ORCID Profile
0000-0001-6709-1785
Current Organisation
The University of Auckland
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Publisher: Informa UK Limited
Date: 27-03-2019
Publisher: Elsevier BV
Date: 1979
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2013
Publisher: Informa UK Limited
Date: 11-1982
Publisher: Elsevier BV
Date: 08-2013
DOI: 10.1016/J.MEHY.2013.04.024
Abstract: Mucoid discharge associated with prosthetic eye wear can be a distressing condition that affects the quality of life of people who have lost an eye. Discharge is the second highest concern of experienced prosthetic eye wearers after health of the companion eye and is prevalent in anophthalmic populations. Specific causes of mucoid discharge such as infections and environmental allergens are well understood, but non-specific causes are unknown and an evidence based protocol for managing non-specific discharge is lacking. Current management is based on prosthesis removal and cleaning, and professional re-polishing of the prosthesis. Tear protein deposits accumulate on prosthetic eyes. These deposits mediate the response of the socket to prosthetic eye wear and their influence (good and bad) is determined by differing cleaning regimes and standards of surface finish. This paper proposes a three-phase model that describes the response of the socket to prosthetic eye wear. The phases are: An initial period of wear of a new (or newly-polished) prosthesis when homeostasis is being established (or re-established) within the socket a second period (equilibrium phase) where beneficial surface deposits have built up on the prosthesis and wear is safe and comfortable, and a third period (breakdown phase) where there is an increasing likelihood of harm from continued wear. The proposed model provides a rationale for a personal cleaning regime to manage non-specific mucoid discharge. Professional care of prosthetic eyes is also important for the management of discharge and evidence for effective surface finishing is reported in this study. Taken together, the proposed regimes for personal and professional care comprise a protocol for managing discharge associated with prosthetic eye wear. The protocol describes prosthetic eye cleaning methods and frequency, and suggests minimum standards for professional polishing. If confirmed, the protocol has the potential to resolve the current varied and contradictory opinions about the management of discharge, and to clarify advice given to patients about how to personally care for their prosthetic eyes.
Publisher: BMJ
Date: 23-09-2005
Publisher: Springer International Publishing
Date: 2015
Publisher: Informa UK Limited
Date: 07-1983
Publisher: Informa UK Limited
Date: 02-2013
DOI: 10.2147/OPTH.S40680
Publisher: Optica Publishing Group
Date: 14-08-2008
Publisher: Informa UK Limited
Date: 07-2018
DOI: 10.1111/CXO.12645
Publisher: Elsevier BV
Date: 1979
DOI: 10.1016/0042-6989(79)90183-4
Abstract: Excised leaves were incubated at various water contents to determine the effect of water status on amino acid composition. Considerable proteolysis took place during incubation with a resultant increase in each amino acid in the non-protein fraction. However, serine, proline, gamma-aminobutyric acid and methyleysteine sulfoxide were the only amino acids in which there was an accumulation (i.e., net synthesis). Serine showed a small but consistent accumulation lasting for 6 days. Proline showed a greater accumulation but this ceased after 2 days.To learn more about the control of the proline accumulation during wilting, turgid and wilted leaves were incubated under aerobic and anaerobic conditions. The amino acid analyses showed that turgid leaves did not accumulate proline and that proline and methylcysteine sulfoxide accumulation was abolished by anaerobiosis. With other amino acids, relative concentration changes between wilted and non-wilted leaves were less striking than the difference between aerobic and anaerobic conditions.Under anaerobic conditions there was an increase in alanine and a large increase in gamma-aminobutyric acid which were not evident in air. Serine, aspartic acid, glutamic acid, and glutamine disappeared more rapidly and glycine disappeared less rapidly under anaerobic than under aerobic conditions.On the basis of these results, several pathways of amino acid degradation were suggested.
