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.

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.

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.

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.

Identification of a retrolental membrane during laser capsulotomy in eyes with a Hydroview intraocular lens.

We report our observation of a distinct membrane on the posterior surface of the Hydroview (Bausch & Lomb Surgical) intraocular lens during laser capsulotomy in 6 patients. In 3 patients, the retrolental membrane was noted during 4 to 6 weeks of follow-up after laser capsulotomy. The technique of a 2-stage laser capsulotomy in this group of patients is described. The possible cause and significance for this observation are also discussed.

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.

Validation of human whole blood oximetry, using a hyperspectral fundus camera with a model eye.

PURPOSE: To assess the accuracy of human blood oximetry measurements in a model eye with a hyperspectral fundus camera. METHODS: Seven human whole blood samples (two arterial, five venous) were obtained, the oxygen saturations measured with a CO oximeter, and the samples inserted into quartz tubes with internal diameters of 100 and 150 µm. The tubes (n = 20; ten 100 µm and ten 150 µm) were placed within a model eye in front of a background reflectance surface with reflectivities of 20%, 60%, and 99%. Spectral images at wavelengths between 500 and 650 nm were acquired with a hyperspectral fundus camera and analyzed with an oximetric model to calculate the oxygen saturation of blood within the tubes. The calculated oxygen saturations were compared with the measured oxygen saturations. The effects of the background reflectivity and tube size on the accuracy of the calculated oxygen saturations were evaluated. RESULTS: Background reflectivity and tube size had no significant effect on the mean oxygen saturation difference (P = 0.18 and P = 0.99, respectively; repeated-measures, two-way ANOVA). The mean differences (SD) between the measured and calculated oxygen saturations in segments of the 100 and 150 µm tubes overlying the 20%, 60%, and 99% background reflectivities were (100 µm) -4.0% (13.4%), -6.4% (9.9%), and -5.5% (10.2%) and (150 µm) -5.3% (10.8%), -5.2% (10.7%), and -5.2% (10.9%), respectively. CONCLUSIONS: There was reasonable agreement between the measured oxygen saturation values and those calculated by the oximetry model. The oximetry model could be used to determine the functional health of the retina.