High-quality DNA isolation protocol for detection of Khapra beetle (Dermestidae: Trogoderma granarium Everts, 1898) in standard wheat germ trap.

BACKGROUND: Khapra beetle (Dermestidae: Trogoderma granarium Everts, 1898) is an internationally significant pest of grain crops and stored grain products. Wheat germ traps, routinely used in surveillance sampling of Khapra beetle provide feed-substrates used by the pest throughout its life cycle. However, Khapra beetle larvae, eggs and other traces of the pest, such as larval frass and exuviae, in wheat germ traps are difficult to sort and taxonomically identify. Additionally, high levels of polysaccharides in wheat germ can inhibit PCR based molecular detection of this pest captured in the traps. METHODS AND RESULTS: We have developed a sensitive and low-cost protocol for extracting trace levels of Khapra beetle DNA from an entire wheat germ trap. Overnight digestion of entire trap contents in 6 mL of ATL buffer, followed by a 40 min lysis step was optimal for DNA extraction. Paired with reported qPCR assays, this protocol allows the detection of a few hairs of T. granarium in a typical 2-gram wheat germ trap. CONCLUSION: This DNA extraction protocol makes it possible to perform a more rapid identification of the pest following wheat germ sample collection. The protocol has potential to improve international efforts for Khapra beetle surveillance.

Meta-Analysis of qPCR for Bovine Respiratory Disease Based on MIQE Guidelines.

Qualitative and quantitative PCR-based tests are widely used in both diagnostics and research to assess the prevalence of disease-causing pathogens in veterinary medicine. The efficacy of these tests, usually measured in terms of sensitivity and specificity, is critical in confirming or excluding a clinical diagnosis. We undertook a meta-analysis to assess the inherent value of published PCR diagnostic approaches used to confirm and quantify bacteria and viruses associated with bovine respiratory disease (BRD) in cattle. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A thorough search of nine electronic databases (Web of Science, EBSCOhost, Cambridge journals online, ProQuest, PubMed, Sage journals online, ScienceDirect, Wiley online library and MEDLINE) was undertaken to find studies that had reported on the use of PCR and/or qPCR for the detection and/or quantification of BRD associated organisms. All studies meeting the inclusion criteria for reporting quantitative PCR for identification of BRD associated microorganisms were included in the analysis. Studies were then assessed on the applications of the Minimum Information for Publication of Quantitative Real-Time PCR Experiment (MIQE) and PCR primer/probe sequences were extracted and tested for in silico specificity using a high level of stringency. Fourteen full-text articles were included in this study. Of these, 79% of the analysed articles did not report the application of the MIQE guidelines in their study. High stringency in silico testing of 144 previously published PCR primer/probe sequences found many to have questionable specificity. This review identified a high occurrence of primer/probe sequences with a variable in silico specificity such that this may have implications for the accuracy of reporting. Although this analysis was only applied to one specific disease state, identification of animals suspected to be suffering from bovine respiratory disease, there appears to be more broadly a need for veterinary diagnostic studies to adopt international best practice for reporting of quantitative PCR diagnostic data to be both accurate and comparable between studies and methodologies.

The Use of the Saccadometer to Identify Saccadic Characteristics in Myasthenia Gravis: A Pilot Study.

