Evaluation of the Amblyopia tracker app.

PURPOSE: The Amblyopia tracker app has been developed to be a tool for parents to monitor changes in vision at home during amblyopia treatment. The aims of this study were to evaluate the feasibility and repeatability of parents testing their children at home and to compare home test results to an assessment in clinic by an orthoptist. METHODS: Children (age < 18 years) with amblyopia (interocular acuity difference of ≥ 0.2logMAR) were recruited. Parents were asked to test their child with the app three times during a two week period followed by an online questionnaire about the usability. Participants also tested within 48 h of their appointment where the measurement was repeated by an orthoptist. RESULTS: Out of 277 potential participants contacted, 37 completed three home measurements, mean age 6.8 years (SD 2.94). Home tests comparisons were made between test two and three to ensure familiarity with the process. Paired t-tests showed no statistically significant difference for either eye or the interocular acuity difference (IAD). However, 29% had a difference in IAD of more than 0.1logMAR on repeated testing, with a maximum of 0.4logMAR difference in the IAD. Questionnaire responses from the parents who participated were predominantly positive with 97% of respondents saying they would use it if were available. Comparison of home and clinical measurements (n = 23, mean age 6.72 SD 2.60) showed no statistically significant differences for either eye or interocular acuity difference (paired t-test, p > 0.3 in all cases). CONCLUSION: Results show no statistically significant differences for the Amblyopia tracker app when used by parents at home on repeated testing, or between the home test by a parent and the test by a clinician. However, variability in the results does indicate that further improvements are required to ensure the results can be used as a reliable clinical tool.

Evaluating the Use of Contrast Sensitivity Tests By Orthoptists in the UK.

Introduction: The importance of the use of contrast sensitivity (CS) tests in orthoptic practice is well established. However, despite the clinical relevance the implementation within clinical care is known to be variable. There are no known studies that investigate the use of CS tests in Orthoptic clinics in the UK, therefore the aim of this study is to gather information from Orthoptists in the UK on their opinion of CS and use of CS testing in clinical practice, now and in the future. Methods: An online survey was distributed via JISC to the British and Irish Orthoptic Journal newsletter three times over a period of four weeks in June 2021 inviting practising orthoptists in the United Kingdom to complete. The questionnaire comprised of a series of questions regarding current use with free text responses for additional information. Results: There were 84 responses to the survey. The preferred test for adult and children testing is Pelli Robson with 50% reporting use of this test. 56% felt there is a need for a new CS test for young children, 12% said no and 32% were unsure. The highest percentage (57.1%) of participants were confident to some degree that their preferred test gave them useful clinical information. Conclusion: The result of the survey demonstrates the variability of CS testing currently in orthoptic practice in the UK. It also highlights the lack of currently available tests for children for CS testing, which may be addressed by the addition of the new Double Happy CS test.

Do Socioeconomic Inequalities Exist Within Ophthalmology and Orthoptics in the UK?: A Scoping Review.

Introduction: It is well documented that socioeconomic disadvantage adversely affects general health and ocular health worldwide. Within orthoptics, while clinicians recognise a relationship between socioeconomic situation and treatment outcome, no previous literature review was found to address this issue. Neither was a UK-specific literature review found to address the same issue for ophthalmology as a whole. Aim: This literature review evaluates evidence for an association between socioeconomic situation and ophthalmic/orthoptic conditions and their treatment outcomes, specifically within the UK. Methods: Keyword searches were conducted on Google Scholar and the University of Liverpool library catalogue. Results for the main analyses were limited to full papers, specific to the UK, written in English. Literature was only included from pre-2000 if more recent evidence was insufficient. Results: There is evidence of socioeconomic disadvantage being associated with the following: reduced visual acuity; reduced attendance at diabetic retinopathy screening appointments; and delayed presentation of glaucoma, cataracts, and diabetic retinopathy. However, evidence linking socioeconomic disadvantage to AMD is mixed. There is limited evidence of the increased prevalence of amblyopia and subsequent barriers to its treatment for socioeconomically underserved children. There is also evidence of a reduction in quality of life for socioeconomically underserved adults with strabismus. Conclusions: Health inequalities within ophthalmology and orthoptics are reported, but with confounding results for some conditions. Further research should explore the reasons behind the inequalities that are found and identify methods of reducing them.

