Survival of medical treatment success in primary open-angle glaucoma and ocular hypertension.

BACKGROUND/AIMS: Topical agents to lower intraocular pressure (IOP) are the most common initial therapeutic measure in glaucoma prevention. This study aims to assess treatment success duration among patients initiating or intensifying topical glaucoma medication. METHODS: Medical records (2013‒2018) for adults initiating/intensifying topical glaucoma medication were extracted from five secondary-care and tertiary-care UK ophthalmology centres. Main study outcomes were time from treatment initiation/intensification to treatment failure (<20% IOP reduction or IOP >21 mm Hg at consecutive clinic visits, or intensification of glaucoma treatment) and time from treatment change to subsequent treatment intensification. RESULTS: Study eyes (n=6587) underwent treatment intensification 0-to-1 glaucoma drop (5358 events), 1-to-2 drops (1469 events) and 2-to-3 drops (857 events) during the observation period. Median time to treatment failure was 1.60 (95% CI 1.57 to 1.65), 1.00 (95% CI 0.94 to 1.07) and 0.92 (95% CI 0.81 to 1.02) years following escalation 0-to-1, 1-to-2 and 2-to-3 drops, respectively. Median time to treatment intensification (non-IOP-based criterion) was 4.68 (95% CI 4.50 to 5.08) years for treatment initiators, 3.83 (95% CI 3.36 to 4.08) years on escalation 1-to-2 drops and 4.35 (95% CI 3.82 to 4.88) years on escalation 2-to-3 drops. On multivariable regression, significant risk factors for both treatment failure and intensification were lower baseline visual field mean deviation, primary open-angle glaucoma and lower eyedrop count in the fellow eye; lower baseline IOP was associated with treatment failure, higher baseline IOP with treatment intensification. CONCLUSION: Large-scale survival analyses provide the expected duration of treatment success from topical glaucoma medication.

European Glaucoma Society - A guide on surgical innovation for glaucoma.

PROLOGUE: Glaucoma surgery has been, for many decades now, dominated by the universal gold standard which is trabeculectomy augmented with antimetabolites. Tubes also came into the scene to complement what we use to call conventional or traditional glaucoma surgery. More recently we experienced a changing glaucoma surgery environment with the "advent" of what we have become used to calling Minimally Invasive Glaucoma Surgery (MIGS). What is the unmet need, what is the gap that these newcomers aim to fill? Hippocrates taught us "bring benefit, not harm" and new glaucoma techniques and devices aim to provide safer surgery compared to conventional surgery. For the patient, but also for the clinician, safety is important. Is more safety achieved with new glaucoma surgery and, if so, is it associated with better, equivalent, or worse efficacy? Is new glaucoma surgery intended to replace conventional surgery or to complement it as an 'add-on' to what clinicians already have in their hands to manage glaucoma? Which surgery should be chosen for which patient? What are the options? Are they equivalent? These are too many questions for the clinician! What are the answers to the questions? What is the evidence to support answers? Do we need more evidence and how can we produce high-quality evidence? This EGS Guide explores the changing and challenging glaucoma surgery environment aiming to provide answers to these questions. The EGS uses four words to highlight a continuum: Innovation, Education, Communication, and Implementation. Translating innovation to successful implementation is crucially important and requires high-quality evidence to ensure steps forward to a positive impact on health care when it comes to implementation. The vision of EGS is to provide the best possible well-being and minimal glaucomainduced visual disability in individuals with glaucoma within an affordable healthcare system. In this regard, assessing the changes in glaucoma surgery is a pivotal contribution to better care. As mentioned, this Guide aims to provide answers to the crucial questions above. However, every clinician is aware that answers may differ for every person: an individualised approach is needed. Therefore, there will be no uniform answer for all situations and all patients. Clinicians would need, through the clinical method and possibly some algorithm, to reach answers and decisions at the individual level. In this regard, evidence is needed to support clinicians to make decisions. Of key importance in this Guide is to provide an overview of existing evidence on glaucoma surgery and specifically on recent innovations and novel devices, but also to set standards in surgical design and reporting for future studies on glaucoma surgical innovation. Designing studies in surgery is particularly challenging because of many subtle variations inherent to surgery and hence multiple factors involved in the outcome, but even more because one needs to define carefully outcomes relevant to the research question but also to the future translation into clinical practice. In addition this Guide aims to provide clinical recommendations on novel procedures already in use when insufficient evidence exists. EGS has a long tradition to provide guidance to the ophthalmic community in Europe and worldwide through the EGS Guidelines (now in their 5th Edition). The EGS leadership recognized that the changing environment in glaucoma surgery currently represents a major challenge for the clinician, needing specific guidance. Therefore, the decision was made to issue this Guide on Glaucoma Surgery in order to help clinicians to make appropriate decisions for their patients and also to provide the framework and guidance for researchers to improve the quality of evidence in future studies. Ultimately this Guide will support better Glaucoma Care in accordance with EGS's Vision and Mission. Fotis Topouzis EGS President

