Personalising screening of sight-threatening diabetic retinopathy - qualitative evidence to inform effective implementation.

BACKGROUND: Internationally, systematic screening for sight-threatening diabetic retinopathy (STDR) usually includes annual recall. Researchers and policy-makers support extending screening intervals, citing evidence from observational studies with low incidence rates. However, there is little research around the acceptability to people with diabetes (PWD) and health care professionals (HCP) about changing eye screening intervals. METHODS: We conducted a qualitative study to explore issues surrounding acceptability and the barriers and enablers for changing from annual screening, using in-depth, semistructured interviews analysed using the constant comparative method. PWD were recruited from general practices and HCP from eye screening networks and related specialties in North West England using purposive sampling. Interviews were conducted prior to the commencement of and during a randomised controlled trial (RCT) comparing fixed annual with variable (6, 12 or 24 month) interval risk-based screening. RESULTS: Thirty PWD and 21 HCP participants were interviewed prior to and 30 PWD during the parallel RCT. The data suggests that a move to variable screening intervals was generally acceptable in principle, though highlighted significant concerns and challenges to successful implementation. The current annual interval was recognised as unsustainable against a backdrop of increasing diabetes prevalence. There were important caveats attached to acceptability and a need for clear safeguards around: the safety and reliability of calculating screening intervals, capturing all PWD, referral into screening of PWD with diabetic changes regardless of planned interval. For PWD the 6-month interval was perceived positively as medical reassurance, and the 12-month seen as usual treatment. Concerns were expressed by many HCP and PWD that a 2-year interval was too lengthy and was risky for detecting STDR. There were also concerns about a negative effect upon PWD care and increasing non-attendance rates. Amongst PWD, there was considerable conflation and misunderstanding about different eye-related appointments within the health care system. CONCLUSIONS: Implementing variable-interval screening into clinical practice is generally acceptable to PWD and HCP with important caveats, and misconceptions must be addressed. Clear safeguards against increasing non-attendance, loss of diabetes control and alternative referral pathways are required. For risk calculation systems to be safe, reliable monitoring and clear communication is required.

High prevalence in Malawi of sight-threatening retinopathy and visual impairment caused by diabetes: identification of population-specific targets for intervention.

AIMS: To report the prevalence of all grades of diabetic retinopathy and associations with demographic, clinical and biochemical variables in people with diabetes in Southern Malawi. METHODS: We report baseline data from a 24-month prospective cohort study. Subjects were systematically sampled from two hospital-based, primary care diabetes clinics. Visual acuity, glycaemic control, systolic blood pressure, HIV status, urine albumin-creatinine ratio, and haemoglobin and serum lipid levels were assessed. Retinopathy was graded at an accredited reading centre using modified Wisconsin grading of four-field mydriatic photographs. RESULTS: A total of 357 subjects were studied. Of these, 13.4% subjects were HIV-positive and 15.1% had anaemia. The overall prevalence rates of any retinopathy, sight-threatening diabetic retinopathy and proliferative retinopathy were 50.1% (95% CI 44.9-55.3), 29.4% (95% CI 24.7-34.1) and 7.3% (95% CI 4.6-10.0), respectively. In multivariate logistic analysis the presence of sight-threatening retinopathy was associated with duration of diabetes (odds ratio 1.11, 95% CI 1.05-1.17), HbA1c (odds ratio 1.31, 95% CI 1.13-1.50), systolic blood pressure (odds ratio 1.03, 95% CI 1.01-1.04), haemoglobin (odds ratio 0.98, 95% CI 0.96-0.99) and LDL cholesterol (odds ratio 1.63, 95% CI 1.18-2.25). No significant association with HIV status was observed. In all, 3.6 and 1.4% of people in our study cohort had visual acuity worse than 6/18 and 6/60 in the better eye, respectively. CONCLUSIONS: The present study found a prevalence of sight-threatening retinopathy in diabetes clinics in one Sub-Saharan African country of approximately four times that reported in recent European studies and a prevalence of proliferative retinopathy approximately 10 times higher. The association of sight-threatening retinopathy with lower haemoglobin level is a new finding. Our results highlight the urgent need for provision of services for retinopathy detection and management to avoid a large burden of vision loss.

Epidemiology of diabetic retinopathy and maculopathy in Africa: a systematic review.

