Search

Globally, 27 aphid species have evolved resistance to almost 100 insecticide active ingredients. A proactive approach to resistance management in pest aphids is needed; this should include risk analysis, followed by regular baseline susceptibility assays for species deemed at high risk of evolving resistance. The cowpea aphid (Aphis craccivora Koch) has evolved insecticide resistance to multiple insecticides outside Australia and was recently identified as a high-risk species in Australia. In this study, we generated toxicity data against four insecticides (representing four unique chemical Mode of Action groups) for populations of A. craccivora collected across Australia. Alpha-cypermethrin was the most toxic chemical to A. craccivora in leaf-dip laboratory bioassays with an average LC50 value across nine populations of 0.008 mg a.i./L, which was significantly lower than dimethoate (1.17 mg a.i./L) and pirimicarb (0.89 mg a.i./L). Small, but significant, differences in sensitivity were detected in some populations against pirimicarb and dimethoate, whereas responses to alpha-cypermethrin and imidacloprid were not significantly different across all aphid populations examined in this study. For all insecticides, the field rate controlled 100% of individuals tested. The data generated will be important for future monitoring of insecticide responses of A. craccivora. Proactive management, including increased reliance on non-chemical pest management approaches and routine insecticide baseline sensitivity studies, is recommended for A. craccivora. Graphical Abstract [ABSTRACT FROM AUTHOR]

Reading is the most common goal among persons with age-related macular degeneration and other retinal diseases that lead to macular loss, as well as the functional task most affected by the resulting central scotomas. This project determined whether reading ability is different when persons with macular loss read with a new hybrid-diffractive spectacle magnifier versus a refractive-aspheric spectacle magnifier and an aplanatic spectacle magnifier. After subjects completed a low-vision examination, we assigned them to groups that compared different types of spectacle magnifiers and assessed their reading acuity, speed, critical print size (print size large enough to provide a subject's best fluent reading), accuracy, and comprehension. Subjects completed visual analog scales to indicate their perceptions of satisfaction with reading, comfort with reading, and cosmesis (comfort with allowing others to see them read) and were asked which of the compared spectacle magnifiers they preferred for prescription. We subjected the data to paired t-tests to ascertain whether differences existed in subjects' reading ability and perceptions between the types of reading devices. Subjects' reading comprehension, perception of satisfaction, and perception of cosmesis were significantly better with the hybrid-diffractive lens than with the refractive-aspheric lens. Although subjects' critical print size was significantly better with the aplanatic lens than with the hybrid- diffractive lens, functional reading ability was not significantly different. More subjects preferred the hybrid-diffractive lenses for prescription. The hybrid-diffractive spectacle magnifiers are an important addition to the optical-device armamentarium for reading with low vision. [ABSTRACT FROM AUTHOR]

Background: Quantifying how chemical tolerance of pest arthropods varies with temperature is important for understanding the outcomes of chemical control, for measuring and monitoring resistance, and for predicting how pesticide resistance will evolve under future climate change. We studied the redlegged earth mite, Halotydeus destructor (Tucker), a winter-active invasive agricultural pest in Australia. Using a replicated block experiment, we tested the effect of different thermal conditions on the expression of chemical tolerance to a pyrethroid and two organophosphates. Our chemical bioassays were conducted on two redlegged earth mite populations: one possessed organophosphate resistance, whilst the other was susceptible to pesticides. Mites were first acclimated at cool (4 °C) and warm (14 °C) conditions and then exposed to pesticides in both cool (11 °C) and warm (18 °C) test conditions., Results: Warm test conditions generally reduced chemical tolerance to all pesticides relative to cool test conditions. Median lethal dose (LD 50 ) values of mites tested under cool conditions were 1.12-3.57-fold greater than of mites tested under warm conditions. Acclimation had a variable and small impact on chemical responses. Thermal factors (ratio between test temperatures) were similar between populations for each active ingredient. Despite reduced chemical tolerances under warm test conditions for individual mite populations, resistance factors (ratio between resistant and susceptible mite populations) were relatively consistent., Conclusion: Our data provides context for prior theoretical work demonstrating climatically constrained pesticide resistances in Australian redlegged earth mites. Estimates of temperature dependent toxicity measured in this study may be useful in parameterizing models of redlegged earth mite control under an increasingly warm and more variable climate. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., (© 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.)