Burden of Glaucoma in the United Kingdom: A Multicenter Analysis of United Kingdom Glaucoma Services.

OBJECTIVE: To determine the spectrum of glaucoma-associated health care resource utilization among outpatients attending National Health Service (NHS) hospital glaucoma clinics and the costs of managing glaucoma in this setting. DESIGN: Retrospective observational cohort study using electronic medical record data. SUBJECTS: Patients aged ≥ 18 years attending 5 NHS glaucoma clinics in the United Kingdom (2013‒2018) with ≥ 12 months of continuous electronic medical record data. METHODS: Deidentified Medisoft Ophthalmology electronic medical record data (January 2013‒December 2018) from 43 742 eligible patients were categorized by year of clinic visit. Extracted information included patient demographics, glaucoma diagnoses, topical glaucoma medication prescription start/stop dates, types/numbers of glaucoma clinic visits, glaucoma investigations (visual acuity, intraocular pressure, visual field, and OCT), and glaucoma procedures received over 12 months after the first ("index") visit of the specified year. Direct glaucoma-related health care costs (clinic visits, investigations, procedures, and ongoing glaucoma medication initiated in the clinic) were estimated from event volumes and unit costs (UK national tariffs) and expressed from the direct-payer perspective. MAIN OUTCOME MEASURES: Glaucoma diagnoses and topical glaucoma medication use at the index clinic visit; numbers of glaucoma clinic visits, investigations and procedures; and glaucoma-related health care costs over 12 months postindex. RESULTS: For the 2016 cohort (n = 21 719), the estimated average total cost of NHS-provided glaucoma care over 12 months was £405 per patient (medical staff services £209, glaucoma investigations £126, glaucoma medication £40, glaucoma procedures £26). Among this cohort, 40.8% had ocular hypertension/suspected glaucoma, 70% had 0-to-mild visual field impairment, and 14% had undergone a glaucoma procedure. Over 12 months, patients received (mean) 2.0 glaucoma clinic visits and 1.5 visual field tests, and 7% underwent glaucoma procedure(s). Results were similar for the other years examined. CONCLUSIONS: Cost estimates for managing patients with glaucoma in the UK are required for effective service planning. Appreciable proportions of patients managed in NHS glaucoma clinics may be considered at low risk of blindness (glaucoma suspects and those with ocular hypertension with mild visual field loss) and may be more appropriately managed with alternative, more affordable models of care.

Combining Structural and Vascular Parameters to Discriminate Among Glaucoma Patients, Glaucoma Suspects, and Healthy Subjects.