BACKGROUND: Myasthenia gravis (MG) often presents with ocular signs that mimic other forms of ocular defects, such as isolated cranial nerve palsy. Normal velocity or even hyperfast saccadic eye movements in the presence of deficits of smooth pursuit have been well described in the literature in myasthenic patients. The reason for these paradoxical clinical findings has been reported to be due to increased postsynaptic folding of the fast-twitch fibers responsible for the execution of a saccade which is absent in those fibers responsible for slower, smooth eye movement. Saccadic characteristics therefore offer a point of differential diagnosis between patients suspected of having ocular motility deficits as a result of MG and those caused by other neuropathies. The advent of portable quantitative saccadic assessment means that previously laboratory-based assessments that require specialist equipment and training may now be undertaken clinically, providing a noninvasive test that can aid the differential diagnosis of the condition. The aim of this pilot study was to investigate the feasibility of the saccadometer (Ober Consulting, Poznan, Poland) in detecting the saccadic characteristics associated with myasthenia, specifically normal peak velocity (PV) in a group of patients confirmed with myasthenia. METHODS: A group of 5 patients with a confirmed diagnosis of MG were recruited from a single site into the study along with 5 age-matched healthy volunteers. All myasthenic patients had ocular signs such as underaction or limitations of motility confirmed through ocular clinical examination. Healthy volunteers were screened for any underlying ocular motility or neurological defects before inclusion within the study. All participants undertook 100 trials of both 10 and 20° amplitude saccades, and mean PV, amplitude, and latency were recorded using the saccadometer for each individual. Overall, mean PV, amplitude, and latency were collated for both myasthenic and healthy control groups for each saccade size and compared. RESULTS: The mean PV was significantly greater (481 ± 103.5 deg/seconds) for myasthenic patients compared with healthy controls (384 ± 42.8 deg/seconds) (P < 0.05) in 10° saccades. PV was also greater in myasthenics for 20° saccades; however, this difference did not reach statistical significance for patients with MG (547 ± 89.8 deg/seconds vs 477 ± 104.5 deg/seconds) (P = 0.14). The latency of participants with MG was not significantly different from those of age-matched healthy participants in 10° saccades but was significantly different for 20° saccades. There was no difference in amplitude measured between the groups. CONCLUSIONS: PV for both 10 and 20° saccades was greater in myasthenic patients compared with healthy controls. All myasthenic patients produced normal velocity saccades in the presence of deficits of smooth ocular motility. The results from this small pilot study demonstrate the potential use of the saccadometer in a clinical setting to provide a noninvasive aid in the diagnosis of patients suspected with myasthenia.

Efficiency Correction Is Required for Accurate Quantitative PCR Analysis and Reporting.

BACKGROUND: Quantitative PCR (qPCR) aims to measure the DNA or RNA concentration in diagnostic and biological samples based on the quantification cycle (Cq) value observed in the amplification curves. Results of qPCR experiments are regularly calculated as if all assays are 100% efficient or reported as just Cq, ΔCq, or ΔΔCq values. CONTENTS: When the reaction shows specific amplification, it should be deemed to be positive, regardless of the observed Cq. Because the Cq is highly dependent on amplification efficiency that can vary among targets and samples, accurate calculation of the target quantity and relative gene expression requires that the actual amplification efficiency be taken into account in the analysis and reports. PCR efficiency is frequently derived from standard curves, but this approach is affected by dilution errors and hampered by properties of the standard and the diluent. These factors affect accurate quantification of clinical and biological samples used in diagnostic applications and collected in challenging conditions. PCR efficiencies determined from individual amplification curves avoid these confounders. To obtain unbiased efficiency-corrected results, we recommend absolute quantification with a single undiluted calibrator with a known target concentration and efficiency values derived from the amplification curves of the calibrator and the unknown samples. SUMMARY: For meaningful diagnostics or biological interpretation, the reported results of qPCR experiments should be efficiency corrected. To avoid ambiguity, the Minimal Information for Publications on Quantitative Real-Time PCR Experiments (MIQE) guidelines checklist should be extended to require the methods that were used (1) to determine the PCR efficiency and (2) to calculate the reported target quantity and relative gene expression value.

Rectus Muscle Resection for Vertical Strabismus in Thyroid Eye Disease.

PURPOSE: Rectus muscle resection in thyroid eye disease (TED) is generally avoided due to the risk of worsening restriction or reactivating inflammation. However, for some patients with large-angle strabismus or diplopia in primary gaze despite maximum recession surgery, rectus muscle resection may be beneficial. We report our surgical experience with rectus muscle resection in the management of vertical strabismus associated with TED. METHODS: Retrospective review of eight patients with TED and vertical diplopia who underwent vertical rectus muscle resection by a single surgeon (IBM) at a tertiary referral centre in Liverpool, UK, from 2001 to 2013. The goal of surgery was elimination of diplopia in primary and reading position. Vertical deviations were measured in prism dioptres (∆) before and after surgery at one month, four months and final visit by prism alternate cover testing at ⅓ m and 6 m. RESULTS: The mean ± standard deviation vertical deviation for near and distance reduced significantly from 14.2∆ ± 8.4∆ and 15.8∆ ± 8.8∆ pre-operatively to 5.7∆ ± 4.9∆ and 6.7∆ ± 7∆ at the four-month visit, respectively (p< 0.05). At the four-month follow-up, five (62.5%) patients achieved binocular single vision in primary and reading position with either no prisms or prisms less than 5∆. Further recession surgery, Harada-Ito procedure, or lateral rectus resection were necessary in four (50%) patients with persistent diplopia. No patient developed recurrence of inflammation or increased muscle restriction. CONCLUSIONS: Vertical rectus resection could be considered as an additional surgical strategy in the management of TED patients with vertical strabismus without adverse sequelae.