Understanding how invasive species respond to novel environments is limited by a lack of sensitivity and throughput in conventional biomonitoring methods. Arthropods in particular are often difficult to monitor due to their small size, rapid lifecycles, and/or visual similarities with co-occurring species. This is true for the agromyzid leafminer fly, Liriomyza sativae, a global pest of vegetable and nursery industries that has recently established in Australia. A robust method based on environmental DNA (eDNA) was developed exploiting traces of DNA left inside "empty" leaf mines, which are straightforward to collect and persist longer in the environment than the fly. This extends the window of possible diagnosis to at least 28 days after a leaf mine becomes empty. The test allowed for visually indistinguishable leafmining damage caused by L. sativae to be genetically differentiated from that of other flies. Field application resulted in the identification of new local plant hosts for L. sativae, including widely distributed weeds and common garden crops, which has important implications for the pest's ability to spread. Moreover, the test confirmed the presence of a previously unknown population of L. sativae on an island in the Torres Strait. The developed eDNA method is likely to become an important tool for L. sativae and other leafmining species of biosecurity significance, which, historically, have been difficult to detect, diagnose and monitor. More generally, eDNA is emerging as a highly sensitive and labour-efficient surveillance tool for difficult to survey species to improve outcomes for agricultural industries, global health, and the environment., (© 2021 John Wiley & Sons Ltd.)

Background: The redlegged earth mite, Halotydeus destructor (Tucker), is a destructive and economically important pest of winter grain crops and pastures in Australia. It is largely controlled by pesticides, but this mite has evolved resistance to pyrethroid and organophosphate chemicals. A national Resistance Management Strategy has been developed for pro-active management to delay further resistance evolution, though its success is reliant on a detailed understanding of the incidence, patterns of spread, current distribution and the nature of resistance in the field. Here, we report on a long-term resistance surveillance programme undertaken between 2006 and 2019 informed by resistance risk forecasting., Results: By mapping the Australian distribution of resistance through time, we show that resistance is present across three Australian states and covers more than 3000 km. This current range includes a recently identified population exhibiting organophosphate resistance representing the most easterly location of resistance in H. destructor. Using field history information, we identify associations for the first time between crop management practices employed by farmers and the presence of pyrethroid resistance. Management strategies that could minimize the risk of further resistance include limiting local spread of resistance through farm hygiene practices, crop rotations and reducing pesticide usage., Conclusion: This study highlights the challenges of resistance in H. destructor but also indicates how quantitative resistance risk analysis can be developed to target field surveillance and delay further resistance. The management strategies highlighted in this study can help maintain the effectiveness of control options but will depend on farmer engagement and adoption. © 2021 Society of Chemical Industry., (© 2021 Society of Chemical Industry.)

The redlegged earth mite (Halotydeus destructor) is an important agricultural pest in Australia, with a wide range of plant hosts. Halotydeus destructor has developed resistance to pyrethroid and organophosphorus insecticides as a consequence of the widespread use of these chemicals by farmers. Neonicotinoids are one of the few remaining insecticide classes registered against H. destructor in which resistance has not been detected, although there have been occasional reports of control difficulties experienced in the field. There is currently no reliable way to accurately test the response of H. destructor (or indeed any mite species) to neonicotinoid insecticides. Here, we developed a new bioassay to assess the response of mites against the neonicotinoid imidacloprid. The method provided consistent results and showed no variation when used by different operators. We generated base-line sensitivity data for imidacloprid across a number of field-collected populations of H. destructor. This is important for future monitoring of mite responses given the considerable selection pressure now being exerted across large areas of the Australian farming landscape through the widespread use of neonicotinoid seed treatments.