Purpose: Compare the ability of peripapillary and macular structural parameters, vascular parameters, and their integration to discriminate among glaucoma, suspected glaucoma (GS), and healthy controls (HCs). Methods: In this study, 196 eyes of 119 patients with glaucoma (n = 81), patients with GS (n = 48), and HCs (n = 67) underwent optical coherence tomography (OCT) and OCT angiography to measure peripapillary retinal nerve fiber layer (pRNFL), macular ganglion cell-inner plexiform layer (mGCIPL) thicknesses, radial peripapillary capillary perfusion density (RPC-PD), and macular GCIPL perfusion density (GCIPL-PD). Parameters were integrated regionally with logistic regression and globally with machine learning algorithms. Diagnostic performances were evaluated with area under the receiver operating characteristic (AUROC) curves. Results: Patients with glaucoma had mild to moderate damage (median, -3.3 dB; interquartile range, -6.5 to -1.4). In discriminating between patients with glaucoma and the HCs, pRNFL thickness had higher AUROC curve values than RPC-PD for average (0.87 vs. 0.62; P < 0.001), superior (0.86 vs. 0.54; P < 0.001), inferior (0.90 vs. 0.71; P < 0.001), and temporal (0.65 vs. 0.51; P = 0.02) quadrants. mGCIPL thickness had higher AUROC curve values than GCIPL-PD for average (0.84 vs. 0.68; P < 0.001), superotemporal (0.76 vs. 0.65; P = 0.016), superior (0.72 vs. 0.57; P = 0.004), superonasal (0.70 vs. 0.56; P = 0.01), inferotemporal (0.90 vs. 0.72; P < 0.001), inferior (0.87 vs. 0.69; P < 0.001), and inferonasal (0.78 vs. 0.65, P = 0.012) sectors. All structural multisector indices had higher diagnostic ability than vascular ones (P < 0.001). Combined structural-vascular indices did not outperform structural indices. Similar results were found to discriminate glaucoma from GS. Conclusions: Combining structural and vascular parameters in a structural-vascular index does not improve diagnostic ability over structural parameters alone. Translational Relevance: OCT angiography does not add additional benefit to structural OCT in early to moderate glaucoma diagnosis.

Forecasting the COVID-19 Epidemic by Integrating Symptom Search Behavior Into Predictive Models: Infoveillance Study.

BACKGROUND: Previous studies have suggested associations between trends of web searches and COVID-19 traditional metrics. It remains unclear whether models incorporating trends of digital searches lead to better predictions. OBJECTIVE: The aim of this study is to investigate the relationship between Google Trends searches of symptoms associated with COVID-19 and confirmed COVID-19 cases and deaths. We aim to develop predictive models to forecast the COVID-19 epidemic based on a combination of Google Trends searches of symptoms and conventional COVID-19 metrics. METHODS: An open-access web application was developed to evaluate Google Trends and traditional COVID-19 metrics via an interactive framework based on principal component analysis (PCA) and time series modeling. The application facilitates the analysis of symptom search behavior associated with COVID-19 disease in 188 countries. In this study, we selected the data of nine countries as case studies to represent all continents. PCA was used to perform data dimensionality reduction, and three different time series models (error, trend, seasonality; autoregressive integrated moving average; and feed-forward neural network autoregression) were used to predict COVID-19 metrics in the upcoming 14 days. The models were compared in terms of prediction ability using the root mean square error (RMSE) of the first principal component (PC1). The predictive abilities of models generated with both Google Trends data and conventional COVID-19 metrics were compared with those fitted with conventional COVID-19 metrics only. RESULTS: The degree of correlation and the best time lag varied as a function of the selected country and topic searched; in general, the optimal time lag was within 15 days. Overall, predictions of PC1 based on both search terms and COVID-19 traditional metrics performed better than those not including Google searches (median 1.56, IQR 0.90-2.49 versus median 1.87, IQR 1.09-2.95, respectively), but the improvement in prediction varied as a function of the selected country and time frame. The best model varied as a function of country, time range, and period of time selected. Models based on a 7-day moving average led to considerably smaller RMSE values as opposed to those calculated with raw data (median 0.90, IQR 0.50-1.53 versus median 2.27, IQR 1.62-3.74, respectively). CONCLUSIONS: The inclusion of digital online searches in statistical models may improve the nowcasting and forecasting of the COVID-19 epidemic and could be used as one of the surveillance systems of COVID-19 disease. We provide a free web application operating with nearly real-time data that anyone can use to make predictions of outbreaks, improve estimates of the dynamics of ongoing epidemics, and predict future or rebound waves.

