Search PubMed⌕ Search

Biomedical subjects

Patricia M Kiely

Publications and source records attributed to Patricia M Kiely.

10 recordsLinked to original sources
PubMed2006

Parietal function in good and poor readers.

BACKGROUND: While there are many psychophysical reports of impaired magnocellular pathway function in developmental dyslexia (DD), few have investigated parietal function, the major projection of this pathway, in good and poor readers closely matched for nonverbal intelligence. In view of new feedforward-feedback theories of visual processing, impaired magnocellular function raises the question of whether all visually-driven functions or only those associated with parietal cortex functions are equally impaired and if so, whether parietal performance is more closely related to general ability levels than reading ability. METHODS: Reading accuracy and performance on psychophysical tasks purported to selectively activate parietal cortex such as motion sensitivity, attentional tracking, and spatial localization was compared in 17 children with DD, 16 younger reading-age matched (RA) control children, and 46 good readers of similar chronological-age (CA) divided into CA-HighIQ and a CA-LowIQ matched to DD group nonverbal IQ. RESULTS: In the age-matched groups no significant differences were found between DD and CA controls on any of the tasks relating to parietal function, although performance of the DD group and their nonverbal IQ scores was always lower. As expected, CA and RA group comparisons indicated purported parietal functioning improves with age. No difference in performance was seen on any of the parietally driven tasks between the DD and age-nonverbal IQ matched groups, whereas performance differentiated the DD group from the age-matched, higher nonverbal IQ group on several such tasks. An unexpected statistical difference in performance between lower reading age (DD and RA children) and all higher reading age (CA) children was seen on a test of chromatic sensitivity, whereas when high and low nonverbal IQ normal readers were compared performance was not different CONCLUSION: The results indicate that performance on purported parietal functions improves with age and may be more associated with nonverbal mentation than reading accuracy. Performance on a cognitively demanding task, traditionally considered to rely on ventral stream functions, was more related to reading accuracy.

Journal Article↗
PubMed2006

The Australian optometric workforce 2005.

BACKGROUND: This paper presents the findings of the Optometrists Association Australia 2005 optometric workforce study. METHODS: Data from the association's database, the Australian Bureau of Statistics, Medicare and the Department of Veterans Affairs were applied to create a profile of the optometric workforce in Australia, including the number of equivalent full-time optometrists (EFTOs), population to optometrist ratios and workloads. RESULTS: In February 2005, 2,866 (76.7 per cent) of the 3,738 optometrists registered to practise in Australia were in clinical practice. Adjusting for the number of hours worked, there were 2,712 EFTOs in Australia. The ratio of population to EFTO for Australia was 7,016. Ratios were higher in the states without schools of optometry (South Australia 9,413, Western Australia 8,810 and Tasmania 8,172) and in the remote and lightly populated Northern Territory (10,521). The lowest ratio was in New South Wales (6,053). The proportion of women in clinical practice has gradually increased since 1977 and was slightly more than 41 per cent in 2005. The percentage of the profession under the age of 40 years was 48.6. The percentages of female and male optometrists under the age of 50 were 89.3 and 72.5, respectively. On average, female optometrists worked approximately 82 per cent of the hours worked by male optometrists. The average time per week spent on Medicare and Veterans Affairs consultations was 25.8 hours. CONCLUSIONS: The profession of optometry in Australia is undergoing considerable change in age and gender make-up. In 2005, the number of optometrists was adequate for the needs of the Australian population. Further analysis is needed to determine whether the supply of optometrists meets community needs at local levels.

Adult↗
PubMed2006

Monocular and binocular thresholds for abruptly and gradually presented illusory contours.

BACKGROUND: In this study, monocular thresholds and binocular summation for abrupt onset/offset versus gradually revealed phantom letter E (illusory contours) stimuli are compared to determine the suitability of these stimuli for assessment of the integrity of two of the major retinal streams: the magnocellular and the parvocellular pathways. Such tests are important in progressive retinal disease where disease severity may differ between the classes of retinal ganglion cells and between the two eyes. Abrupt onset phantom contours have long been considered to activate the magnocellular visual pathway and we propose that gradually revealed high contrast ramped onset/offset stimuli are more likely to promote the more sustained processing of the parvocellular stream. METHODS: Contrast discrimination thresholds for monocular and binocular viewing were compared in a counter-balanced order in 70 young normal subjects, using tests of contrast threshold for a flicker-defined letter E produced by alternation of light and dark dots. Three onset/offset conditions were used - abrupt onset that was maintained for 34 milliseconds (four frames of 8.5 milliseconds) then discontinued, ramped onset over 34 milliseconds (four frames) with offset over 34 milliseconds and ramped onset over 85 milliseconds (10 frames) with offset over 85 milliseconds. RESULTS: Contrast thresholds for identification of the orientation of the E, when presented with four frames ramped onset and offset when compared to the four frames abrupt onset/offset were three times higher, irrespective of monocular or binocular viewing conditions. Threshold contrasts were seven times higher when the 10 frames ramped onset/offset stimuli were compared to abrupt four frames onset/offset. Binocular contrast thresholds were reduced by approximately 40 per cent compared to monocular thresholds for all conditions. The binocular increase in contrast sensitivity is approximately equal for abrupt transiently presented stimuli and for gradually presented more sustained stimuli. DISCUSSION: The results indicate that the same mechanisms of monocular processing and binocular summation are used for identification of a flickering contrast-defined phantom contour under presentation conditions, which are characteristic of the temporal and contrast preferences of the primate magnocellular and parvocellular visual pathways. This suggests that the phantom contour E test may be useful for clinical differentiation of the integrity of the M and P retinal ganglion-derived visual pathways, regardless of whether it is applied monocularly or binocularly.