Comparison of current paediatric contrast sensitivity assessments using simulated reduced contrast thresholds.

PURPOSE: There are limited tests of contrast sensitivity (CS) for use in children. The Hiding Heidi (HH) is suitable for all cognitive abilities, but has a ceiling effect. The Double Happy (DH) test has comparable thresholds to the Pelli Robson (PR), however the ability to detect changes in contrast has not been established. This study aims to compare contrast thresholds and agreement between HH and the DH, comparing to the PR chart in normal conditions and under reduced visual and lighting conditions. METHODS: Tests were repeated under different conditions to reduce the contrast. Room illumination was 20,900{plus minus}2% lux in bright conditions and 2,000{plus minus}2% lux in dim conditions, both conditions were repeated with the addition of simulation spectacles to reduce the clarity of vision. Participants' CS was measured uniocularly using the PR, HH and DH tests. RESULTS: 50 participants, age 18-62 years (mean{plus minus}standard deviation: 24.5{plus minus}7.98), were assessed. On HH 94% (n = 47) reached the maximum score, with the DH it was 18% (n = 9). The difference in reduction between conditions was smaller with HH in comparison to PR and DH, but significantly different from baseline conditions. Under dim conditions the reduction in PR and DH was -0.21 logCS units, but only -0.04 logCS for HH. CONCLUSION: The DH test has better agreement with PR than HH and is better at detecting CS changes, highlighting the advantages of use in clinical practice.

Test retest variability in stereoacuity measurements.

Background: A clinician's choice of stereotest is influenced by the robustness of the measurement, in terms of sensitivity, specificity and test-retest variability. In relation to the latter aspect, there are limited data on the test-retest variability of these new tests and how they compare to the more commonly used stereotests. Therefore, the aim of the study was to determine the test-retest variability of four different measures of stereoacuity (TNO, Frisby, Lang Stereopad and Asteroid (Accurate STEReotest On a mobIle Device)) and to compare the stereoacuity measurements between the tests in an adult population. Methods: Stereoacuity was measured twice using TNO, Frisby, Lang Stereopad and Asteroid. Inclusion criteria included adult participants (18 years and older), no known ophthalmic condition and VA (Visual Acuity) equal to or better than 0.3 logMAR (Logarithm of the Minimum Angle of Resolution) with interocular difference of less than 0.2 logMAR. Bland-Altman analysis was used to assess agreement within and between stereotests. Differences in stereo thresholds were compared using signed Wilcoxon tests. Results: Fifty-four adults (male: 23 and female: 31) with VA equal to or better than 0.3 logMAR in either eye and interocular difference less than 0.2 logMAR were assessed (mean age: 38 years, SD: 12.7, range: 18-72). The test-retest variability of all the clinical stereotests, with the exception of the Lang Stereopad (p = .03, Wilcoxon signed-rank test), was clinically insignificant as the mean bias was equal or less than 0.06 log seconds of arc (equivalent to 1.15 seconds of arc). While the Asteroid test had the smallest variation between repeated measures (mean bias: -0.01 log seconds of arc), the Frisby and Lang Stereopad tests had the narrowest and widest limits of agreement respectively. When comparing results between tests, the biggest mean bias was between Frisby and Lang Stereopad (-0.62 log seconds of arc), and 64.8% and 31.5% of differences were in the medium (21-100" of arc) and larger (>100" of arc) ranges respectively. Conclusion: The TNO and Frisby tests have good reliability but measure stereoacuity over a narrower range compared to the Asteroid which shows less variation on repeated testing but has a larger testing range. The data reported here show varying degrees of agreement in a cohort of visually normal participants, and further investigation is required to determine if there is further variability when stereoacuity is reduced.

Corrigendum: Using a Computerised Staircase and Incremental Optotype Sizes to Improve Visual Acuity Assessment Accuracy.

[This corrects the article DOI: 10.22599/bioj.271.].

Gestational age-specific hematological patterns in preterm infants following necrotizing enterocolitis.