Publisher: Informa UK Limited
Date: 07-1994
Publisher: Springer International Publishing
Date: 2015
Publisher: Springer International Publishing
Date: 2015
Publisher: Wiley
Date: 10-09-2010
DOI: 10.1111/J.1442-9071.2010.02381.X
Abstract: To identify the concerns of experienced artificial eye wearers and investigate whether these had changed since they lost their eye. A retrospective study of private practice patients. Sixty-three experienced artificial eye wearers. An anonymous questionnaire was posted to participants. Paired Wilcoxon tests were used to investigate changes to concern levels over time. Ordinal logistic regression was used to investigate associations of demographic variables with concern levels. Changes in level of concern over time. At the time of initial eye loss, participants were mainly concerned about the health of their remaining eye, coping with monocularity and receiving good advice. Between initial eye loss and the present, reductions in concern occurred with judging distance, peripheral vision, appearance, receiving good advice, comfort, retention, colour and movement of the artificial eye, fullness of orbit, loss of balance and postoperative pain. Patients whose jobs involved the public were more concerned about appearance and reduced visual range than those in other occupations. Participants' chief present-day concerns were health of the remaining eye and watering, crusting and discharge. All results above had a probability <0.05. The study emphasized patients' concerns about the health of their remaining eye and their need for good advice at time of eye loss. Knowledge that their initial concerns about judging distance, reduced peripheral vision and appearance all decrease over time may help clinicians in counselling these patients. Watering, crusting and discharge was the chief present-day concern after health of the remaining eye.
Publisher: Informa UK Limited
Date: 1991
Publisher: American Medical Association (AMA)
Date: 07-1984
DOI: 10.1001/ARCHOPHT.1984.01040030862034
Abstract: Although visual disability from corneal edema is a well-recognized clinical finding, it is not easily confirmed by routine visual assessment. A more reliable assessment of visual changes resulting from corneal edema of varying origins is achieved by measurement of changes in the contrast sensitivity function. The measurements can be sensitized by the presence of a glare source to allow a more accurate determination of the nature of the visual loss. Even in the absence of a measurable loss of visual acuity, corneal edema leads to diminished visual function. The magnitude and type of this loss is dependent on the origin of the edema and the site of the corneal response.
Publisher: Informa UK Limited
Date: 11-1991
Publisher: Informa UK Limited
Date: 2012
DOI: 10.1111/J.1444-0938.2011.00646.X
Abstract: This study reports how illumination and observation angles affect assessments of the openness of the anterior chamber angle using the van Herick technique. The angle of the tangent to the corneal surface at the temporal limbus was measured for 50 participants. The effect on anterior chamber depth to corneal thickness (AC:C) ratio of varying the illumination angle away from the perpendicular to this tangent was measured. The effect of varying observation angle was also evaluated. An optical model was constructed to simulate the parameters likely to affect measurement of the AC:C ratio. The average angle of the tangent to the corneal surface at the temporal limbus was 43.1 ± 5.4° (SD). With illumination perpendicular to the limbal-corneal surface, varying the observation angle caused clinically unimportant (less than 0.1 ratio difference) but statistically significant changes in AC:C ratios (F = 7.235, p < 0.0001 repeated measures ANOVA). With observation 60° away from illumination, varying the illumination angle away from the perpendicular to the limbal-corneal surface caused clinically important and statistically significant changes in AC:C ratios (F = 75.981, p < 0.0001 repeated measures ANOVA). The optical model confirmed the experimental results and predicts that the conclusions are applicable outside our study population. Illumination should be within 10° either side of the perpendicular to the corneal surface at the limbus for measurements of the AC:C ratio. The observation angle away from the illumination direction is not critical and 60° is appropriate, but smaller angles can be used.