Adult↗
PubMed2005

Changes in ocular accommodation when shifting between global and local attention.

BACKGROUND: The link between cognitive changes in attentional focus and the physiological parameters of the eye is not well understood. The aim of the current work was to examine the role of ocular accommodation, that is, the process of changing the shape of the crystalline lens in order to focus an image onto the retina, in active shifts of visual attention between global and local information. METHOD: Ten adult participants (aged 19 to 27) viewed sequences of complex global/local figures presented at the same location. They were asked to identify either a global or local red target letter and to look for either a global or local letter x (probe) in the sequence following. Target and probe items were separated by a temporal gap of approximately one second. Refraction was measured using a Canon Autorefractor R1 at the time of target appearance and again at the time of probe presentation. Particular interest was paid to trials where participants were required to shift attention either from a local to global level or in the reverse direction. The difference between the two measurements of refraction gave a 'change score' which provided an indication of the change of accommodation. RESULTS: No significant change in refraction was observed when shifting from the local to the global condition. A mean change in refraction of -0.128 dioptres was observed for the global to local condition. The 95 per cent confidence interval for this difference did not overlap zero, indicating a significant change in refraction, which was attributed to an increase in accommodation. DISCUSSION: The results suggest that while a change in accommodation occurs in shifting attention from the global to the local aspect of the complex figures, a similar change is not observed in the reverse direction. These results are consistent with the hypothesis that it is more difficult to restrict attentional focus than it is to widen it.

Accommodation, Ocular↗
PubMed2004

Clinical application of the multifocal visual evoked potential.

BACKGROUND: Measures of visual function thresholds such as visual acuity and visual fields are generally dependent on subjective responses and assume maintenance of fixation, attention and motivation. In the young, elderly, cognitively impaired or malingering populations, such measures may be inaccurate or difficult to obtain. The Visual Evoked Response Imaging System (VERIS) has been claimed to give more objective topographic recordings of retinal and cortical function. This paper aims to explore the adequacy of this technique in four unusual, unrelated, clinically difficult cases. METHODS: Multifocal visual evoked potentials (mfVEPs) recorded on the VERIS System 3.01 are used to assess visual function in four cases with contradictory clinical findings or unreliable subjective responses. RESULTS: Patient 1 had sustained a head injury and had normal ocular and pupil examination but light perception in the right eye and 6/5 acuity in the left. Multifocal VEPs showed a marked depression of the right visual field with little macular response. Patient 2 had sustained a head injury, had a left field hemianopia, possible macular sparing and loss of much of the right field, reduced but variable visual acuities, good near vision and normal ocular fundi. Multifocal VEPs showed a severe depression in both visual fields (L more than R) with little macular response. Patient 3 had a left optic nerve meningioma and experienced great difficulty with visual field assessment. mfVEPs showed a bilateral depression in the superior field particularly the left field, with a larger deficit in the left eye. Patient 4 had unexplained visual acuity and peripheral field deficits. mfVEP results were inconclusive in this case. DISCUSSION: Where there is difficulty performing traditional techniques or conflicting clinical findings, mfVEPs may provide additional objective information to aid in the assessment of patients.

Adult↗
PubMed2003

Practice standards for optometry and optometric practice accreditation.

BACKGROUND: To assist optometrists to deliver care more efficiently and effectively, in 1995 Optometrists Association Australia decided to develop standards that would assist optometrists in better managing their practices. Existing practice management standards for health professionals were thought to be either not specific enough for optometric practice or to have shortcomings in the context of optometric practice in Australia. METHODS: Following a literature search, material previously developed by Optometrists Association Australia to assist practitioners with management of their practices and standards from other professions were used to assist with the development of a draft set of standards for optometric practices in Australia. Successive drafts were circulated for comment to optometrists in practice, non-optometrists with experience in the development of practice standards for other health professions and to Australian General Practice Accreditation Limited. The comments were used to refine the standards and the accreditation guidelines to their final form. RESULTS: Optometric Practice Standards suitable for use in a practice accreditation program were developed. The standards comprise seven sections--Practice administration, Quality assurance, Rights and needs of the patient, Practice services, Practice facilities, Communication and Patient records. These sections are divided into criteria that provide the detail of the requirements of the standard. Indicators describing how criteria can be assessed accompany the criteria.

