced occlusion (20/55) groups. The 90% prevalence of strabismus in the intensive occlusion group was slightly higher than the 63% prevalence in the reduced occlusion group, although this difference was not significant (P =.18). CONCLUSIONS: These results suggest that a reduced occlusion protocol may be associated with better binocular sensory outcomes and a reduced prevalence of strabismus without compromising good visual acuity in children treated for congenital unilateral cataract.

Cataract↗

PubMed2001

The Amblyopia Treatment Index.

OBJECTIVE: To develop a questionnaire to assess the acceptability of amblyopia treatment and its effect on the child and family. METHODS: A 20-item parental survey was developed and pilot tested on 64 subjects, aged 3 to 6 years, participating in the Amblyopia Treatment Study, a randomized trial comparing patching and atropine as treatments for moderate amblyopia. The survey was administered after 4 weeks of treatment. A descriptive item analysis and an internal consistency reliability analysis were performed. RESULTS: Nineteen of the 20 items demonstrated adequate variability as evidenced by the frequency distributions for item responses. Only 4 (<1%) of 1280 possible item responses were missing, one each by 4 different respondents. Factor analysis identified 3 treatment-related factors--"adverse effects," "compliance," and "social stigma"--among 11 of the 20 items. The internal-consistency reliability alpha for the 5-item adverse effects subscale was 0.82, the 4-item compliance subscale alpha was 0.81, and the 2-item social stigma subscale alpha was 0.84. CONCLUSIONS: The Amblyopia Treatment Index appears to be a useful instrument for assessing the impact of amblyopia treatment in 3- to 6-year-old children.

Amblyopia↗

PubMed2001

Stereoacuity and foveal fusion in adults with long-standing surgical monovision.

PURPOSE: Although binocular vision deficits occur in children who have a constant esotropia onset following significant maturation of stereopsis, it is uncertain whether adults are susceptible to changes to binocular vision. We examined binocular vision in adults with longstanding surgical monovision (> or =6 month's duration) to determine whether the binocular visual system remains susceptible to change. METHODS: Participants included 32 adults with longstanding monovision through laser-assisted in situ keratectomy or photorefractive keratectomy and 20 age-matched control subjects. After full binocular correction, binocular function was measured by using the Randot Stereoacuity Test, the Randot Preschool Stereoacuity Test, and the Worth 4-dot test at near and distance. Monovision patients were grouped as having low anisometropia (<1.5 spherical D) or moderate anisometropia (> or =1.5 spherical D). RESULTS: Non-parametric analysis of variance revealed a significant difference between group median stereoacuity (H = 16.062; P <.001). Pairwise multiple comparisons indicated both groups with monovision had significantly worse stereoacuity compared with control subjects (P <.05). Median stereoacuity values were 100 seconds of arc for patients with low anisometropia, 150 seconds of arc for patients with moderate anisometropia, and 40 seconds of arc for control subjects. A larger proportion of patients with moderate anisometropia failed the Worth-4 dot test at distance than control subjects (z = 2.619; P =.009). CONCLUSIONS: Reduced stereoacuity and an absence of foveal fusion in adults with longstanding surgical monovision suggest continued susceptibility of the binocular visual system to anomalous binocular experience.

Adult↗

PubMed2001

Stereoacuity at age 3.5 y in children born full-term is associated with prenatal and postnatal dietary factors: a report from a population-based cohort study.

BACKGROUND: Observational studies suggested that breast-feeding benefits the visual development of preterm children, which has been attributed to the presence of docosahexaenoic acid (DHA) in breast milk but not most formula milks. Randomized studies showed that preterm children require a dietary supply of DHA in the first few weeks of life for optimal visual development, but it is unclear whether full-term children experience similar benefits from breast milk or DHA supplements. OBJECTIVE: The objective of this study was to compare stereoacuity at age 3.5 y in healthy, full-term children who were breast-fed and in similar children who had not been breast-fed after adjustment for socioeconomic status and maternal diet. DESIGN: Prospectively collected data on maternal diet during pregnancy (including intake of oily fish), the child's diet, and the socioeconomic status of the family were examined. Stereoacuity at age 3.5 y was assessed. RESULTS: Children who had been breast-fed for 4 mo were more likely to achieve high-grade stereopsis, or stereoscopic vision, than were children who had not been breast-fed (adjusted odds ratio: 2.77; 95% CI: 1.54, 4.97). The mother's antenatal blood DHA content was associated with her intake of oily fish (P < 0.0001). Children whose mothers ate oily fish during pregnancy were also more likely to achieve high-grade stereopsis than were children whose mothers did not eat oily fish (adjusted odds ratio: 1.57; 95% CI: 1.00, 2.45). CONCLUSIONS: The results of this study suggest that for full-term infants, breast-feeding is associated with enhanced stereopsis at age 3.5 y, as is a maternal DHA-rich antenatal diet, irrespective of later infant feeding practice.