Comparison of preserved bimatoprost 0.01% with preservative-free tafluprost: A randomised, investigator-masked, 3-month crossover, multicentre trial, SPORT II.

IMPORTANCE: This study compares the efficacy and tolerability of a preservative-free prostaglandin analogue (tafluprost 15 mg/ml) to a prostaglandin analogue that uses 0.02% of benzalkonium chloride (bimatoprost 0.1 mg/ml). BACKGROUND: Different prostaglandin analogues have been commercially approved, with differences in tolerability. DESIGN: Prospective, randomised, investigator-masked, 3-month crossover, multicentre trial. PARTICIPANTS: Sixty-four patients with ocular hypertension or open-angle glaucoma were randomised to two groups, after a 4-week washout period from their current topical drop regimen. METHODS: Participants were randomised to tafluprost (Group 1; n = 33) or bimatoprost (Group 2; n = 31). At month 3, each group switched to the opposite treatment. IOP was evaluated at multiple timepoints. MAIN OUTCOME MEASURES: The primary outcome was difference in mean IOP between the two groups at the final visit. Secondary outcomes included change from baseline IOP at month 3 and month 6, difference in mean IOP at month 3 and difference in IOP at all timepoints. Safety outcomes included best-corrected visual acuity (BCVA), adverse events, ocular tolerability, optic nerve assessment and slit lamp biomicroscopy. RESULTS: Both medications significantly lowered IOP at month 6 compared to baseline: 5.4 mmHg (27%) for tafluprost and 6.8 mmHg (33%) for bimatoprost (p < 0.0001). No significant differences in any of the safety measures (including conjunctival hypearemia) were detected. CONCLUSIONS AND RELEVANCE: Bimatoprost produced a statistically significant greater IOP reduction compared to tafluprost with minimal to no difference in side effects. This should be borne in mind when weighing up the pros and cons of preserved versus preservative-free prostaglandin analogue therapy. CLINICALTRIALS.GOV IDENTIFIER: NCT02471105.

Real-World Outcomes of Selective Laser Trabeculoplasty in the United Kingdom.

PURPOSE: Selective laser trabeculoplasty (SLT) is a common treatment option for managing glaucoma and ocular hypertension. We assessed the real-world effectiveness of SLT and baseline factors associated with treatment success in the United Kingdom. DESIGN: Retrospective observational study of de-identified electronic medical records (Medisoft Glaucoma module [Medisoft Ltd, Leeds, UK]) from 5 UK ophthalmology teaching centers. PARTICIPANTS: Adult patients undergoing their first recorded SLT. For bilateral SLT (same day), analyses included 1 randomly selected eye. METHODS: Patient demographics, procedure details, and clinical outcomes data were extracted. Factors associated with treatment success were assessed using multivariable Cox regression. MAIN OUTCOME MEASURES: Change from baseline in intraocular pressure (IOP) and glaucoma medication use at 12 to 18 and 24 to 36 months post-SLT. A Kaplan-Meier survival analysis was also conducted. Failure of SLT was defined as any further glaucoma procedure post-SLT or any of the following at 2 consecutive visits: IOP >21 mmHg, IOP reduction <20% from baseline, or increase in glaucoma medications from baseline. RESULTS: A total of 831 SLT-treated eyes (mean baseline IOP 22.0 mmHg) of 831 patients were analyzed. At 12 to 18 and 24 to 36 months post-SLT, respectively, significant reductions in IOP (-4.2 [95% confidence interval {CI}, -4.7 to -3.7] and -3.4 [95% CI, -4.1 to -2.7] mmHg; both P < 0.0001) and significant increases in the number of glaucoma medications (0.13 [95% CI, 0.04-0.23], P = 0.007, and 0.20 [95% CI, 0.06-0.33], P = 0.005) were observed. Survival analysis demonstrated treatment success in 70%, 45%, and 27% of eyes at 6, 12, and 24 months post-SLT, respectively. Higher baseline IOP was strongly associated with treatment success (hazard ratio [HR], 0.67 for baseline IOP >21 mmHg vs. ≤21 mmHg, 95% CI, 0.57-0.80; P < 0.001). Selective laser trabeculoplasty success was not significantly associated with age (P = 0.78), baseline visual field mean deviation (P = 1.00), or concurrent use of IOP-lowering medication (P = 0.52). CONCLUSIONS: Most patients initially responded to SLT, but the majority failed within 1 year. Efficacy of SLT was better in patients with higher baseline IOP but did not differ by glaucoma severity or concurrent use of IOP-lowering medication. These findings may help inform which patients are suitable for SLT therapy.

