There are a multitude of applications using modern tablet computers for vision testing that are accessible to ophthalmology patients. While these may be of potential future benefit, they are often unsupported by scientific assessment. This report investigates the pertinent physical characteristics behind one of the most common highest specification tablet computers with regard to its capacity for vision testing. We demonstrate through plotting of a gamma curve that it is feasible to produce a precise programmable range of central luminance levels on the device, even with varying background luminance levels. It may not be possible to display very low levels of contrast, but carefully using the gamma curve information allows a reasonable range of contrast sensitivity to be tested. When the screen is first powered on, it may require up to 15 min for the luminance values to stabilize. Finally, luminance of objects varies towards the edge of the screen and when viewed at an angle. However, the resulting effective contrast of objects is less variable. Details of our assessments are important to developers, users and prescribers of tablet clinical vision tests. Without awareness of such findings, these tests may never reach satisfactory levels of clinical validity and reliability.

Background: The effect of sarcopenia based on the total psoas muscle area (TPMA) on CT is inconclusive in patients undergoing abdominal aortic aneurysm (AAA) intervention. The aim of this prospective cohort study was to evaluate morphometric sarcopenia as a method of risk stratification in patients undergoing elective AAA intervention. Methods: TPMA was measured on preintervention CT images of patients undergoing elective endovascular aneurysm repair (EVAR) or open aneurysm repair. Mortality was assessed in relation to preintervention TPMA using Cox regression analysis, with calculation of hazard ratios at 30 days, 1 year and 4 years.Postintervention morbidity was evaluated in terms of postintervention care, duration of hospital stay and 30-day readmission. Changes in TPMA on surveillance EVAR imaging were also evaluated.Results: In total, 382 patient images acquired between March 2008 and December 2016 were analysed. There were no significant intraobserver and interobserver differences in measurements of TPMA. Preintervention TPMA failed to predict morbidity and mortality at all time points. The mean(s.d.) interval between preintervention and surveillance imaging was 361⋅3(111⋅2) days. A significant reduction in TPMA was observed in men on surveillance imaging after EVAR (mean reduction 0⋅63(1⋅43) cm 2 per m 2 ; P < 0⋅001). However, this was not associated with mortality (adjusted hazard ratio 1⋅00, 95 per cent c.i. 0⋅99 to 1⋅01; P = 0⋅935). Conclusion: TPMA is not a suitable risk stratification tool for patients undergoing effective intervention for AAA.

Purpose: The XenÒ Gel Stent (Allergan, Irvine, CA, USA) is a minimally invasive glaucoma surgery device implanted to reduce intra-ocular pressure (IOP) in glaucoma. The stents can fail to drain post-operatively due to scarring of the conjunctiva around the stent opening. Data on the success rates of revision surgery in patients with Xen stent failure are scarce. We present the first detailed report of the steps, outcomes and complications of Xen revision surgery with 12 months of follow-up data. Methods: We share our experiences on the circumstances in which to perform Xen revision surgery, the steps of the surgery and the results of a retrospective interventional case series of all Xen revisions performed at a single centre from 2013 to 2018. Results: A total of 151 Xen implants were inserted into eyes at our tertiary centre during the study period, of which 21 eyes (patients) underwent revision surgery. Mean pre-operative Enhanced Digital Features To view enhanced digital features for this article go to https://doi.org/10.6084/ m9.figshare.11771391.

Objective To explore self-inflicted retinal burns from laser pointers in children. Methods Literature review of laser pointer retinal injuries in childhood and online survey of UK Consultant Ophthalmologists. A cohort of local children with self-inflicted injury is described. The matter is topical. We review progress in recent legislation and policy change in the UK. Results Four of 77 case reports of laser burns in childhood analysed reported psychological or behavioural issues. Three of four children in our cohort had such issues. Delay in diagnosis occurred in two of our patients. Structural retinal damage persisted for over 12 months in all four children (seven eyes). Our survey of UK ophthalmologists found 159 cases of injury (85% male), 80% under 20 years of age. The majority of the laser pointers were purchased online. Many patients (36%) suffered moderate vision loss (6/18 to 6/60 Snellen), while 17% (at least 11 patients) suffered severe vision loss (<6/60 Snellen). Conclusion We highlight the risk of macular damage and vision loss from handheld lasers specifically in children with behavioural, learning or mental health issues. The diagnosis may be difficult or delayed in such children. In children with uncertain macular changes, ophthalmologists should explore the history for possible instances of exposure to handheld lasers pointers. Regulatory authorities and manufacturers of handheld lasers need to be aware of the risk to children. Furthermore, there is a need to better inform parents, carers and teachers of the risk of ocular self-injury from such lasers pointers.