Animals↗

PubMed2000

Hyperacuity deficits in anisometropic and strabismic amblyopes with known ages of onset.

In order to evaluate the influence of etiology of amblyopia and of age at onset of amblyopia on the resulting constellation of spatial vision deficits, resolution/vernier and recognition/resolution acuity ratios were measured in groups of children with either strabismic amblyopia or anisometropic amblyopia with known ages of onset. Strabismic amblyopia with infantile onset (<9 months) and strabismic amblyopia with late onset (18-30 months) were both associated with abnormally low resolution/vernier and abnormally high recognition/resolution acuity ratios. Among amblyopes with infantile onset (<9 months), moderate amblyopia was associated with different resolution/vernier and recognition/resolution acuity ratios in anisometropic and strabismic groups. Infantile amblyopes with poor acuity outcomes included children who initially presented with anisometropia but later developed strabismus and children who initially presented with esotropia but later developed anisometropia; both subgroups with mixed amblyopia had poor resolution/vernier acuity ratios. Data from moderate amblyopes support the hypothesis that anisometropia and strabismus disrupt visual maturation in fundamentally different ways rather than simply at different stages in visual development.

Age of Onset↗

PubMed2000

Why does early surgical alignment improve stereoacuity outcomes in infantile esotropia?

PURPOSE: Recent studies of infantile esotropia suggest that early surgical alignment may enhance stereopsis and that alignment during the first 6 months of life may be optimal. Early surgery both establishes alignment during an early critical period for the development of stereopsis and minimizes the duration of misalignment. Here we examine the role of these 2 factors in promoting improved stereopsis outcomes. METHODS: Participants were 129 consecutive patients enrolled in a prospective study of infantile esotropia who were followed up for a minimum of 5 years. At ages 5 to 9 years, Randot stereopsis was evaluated. RESULTS: Multiple linear regression indicated that duration of misalignment, but not age at alignment or age at onset, was a significant factor in determining random dot stereopsis outcomes. Moreover, patients with stereopsis were less likely to have a loss of horizontal eye alignment requiring surgery than patients without stereopsis (14% versus 32%; z = 1.96, P =.05). Patients with stereopsis were also less likely to have dissociated vertical deviation than patients without stereopsis (25% versus 63%; z = 3.36, P <.001). CONCLUSIONS: The results suggest that early surgical alignment is associated with better stereopsis in those patients with infantile esotropia who were treated during the first 24 months of life, because early surgery minimizes the duration of misalignment, not because alignment is achieved during an early critical period of visual maturation. Random dot stereopsis can also be achieved in patients with alignment provided that the duration of misalignment is not prolonged. Improved outcomes of random dot stereopsis are associated with more stable long-term alignment outcomes.

Child↗

PubMed2000

Factors influencing stereoacuity in accommodative esotropia.

PURPOSE: Despite successful optical realignment, many children with accommodative esotropia (ET) have abnormal stereoacuity. In a prospective study, we examined the influence of age of onset, age at alignment, duration of constant misalignment, and accommodative convergence/accommodation ratio on random dot stereoacuity outcomes in accommodative ET. METHODS: Participants were 111 consecutive children with accommodative ET. Random dot stereoacuity was measured using the Randot preschool stereoacuity test, the Randot stereoacuity test, the infant random dot stereoacuity cards, and the Lang 1. RESULTS: Age of onset has only a minor influence on stereoacuity (P <.02); children with onset >/=age 25 months have better stereoacuity compared with children with an onset between ages 7 and 17 months. Age at alignment has a minor influence on stereoacuity (P <.001); children with intermittent ET who have been treated have better stereoacuity than children with a constant ET aligned between ages 6 and 24 months and after age 24 months. Duration of constant misalignment has the strongest influence on stereoacuity (P <.001); children who had intermittent misalignment or who had a constant misalignment of less than 4 months' duration have better stereoacuity than patients who had a constant misalignment greater than 4 months' duration. The accommodative convergence/accommodation ratio does not influence stereoacuity outcomes (P >.10). CONCLUSIONS: Fine random dot stereoacuity is associated with a constant misalignment of less than 4 months' duration. These findings promote prompt and aggressive treatment of accommodative ET at the onset of intermittent or constant misalignment.