Inferior Oblique Botulinum Toxin Injection: A Postoperative Diplopia Test for Secondary Inferior Oblique Muscle Overaction.

PURPOSE: To evaluate the utility of botulinum toxin injection into the inferior oblique muscle for secondary inferior oblique muscle overaction. METHODS: A retrospective review of 18 patients and 23 injections performed over a 9-year period. Indications and deviations in primary position and contralateral gaze before and after injection were recorded. Functional outcomes and further management (conservative vs surgical) were observed. RESULTS: In 14 patients, chemodenervation resulted in a temporary improvement in symptoms. Eleven of these patients went on to have inferior oblique myectomy with resolution of their diplopia. Two patients preferred to receive regular injections of botulinum toxin as a treatment. CONCLUSIONS: Botulinum toxin chemodenervation of the inferior oblique muscle in cases of secondary inferior oblique muscle overaction is useful where one needs to establish a risk of overcorrection following planned inferior oblique muscle weakening. This is particularly true in cases where the primary position deviation may be small but symptoms of diplopia exist on contralateral side gaze, giving rise to a narrowed field of binocular single vision.

Unaugmented Muscle Union Surgery for Heavy Eye Syndrome Without Combined Medial Rectus Recession.

PURPOSE: Simple loop myopexy or retro-equitorial muscle union surgery has been shown to effectively treat the strabismus seen in heavy eye syndrome. In most cases, this has been described with combined recession of the medial rectus muscle, particularly where medial rectus contracture was demonstrated on forced duction testing intraoperatively. The authors report the outcomes of muscle union surgery alone without combined medial rectus recession in 29 eyes with heavy eye syndrome. METHODS: A retrospective review was conducted of 26 patients and 29 eyes with heavy eye syndrome treated with a simple loop myopexy procedure. The preoperative and postoperative deviations in primary position were measured along with restriction in ocular motility in abduction and elevation. Patients with residual esotropia and/or persistence of symptoms were offered a second-stage medial rectus recession procedure. RESULTS: In 21 patients, muscle union was sufficient in improving the diplopia or cosmetic appearance of the eyes. In these cases, the average preoperative deviation improved from 21.2 ± 16.3 to 5.5 ± 9.1 prism diopters (PD). Eight eyes went on to have a second-stage medial rectus recession with excellent outcomes. CONCLUSIONS: The authors found that muscle union surgery alone is an effective and successful procedure in restoring the ocular motility disturbance and also in treating heavy eye syndrome. There was a much lower incidence (up to 70% lower) of medial rectus recession than other similar case series. There were no cases of overcorrection and no complications.

Treatment of age-related distance esotropia with unilateral lateral rectus resection.

PURPOSE: To report the results of a series of patients who underwent lateral rectus resection of a single muscle using nonadjustable sutures to correct acquired concomitant esotropia (age-related distance esotropia). METHODS: The medical records of patients with symptomatic age-related distance esotropia who were treated by unilateral lateral rectus resection were retrospectively reviewed. Pre- and postoperative near and distance prism diopter measurements were compared. RESULTS: The average age of the patients was 79.8 years (range, 68-90 years). The mean lateral rectus resection was 4.9 ± 1.3 mm. All patients had complete resolution of diplopia after surgery. Median distance esotropia measurements in primary gaze were reduced from 16.0(Δ) preoperatively to 0(Δ) postoperatively (P < 0.005) at final follow-up. Any preoperative near esotropia was also completely resolved. CONCLUSIONS: In this patient cohort, age-related distance esotropia was effectively managed solely with unilateral lateral rectus resection.

Longitudinal study of winter mortality disease in Sydney rock oysters Saccostrea glomerata.