OBJECTIVE: To investigate gestational age (GA) specific hematological and transfusion response patterns in preterm infants following necrotizing enterocolitis (NEC). DESIGN: A retrospective study comparing hematological/transfusion information in three GA groups' infants: Group A ≤ 28 weeks. Group B 28-32 weeks, Group C > 32 weeks following necrotizing enterocolitis. RESULTS: Group A infants responded with significantly higher WBC count, thrombocytopenia, higher absolute neutrophil, and higher absolute monocyte and lower absolute lymphocyte counts following NEC onset, received more blood transfusions before NEC onset (59.8 versus 30.0%; p = .007), and had higher odds of surgical NEC (OR 3.39 [95% CI 1.19-10.38]; p = .02) than group C. One unit increase in absolute lymphocyte count on the day, and 24 h following NEC was significantly associated with lower surgical NEC odds than groups C. CONCLUSION: The infant's in-group A had significantly different hematological response patterns following NEC than infants with higher gestational age (groups B and C).

Using a Computerised Staircase and Incremental Optotype Sizes to Improve Visual Acuity Assessment Accuracy.

Background: Given the impact of visual acuity results on diagnosis and management, it is essential that the test is accurate, determined by factors such as test-retest variability. Standardisation improves accuracy, which can be performed via a computerised staircase methodology. Standard clinical tests with scoring of 0.02 per optotype implies an incremental score per optotype despite optotype size remaining constant on each line. The aim of this study is to establish if near continuous incremental optotype display and scoring improves test-retest variability compared to current testing methods. Methods: A computerised three up, one down adaptive staircase was used to display Kay Picture optotypes on an LCD monitor. Three methods of visual acuity assessment were undertaken: ETDRS, Kay Pictures and computerised Kay Pictures. Tests were performed twice under standard clinical conditions. Results: One hundred nineteen adults were tested. Test-retest variability for computerised Kay pictures was 0.01 logMAR (±0.04, p = 0.001). Good levels of agreement were observed for computerised Kay pictures in terms of test-retest variability, where the test had the smallest mean bias (0.01 logMAR compared to 0.03 and 0.08 logMAR for Kay Pictures and ETDRS respectively) and narrowest limits of agreement. Participants performed better in computerised Kay pictures than Kay Pictures by 0.03 logMAR, and better in ETDRS than computerised Kay pictures by 0.1 logMAR. Conclusion: Computerised Kay pictures exhibited a low test-retest variability, demonstrating it is reliable and repeatable. This repeatability measure is lower than the test-retest variability of the ETDRS and Kay Pictures tests.

Changes to Visual Parameters Following Virtual Reality Gameplay.

Introduction: Virtual reality (VR) gameplay is popular with a range of games and educational resources available. However, it puts high demands on the visual system. Current evidence shows conflicting impacts on visual parameters. Therefore, this study explores the changes to vision following VR gameplay. Methods: The study was conducted at the School of Health Sciences, University of Liverpool. All participants had binocular vision with good visual acuity and no manifest strabismus. Participants were assessed before and after playing 15 minutes of the VR game Beat Saber, which incorporated convergence and divergence movements. Clinical assessments including near point of convergence (NPC) and near point of accommodation (NPA) using the RAF rule; accommodative convergence to accommodation (AC/A) ratio; motor fusion using the prism fusion range (at 33cm), accommodation facility using +2.00/-2.00DS flipper lenses, and stereoacuity using the Frisby stereo test were assessed before and after playing. Results: Seventy-eight participants (19-25 years old) were included in the study, with 16 males and 41 females respectively. The breakpoint of convergence reduced by 0.5 cm (p = 0.001). The binocular accommodative facility improved by 2 cycles per minute (cpm); p = 0.004. The mean, near horizontal prism fusion range (PFR) base break and recovery points both worsened by of 5.0 dioptres (p = 0.003), whereas the mean near horizontal PFR base in recovery point improved by of 4.0 dioptres (p = 0.003). Discussion: The study validated previous findings as VR gameplay over-exercised and fatigued convergence muscles, but to a small degree. The VR experience improved the participants' ability to change focus quickly and improve accommodation, as well as the divergence function of the eye. However, as the participants were retested directly after the VR gameplay, the findings were limited to short term effects on vision.

