Analysing barriers to service improvement using a multi-level theory of innovation: the case of glaucoma outpatient clinics

The development and implementation of innovation by healthcare providers is understood as a multi-determinant and multi-level process. Theories at different analytical levels (i.e. micro and organisational) are needed to capture the processes that influence innovation by provide. This article combines a micro theory of innovation, actor-network theory, with organisational level processes using the 'resource based view of the firm'. It examines the influence of, and interplay between, innovation-seeking teams (micro) and underlying organisational capabilities (meso) during innovation processes. We used ethnographic methods to study service innovations in relation to ophthalmology services run by a specialist English NHS Trust at multiple locations. Operational research techniques were used to support the ethnographic methods by mapping the care process in the existing and redesigned clinics. Deficiencies in organisational capabilities for supporting innovation were identified, including manager-clinician relations and organisation-wide resources. The article concludes that actor-network theory can be combined with the resource-based view to highlight the influence of organisational capabilities on the management of innovation. Equally, actor-network theory helps to address the lack of theory in the resource-based view on the micro practices of implementing change

In vivo imaging of the lamina cribrosa

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Avoidable sight loss from glaucoma:is it unavoidable?

Aims: To review the characteristics of patients attending a tertiary ophthalmic referral centre certified as sight impaired (SI) or severely sight impaired (SSI) from glaucoma. Methods: One hundred consecutive patients certified SI/SSI from the Glaucoma Service at Moorfields Eye Hospital, London, from January 2007 were identified from the England and Wales certification of visual impairment database. Clinical and demographic data were collected from hospital case records. Results: The median (IQR) age of patients at presentation was 66.3 (55.6 to 75.3) years; median (IQR) interval to certification was 62.2 (22.5 to 129.3) months. Fifty-seven patients presented with bilateral SSI (median (IQR) age 70.4 (59.0 to 76.9) years); interval to certification was 35.4 (5.6 to 78.1) months. Seventeen patients presented with a bilateral SI (median (IQR) age 62.1 (58.7 to 68.4) years; median (IQR) interval to certification: 137.4 (64.4 to 190.4) months). Twentyeight patients showed disease progression while under National Health Service hospital eye service care, five of whom had no certifiable visual impairment in either eye at presentation. This was attributed to inadequate intraocular pressure control; five of these patients (18%) were deemed poorly compliant to topical hypotensive medication. Conclusions: Over 80% patients on the certification of visual impairment register from Moorfields Eye Hospital with glaucoma as the primary cause had a significant visual disability at presentation, with almost two-thirds of patients presenting bilaterally 'blind'. There appear to be delays to certification. Despite being under the hospital eye service, a number of glaucoma patients still progress to certifiable visual impairment

Quality of Life in the Tube Versus Trabeculectomy Study

To report the vision-specific quality-of-life (QoL) outcomes in the Tube Versus Trabeculectomy (TVT) Study. Multicenter randomized clinical trial. Setting: Seventeen clinical centers. Patients 18-85 years of age with medically uncontrolled glaucoma who had previous cataract and/or glaucoma surgery. Tube shunt (350-mm Baerveldt glaucoma implant) or trabeculectomy with MMC. Vision-specific QoL using the NEI VFQ-25 and estimation of minimally important differences (MID) were the main outcome measures. Cross-sectional distribution- and anchor-based approaches were used to estimate MID. Clinical anchor measures included the mean deviation (MD) and logMAR visual acuity (VA) measurements. Clinically significant changes in anchor were defined as ≥2 dB MD and ≥0.2 logMAR. No significant differences in composite scores were observed between treatment groups, and no significant change in scores were seen over time. Mean (SD; range) values of clinical anchors at baseline were -16.6 (9.3; -32 to -0.5) dB for the surgical eye and 0.2 (0.3; -0.1 to 1.3) logMAR VA in the better-vision eye. For anchor-based cross-sectional analysis, composite score MID (95% CI) was 6.3 (4.6-7.9) for better-eye VA and 1.4 (0.9-1.9) for surgical eye MD. Distribution-based MID for the composite score was 6.0. Trabeculectomy and tube shunt surgery had similar impact on patient-reported vision-specific QoL measured using the NEI VFQ-25. In this cohort of patients with advanced glaucoma, MIDs varied depending on the clinical anchor used. Distribution-based MIDs corresponded well with anchor-based MIDs based on VA measures. The MID values reported here may be useful for others wishing to interpret NEI VFQ-25 scores in their advanced glaucoma patient cohort