Publisher: Informa UK Limited
Date: 07-2013
DOI: 10.1111/CXO.12004
Abstract: The aim of this study was to investigate the inflammatory response of the anophthalmic socket to prosthetic eye wear. One hundred and two prosthetic eye wearers were recruited for this observational study. Photographic grading scales were used to measure the severity of conjunctival inflammation and the extent and intensity of stained deposits on the prosthetic eyes. Tear volume was measured with the phenol red thread test. For mucoid discharge, visual analogue scales were used to assess frequency of occurrence, colour, volume and viscosity. For the prostheses, assessments were made of weight, shape, wearing time and frequency of cleaning. Anophthalmic sockets had more severe conjunctival inflammation than their companion eyes (p = 0.0001). The difference in inflammation between the companion eye and the anophthalmic socket was associated with discharge volume (p = 0.01) and discharge viscosity (p = 0.007) with greater difference in inflammation being associated with higher levels of discharge volume and viscosity. A greater difference in inflammation was also associated with less surface deposition (p = 0.009). No evidence of associations was found between difference in conjunctival inflammation and the other variables. Recently developed grading scales for measuring inflammation in anophthalmic sockets and deposits on prosthetic eyes were used for the first time in this study. It is recommended that in clinical practice, inflammation grades for both socket and companion eye conjunctivae be compared, when determining if prosthesis-induced inflammation is present. The finding that more discharge was associated with more conjunctival inflammation is logical but the finding that less inflammation was associated with more deposits is counter-intuitive to those familiar with the contact lens literature. The apparently benign nature of at least some deposits on the prostheses raises questions about the maintenance of prosthetic eyes. We conclude that the simple presence of deposits is unlikely to be linked with inflammation of the conjunctiva in wearers of prostheses, who like those in this study, cleaned their prostheses regularly but not frequently.
Publisher: Informa UK Limited
Date: 05-1979
Publisher: Informa UK Limited
Date: 07-1983
Publisher: Informa UK Limited
Date: 1989
Publisher: Informa UK Limited
Date: 09-1976
Publisher: Informa UK Limited
Date: 07-2020
DOI: 10.1111/CXO.12998
Abstract: The New Zealand Ministry of Health provides funding for the delivery of health care across regions via 20 District Health Boards. Funding includes the subsidisation of therapeutic pharmaceutical agents/drugs. The distribution of optometrists and ophthalmologists across the regions was investigated to understand the accessibility of eye care in New Zealand. Changes made to the optometrists' scope of practice in 2005 and in 2014 increased the range of drugs that suitably qualified optometrists could prescribe. Therefore, the distribution of optometrists authorised to prescribe drugs and those not authorised to prescribe drugs was also investigated. Information from the New Zealand Optometrists and Dispensing Opticians Board register and information from the Medical Council's website were used to create a database of ophthalmic practitioners and their locations. The χ Ophthalmologists were distributed across the regions in proportion to the regional population size. However, optometrists were concentrated in Auckland and other regions with high populations. Optometrists authorised to prescribe drugs comprised over 74 per cent of optometrists and were the majority of optometrists in most regions. Many of the regions with populations less than 200,000 had high population-to-practitioner ratios, indicating that they may not have sufficient numbers of ophthalmic practitioners in order to provide for the ocular needs of the community. Better distribution of the optometric workforce could make eye care more accessible in many regions of New Zealand.
Publisher: Springer International Publishing
Date: 2015
Publisher: Informa UK Limited
Date: 03-1986
Publisher: Informa UK Limited
Date: 08-07-1998
DOI: 10.1111/J.1444-0938.1998.TB06776.X
Abstract: BACKGROUND: High visibility helmets must be worn by forestry workers in New Zealand for protection and as conspicuous 'clothing' to alert workers to the presence and location of other workers. The colours yellow-green (fluorescent yellow-green) and 'watermelon' (fluorescent pink) are used and both appear to be conspicuous. To solve a controversy, we investigated which helmet colour is more visible for use in a forest setting for workers having normal or defective colour vision. METHOD: We obtained threshold angular sizes for two-millimetre square s les of helmet material presented against a textured background containing colours representative of those found in the foliage and bark of the most common forest type (Pinus Radiata). Observers with normal colour vision (n = 22) and with deutan (n = 8) and protan (n = 6) defects participated. Subjects with mild colour vision defects were excluded. RESULTS: The yellow-green colour was significantly more visible than the pink for the normal (p +/- 0.001) and protan (p +/- 0.05) observers. For the deutan observers the pink helmet colour was significantly more visible (p +/- 0.01). The median equivalent outdoor detection distances were for normal observers 400 m (pink) and 500 m (yellow-green) for protan observers 185 m (pink) and 500 m (yellow-green) and for deutan observers 550 m (pink) and 450 m (yellow-green). CONCLUSIONS: The yellow-green helmet can be detected at large distances by all observers. The yellow-green helmet has greater reflectance and therefore greater luminance contrast. The pink helmet colour can be confused with green forest background colours by observers with protan defects. For some observers with a protan colour vision defect, detection distances for the pink helmet colour are less than half of normal detection distances.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-2007
Publisher: Informa UK Limited
Date: 11-1987
Publisher: Informa UK Limited
Date: 2015
DOI: 10.1111/CXO.12232
Abstract: In this review of the visual development of children with Down syndrome we were specifically interested in how refractive error, binocular alignment and accommodation are different in Down syndrome from the general population. The differences and their aetiology will help practitioners make informed decisions about the visual assessment and management of these children. Articles found using searches through Scopus, Medline and Google Scholar were evaluated by examining s le sizes, appropriate use of controls, methods of measurement and statistical significance of findings. Where the strength of evidence in an article might be weak, this is reported in the review. The development of the visual and oculomotor systems is substantially different in Down syndrome compared with the general population. Assessment and optometric management of this special population need to be directed accordingly.