Developmental Regulation and Functional Prediction of microRNAs in an Expanded Fasciola hepatica miRNome.

The liver fluke, Fasciola hepatica, is a global burden on the wellbeing and productivity of farmed ruminants, and a zoonotic threat to human health. Despite the clear need for accelerated discovery of new drug and vaccine treatments for this pathogen, we still have a relatively limited understanding of liver fluke biology and host interactions. Noncoding RNAs, including micro (mi)RNAs, are key to transcriptional regulation in all eukaryotes, such that an understanding of miRNA biology can shed light on organismal function at a systems level. Four previous publications have reported up to 89 mature miRNA sequences from F. hepatica, but our data show that this does not represent a full account of this species miRNome. We have expanded on previous studies by sequencing, for the first time, miRNAs from multiple life stages (adult, newly excysted juvenile (NEJ), metacercariae and adult-derived extracellular vesicles (EVs)). These experiments detected an additional 61 high-confidence miRNAs, most of which have not been described in any other species, expanding the F. hepatica miRNome to 150 mature sequences. We used quantitative (q)PCR assays to provide the first developmental profile of miRNA expression across metacercariae, NEJ, adult and adult-derived Evs. The majority of miRNAs were expressed most highly in metacercariae, with at least six distinct expression clusters apparent across life stages. Intracellular miRNAs were functionally analyzed to identify target mRNAs with inversely correlated expression in F. hepatica tissue transcriptomes, highlighting regulatory interactions with key virulence transcripts including cathepsin proteases, and neuromuscular genes that control parasite growth, development and motility. We also linked 28 adult-derived EV miRNAs with downregulation of 397 host genes in F. hepatica-infected transcriptomes from ruminant lymph node, peripheral blood mononuclear cell (PBMC) and liver tissue transcriptomes. These included genes involved in signal transduction, immune and metabolic pathways, adding to the evidence for miRNA-based immunosuppression during fasciolosis. These data expand our understanding of the F. hepatica miRNome, provide the first data on developmental miRNA regulation in this species, and provide a set of testable hypotheses for functional genomics interrogations of liver fluke miRNA biology.

Evaluation of a New Method to Track Changes in Vision at Home for Children Undergoing Amblyopia Treatment.

PURPOSE: A new amblyopia tracker app has been designed to provide parents with a method of monitoring a child's vision by presenting a single optotype size that the tester moves to identify the furthest distance the optotypes can be seen. The aim of this study is to evaluate this methodology in adults, comparing the findings to visual acuity (VA) measured with the iSight app and to determine the test retest variability. METHODS: Adults, aged 18-39 years, with no known eye condition and VA ≤ 0.7 logMAR were recruited. Bangerter filters were used to simulate amblyopia, where VA was reduced below 0.0 with an interocular difference of at least 0.2 logMAR. Testing for both apps was performed monocularly, with the test order being randomised. RESULTS: Data from 32 subjects were analysed. For the test retest variability analysis, paired t-tests showed no statistically significant difference between the tests for either eye, either app or the interocular acuity difference (p > 0.3 in all cases). Bland Altman plots showed similar limits of agreement between the two apps. When comparing measurements between the apps there was no statistically significant difference on the first or second test, either eye or the interocular acuity difference (p > 0.5 in all cases). CONCLUSION: The results support the theory that changing distance is a valid method of assessing VA as the measurements agree well with the standard approach of reducing optotype size. Test retest variability is similar between the two apps and there is good agreement between the measurements.

The Accuracy of GP Referrals into Manchester Royal Eye Hospital Orthoptic Department.