Accommodation, Ocular↗

PubMed2000

A randomized controlled trial of early dietary supply of long-chain polyunsaturated fatty acids and mental development in term infants.

The effects of dietary docosahexaenoic acid (DHA) supply during infancy on later cognitive development of healthy term infants were evaluated in a randomized clinical trial of infant formula milk supplemented with 0.35% DHA or with 0.36% DHA and 0.72% arachidonic acid (AA), or control formula which provided no DHA or AA. Fifty-six 18-month-old children (26 male, 30 female) who were enrolled in the trial within the first 5 days of life and fed the assigned diet to 17 weeks of age were tested using the Bayley Scales of Infant Development, 2nd edition (BSID-II) (Bayley 1993) at the Retina Foundation of the Southwest, Dallas, TX. These children had also been assessed at 4 months and 12 months of age for blood fatty-acid composition, sweep visual evoked potential (VEP) acuity, and forced-choice preferential looking (FPL) acuity (Birch et al. 1998). Supplementation of infant formula with DHA+AA was associated with a mean increase of 7 points on the Mental Development Index (MDI) of the BSID-II. Both the cognitive and motor subscales of the MDI showed a significant developmental age advantage for DHA- and DHA+AA-supplemented groups over the control group. While a similar trend was found for the language subscale, it did not reach statistical significance. Neither the Psychomotor Development Index nor the Behavior Rating Scale of the BSID-II showed significant differences among diet groups, consistent with a specific advantage of DHA supplementation on mental development. Significant correlations between plasma and RBC-DHA at 4 months of age but not at 12 months of age and MDI at 18 months of age suggest that early dietary supply of DHA was a major dietary determinant of improved performance on the MDI.

Analysis of Variance↗

PubMed2000

Interobserver test-retest reliability of the Randot preschool stereoacuity test.

PURPOSE: Random dot stereoacuity can be quantified to between 40 and 800 seconds of arc in preschool children by using the Randot Preschool Stereoacuity test (Stereo Optical Co, Inc, Chicago, Ill). To incorporate this test into clinic and research settings, the reliability of its stereoacuity scores obtained by separate examiners needs to be evaluated. The purpose of this study was to evaluate its interobserver test-retest reliability. METHODS: Participants included 102 consecutive children with binocular sensory function ranging from fine to no measurable stereopsis. Clinical research participants included children with anomalous binocular vision caused by strabismus, cataracts, anisometropia, and ptosis. In a prospective study, random dot stereoacuity was measured twice under masked testing conditions by 2 examiners within a 1-hour period. RESULTS: Interobserver test-retest reliability of the Randot Preschool Stereoacuity test is high among a population of children with diverse binocular sensory function. The correlation coefficient between individual test scores was highly significant (r = 0.97, P<.001). Mean differences between the 2 scores (0.021 log seconds of arc) were not significantly different from zero (t(99) = 1.33, P>.1). The upper and lower limits of agreement were narrow, reflecting both the large sample size and the small variation between the 2 test scores. Interobserver test-retest reliability of the Randot Preschool Stereoacuity test was nearly constant across levels of functional stereoacuity, patient categorization, and age at the time of the test. CONCLUSIONS: The high agreement between the Randot Preschool Stereoacuity test scores by 2 independent observers supports its use in clinical management and research settings for the quantitative assessment of binocular sensory vision, as well as in multicentered research studies.

Child↗

PubMed2000

Impact of early dietary intake and blood lipid composition of long-chain polyunsaturated fatty acids on later visual development.