Accreditation↗
PubMed2002

Referral rates for a functional vision screening among a large cosmopolitan sample of Australian children.

The aim of this study was to investigate the incidence of functional vision problems in a large unselected cosmopolitan population of primary school-age children and to investigate whether constant clinical criteria for functional vision problems would be implemented by the practitioners involved in the screening. Refractive errors, near point of convergence, stereopsis, strabismus, heterophoria and accommodative facility were assessed for 2697 children (3-12 years) of varying racial backgrounds living in Australia. The spherical component of the refractive error ranged from -7.75 to +9.50 D (mean +0.54 D, +/-0.79) with a distribution skewed towards hypermetropia; astigmatism ranged from 0 to 4.25 D (mean -0.16 D, +/-0.35). There was a trend towards less hypermetropia and slightly more astigmatism with age. Mean near point of convergence was 5.4+/-2.9 cm, heterophoria at far and near was 0.12+/-1.58delta exophoria and 1.05+/-2.53delta exophoria, respectively, 0.55% of children exhibited vertical phoria at near >0.5delta, accommodative facility ranged from 0 to 24 cycles per minute (cpm) (mean 11.2 cpm, +/-3.7), stereopsis varied from 20 to 800 s (") of arc with 50% of children having 40" or better. The prevalence of strabismus was particularly low (0.3%). Twenty percent of the children were referred for further assessment based on criteria of one or more of: stereopsis >70", accommodative facility <8 cpm, near point of convergence (NPC) >9 cm, near exophoria >10delta or near esophoria >5delta, shift in eso or exophoria > or = 4delta between distance and near, astigmatism > or = 1 D, myopia more than -0.75 D, or hyperopia >+1.50 D. Post-hoc analysis of the record cards seeking the reason for further assessment indicates that referrals appear to have been based upon clinical intuition rather than on a set number of borderline or unsatisfactory results.

Accommodation, Ocular↗
PubMed2001

Is there an association between functional vision and learning to read?

Background: Controversy exists about the role of visual parameters and vision in learning to read. This study aims to determine whether ocular parameters or performance on a dynamic test of visual function differs for children of differing reading ability. Methods: Two hundred and eighty-four children (mean age 9.9 +/- 1.8 years) received a vision screening emphasising binocular anomalies associated with discomfort at near (distance and near visual acuity, distance vision challenged with binocular +1 D lenses, near heterophoria, near point of convergence, stereopsis and accommodative facility). Non-verbal mentation age and reading accuracy were assessed. One hundred and six children performed a computerised task of motion coherence detection. Children were classified as normal readers (n = 195), children with dyslexia (n = 49) or learning disabled children (n = 40) based on their mentation age and their reading age. Results: There were no statistically significant differences or correlations between visual parameters and reading performance. Over thirty per cent of the children had accommodative facilities below or equal to six cycles per minute. Children with learning disabilities performed worst on the motion coherence task but this was statistically significant only when compared to the performance of dyslexics. Discussion: The lack of association between ophthalmic parameters and poor reading ability supports the view of the Committee on Children with Disabilities. However, 39 per cent of the children might be expected to experience difficulty 'reading to learn', as suggested by the American Academy of Optometry, as they showed anomalies associated with visual discomfort with prolonged reading. The motion coherence test did not differentiate dyslexics from normal readers and was worst in children with learning disability. Accommodative facility testing remained the most useful predictor of potential visual discomfort.

Journal Article↗
PubMedDate not supplied

Optometric therapeutic competency standards 2000.

BACKGROUND: Competency standards for entry-level to the profession of optometry in Australia were first developed in 1993 and then revised in 1997. The competencies require that optometrists entering the profession have the skills to use ocular diagnostic drugs but did not consider the prescription of topical therapeutic ocular drugs by optometrists. Following the introduction of legislation in the Australian state of Victoria that permitted optometrists to be licensed by the relevant state registration board to prescribe topical therapeutic ocular medication, Optometrists Association Australia (OAA) was asked to develop therapeutic competency standards that could be used in the assessment of the suitability of optometrists for such licensing. METHODS: Expert members of the profession and representatives from optometry schools, registration boards in Australia and New Zealand, state divisions of OAA and the New Zealand Association of Optometrists (NZAO) were consulted in the process of developing these standards. RESULTS: Nine new performance criteria with associated indicators, within Units 3 and 5 of the revised entry-level standards, were developed. Additions were made to the indicators for 25 of the previously developed performance criteria (within all six original units of competency). The modified therapeutic competency standards were adopted on behalf of the profession by the National Council of OAA in March 2000. DISCUSSION: These therapeutic competency standards may be used as a basis for licensing authorities to develop an assessment process to determine suitability of optometrists for licensing to prescribe topical therapeutic ocular medications. At this stage, the therapeutic competencies cannot be regarded as entry-level competencies in Australia but as second-tier competencies. However, it is anticipated that the therapeutic competencies will come to be regarded as entry-level over the coming years.

Journal Article↗