Winter mortality (WM) is a poorly studied disease affecting Sydney rock oysters Saccostrea glomerata in estuaries in New South Wales, Australia, where it can cause significant losses. WM is more severe in oysters cultured deeper in the water column and appears linked to higher salinities. Current dogma is that WM is caused by the microcell parasite Bonamia roughleyi, but evidence linking clinical signs and histopathology to molecular data identifying bonamiasis is lacking. We conducted a longitudinal study between February and November 2010 in 2 estuaries where WM has occurred (Georges and Shoalhaven Rivers). Results from molecular testing of experimental oysters for Bonamia spp. were compared to clinical disease signs and histopathology. Available environmental data from the study sites were also collated and compared. Oyster condition declined over the study period, coinciding with decreasing water temperatures, and was inversely correlated with the presence of histological lesions. While mortalities occurred in both estuaries, only oysters from the Georges River study site showed gross clinical signs and histological changes characteristic of WM (lesions were prevalent and intralesional microcell-like structures were sometimes noted). PCR testing for Bonamia spp. revealed the presence of an organism belonging to the B. exitiosa-B. roughleyi clade in some samples; however, the very low prevalence of this organism relative to histological changes and the lack of reactivity of affected oysters in subsequent in situ hybridisation experiments led us to conclude that this Bonamia sp. is not responsible for WM. Another aetiological agent and a confluence of environmental factors are a more likely explanation for the disease.

High-throughput direct fecal PCR assay for detection of Mycobacterium avium subsp. paratuberculosis in sheep and cattle.

Johne's disease (JD) is a chronic enteric disease caused by Mycobacterium avium subsp. paratuberculosis that affects ruminants. Transmission occurs by the fecal-oral route. A commonly used antemortem diagnostic test for the detection of M. avium subsp. paratuberculosis in feces is liquid culture; however, a major constraint is the 2- to 3-month incubation period needed for this method. Rapid methods for the detection of M. avium subsp. paratuberculosis based on PCR have been reported, but comprehensive validation data are lacking. We describe here a new test, the high-throughput-Johnes (HT-J), to detect M. avium subsp. paratuberculosis in feces. Its diagnostic accuracy was compared with that of liquid radiometric (Bactec) fecal culture using samples from cattle (1,330 samples from 23 herds) and sheep (596 samples from 16 flocks). The multistage protocol involves the recovery of M. avium subsp. paratuberculosis cells from a fecal suspension, cell rupture by bead beating, extraction of DNA using magnetic beads, and IS900 quantitative PCR. The limit of detection of the assay was 0.0005 pg, and the limit of quantification was 0.005 pg M. avium subsp. paratuberculosis genomic DNA. Only M. avium subsp. paratuberculosis was detected from a panel of 51 mycobacterial isolates, including 10 with IS900-like sequences. Of the 549 culture-negative fecal samples from unexposed herds and flocks, 99% were negative in the HT-J test, while 60% of the bovine- and 84% of the ovine-culture-positive samples were positive in the HT-J test. As similar total numbers of samples from M. avium subsp. paratuberculosis-exposed animals were positive in culture and HT-J tests in both species, and as the results of a McNemar's test were not significant, these methods probably have similar sensitivities, but the true diagnostic sensitivities of these tests are unknown. These validation data meet the consensus-based reporting standards for diagnostic test accuracy studies for paratuberculosis and the Minimum Information for Publication of Quantitative Real-Time PCR Experiments (MIQE) guidelines (S. A. Bustin et al., Clin. Chem. 55:611-622, 2009, doi:10.1373/clinchem.2008.112797). The HT-J assay has been approved for use in JD control programs in Australia and New Zealand.

Emergence of epizootic ulcerative syndrome in native fish of the Murray-Darling River System, Australia: hosts, distribution and possible vectors.