Publisher: Wiley
Date: 08-02-2011
DOI: 10.1111/J.1460-9592.2011.03525.X
Abstract: The International Organization for Standardization (ISO) recently published an International Standard (ISO 7376:2009) which specifies illuminance levels and tests for illumination from hook-on type laryngoscopes used for intubation. A clinical study examining luminance for laryngoscopy found that 100 cd·m(-2) was the minimum level acceptable for laryngoscopy. The purpose of this study was to measure the quality of light from laryngoscopes available for use by anesthetists in an anesthetic department and compare them to the ISO illuminance standard and published minimum acceptable luminance limits. A measuring device was constructed to support each laryngoscope in a standardized manner. For 190 reusable laryngoscopes, illuminance was measured with a lux meter at the base of this device. Eighteen clinically available laryngoscopes were then examined in detail, as a snapshot study, with multiple light recordings according to the ISO Standard. We also measured the luminance provided by each laryngoscope. Only two of the 18 laryngoscopes met the minimum illuminance level of 500 lux after 10 min. Nine laryngoscopes provided a luminance <100 cd·m(-2), which is the reported minimum required luminance for laryngoscopy. None of the 18 laryngoscopes tested complied with the ISO standard for laryngoscope light distribution. Laryngoscope light should be regularly audited. Results from these audits can be used to retire or repair substandard laryngoscopes to maintain acceptable standards of laryngoscope light. Audit results produce tangible evidence that is useful when applying for capital expenditure. Light measurements are not easy to make. There needs to be a convenient device to reliably measure laryngoscope illumination.
Publisher: Optica Publishing Group
Date: 07-1992
DOI: 10.1364/AO.31.003668
Publisher: Informa UK Limited
Date: 2013
DOI: 10.1111/J.1444-0938.2012.00754.X
Abstract: The aim was to develop tools to measure the condition of ocular prostheses and the socket's response to prosthetic eyewear. A novel staining technique for displaying deposits on prosthetic eyes was developed. Equal interval perceptual grading scales for measuring inferior palpebral conjunctival inflammation, and anterior and posterior stained surface deposits on prosthetic eyes were developed from 800 photographs of 43 volunteers. The photographs for each scale were chosen by the authors. A group of four ophthalmologists, three optometrists and three senior students was consulted about selection criteria and asked to position the photographs along a 1.5 m rule to determine equal intervals. Photographs judged not to represent exactly equal perceptual intervals were exchanged with others from the original pool. The final scales (a five-photograph scale for inflammation and two 11 photograph scales for deposits) were assessed for inter-rater reliability and test-retest reliability by groups of senior optometry students. Standard deviations for inter-rater reliability tests were 0.52 scale units for the inflammation scale, 0.99 for the anterior surface deposits scale and 1.03 for the posterior surface deposits scale. The standard deviation of the test-retest differences for inflammation was 0.6 scale units and for both anterior and posterior surface deposits it was 0.71. A novel technique for displaying and measuring the intensity and extent of deposit formation on prosthetic eye surfaces has been described. The two equal interval perceptual grading scales that have been developed to quantify the extent of deposit formation together with the equal interval perceptual scale for grading severity of palpebral conjunctival inflammation will for the first time allow the effects of prosthetic eye wear to be evaluated. Further research to validate the scale for palpebral conjunctival inflammation in a clinical setting is recommended. The technique for staining deposits on prosthetic eyes is recommended for clinical practice.