BACKGROUND: In contrast to human milk, current infant formulas in the United States do not contain omega3 and omega6 long-chain polyunsaturated fatty acids. This may lead to suboptimal blood lipid fatty acid profiles and to a measurable diminution of visual function in developing term infants. The need for docosahexaenoic acid and arachidonic acid supplementation in the infant diet was evaluated in a double-blind, randomized clinical trial. METHODS: Healthy term infants were randomized to diets of (1) commercial formula, (2) docosahexaenoic acid-enriched formula (0.35% of total fatty acids), or (3) docosahexaenoic acid- (0.36%) and arachidonic acid- (0.72%) enriched formula. Eighty-seven infants completed the 17-week nutritional trial, and 58 were observed until 52 weeks of life. A reference group was exclusively breast fed for at least 17 weeks (n = 29). Outcome measures included electroretinographic responses, visual evoked potentials, and blood fatty acid analysis in infants at birth and at 6, 17, and 52 weeks of age. RESULTS: Commercial formula-fed infants had 30% to 50% lower content of docosahexaenoic acid in total red blood cell lipids during the 17-week feeding trial compared with breastfed infants. Significant differences persisted at the 1-year follow-up. Arachidonic acid content was consistently reduced in the commercial formula group by 15% to 20%. Infants fed long-chain polyunsaturated fatty acid-enriched formulas had docosahexaenoic acid and arachidonic acid blood lipid profiles resembling those of human milk-fed infants. Infants receiving this enriched formula had more mature electroretinographic responses than commercial formula-fed infants at 6 weeks of age. Human milk-fed and docosahexaenoic acid-enriched formula-fed infants had better visual acuity than commercial formula-fed infants at both 17 and 52 weeks of age. Early (17-week) fatty acid profiles in blood lipids were correlated with later (52-week) visual function development in study infants. CONCLUSIONS: Results from this clinical trial demonstrate that long-chain polyunsaturated fatty acid supplementation of formula in term infants produces blood lipid fatty acid profiles that are similar to those observed in breast-fed infants. This supplementation leads to better visual function later in life (i.e., 1 year of age) than that shown by infants fed commercial formula.

Arachidonic Acid↗

PubMed2000

Motion VEPs, stereopsis, and bifoveal fusion in children with strabismus.

PURPOSE: The link between nasal-temporal motion asymmetries and anomalous binocular sensory function in infantile esotropia (ET) has led to the idea that visual evoked potential responses to horizontal motion (mVE) is an alternative measure of sensory binocularity to stereopsis. A second hypothesis is that the mVEP response is a marker for bifoveal fusion. The purpose of this study was to directly evaluate these two hypotheses by examining the correspondence between the mVEP response and both stereoacuity and bifoveal fusion in a cohort of strabismic patients with variable binocular sensory function. METHODS: Motion VEPs, random dot stereopsis, and bifoveal fusion were measured in 94 children: 20 with infantile ET, 16 with infantile accommodative ET, 22 with late-onset accommodative ET, 10 with intermittent infantile strabismus, and 26 normal control participants. RESULTS: Patients with infantile ET and infantile accommodative ET had high concordance between mVEP responses and stereoacuity and mVEP responses and bifoveal fusion. Asymmetric mVEP responses were highly concordant with both no measurable stereopsis and an absence of fusional vergence. Patients with late-onset accommodative ET and intermittent infantile strabismus revealed discordance between the mVEP response and stereoacuity and high concordance between the mVEP response and bifoveal fusion. Asymmetric mVEP responses were highly concordant with the absence of bifoveal fusion and the minimum-size prism to elicit fusional vergence. CONCLUSIONS: The qualitative and quantitative relationship between the mVEP response and fusional vergence suggests that the mVEP response is an objective measure of bifoveal fusion. The availability of such a test will facilitate studies of normal development of bifoveal fusion and development of monofixation syndrome in strabismus.

Accommodation, Ocular↗

PubMed2000

Co-development of VEP motion response and binocular vision in normal infants and infantile esotropes.