BACKGROUND: There is little research that examines the accuracy of paediatric referrals into secondary and tertiary care, particularly those from general practicioners (GPs) to ophthalmology and orthoptic departments. Inaccurate referrals could have a detrimental effect on service delivery and NHS funding as well as patient experience. Available evidence shows GP referral accuracy to range between 39% and 90% across different areas of medicine with accuracy of GP referral to ophthalmology between 56% and 66%. METHODS: A retrospective case note analysis was carried out on 99 case notes to examine the accuracy of paediatric GP referrals (including those via the community optometrist) into the Orthoptic Department at Manchester Royal Eye Hospital (MREH). RESULTS: GP referral accuracy was found to be 63% for strabismus cases, 50% for reduced vision/amblyopia cases, 45% for NAD cases, 100% of nystagmus cases and 92% of "other" cases. GPs were significantly less accurate than community optometrists (p = 0.01). Referrals from GPs alone had an accuracy rate of 65% compared to 87% of GP referral via community optometrist. Accuracy of referral appeared to improve with age, however this was not found to be statistically significant (p = 0.06). CONCLUSION: This study found orthoptic referral accuracy for GPs in Manchester to be similar to other areas of medicine. While acceptable compared to other areas of medicine, improving referral accuracy is essential to improve NHS spending, service delivery, and patient experience. To aid with this the aim is to design and implement a virtual training package that focuses on detection of strabismus to improve referral accuracy.

Orthoptic assessment of vision in patients with complex disability: the importance of understanding the patient's communication methods.

Care for children with acquired brain injury requires a multi-disciplinary team (MDT) to maximize rehabilitation. These children frequently present to the orthoptic clinic with complex difficulties impacting visual functions and eye movements. We report on one case which led to a reevaluation of our current assessment methods, clinical care pathways and the contents of clinic correspondence. We present a case report of a 14-year-old girl who suffered a cardiac arrest due to underlying Wolff-Parkinson-White syndrome; MRI revealed hypoxic brain injury with extensive white matter and basal ganglia volume loss. On presentation, it was evident there was a significant impact on visual function. Conventional optotype acuity testing was not possible. Her inability to maintain fixation made observational responses unreliable. Observations revealed no steady fixation, exotropia and roving eye movements. Although she was reported to be unable to speak, progress with communication was reported and she was able to give repeatable, reliable responses to indicate "yes" or "no." These cues were used and a response of 1.70 cycles per degree was obtained under binocular conditions. This communication method was also utilized to assess visual fields by confrontation. However, the clinic letter written by the ophthalmologist based on the orthoptic assessment simply provided the acuity score with no interpretation of the information or how it was obtained. This case highlighted the importance of understanding a child's communication methods so that assessment can be appropriately adapted. The referral letter was lacking in detail regarding the patient's abilities but equally the ophthalmology letter provided limited detail impacting on the MDT practitioner's ability to understand and apply the information. This case has highlighted the importance of good communication: professionals need to acknowledge and work with an individual's communication methods so that assessment can be completed. Professionals also need to improve communication of relevant findings to others involved in the patient's care.

Herpes simplex keratoconjunctivitis in the immediate postoperative period after strabismus surgery.

The authors describe the case of bilateral herpes simplex keratoconjunctivitis (HSK) following uncomplicated 7 mm bilateral lateral rectus recessions in a 3-year-old child. The recovery was initially unremarkable, and the standard postoperative drops of dexamethasone and chloramphenicol (non-preservative free) were prescribed. The child presented 8 days postoperatively with fever, right upper lid swelling and ptosis. She was admitted for intravenous antibiotics for suspected pre-septal cellulitis. Over the next 2 days, she deteriorated with bilateral lid involvement. An examination under anesthesia (EUA) revealed bilateral corneal epithelial (dendritic and geographical) ulcers with conjunctival erosions and pseudo membranes prompting a diagnosis of HSK. This was confirmed by polymerase chain reaction (PCR) testing. The child recovered within 2 weeks after starting oral and topical antiviral medication. This case highlights the importance of EUA in infections not responding to standard treatment. Although HSK is known to occur after topical steroid use and ocular surgery, we were not able to find any other cases in the literature and believe this is the first reported case of bilateral HSK in the immediate postoperative period after strabismus surgery.

Hematological predictors of mortality in neonates with fulminant necrotizing enterocolitis.