Publisher: Informa UK Limited
Date: 10-2012
DOI: 10.2147/OPTH.S37250
Publisher: Informa UK Limited
Date: 05-2011
Publisher: Informa UK Limited
Date: 05-2018
DOI: 10.1111/CXO.12665
Publisher: Informa UK Limited
Date: 11-1986
Publisher: Informa UK Limited
Date: 09-2002
Publisher: Springer International Publishing
Date: 2015
Publisher: Elsevier BV
Date: 10-2015
Publisher: BMJ
Date: 06-2013
Publisher: Wiley
Date: 17-10-2012
DOI: 10.1111/J.1741-6612.2012.00627.X
Abstract: To establish associations between sensory-related disability and quality of life (QOL). A total of 3817 people aged 75 years and older, including 173 Māori aged 61 years and older, were surveyed. Measures included: sociodemographic and health factors World Health Organization quality of life (WHOQOL)-BREF for QOL and self-rated hearing- and vision-related disability. Hearing disability was reported by 866 (51%) men and 736 (36%) women. A total of 974 (26% of all, 61% of hearing disabled) used hearing aids. A total of 513 (30%) men and 618 (30%) women reported vision disability. Vision and hearing disability were both independently associated with lower QOL, with hearing difficulty affecting physical and social domains more, and the environmental domain least. Vision difficulty impacted the environmental domain most and the social domain least. QOL impact was higher for those with both hearing and visual disability (631, 17%). Hearing and vision disability are associated with poorer QOL.
Publisher: Informa UK Limited
Date: 05-2006
DOI: 10.1111/J.1444-0938.2006.00032.X
Abstract: Increasing age and UV exposure are well-known associations with precancerous and cancerous skin lesions, including actinic (solar) keratosis, and squamous and basal cell carcinomata. This report describes a patient with a facial skin lesion close to an eye that was initially believed to be actinic (solar) keratosis but was subsequently diagnosed as a basal cell carcinoma (BCC). The diagnosis of BCC was helped pre-operatively by manipulation of the surrounding facial skin, which revealed the characteristic rolled edges and telangiectasis. Referral to his general medical practitioner (GP) resulted in surgical excision of the lesion. This procedure was performed inexpensively by the local GP as the lesion was not large and was in an accessible position. The lesion and the course of recovery over four weeks were documented photographically. The lesion was surgically excised and the diagnosis of basal cell carcinoma was confirmed by pathological examination. The wound healed well and the final cosmetic result was excellent. This patient illustrates the importance of careful observation and photo-documentation of suspicious skin lesions. A review of the treatment options for these lesions is included in this report.
Publisher: Springer Science and Business Media LLC
Date: 19-11-2015
DOI: 10.1038/SREP16921
Abstract: Prenatal exposure to recreational drugs impairs motor and cognitive development however it is currently unknown whether visual brain areas are affected. To address this question, we investigated the effect of prenatal drug exposure on global motion perception, a behavioural measure of processing within the dorsal extrastriate visual cortex that is thought to be particularly vulnerable to abnormal neurodevelopment. Global motion perception was measured in one hundred and forty-five 4.5-year-old children who had been exposed to different combinations of meth hetamine, alcohol, nicotine and marijuana prior to birth and 25 unexposed children. Self-reported drug use by the mothers was verified by meconium analysis. We found that global motion perception was impaired by prenatal exposure to alcohol and improved significantly by exposure to marijuana. Exposure to both drugs prenatally had no effect. Other visual functions such as habitual visual acuity and stereoacuity were not affected by drug exposure. Prenatal exposure to meth hetamine did not influence visual function. Our results demonstrate that prenatal drug exposure can influence a behavioural measure of visual development, but that the effects are dependent on the specific drugs used during pregnancy.