PURPOSE: To determine the maturational course of nasotemporal asymmetry in infantile esotropia and to define the relationships among the symmetry of the motion visual evoked potential (MVEP), eye alignment, fusion, and stereopsis. METHODS: Sixty healthy term infants and 34 infants with esotropia participated. Nasotemporal MVEP asymmetry was assessed by the presence of a significant F1 response component with an interocular phase difference of approximately 180 degrees and by an amplitude "asymmetry index." Fusion was evaluated using the 4 p.d. base out prism test. Random dot stereoacuity was assessed in infants with forced-choice preferential looking (FPL) using the Infant Random Dot Stereocards. Eye alignment was assessed by the alternate prism and cover or the modified Krimsky test. RESULTS: Normal infants 2 to 3 months of age exhibited marked nasotemporal MVEP asymmetry, which rapidly diminished by 6 to 8 months. Neonates did not exhibit MVEP asymmetry. There was good concordance between fusion and MVEP symmetry and between stereopsis and MVEP symmetry; the concordance between MVEP symmetry and orthoposition of the visual axes was significantly poorer. The same proportion of normal and young esotropic infants showed symmetrical MVEPs. Regardless of the age at surgery, most patients with infantile esotropia had asymmetrical MVEPs after surgery. CONCLUSIONS: These data support a strong link between fusion and MVEP symmetry during both normal maturation and in infantile esotropia. Furthermore, the finding that the youngest infants with esotropia do not differ significantly from normal suggests that the nasotemporal asymmetry found in older patients with infantile esotropia does not represent an arrest of maturation but, rather, a pathologic change of the motion pathways.

Depth Perception↗

PubMed2000

Infant hyperacuity for radial deformation.

PURPOSE: Poor response rates and/or the confounding of motion and offset responses make it difficult to interpret results of previous studies of infant hyperacuity. The aim of the present study was to design a protocol that overcomes these limitations and to investigate the normal maturation of hyperacuity. METHODS: Hyperacuity of 31 healthy term infants aged 4 to 12 months was measured using radial deformation of static circular D4 patterns with a two-alternative, forced-choice, preferential-looking (FPL) protocol and maximum likelihood threshold estimation. FPL grating resolution acuity was assessed on the same visit. RESULTS: Both hyperacuity and resolution acuity were 1.1 to 1.2 logMAR (12-16 minutes arc) at 4 months of age. Hyperacuity improved rapidly to approximately 0.3 logMAR (2.0 minutes arc) by 9 to 12 months of age. This 0.9 log unit improvement in the hyperacuity still leaves the 12-month-old infant at a level 0.4 log unit poorer than adults' thresholds. Resolution acuity improved more gradually to approximately 0.7 logMAR (5 minutes arc) by 9 to 12 months of age. This 0.4 log unit improvement leaves the 12-month-old infant at a level 0.6 log unit poorer than adults' resolution acuity. CONCLUSIONS: Hyperacuity measured via radial deformation thresholds matures very rapidly between 4 and 6 months of age and continues to mature more slowly throughout infancy and into early childhood. The radial deformation protocol may provide a sensitive index for detecting and monitoring abnormalities in spatial vision in cases of infantile esotropia.

Adult↗

PubMed1999

Fatty acid profile of buccal cheek cell phospholipids as an index for dietary intake of docosahexaenoic acid in preterm infants.

Cheek cells (buccal epithelia) were utilized as a noninvasive index of fatty acid status in a study of the effects of n-3 long chain polyunsaturated fatty acid supplementation on visual function in preterm infants. The fatty acid profile of cheek cell phospholipids was directly correlated with the dietary docosahexenoic acid (DHA) intake of infants receiving: (i) primarily human milk; (ii) n-3 fatty acid-deficient, corn oil-based, commercial formula (CO); (iii) alpha-linolenic acid-enriched, soy oil-based, commercial formula; or (iv) experimental formula enriched with soy and marine oils providing a DHA level equivalent to that in human milk. In a subset of infants with complete cheek cell fatty acid profiles and visual function assessments, preterm infants at both 36 wk (n = 63) and 57 wk (n = 45) postconceptional age had significantly (P < 0.0005) reduced cheek cell phospholipid DHA levels in the n-3-deficient, CO-fed group compared to the other diet groups. The DHA content in cheek cell phospholipids was highly correlated (P < 0.0005) with that of both red blood cell lipids and plasma phospholipids at the 36- and 57-wk time points. The DHA content in cheek cell lipids of infants at 36 wk was significantly correlated with electroretinographic responses (r = -0.29; P < 0.03) and visual acuity (r = -0.31; P < 0.02) as measured by visual-evoked potentials (VEP). Cheek cell DHA was highly correlated (r= -0.57; P < 0.0005) with VEP acuity at the 57-wk time point. These results suggest that the fatty acid profile of cheek cells is a valid index of essential fatty acid status, can be monitored frequently, and is associated with functional parameters in infants.

Cheek↗