Insecticide resistance is an ever-increasing problem that threatens food production globally. Within Australia, the grain industry has a renewed focus on resistance due to diminishing chemical options available to farmers and the increasing prevalence and severity of resistance encountered in the field. Chemicals are too often used as the major tool for arthropod pest management, ignoring the potent evolutionary forces from chemical selection pressures that lead to resistance. A complex array of factors (biological, social, economic, political, climatic) have contributed to current trends in insecticide usage and resistance in the Australian grain industry. We review the status of insecticide resistance and provide a context for how resistance is currently managed. We discuss emerging technologies and research that could be applied to improve resistance management. This includes generating baseline sensitivity data for insecticides before they are launched, developing genetic diagnostics for the full complement of known resistances, expanding resistance monitoring programs, and utilizing new technologies. Additional benefits are likely to be achieved through a combination of industry awareness and engagement, risk modeling, adoption of integrated pest management tactics, greater collaboration between industry stakeholders, and policy changes around chemical use and record keeping. The Australian grain context provides lessons for other agricultural industries. © 2018 Society of Chemical Industry., (© 2018 Society of Chemical Industry.)

Purpose: The Department of Veterans Affairs LVES Study is a multicenter study to determine the effectiveness of the Low Vision Enhancement System (LVES) as a visual rehabilitation device. The purpose of this study was to explore the efficacy of the Beta 1 manual-focus LVES for improving visual acuity and contrast sensitivity., Methods: Patients whose visual acuity was 20/80 or worse in the better eye from any disease, who did not have significant visual field loss, who had previous low vision experience and were capable of working with the LVES were enrolled in a comprehensive prospective multicenter clinical evaluation. Initially, corrected spectacle visual acuities were measured using a standardized ETDRS chart. Contrast sensitivities were also measured with spectacle correction using a standardized Peli-Robson chart. These results were then compared to the acuities and contrast sensitivity obtained with the LVES at optimal magnification. Also, visual acuities were measured using an Eschenbach 3x spectacle-mounted binocular telescope, then compared to the acuities obtained using the LVES set at the lowest magnification (3x)., Results: All patients who completed the study demonstrated an improvement in visual acuity, with a median improvement of six lines of Snellen equivalent acuity using the LVES. Improvement in visual acuity was the same in both ARMD and non-ARMD causes of vision loss. Mean contrast sensitivity improved in 52 of 58 patients tested, with a mean improvement of 0.49 log units., Conclusion: The LVES significantly improves both visual acuity and contrast sensitivity in visually impaired patients who fall within the study criteria. Up to 10-fold improvement in visual acuity and up to 1.80 log units improvement in contrast sensitivity were noted in the study group when the LVES was used.

The prevalence of severe visual impairment increases with age. Additionally, visually impaired elders are much more likely to have mobility restrictions than their normal-sighted peers. Specifically, individuals with visual impairment between 65 and 74 years of age are three to four times more likely to have difficulty walking, going outside, and getting in and out of bed. This article reviews the eye and vision problems associated with aging and discusses management options.

The risks of acquisition of infectious diseases including the human immunodeficiency virus--1 (HIV) to practitioners and patients in the practice of optometry is discussed. Measures that reduce the risk of contracting or transmitting HIV and other infectious diseases in optometry are presented. Effective disinfection including that for HIV are discussed.

Two cases of suspected cytomegalovirus (CMV) retinitis treated with ganciclovir and followed for 18 and 5 months are presented. Each patient developed optic neuropathy and experienced reduced vision despite effective control of their retinitis. In addition to objective ocular findings, subjective visual function changes (perimetry, contrast sensitivity and accommodation) in long term follow up of AIDS patients are reported for the first time. A discussion of CMV, its treatment and complications follows.

Primary cysts of the iris usually arise from the pigment epithelial layers and are almost always benign, stationary lesions which require no treatment. Those cysts which are secondary to such agents as trauma or inflammation are, however, characterized by progressive enlargement and visual complications. The major clinical significance of iris cysts lies in their similarity to iris melanomas. Cysts should be monitored for enlargement and/or other complications such as inflammation or secondary glaucoma.