Publisher: Public Library of Science (PLoS)
Date: 13-12-2018
Publisher: Elsevier BV
Date: 02-2021
Publisher: Informa UK Limited
Date: 07-1990
Publisher: Informa UK Limited
Date: 03-1992
Publisher: Informa UK Limited
Date: 11-2007
DOI: 10.1111/J.1444-0938.2007.00150.X
Abstract: Machines are Peter Turner's life. They always have been, are now and probably always will be. He can blame his parents for this because despite urging Peter to become an optometrist they gave him inventive genes, a love of technology and holiday work in a factory fitting and turning, and welding. In the 30 years since completing his State Diploma in Optics in New Zealand (SDONZ), Peter has designed and developed three key pieces of optical equipment: a Sun-Following Radio Telescope, a CCTV read/write system and the Berkeley Glare & Acuity Test (BEGAT). He has also completed myriad technological innovations for friends and family ranging from a motorised chair and stand unit for optometric rooms to components for venetian blind manufacturing.
Publisher: Informa UK Limited
Date: 07-1992
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 1999
DOI: 10.1097/00006324-199901000-00028
Abstract: The visual acuity of visually impaired patients has been reported to improve after a refraction, despite pinhole test results that show a decline or no change in acuity. Our aim was to investigate whether the pinhole-induced reduction in retinal illuminance accounted for these unreliable predictions of best-corrected acuity. Participants were 64 adult patients referred for low-vision rehabilitation. Neutral density filters reproduced the pinhole-induced luminance loss, allowing pinhole test and postrefraction acuities to be measured at essentially equivalent levels of retinal illuminance. The following data were collected in random order from each subject's better eye: (1) habitual visual acuity, (2) habitual visual acuity with filter, (3) habitual visual acuity with pinhole, (4) best-corrected ostrefraction visual acuity, (5) postrefraction visual acuity with filter. On average, the pinhole test under-estimated postrefraction visual acuity by six letters (95% confidence limits = +/- 20). The pinhole test underestimated postrefraction visual acuity with the filter by two letters (95% confidence limits = +/- 16). Among subjects whose acuity improved with the pinhole test (N = 24), 83% experienced better postrefraction visual acuity. Among subjects whose acuity declined or remained unchanged with the pinhole test (N = 40), 50% achieved better postrefraction visual acuity. The pinhole-induced luminance loss contributed to inadequate predictions of postrefraction visual acuity. Pinhole test results were enormously variable, underestimating and overestimating postrefraction visual acuity. The pinhole test was less reliable when improvements in postrefraction visual acuity were small. Visually impaired patients deserve periodic refractions, and the pinhole test result should not be used as a dichotomizer for clinical decisions regarding the need for a refraction.
Publisher: Informa UK Limited
Date: 08-07-1998
DOI: 10.1111/J.1444-0938.1998.TB06775.X
Abstract: BACKGROUND: New Zealand Police regulations (1996) allow the unaided visual acuity requirement of 6/12 to be achieved following refractive surgery (except radial keratotomy or keratoplasty) provided applicants also achieve normal (95 per cent confidence limit data from the literature): glare disability, contrast sensitivity, and low luminance visual acuity, one year or more after treatment. METHODS: To confirm the limits adopted, 80 young normal adults were subjected to the tests in the regulations. To examine the operation of the current standards, the results of 34 post-photorefractive keratectomy (post-PRK) police applicants are reported. Glare disability was the loss of high contrast visual acuity (VA) with the Mentor Brightness Acuity Tester at medium intensity. Contrast sensitivity (CS) was examined using both Melbourne Edge Test thresholds and the VA difference between high and low contrast Bailey-Lovie charts. Low luminance VA was measured using high contrast Bailey-Lovie charts viewed through a one per cent transmittance filter. RESULTS: The 95 per cent confidence limits found for normal performance were as follows. Glare disability: no more than 10 letters worse than VA without glare. Contrast sensitivity: no more than 12 letters difference between high contrast and low contrast letter acuity together with an edge contrast threshold of not less than 20 dB (CS = 100). These results were close to the values adopted for the current standard. The 95 per cent confidence limit for low luminance VA was a loss of 24 letters (almost five lines) and not the three lines of loss estimated from the literature. Two of the 34 post-PRK applicants failed. One was unable to achieve 6/6 acuity with best refraction. The second could not meet the low luminance VA limit (loss no more than three lines). No failures have been due to glare disability or poor contrast sensitivity even though one applicant had obvious corneal haze.
Publisher: Informa UK Limited
Date: 05-2012
DOI: 10.2147/OPTH.S31126
Publisher: Informa UK Limited
Date: 03-1986
No related grants have been discovered for Robert Jacobs.