Ophthalmic simulated surgical competency assessment rubric (Sim-OSSCAR) for trabeculectomy.

BACKGROUND/AIMS: To develop, test and determine whether a surgical-competency assessment tool for simulated glaucoma surgery is valid. METHODS: The trabeculectomy ophthalmic simulated surgical competency assessment rubric (Sim-OSSCAR) was assessed for face and content validity with a large international group of expert eye surgeons. Cohorts of novice and competent surgeons were invited to perform anonymised simulation trabeculectomy surgery, which was marked using the Sim-OSSCAR in a masked fashion by a panel of four expert surgeons. Construct validity was assessed using a Wilcoxon rank-sum test. Krippendorff's alpha was calculated for interobserver reliability. RESULTS: For the Sim-OSSCAR for trabeculectomy, 58 of 67 surgeons (86.6%) either agreed or strongly agreed that the Sim-OSSCAR is an appropriate way to assess trainees' surgical skill. Face validity was rated as 4.04 (out of 5.00). Fifty-seven of 71 surgeons (80.3%) either agreed or strongly agreed that the Sim-OSSCAR contents represented the surgical technique of surgical trabeculectomy. Content validity was rated as 4.00. Wilcoxon rank-sum test showed that competent surgeons perform better than novices (p=0.02). Interobserver reliability was rated >0.60 (Krippendorff's alpha) in 19 of 20 steps of the Sim-OSSCAR. CONCLUSION: The Sim-OSSCAR for trabeculectomy, a newly developed and validated assessment tool for simulation glaucoma surgery, has validity and reliability. It has the potential to play a useful role in ophthalmic surgical education.

A Comparison of Deep Sclerectomy Trainer Versus Trainee Outcomes.

PURPOSE: The aim of this study was to compare the results of deep sclerectomy (DS) and combined deep sclerectomy with phacoemulsification (phaco-DS) performed by clinical fellows with those by an experienced glaucoma surgeon and DS trainer. PATIENTS AND METHODS: This is a retrospective nonrandomized study of 266 eyes of 226 consecutive patients who had DS or phaco-DS between March 2014 and December 2016 which were included from a database of all glaucoma surgery performed in our department. A minimum of 9 months follow-up was required. The cases were recorded as to whether a fellow or consultant performed the entire procedure. Overall, 114 surgeries were performed by the consultant and 164 surgeries were performed by the fellow, in which 91 cases received no assistance from the consultant. Intraocular pressure (IOP) success criteria were: (A) IOP<22 mm Hg and/or 20% decrease from baseline off any glaucoma medications and (B) IOP<16 mm Hg and/or 30% drop from baseline off any glaucoma medications. RESULTS: No statistically significant difference was noted by any criteria (P<0.05) between the 2 groups. The Kaplan-Meir IOP success rates at 2 years with criteria B (IOP<16 mm Hg without medications) were 64% for consultant, 76% for independent surgeries done by a fellow and 72% for surgeries with assistance from the consultant trainer (P=0.15). There were no significant differences between measured IOPs at any time after surgery. Intraoperative perforation of trabeculo-Descemet membrane was noted in 4 cases (3.5%) done by the consultant and 12 cases (7.3%) performed by fellows (Fisher exact P=0.19). CONCLUSIONS: IOP outcomes of DS and phaco-DS were not adversely affected if fellows performed surgery, whether under supervision or independently.

Latanoprost for open-angle glaucoma (UKGTS): a randomised, multicentre, placebo-controlled trial.