Epizootic ulcerative syndrome (EUS) is a fish disease of international significance and reportable to the Office International des Epizootics. In June 2010, bony herring Nematalosa erebi, golden perch Macquaria ambigua, Murray cod Maccullochella peelii and spangled perch Leiopotherapon unicolor with severe ulcers were sampled from the Murray-Darling River System (MDRS) between Bourke and Brewarrina, New South Wales Australia. Histopathology and polymerase chain reaction identified the fungus-like oomycete Aphanomyces invadans, the causative agent of EUS. Apart from one previous record in N. erebi, EUS has been recorded in the wild only from coastal drainages in Australia. This study is the first published account of A. invadans in the wild fish populations of the MDRS, and is the first confirmed record of EUS in M. ambigua, M. peelii and L. unicolor. Ulcerated carp Cyprinus carpio collected at the time of the same epizootic were not found to be infected by EUS, supporting previous accounts of resistance against the disease by this species. The lack of previous clinical evidence, the large number of new hosts (n = 3), the geographic extent (200 km) of this epizootic, the severity of ulceration and apparent high pathogenicity suggest a relatively recent invasion by A. invadans. The epizootic and associated environmental factors are documented and discussed within the context of possible vectors for its entry into the MDRS and recommendations regarding continued surveillance, research and biosecurity are made.

The effect of scleral exoplant removal on strabismus following retinal detachment repair.

PURPOSE: Scleral buckling for retinal detachment is a well-reported cause of secondary strabismus. We analyzed the effects on motility of removal of the exoplant alone to determine whether this is warranted as a separate step in the surgical management of these patients. METHODS: A retrospective case series of patients who underwent scleral exoplant removal due to symptomatic strabismus development following retinal detachment repair from 2007 to 2009 was conducted. Manifest horizontal and vertical deviations were treated as vectors of a single combined deviation (|dev|). Pre- and postoperative manifest |dev| in the primary position (|dev|(pp)) and in the gaze position of maximal deviation (|dev|(max)) were analyzed. RESULTS: Five patients were identified, all with symptomatic, binocular diplopia in the primary position prior to exoplant removal. Median |dev|(pp) prior to exoplant removal was 21(Δ) and following removal was 21(Δ) (P = 0.81). The median |dev|(max) prior to exoplant removal was 33(Δ) and following removal, 22(Δ) (P = 0.82). Median follow-up was 8 months. There were no cases of retinal redetachment following the exoplant removal. No patient reported any subjective improvement of their diplopia. All 5 patients went on to have strabismus surgery as a separate procedure. CONCLUSIONS: Median primary position deviation was unchanged by scleral buckle removal, and Exoplant removal has minimal long-term benefit on the strabismus following scleral buckling procedures.

Culture phenotypes of genomically and geographically diverse Mycobacterium avium subsp. paratuberculosis isolates from different hosts.

Mycobacterium avium subsp. paratuberculosis causes paratuberculosis (Johne's disease) in ruminants in most countries. Historical data suggest substantial differences in culturability of M. avium subsp. paratuberculosis isolates from small ruminants and cattle; however, a systematic comparison of culture media and isolates from different countries and hosts has not been undertaken. Here, 35 field isolates from the United States, Spain, Northern Ireland, and Australia were propagated in Bactec 12B medium and Middlebrook 7H10 agar, genomically characterized, and subcultured to Lowenstein-Jensen (LJ), Herrold's egg yolk (HEY), modified Middlebrook 7H10, Middlebrook 7H11, and Watson-Reid (WR) agars, all with and without mycobactin J and some with sodium pyruvate. Fourteen genotypes of M. avium subsp. paratuberculosis were represented as determined by BstEII IS900 and IS1311 restriction fragment length polymorphism analysis. There was no correlation between genotype and overall culturability, although most S strains tended to grow poorly on HEY agar. Pyruvate was inhibitory to some isolates. All strains grew on modified Middlebrook 7H10 agar but more slowly and less prolifically on LJ agar. Mycobactin J was required for growth on all media except 7H11 agar, but growth was improved by the addition of mycobactin J to 7H11 agar. WR agar supported the growth of few isolates. The differences in growth of M. avium subsp. paratuberculosis that have historically been reported in diverse settings have been strongly influenced by the type of culture medium used. When an optimal culture medium, such as modified Middlebrook 7H10 agar, is used, very little difference between the growth phenotypes of diverse strains of M. avium subsp. paratuberculosis was observed. This optimal medium is recommended to remove bias in the isolation and cultivation of M. avium subsp. paratuberculosis.

The psychosocial effects of adult strabismus: a review.