The functional consequences of glaucoma for eye-hand coordination

PURPOSE. To examine whether patients with glaucoma exhibit differences in visually guided reaching-and-grasping (prehension) behavior compared with normally sighted control subjects. METHODS. Sixteen patients with glaucoma and 16 control subjects with no ocular disease participated. Participants were required to reach out and precision grasp one of two cylindrical objects placed on a table top in front of them in laboratory conditions in three viewing conditions (binocular, right eye alone, left eye alone). Lightweight reflective markers were placed on the subject’s preferred hand for recording its movement in three-dimensional space. Three motion capture units recorded the motion of these markers as the subjects reached out and precision grasped household objects. Various indices of prehension planning, execution, and control were quantified. Visual fields (VF) were measured using standard automated perimetry generating monocular mean deviation (MD) scores. Binocular VF sensitivity was estimated by using the integrated visual field (IVF). Stereoacuity was measured with the Frisby stereoacuity test. Significant differences in prehension movement between patients and control subjects in each viewing condition were investigated, and associations between prehension kinematics and VF sensitivity were examined. RESULTS. The patients and control subjects were of a similar age (median [range]: patient group, 72.2 years [62.5–86.9]; control group, 69.0 years [64.3–78.3]). The patient group had asymmetrical disease and relatively minor binocular overlapping defects (better eye MD, −5.7 dB [−16.7 to +0.45 dB]; worse eye MD, −11.8 dB [−29.3 to −1.5 dB]; IVF score, 3 [0–36]). They exhibited slightly poorer stereoacuity levels than did the control subjects (patient group, 55 sec arc [40–110]; control group, 40 sec arc [20–80; Mann-Whitney U test, P < 0.05]). They also showed statistically significant delays in average movement onset (MO: ∼100 ms delay, Mann-Whitney U test P < 0.0001) and overall movement time (OMD: ∼140 ms delay; Mann-Whitney U test P < 0.05), suggesting impairments in initial movement planning and control. Deficits were exhibited in the reaching component, with data suggesting that glaucomatous patients made more tentative movements when reaching for the object. These deficits correlated with both increasing severity of VF defect and impaired stereoacuity. There were no differences in grasping characteristics between patients and control subjects in this sample. CONCLUSIONS. This study provides evidence that patients with glaucoma exhibit deficits in eye–hand coordination compared with the age-matched normally sighted control. Further study is needed to assess the specific effect of field loss location on prehension kinematics

Optic disc and visual field changes after trabeculectomy

PURPOSE. To assess the changes in optic nerve head (ONH) structure and visual field (VF) sensitivity over time in a cohort of patients with glaucoma after trabeculectomy.METHODS. The MoreFlow Medical Research Council 5-Flurouracil (5-FU) study was an 80-month prospective randomized controlled trial of per-operative 5-FU versus placebo on the outcomes of primary trabeculectomy. Before surgery, patients had ONH imaging with a retinal tomograph and full-threshold visual field testing. After surgery, ONH imaging was performed annually and VF testing at 4-month intervals. This analysis included only patients with a minimum of 3 years' postoperative ONH and VF data. ONH images were analyzed by linear regression of sector rim area (RA) over time with change defined as a significant slope >1% of baseline RA per year in any sector. VFs were analyzed with point-wise linear regression analysis (PLRA) techniques with the stringent three-omitting criteria used. Eyes were classed as progressing or not based on analysis with either technique. Patients' median IOP level, intervisit IOP fluctuation, and percentage reduction in IOP over the follow-up period were also determined.RESULTS. Two hundred fifty eyes of 250 patients were suitable for analysis. Of these, 70 (28%) eyes were deemed to show glaucoma progression approximately 5 years after surgery: 20 eyes by ONH alone, 35 by VF alone, and 15 by both methods. Of the 15 shown to be progressing by both ONH and VF analysis, only 7 (3% total cohort) showed congruity in the location of change. Eyes showing changes in both ONH and VF sensitivity had slightly higher median follow-up IOP (median IOP [interquartile range; IQR] nonprogressors 14.0 mm Hg [11.8-16.0 mm Hg], progressors 15.1 mm Hg [12.7-17.0 mm Hg]; Mann-Whitney U test [MWU]; P = 0.03) and lower degrees of IOP reduction from baseline (percentage IOP reduction [IQR]: nonprogressors -38.4% [-51.8% to -26.4%]; progressors -31.4% [-43.1% to -21.5%]; MWU P = 0.01) compared with eyes showing no progression.CONCLUSIONS. The study demonstrates that approximately one third of eyes continued to show progression of glaucoma at five years after trabeculectomy, as determined by trend-based analysis of ONH structural changes and VF sensitivity over time. The study suggests that the degree of IOP reduction after trabeculectomy may play an important role in the progression of glaucoma as detected by both functional and structural methods. (Invest Ophthalmol Vis Sci. 2009; 50: 4693-4699) DOI:10.1167/iovs.08-311

Changing trends in the incidence of bleb-related infection in trabeculectomy

Aim: To investigate the incidence of late onset blebrelated infection (BRI) following Mitomycin C (MMC) augmented trabeculectomy procedures at a single institution. Methods: This was a retrospective case series analysis of late onset BRI, defined as either blebitis or endophthalmitis occurring at least 1 month following a glaucoma filtration procedure. Data collected from hospital charts included the position of the conjunctival flap base. Two cohorts were examined: the first a sample of 194 intraoperative MMC augmented trabeculectomies undertaken over a 4-year period from 1993 to 1997, and the second a sample of 764 MMC trabeculectomies performed in a 4-year period between the years 1999 and 2005. Results: A total of 11 cases of BRI (cumulative incidence 5.7%) were identified in the cohort from 1993 to 1997. BRI cases had trabeculectomies performed with a limbus-based conjunctival flap and presented at a median IQR 14.8 (9.4-42.9) months after surgery. In the 1999-2005 cohort, nine cases of BRI were identified (cumulative incidence 1.2%). All these BRI cases had a fornix-based conjunctival flap and presented at a median IQR 19.2 (6.1-44.1) months after trabeculectomy surgery. Conclusion: This study found that the incidence of BRI was higher in MMC augmented trabeculectomy shortly after the introduction of MMC, but subsequently reduced to a lower level. While many changes in surgical technique had occurred in the intervening period, the most significant change was from limbus-based to fornix-based conjunctival flap. However, the retrospective nature of the study prevents the authors from concluding that there is a causative relationship between changes in surgical technique and BRI