BACKGROUND: Treatments for open-angle glaucoma aim to prevent vision loss through lowering of intraocular pressure, but to our knowledge no placebo-controlled trials have assessed visual function preservation, and the observation periods of previous (unmasked) trials have typically been at least 5 years. We assessed vision preservation in patients given latanoprost compared with those given placebo. METHODS: In this randomised, triple-masked, placebo-controlled trial, we enrolled patients with newly diagnosed open-angle glaucoma at ten UK centres (tertiary referral centres, teaching hospitals, and district general hospitals). Eligible patients were randomly allocated (1:1) with a website-generated randomisation schedule, stratified by centre and with a permuted block design, to receive either latanoprost 0·005% (intervention group) or placebo (control group) eye drops. Drops were administered from identical bottles, once a day, to both eyes. The primary outcome was time to visual field deterioration within 24 months. Analyses were done in all individuals with follow-up data. The Data and Safety Monitoring Committee (DSMC) recommended stopping the trial on Jan 6, 2011 (last patient visit July, 2011), after an interim analysis, and suggested a change in primary outcome from the difference in proportions of patients with incident progression between groups to time to visual field deterioration within 24 months. This trial is registered, number ISRCTN96423140. FINDINGS: We enrolled 516 individuals between Dec 1, 2006, and March 16, 2010. Baseline mean intraocular pressure was 19·6 mm Hg (SD 4·6) in 258 patients in the latanoprost group and 20·1 mm Hg (4·8) in 258 controls. At 24 months, mean reduction in intraocular pressure was 3·8 mm Hg (4·0) in 231 patients assessed in the latanoprost group and 0·9 mm Hg (3·8) in 230 patients assessed in the placebo group. Visual field preservation was significantly longer in the latanoprost group than in the placebo group: adjusted hazard ratio (HR) 0·44 (95% CI 0·28-0·69; p=0·0003). We noted 18 serious adverse events, none attributable to the study drug. INTERPRETATION: This is the first randomised placebo-controlled trial to show preservation of the visual field with an intraocular-pressure-lowering drug in patients with open-angle glaucoma. The study design enabled significant differences in vision to be assessed in a relatively short observation period. FUNDING: Pfizer, UK National Institute for Health Research Biomedical Research Centre.

Ultrasound-guided multilevel paravertebral blocks and total intravenous anesthesia improve the quality of recovery after ambulatory breast tumor resection.

BACKGROUND: Regional anesthesia improves postoperative analgesia and enhances quality of recovery (QoR) after ambulatory surgery. This randomized, double-blinded, parallel-group, placebo-controlled trial examines the effects of multilevel ultrasound-guided paravertebral blocks (PVBs) and total intravenous anesthesia on QoR after ambulatory breast tumor resection. METHODS: Sixty-six women were randomized to standardized general anesthesia (control group) or PVBs and propofol-based total intravenous anesthesia (PVB group). The PVB group received T1-T5 PVBs with 5 ml of 0.5% ropivacaine per level, whereas the control group received sham subcutaneous injections. Postoperative QoR was designated as the primary outcome. The 29-item ambulatory QoR tool was administered in the preadmission clinic, before discharge, and on postoperative days 2, 4, and 7. Secondary outcomes included block success, pain scores, intra- and postoperative morphine consumption, time to rescue analgesia, incidence of nausea and vomiting, and hospital discharge time. RESULTS: Data from sixty-four patients were analyzed. The PVB group had higher QoR scores than control group upon discharge (146 vs. 131; P < 0.0001) and on postoperative day 2 (145 vs. 135; P = 0.013); improvements beyond postoperative day 2 lacked statistical significance. None of the PVB group patients required conversion to inhalation gas-based general anesthesia or experienced block-related complications. PVB group patients had improved pain scores on postanesthesia care unit admission and discharge, hospital discharge, and postoperative day 2; their intraoperative morphine consumption, incidence of nausea and vomiting, and discharge time were also reduced. CONCLUSION: Combining multilevel PVBs with total intravenous anesthesia provides reliable anesthesia, improves postoperative analgesia, enhances QoR, and expedites discharge compared with inhalational gas- and opioid-based general anesthesia for ambulatory breast tumor resection.