OBJECTIVE: Determine whether hematological and transfusion patterns following, the onset of NEC can identify infants likely to develop fulminant, fatal necrotizing enterocolitis (NEC). DESIGN: Determine hematological predictors of fulminant NEC. RESULTS: Of 336 neonates with NEC, 35 (10%) who developed fulminant NEC were born with higher birth weights and more frequently developed radiologically evident pneumoperitoneumand/or portal venous gas. Following the diagnosis of NEC, these infants were more likely to rapidly develop thrombocytopenia, lymphopenia, neutropenia, and lower total white blood cell counts compared to medical/surgical non-fulminant type. They were also more likely to have received a red blood cell (RBC) transfusion (76.7% vs. 53.1%, p = 0.001) within 48 h after disease onset and platelet transfusion (24.2% vs. 11.7%; p = 0.03) before the onset of NEC. CONCLUSION: Neonates with fulminant NEC frequently developed thrombocytopenia, lymphopenia, neutropenia, and leukopenia, received RBC transfusions after or platelet transfusions before the onset of NEC developed the fulminant disease.

Strabismus Surgery for Esotropia, Down Syndrome and Developmental Delay; Is an Altered Surgical Dose Required? A Literature Review.

BACKGROUND AND PURPOSE: There is a high rate of strabismus, in particular esotropia, in children with Down syndrome or developmental delay, which frequently requires surgical correction. A paper in 1994 advocated that the surgical dose be adjusted due to an altered response in these children. The aim of this literature review is to evaluate the available evidence to establish whether an altered surgical approach is required in either population. METHODS: A literature review was conducted using PubMed and Web of Knowledge. Only English language papers were eligible for inclusion. The papers were collated in chronological order for analysis, and their references searched for further relevant papers. Forward citation searches were also undertaken. RESULTS: A 2 × 2 comparison is made between publications on Down syndrome (in isolation) and developmental delay populations (including Down syndrome) with adjusted versus non-adjusted surgery. Published surgical success rates on esotropia from unaltered surgical doses range from 62.0%-85.7% (four papers) in the Down syndrome cohort, with none of the adjusted surgeries having a successful outcome. Surgical success rates from adjusted surgical doses in developmental delay cohort range from 37.5%-86.0% (seven papers), with one unadjusted surgical success rate of 76.0%. The results across the studies are summarised in a table and discussed. CONCLUSIONS: An exaggerated surgical effect in individuals with developmental delay has been reported, and this population may benefit from a reduced surgical dose. Published research does not support giving a reduced surgical dose in individuals with Down syndrome, but more research needs to be done to make a definitive conclusion.

Normative data for the redesigned Kay Pictures visual acuity test.

The Kay Picture Test of visual acuity is used extensively in the diagnosis and management of children. The test has been redesigned and validated to meet the international visual acuity chart guidelines, necessitating the collection of new normative data. The data presented here demonstrates that the visual acuities of children <60 months of age with no visual deficiency improve with age and show no significant intraocular difference. This is the first report of normative data in young children for the redesigned Kay Pictures Test (singles format).

The impact of foetal restrictions on mode of delivery in women with inherited bleeding disorders.

OBJECTIVES: Management of pregnancy in women with congenital bleeding disorders (CBD) is challenging and requires understanding of risks conferred to both the mother and the foetus. Some elements of labour management are considered to increase the risk of neonatal bleeding and are not recommended for neonates at risk of a significant bleeding disorder. The impact of these restrictions on obstetric outcomes in women with CBD is unknown. METHODS: We retrospectively reviewed obstetric outcomes in a large cohort of women with CBD attending a specialised obstetric/haematology antenatal clinic over a 6-year period. RESULTS: Ninety-four pregnancies in 76 women with a wide variety of CBDs were assessed. Foetal precautions were recommended in the majority of cases (88%). Twenty (21.2%) were delivered by elective Caesarean section (CS), predominantly for obstetric indications. Of the 63 women who laboured with foetal precautions in place, 6 (10%) had a CS that was performed because of these precautions. There was no neonatal bleeding but primary postpartum haemorrhage (PPH) occurred in 12.2% of women. CONCLUSIONS: These data show that foetal precautions in labour recommended for women with CBDs will influence mode of delivery in approximately 10% of cases. This is important information for counselling these women about labour and delivery.

Analgesia, anaesthesia and obstetric outcome in women with inherited bleeding disorders.