Purpose: Patients with Stickler syndrome are at high risk of giant retinal tears (GRTs) and detachments. Vitreoretinal interventions can reduce this risk, but there is presently no consensus about the optimal prophylactic approach. The aim of our study was to determine whether 360°laser prophylaxis is a safe and effective procedure to prevent GRT detachments in patients with Stickler syndrome.Methods: Study subjects were recruited retrospectively through the databases of the vitreoretinal and ophthalmic genetic tertiary services in Manchester, United Kingdom. Clinical data were collected including on prophylactic intervention, the occurrence of retinal detachment, and the presence/type of retinal breaks.Results: One hundred thirteen eyes from 63 patients with Stickler syndrome were studied; 72.6% (82/113) of these eyes received 360°laser prophylaxis. Of these, 9% had a retinal detachment, but no GRTs occurred. Among the 27.4% (31/113) of eyes that had no prophylactic treatment, 23% suffered a retinal detachment and 42.9% of these were associated with a GRT.Conclusion: Patients who underwent laser prophylaxis had fewer retinal detachments and no GRTs during an average of 6.1 years of follow-up (median 5 years), suggesting that this is a safe and effective approach for individuals with Stickler syndrome.

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Purpose To report on the composition and performance of the portfolio of Ophthalmology research studies in the United Kingdom's National Institute for Health Research (NIHR) Clinical Research Network (UK CRN).Methods Ophthalmology studies open to recruitment between 1 April 2010 and 31 March 2018 were classified by: subspecialty, participant age, gender of Chief Investigator, involvement of genetic investigations, commercial/ non-commercial, interventional/observational design. Frequency distributions for each covariate and temporal variation in recruitment to time and target were analysed. Results Over 8 years, 137,377 participants were recruited (average of 15,457 participants/year; range: 5485-32,573) with growth by year in proportion of commercial studies and hospital participation in England (76% in 2017/18). Fourteen percent of studies had a genetic component and most studies (82%) included only adults. The majority of studies (41%) enrolled patients with retinal diseases, followed by glaucoma (17%), anterior segment and cataract (13%), and ocular inflammation (6%). Overall, 68% of non-commercial studies and 55% of commercial studies recruited within the anticipated time set by the study and also recruited to or exceeded the target number of participants. Conclusions High levels of clinical research activity, growth and improved performance have been observed in Ophthalmology in UK over the past 8 years. Some sub-specialties that carry substantial morbidity and a very high burden on NHS services are underrepresented and deserve more patient-centred research. Yet the NIHR and its CRN Ophthalmology National Specialty Group has enabled key steps in achieving the goal of embedding research into every day clinical care.

PurposeAlthough Chlamydia trachomatis and Neisseria gonorrhoeae are the commonest sexually transmitted infections in England, reports of ocular co-infection in the literature are limited. We report such a case which responded well to treatment, and discuss the literature and evidence currently available with regards to management of these cases.ObservationsThe patient is a 48-year-old bisexual gentleman who presented to the eye clinic of a UK hospital with redness, discharge and blurred vision in his left eye for one week. Initially he had mucopurulent discharge but his cornea was clear. He did not comply with prescribed treatment and returned two days later with bilateral symptoms and corneal thinning in his left eye peripherally.PCR tests for Chlamydia trachomatis and Neisseria gonorrhoeae were positive and the patient was commenced on intravenous ceftriaxone, oral and topical levofloxacin eye drops. After 48 hours of inpatient treatment the patient showed clinical improvement.Conclusions and importanceOphthalmologists should be aware of the possibility that Chlamydia trachomatis and Neisseria gonorrhoeae can cause co-infection in adult conjunctivitis, and of the straightforward method of treatment for such individuals. Delayed diagnosis and treatment of affected patients can lead to corneal complications and potential blindness. It is advisable to discuss these cases with the local microbiology service wherever possible, and referral to a sexual health service is imperative.