Correction of adult strabismus is not a cosmetic procedure but one that restores normality to an individual's appearance that has been altered by a disease process. Two fundamental principles underpinning facial attractiveness are symmetry and averageness-manifest strabismus affects both of these giving an unconscious signal of poor genetic history. The presence of manifest strabismus adversely affects many aspects of patients' lives including finding a partner, job prospects and interaction with peers, and may manifest more seriously as psychiatric disorders. Surgical correction has been shown to be safe and effective for the functional problems of strabismus in adults but the hugely positive effects on the psychosocial aspects are only now becoming apparent. The advent of a new adult strabismus specific quality-of-life questionnaire and its subsequent validation will make this quantification of improvement easier. The wider medical community and the public at large should be made aware of the benefits of corrective strabismus surgery in adults.

The psychosocial effects of strabismus: effect of patient demographics on the AS-20 score.

PURPOSE: The introduction of the AS-20 strabismus-specific quality-of-life questionnaire allows clinicians to quantify the effects of strabismus on adults for the first time. We correlated strabismic patients' demographic and clinical findings to their AS-20 scores. METHODS: A consecutive cohort of patients from an ongoing prospective study of adults with manifest strabismus was recruited. The patients' age, sex, socioeconomic status (SES), magnitude, and direction of deviation were correlated to their AS-20 scores. Patients' zip codes were used to derive a score for their SES based on the English 2007 Index of Multiple Deprivation score (IMD2007). RESULTS: A total of 61 questionnaires with all demographic and clinical data were available. The median magnitude of deviation was 20.4(Δ) in this group. The mean AS-20 score was 49.5 (SD 21.6). Women had significantly lower AS-20 scores than men (p = 0.02). There was no difference in AS-20 scores between individuals with eso- and exodeviations (p = 0.7). Multiple linear regression analysis shows female sex and lower SES to be significantly associated with lower AS-20 scores (p = 0.03 and p = 0.006, respectively). CONCLUSIONS: Strabismic patients who are female or live in a more deprived area have a significantly lower AS-20 score.

Perioperative management of anticoagulated patients having cataract surgery: National audit of current practice of members of the Royal College of Ophthalmologists.

An 11-item questionnaire was mailed to 891 consultant members of the Royal College of Ophthalmologists (RCOphth) to audit compliance with RCOphth guidelines for perioperative management of anticoagulated patients having cataract surgery. Four hundred ninety-nine questionnaires were analyzed. The results showed that 29.5% of respondents adhered to all aspects of RCOphth guidelines; that is, they checked the international normalized ratio (INR) preoperatively, continued warfarin, operated within the desired therapeutic INR range for the condition that warfarin was being used to treat (as set by the treating physician), and considered sub-Tenon or topical anesthesia in anticoagulated patients.

Growth pattern and partial proteome of Mycobacterium avium subsp. paratuberculosis during the stress response to hypoxia and nutrient starvation.

Mycobacterium avium subsp. paratuberculosis is an important pathogen that causes Johne's disease in animals and has been implicated in Crohn's disease in man yet few data exist on its physiological adaptation in either the host or the environment. In this study, the proteomic responses of the two distinct strains of M. a. paratuberculosis, cattle (C) and sheep (S), to hypoxia and starvation were studied in vitro. Nutrient starvation inhibited growth of both strains and was lethal for S strain after 12 weeks. Hypoxia induced a state of very low metabolic activity but rapid resuscitation occurred upon restoration of an aerobic atmosphere, consistent with the dormancy response of other mycobacteria. A total of 55 protein spots differentially expressed in response to starvation and/or hypoxic stress in one or both strains were identified from 2D gels and classified based on biological function. Antioxidant enzymes, oxidoreducatse enzymes and proteins involved in amino acid metabolism, fatty acid metabolism, ATP and purine biosynthesis, proteolysis, cell wall synthesis, protein synthesis, signal recognition and hypothetical proteins with putative functions including dormancy response regulators and universal stress proteins were identified. These proteins are potential screening targets for future diagnosis, prevention and control of M. a. paratuberculosis infection and their identification will assist understanding the pathogenesis of diseases caused by this organism.

The role of botulinum toxin in decompensated strabismus.