The Bilevel Telemicroscope Apparatus (BITA) is a new galilean telescope designed to offer improved cosmesis, weight, field of view and spatial orientation over more traditional spectacle-mounted telescopic systems. This paper describes the characteristics of the new telescope and presents two cases where the BITA was successfully prescribed.

The mentally handicapped represent up to six million individuals who require the eye and vision care the optometrist can provide. Few of these individuals, however, ever receive this care. This paper reviews the pertinent aspects of each of these syndromes and briefly describes the associated oculo-visual anomalies that are frequently seen. The optometric clinician should actively participate in the primary health care needs of children and adults diagnosed as having mental retardation.

Fragile X (fra[X]) syndrome is a newly discovered, but relatively common, genetic disorder with an estimated frequency of 1:1000. Several ocular dysfunctions may be associated with this syndrome, but there are few articles that fully report on these. A review of this genetic disorder is provided, as well as a discussion of a case review of a family with three siblings with fragile X syndrome. Since this disorder is the most common familial cause of mental retardation, is second only to Down's syndrome as a genetic cause for mental retardation, and may play a significant role in learning disabilities, the eye care practitioner should be aware of its importance.

As an investigational fibrinolytic agent for acute myocardial infarction, intravenous recombinant tissue-type plasminogen activator (rt-PA) has been administered primarily in tertiary care and university centers. To determine the value of early initiation of such therapy, two satellite community hospital emergency rooms were established for use of rt-PA and the experience was compared among 142 consecutive patients who were transferred to a regional center for acute cardiac catheterization after intravenous rt-PA therapy. In Group I (n = 19), patients received rt-PA after interhospital transport to the regional center, but before cardiac catheterization. In Group II (n = 70), rt-PA therapy was initiated by the helicopter physician and nurse team after their arrival at the local community hospital emergency room. Group III patients (n = 53) had rt-PA administered in the local community hospital by the emergency room physician. Group III patients had earlier initiation of therapy (2.1 +/- 0.8 hours in Group III versus 3.8 +/- 1.2 hours in combined Groups I and II, p less than 0.001) and an increased rate of infarct vessel recanalization on the 90 minute coronary angiogram (81 in Group III versus 67% in combined Groups I and II, p = 0.057). The patients in Group III had a higher acute left ventricular ejection fraction (54 +/- 8% versus 50 +/- 9.5% in combined Groups I and II, p less than 0.01) and a trend toward an increased 7 day ejection fraction (55.5 +/- 9% versus 51.7 +/- 9.5%, respectively, p = 0.08).(ABSTRACT TRUNCATED AT 250 WORDS)

The Veterans Administration has been named the 1982 recipient of the American Optometric Association's Apollo Award for significant contribution to the visual welfare of veterans through the VICTORS concept.

Ocular manifestations of hypertension involve both retinal and choroidal circulation. Clinical and pathological studies suggest that choroidal changes are present in benign and malignant hypertension, though significantly greater in the later. Lesions classically described as Siegrist and Elschnig spots are described. Clinical evidence of choroidopathy from hypertension and arteriosclerosis has a significant prognostic value for life.

A form of postgraduate optometric education began in 1973 with the initiation of residency programs within two colleges of optometry. The availability of residency programs for optometrists, however, was essentially nonexistent until the Veterans Administration became actively involved. The first Veterans Administration Optometry Residency Program was established by the Kansas City Veterans Administration Medical Center and the Illinois College of Optometry. This paper briefly discusses the development and philosophy of this program and describes its clinical and academic content and future goals.

Caruncle tumors are rare and difficult to definitively diagnose using standard clinical examination techniques. Because some of these lesions may be cancerous, eventually leading to local invasion of tissue, metastasis, and even death, biopsy with histologic evaluation may be indicated. A brief discussion of caruncle tumors and a case report is presented.

VICTORS, an acronym for Vision Impairment Center to Optomize Remaining Sight, is an innovative low vision rehabilitation program expanding the Veterans Administration's treatment capabilities for the partially sighted veteran. Part II provides the procedures and data on the first 125 patients to complete the program. Part I provided an over-view and description of VICTORS.