Examining visual field loss in patients in glaucoma clinics during their predicted remaining lifetime.

PURPOSE: To evaluate the proportion of patients in glaucoma clinics progressing at rates that would result in visual disability within their expected lifetime. METHODS: This retrospective study used visual field (VF) series of at least 3 years' duration from 3790 UK patients in glaucoma clinics calculating rates of loss for each eye using linear regression of mean deviation (MD) over time. Residual life expectancies derived from the UK Office of National Statistics actuarial tables for each patient were combined with these rates to estimate predicted MDs at end of expected lifetime. The proportion of patients projected to progress to visual impairment (MD: -14 dB or worse) or statutory blindness (MD: -22 dB or worse) in both eyes before end of expected lifetime was calculated. RESULTS: Only 3.0% (95% confidence interval [CI] 2.7%-3.4%) of patient eyes progressed at faster than -1.5 dB/year (n = 7149 eyes). Of those patients with both eyes followed, 5.2% (CI 4.5%-6.0%) were predicted to progress to statutory blindness, with a further 10.4% (CI 9.4%-11.4%) reaching visual impairment in their lifetime. More than 90% (CI 85.7%-94.3%) of patients predicted to progress to statutory blindness, had an MD worse than -6 dB in at least one eye at presentation. CONCLUSIONS: This modeling exercise indicates that most patients in glaucoma clinics are not at high risk of progressing to statutory blindness. The likelihood of patients suffering impairment in their lifetimes is linked to VF loss at presentation, which illuminates the importance of reliably detecting significant VF defects in primary care.

Assessment of acute mild hypoxia on retinal oxygen saturation using snapshot retinal oximetry.

PURPOSE: To study the effect of acute mild hypoxia on retinal oxygen saturation. METHODS: Spectral retinal images were acquired under normoxic and hypoxic conditions for 10 healthy human volunteers (six male, four female, aged 25 ± 5 years [mean ± SD]) using a modified fundus camera fitted with an image-replicating imaging spectrometer (IRIS). Acute, mild hypoxia was induced by changing the oxygen saturation of inhaled air from 21% to 15% using a hypoxia generator with subjects breathing the hypoxic gas mixture for 10 minutes. Peripheral arterial oxygen saturation of the subjects was monitored using fingertip-pulse oximetry. Images were processed to calculate oxygen saturation, arteriovenous difference in oxygen saturation, and vessel diameter. Data are presented as mean ± SD and were analyzed using paired sample t-test with significance accepted at P < 0.05. RESULTS: The retinal arterial and venous oxygen saturation was 98.5% ± 1.6% and 70.7% ± 2.7% during normoxia. A reduction in the fraction of inspired oxygen resulted in a decline (P < 0.001) in both retinal-arterial and venous oxygen saturation to 90.3% ± 2.0% and 62.4% ± 2.2%, respectively. The arteriovenous oxygen saturation difference in normoxia (27.8% ± 2.9%) and hypoxia (27.9% ± 2.1%) did not change. Retinal arteriolar and venular diameters increased (P < 0.001) by 4% and 3%, respectively, under hypoxia. CONCLUSIONS: The acute inhalation of a hypoxic gas mixture resulted in a decline in both retinal-arterial and venous saturation, while arteriovenous oxygen difference was maintained with an accompanying significant increase in retinal vessel diameter. This may suggest an autoregulatory response to acute mild hypoxia.

Trabeculectomy in the 21st century: a multicenter analysis.