BACKGROUND: The surgical management of decompensated strabismus is well described. Conservative treatment may employ the use of lenses and prisms. However, the use of botulinum toxin in decompensated squint is poorly documented. In these patients, with the potential for fusion, botulinum toxin may serve to stabilize the ocular alignment by bringing the images within the fusion range. PURPOSE: The aim of this study was to assess the role of botulinum toxin in the treatment of decompensated squints. METHODS: A retrospective case series involving 92 patients with decompensated squints between December 1990 and July 2005. Botulinum toxin was injected into the lateral rectus in 45 cases and into the medial rectus in 47. This was performed under local anesthesia in 74 cases, the remainder with ketamine anesthesia. Patients were assessed preoperatively at 2 weeks, 4 months, and a minimum of 12 months postoperatively. We defined successful treatment where the resultant stabilized deviation was less than or equal to 10 prism diopters with resolution of diplopia. RESULTS: In this study, 47 patients had a decompensated microesotropia and 45 had a decompensated exophoria. We found that 27 (29.3%) patients were asymptomatic following injection of botulinum toxin. Fourteen (15.2%) patients were better controlled and did not require further intervention. Subsequent surgery was performed in 45 patients (48.9%). CONCLUSION: Our results suggest almost half of those patients requiring treatment for decompensated squint benefit from botulinum toxin, without requiring surgical intervention. This approach is less invasive and allows potential for recovery of binocular function.

Botulinum toxin injection for postoperative diplopia testing in adult strabismus.

PURPOSE: To investigate the use of botulinum toxin type A in identifying adult patients with constant strabismus who are at high risk of developing intractable diplopia after surgery. METHODS: A retrospective review of adult patients with constant horizontal strabismus who had botulinum toxin injection to evaluate their risk of postoperative diplopia. These patients reported diplopia when prisms were used to neutralize the deviation. RESULTS: One hundred ninety-five adults were studied; their mean age was 40.3 +/- 14 years (range, 16 to 73 years). One hundred thirty-three (68%) had botulinum toxin injected into a lateral rectus muscle; 62 (32%) had injections in a medial rectus muscle. Only 14 (7%) developed diplopia; 9 (4.6%) of these had troublesome diplopia but 5 (2.6%) could cope with the double vision and elected to have surgery. Surgical correction was recommended to the remaining 181 (93%) who did not experience diplopia. Complications of botulinum toxin injection were ptosis (10 patients, 5.1%) and superior oblique muscle weakness (3 patients, 1.5%). Twenty-six patients (13.3%) had a poor response to the first injection and required a second injection with a double dose. Surgery did not result in intractable diplopia after 6 weeks in any patient with a negative botulinum toxin diplopia test. CONCLUSIONS: Botulinum toxin is a useful diagnostic tool for identifying patients with a low risk or no risk of postoperative diplopia despite a positive prism diplopia test.

Evaluation of radiometric faecal culture and direct PCR on pooled faeces for detection of Mycobacterium avium subsp. paratuberculosis in cattle.

Dilution rates for pooled faecal culture (PFC) and direct IS900 polymerase chain reaction (D-PCR) tests were evaluated on faecal samples from infected cows mixed with uninfected faeces in dilutions from 1 in 5 to 1 in 50. PFC was performed by radiometric culture, with confirmation by IS900 PCR and restriction endonuclease analysis (PCR/REA) on growth, and by mycobactin dependency testing on solid medium. Using 37 culture positive faecal samples from 12 subclinical cows, 83.8% and 94.6% of samples were confirmed positive in the PFC assay at dilutions of 1 in 50 and 1 in 30, respectively. Lower dilutions (1 in 5 to 1 in 20) provided only marginally better sensitivity, and confirmation of PFC growth by PCR/REA was significantly more sensitive than mycobactin dependency. D-PCR had significantly lower sensitivity than PFC confirmed by PCR/REA, with pools of 1 in 50, 30, 10 and 5 yielding positive results in 64.9%, 70.3%, 78.4% and 83.8% of samples, respectively. Cattle considered to be shedding 1.5 x 10(6) viable M. avium subsp. paratuberculosis (Map)/g faeces (on the basis of estimated losses in processing and growth rates in radiometric broth) were positive at dilutions up to 1 in 50 in the PFC and D-PCR. Those shedding 5 x 10(5) viable Map/g were positive in the PFC at dilutions up to 1 in 40, but required a 1 in 10 dilution or less for D-PCR. The results suggest that for cattle shedding relatively high concentrations of Map in faeces (>2 x 10(5) viable Map/g), maximal dilutions of 1 in 30 for PFC and 1 in 10 for D-PCR would be applicable.