OBJECTIVE: Vertebral canal haematoma (VCH) complicates 1 in 168,000 obstetric epidurals (Ruppen et al., 2006). This risk is increased in women with inherited bleeding disorders (IBD). The impact of a contraindication to regional anaesthesia on pain management and obstetric outcome in these women is unknown. The purpose of this study was to determine anaesthetic use and obstetric outcomes in a cohort of women with IBD. STUDY DESIGN: 97 women with IBD that delivered 130 babies at the CWIUH from Jan 2011 to Dec 2016 were identified from a maternal medicine database. Multidisciplinary planning of peripartum care was communicated to labour ward staff using a simple checklist. The primary bleeding disorders were: Von Willebrands disease (VWD) Type 1 27 (27.8%); VWD Type 2A 3 (3.8%); Low VWF 3 (3.8%); Bleeding disorder of unknown aetiology (BDUA) 19 (19.6%); deficiency of Factors VII, VIII, IX, X, and XI 13 (13.4%); Carriers of Factor VIII, IX, X, XIII deficiency 17 (17.5%); 5 had combined deficiencies (5.2%) and there was one platelet function defect. 9 had a family history of a bleeding disorder (9.3%). Haemostatic support, analgesia, mode of delivery and maternal and fetal outcomes were compared between pregnancies where regional anaesthesia was permitted and those that were not using the Chi-squared test. RESULTS: When pregnancies where regional anaesthesia was not recommended (49) were compared with pregnancies where regional anaesthesia was considered safe (81), the women were more likely to see an anaesthetist before labour 46 (94%) vs 46 (61%): p < 0.001; to require prophylactic haemostatic support for delivery 30 (61%) vs 1 (1%): p < 0.001; to use a remifentanil infusion 15 (31%) vs 0: p < 0.001, and have general anaesthesia for Caesarean Section (CS) 10 (20%) vs 1(1%): p < 0.001. Vaginal birth 35 (71%) vs 53(65%): p = 0.4 and CS rates 14 (29%) vs 26 (32%) p = 0.28 were similar. Postpartum haemorrhage (PPH) was more common 11 (24%) vs 9(12%) vs p = 0.07 but not statistically so. There were no cases of neonatal bleeding or VCH. CONCLUSION: Contraindication to neuraxial blockade in labouring women with IBD does not influence mode of delivery. This information is reassuring to these women who may be anxious about delivery without regional anaesthesia.

The effect of induced fusional demand on static and dynamic stereoacuity thresholds: the digital Synoptophore.

BACKGROUND/AIMS: The ability to extract depth from disparity may be hindered under fusional stress, as alignment of the eyes may be more difficult to maintain consistently. Therefore we aim to determine the effect of fusional demand on stereoacuity in individuals with no known binocular vision impairments. METHODS: A novel static and dynamic binocular depth detection task, capable of assessing many discrete levels of stereoacuity, was presented on digital displays attached to each tube of the Synoptophore. Stereoacuity was measured with any latent deviation fully corrected and compared to that measured at the 'recovery' angle. This recovery angle is where single vision is restored after decompensation to diplopia, during vergence range assessment. RESULTS: Seventy-two subjects (50 Female, 22 Male; mean (SD) age 22 (6) years) were assessed. The amount of fusional demand was between 1 and 26 prism dioptres (PD), with a mean (SD) of 8(6)PD. Under zero fusion demand the mean (SD) static and dynamic depth detection thresholds were 322(53)" and 69(23)". Under fusional stress these were 224(40)" and 77(21)". There was no significant difference between thresholds in stressed and zero demand fusion (p = 0.08). Dynamic depth detection thresholds were significantly lower than static (P < 0.01). CONCLUSION: Fusional stress does not appear to impact on stereoacuity. The numerical value of the recovery point varied amongst individuals, but this represents a common point, where single vision is easily restored and binocularity well established. Due to individual differences in the ability to control a certain amount of fusional stress (e.g. vergences stress of 10PD, when recovery is 8PD, will perturb binocularity more than a person with a recovery of 20PD), previous reports may not accurately represent the effect of fusional stress. Whilst our findings are contrary to previous reports, we did not stress fusion beyond the recovery point and used a more accurate/repeatable method to measure stereoacuity.