OBJECTIVE: To evaluate the efficacy and safety of current trabeculectomy surgery in the United Kingdom. DESIGN: Cross-sectional, multicenter, retrospective follow-up. PARTICIPANTS: A total of 428 eyes of 395 patients. METHODS: Consecutive trabeculectomy cases with open-angle glaucoma and no previous incisional glaucoma surgery from 9 glaucoma units were evaluated retrospectively. Follow-up was a minimum of 2 years. MAIN OUTCOME MEASURES: Surgical success, intraocular pressure (IOP), visual acuity, complications, and interventions. Success was stratified according to IOP, use of hypotensive medications, bleb needling, and resuturing/revision for hypotony. Reoperation for glaucoma and loss of perception of light were classified as failures. RESULTS: Antifibrotics were used in 400 cases (93%): mitomycin C (MMC) in 271 (63%), 5-fluorouracil (5-FU) in 129 (30%), and no antifibrotic in 28 (7%). At 2 years, IOP (mean ± standard deviation) was 12.4 ± 4 mmHg, and 342 patients (80%) achieved an IOP ≤ 21 mmHg and 20% reduction of preoperative IOP without IOP-lowering medication, whereas 374 patients (87%) achieved an IOP ≤ 21 mmHg and 20% reduction of preoperative IOP overall. An IOP ≤18 mmHg and 20% reduction of preoperative IOP were achieved by 337 trabeculectomies (78%) without IOP-lowering treatment and by 367 trabeculectomies (86%) including hypotensive medication. Postoperative treatments included suture manipulation in 184 patients (43%), resuturing or revision for hypotony in 30 patients (7%), bleb needling in 71 patients (17%), and cataract extraction in 111 of 363 patients (31%). Subconjunctival 5-FU injection was performed postoperatively in 119 patients (28%). Visual loss of >2 Snellen lines occurred in 24 of 428 patients (5.6%). A total of 31 of the 428 patients (7.2%) had late-onset hypotony (IOP <6 mmHg after 6 months). In 3 of these, visual acuity decreased by >2 Snellen lines. Bleb leaks were observed in 59 cases (14%), 56 (95%) of which occurred within 3 months. Two patients developed blebitis. Bleb-related endophthalmitis developed in 1 patient within 1 month postoperatively and in 1 patient at 3 years. There was an endophthalmitis associated with subsequent cataract surgery. CONCLUSIONS: This survey shows that good trabeculectomy outcomes with low rates of surgical complications can be achieved, but intensive proactive postoperative care is required.

The effectiveness of schemes that refine referrals between primary and secondary care--the UK experience with glaucoma referrals: the Health Innovation & Education Cluster (HIEC) Glaucoma Pathways Project.

OBJECTIVES: A comparison of glaucoma referral refinement schemes (GRRS) in the UK during a time period of considerable change in national policy and guidance. DESIGN: Retrospective multisite review. SETTING: The outcomes of clinical examinations by optometrists with a specialist interest in glaucoma (OSIs) were compared with optometrists with no specialist interest in glaucoma (non-OSIs). Data from Huntingdon and Nottingham assessed non-OSI findings, while Manchester and Gloucestershire reviewed OSI findings. PARTICIPANTS: 1086 patients. 434 patients were from Huntingdon, 179 from Manchester, 204 from Gloucestershire and 269 from Nottingham. RESULTS: The first-visit discharge rate (FVDR) for all time periods for OSIs was 14.1% compared with 36.1% from non-OSIs (difference 22%, CI 16.9% to 26.7%; p<0.001). The FVDR increased after the April 2009 National Institute for Health and Clinical Excellence (NICE) glaucoma guidelines compared with pre-NICE, which was particularly evident when pre-NICE was compared with the current practice time period (OSIs 6.2-17.2%, difference 11%, CI -24.7% to 4.3%; p=0.18, non-OSIs 29.2-43.9%, difference 14.7%, CI -27.8% to -0.30%; p=0.03). Elevated intraocular pressure (IOP) was the commonest reason for referral for OSIs and non-OSIs, 28.7% and 36.1%, respectively, of total referrals. The proportion of referrals for elevated IOP increased from 10.9% pre-NICE to 28.0% post-NICE for OSIs, and from 19% to 45.1% for non-OSIs. CONCLUSIONS: In terms of 'demand management', OSIs can reduce FVDR of patients reviewed in secondary care; however, in terms of 'patient safety' this study also shows that overemphasis on IOP as a criterion for referral is having an adverse effect on both the non-OSIs and indeed the OSIs ability to detect glaucomatous optic nerve features. It is recommended that referral letters from non-OSIs be stratified for risk, directing high-risk patients straight to secondary care, and low-risk patients to OSIs.