The Parsons visual acuity test (PVAT) uses modified Allen test targets for visual acuity assessment in young children and persons who are difficult to test. Using this method, we were able to obtain a visual acuity threshold in 44% of 18- to 24-month-old children and in 90% of children aged 25 to 36 months. At all ages tested, the mode for visual acuity was 20/30; however, the percentage of those with 20/20 increased with age. The decision whether to refer was correctly made by means of the PVAT criterion 83% of the time.

Reis-Bucklers' corneal dystrophy is an autosomal dominant disorder which primarily affects Bowman's membrane. Visual acuity begins to decrease around the age of 5 and continues to deteriorate over the next 20 years. The optometrist should be aware of the disorder so that the patient may be counseled regarding the genetic implications and should refer the patient to a corneal specialist when transplantation is required.

At present, there are 33 Veterans Administration (VA) Medical Centers providing 1-year COE (Council on Optometric Education) accredited residency training programs for 46 recent graduates. This paper describes the types of programs available, discusses the staffing of the clinics, and details the clinical experience.

The perception of the eccentricity of a suprathreshold light flash (III/4e) presented in a Goldmann perimeter was measured in four ophthalmologically normal observers and three young observers with retinitis pigmentosa (RP). The task was to indicate the perceived distance from central fixation of each light flash by making a mark on a 180-mm line drawn on a sheet of paper. In the center of the line was a hash mark. Observers were instructed that the hash mark should correspond to fixation and the ends of the line to the limits of the visual field. The vertical, horizontal, and both 45 degree oblique meridians were tested. The results showed that: 1. The extent of the field along the tested meridian determined perceived eccentricity, i.e., eccentricity of 45 degrees in the temporal field of normals was perceived as equally eccentric as 30 degrees in the superior field. 2. The central 20 degrees were taken to represent more of the perceptual field than any other 20 degrees. 3. Along a meridian, the eccentricity which extends from fixation to 16% of the way to the field limit along the meridian is perceived as extending to 25% of the field by normal observers. 4. On the other hand, observers with RP reported that along a meridian the eccentricity extending from fixation to 8% of the field limit is perceived as extending to 25% of the field. Kinetic primary with the II/4 target showed no evidence of field constriction in observers with RP. However, losses in sensitivity are evident starting at about 10 degrees. Full field single flash electroretinograms were unrecordable in the observers with RP.(ABSTRACT TRUNCATED AT 250 WORDS)

Computers are invading all facets of optometric practice including low vision care. This brief paper will discuss indications for prescribing computer low vision aids, hardware and software currently available, and provide several short case reports to illustrate how the visually impaired individual can utilize this new technology.

Refractive errors in 311 children between the ages of 18 and 48 months were assessed utilizing standard cycloplegic retinoscopy and a noncycloplegic near retinoscopy technique as promulgated by Mohindra. Results from this study indicate little agreement between the two objective refraction methods.

This paper presents a brief historical review and details of one case of this condition. Terrien's marginal corneal degeneration involves a relatively painless degeneration of the superior corneal stroma, with the most prominent clinical finding being the marked irregular astigmatism which accompanies the corneal thinning.

Today's busy practitioner often has little time to fully review his patient's records and thereby runs the risk of not seeing all the previously collected information. The problem-oriented system of patient record keeping provides one systematic logical method for recording data with previous information easily obtained to allow the practitioner to better utilize past and present data in making patient care decisions. This paper outlines the problem-oriented method and how it may be used in daily optometric practice.

Fabry's disease is one of the sphingolipidoses which results from the enzyme deficiency, alpha-galactosidase-A. It is a rare, hereditary, multiorgan disorder affecting the eye, skin, kidney, gastrointestinal system, heart, reticuloendothelial system, and central nervous system. Because all affected males and 90% of affected females exhibit ocular abnormalities, optometrists may be the first health care practitioners to identify these individuals.