AIM: To summarize findings from studies reporting the prevalence and incidence of diabetic retinopathy and diabetic maculopathy in African countries in light of the rising prevalence of diabetes mellitus. METHODS: Using a predefined search strategy, we systematically searched MEDLINE, EMBASE, Science Citation index and Conference Proceedings Citation index, African Index Medicus and the grey literature database 'OpenSIGLE' for studies published between January 1990 and February 2011. Included studies reported prevalence or incidence of diabetic retinopathy or diabetic maculopathy of subjects with diabetes resident in African countries. RESULTS: Sixty-two studies from 21 countries were included: three population-based surveys; two cohort studies; five case-control studies; 32 diabetes clinic-based, nine eye clinic-based and 11 other hospital-based surveys. Included studies varied considerably in terms of patient selection, method of assessing the eye and retinopathy classification. In population-based studies, the reported prevalence range in patients with diabetes for diabetic retinopathy was 30.2 to 31.6%, proliferative diabetic retinopathy 0.9 to 1.3%, and any maculopathy 1.2 to 4.5%. In diabetes clinic-based surveys, the reported prevalence range for diabetic retinopathy was 7.0 to 62.4%, proliferative diabetic retinopathy 0 to 6.9%, and any maculopathy 1.2 to 31.1%. No obvious association between prevalence and income level of the country was detected. CONCLUSIONS: Large, community-based cross-sectional and cohort studies are needed to investigate rates and determinants of prevalence of diabetic retinopathy, incidence and progression in Africa. Consensus is needed on the most appropriate methods of identification and classification of retinopathy for research and clinical practice. Estimates of prevalence of diabetic retinopathy, proliferative diabetic retinopathy and maculopathy are comparable with recent European and American studies.

Safety and acceptability of an organic light-emitting diode sleep mask as a potential therapy for retinal disease.

PurposeThe purpose of the study was to study the effect of an organic light-emitting diode sleep mask on daytime alertness, wellbeing, and retinal structure/function in healthy volunteers and in diabetic macular oedema (DMO).Patients and methodsHealthy volunteers in two groups, 18-30 yrs (A), 50-70 yrs (B) and people with DMO (C) wore masks (504 nm wavelength; 80 cd/m2 luminance; ≤8 h) nightly for 3 months followed by a 1-month recovery period. Changes from baseline were measured for (means): psychomotor vigilance task (PVT) (number of lapses (NL), response time (RT)), sleep, depression, psychological wellbeing (PW), visual acuity, contrast sensitivity, colour, electrophysiology, microperimetry, and retinal thickness on OCT.ResultsOf 60 participants, 16 (27%) withdrew, 8 (13%) before month 1, due to sleep disturbances and mask intolerance. About 36/55 (65%) who continued beyond month 1 reported ≥1 adverse event. At month 3 mean PVT worsened in Group A (RT (7.65%, P<0.001), NL (43.3%, P=0.005)) and mean PW worsened in all groups (A 28.0%, P=0.01, B 21.2%, P=0.03, C 12.8%, P<0.05). No other clinically significant safety signal was detected. Cysts reduced/resolved in the OCT subfield of maximal pathology in 67% Group C eyes. Thinning was greater at 3 and 4 months for greater baseline thickness (central subfield P<0.001, maximal P<0.05).ConclusionSleep masks showed no major safety signal apart from a small impairment of daytime alertness and a moderate effect on wellbeing. Masks were acceptable apart from in some healthy participants. Preliminary data suggest a beneficial effect on retinal thickness in DMO. This novel therapeutic approach is ready for large clinical trials.

Changes in optic nerve head blood flow in children with cerebral malaria and acute papilloedema.

OBJECTIVE: To investigate capillary blood flow in the optic nerve head (ONH) of children with cerebral malaria. METHODS: Malawian children with cerebral malaria admitted to a paediatric research ward were examined by direct and indirect ophthalmoscopy. ONH blood flow was measured using laser Doppler flowmetry (LDF) in suitable patients. Mean blood volume and velocity were obtained from 30 to 60 s recordings from the temporal ONH and used to calculate blood flow. These were compared with admission variables, funduscopic findings and disease outcomes. RESULTS: 45 children with cerebral malaria had LDF recordings; 6 subsequently died and 5 survivors had neurological sequelae. 12 (27%) had papilloedema. The mean microvascular blood volume was higher in patients with papilloedema (3.28 v 2.54 arbitrary units, p = 0.002). The blood velocity correlated directly with haematocrit (r = 0.46, p = 0.001) and inversely with blood glucose (r = -0.49, p = 0.001). CONCLUSION: The increase in ONH microvascular blood volume in papilloedema measured by LDF is consistent with current theories of pathogenesis of papilloedema. LDF has potential as a tool to distinguish papilloedema from pseudopapilloedematous disc swellings. The relationship between blood velocity and haematocrit may relate to levels of sequestration in cerebral malaria.

Cost-effectiveness of community versus hospital eye service follow-up for patients with quiescent treated age-related macular degeneration alongside the ECHoES randomised trial.

OBJECTIVES: To assess the cost-effectiveness of optometrist-led follow-up monitoring reviews for patients with quiescent neovascular age-related macular degeneration (nAMD) in community settings (including high street opticians) compared with ophthalmologist-led reviews in hospitals. DESIGN: A model-based cost-effectiveness analysis with a 4-week time horizon, based on a 'virtual' non-inferiority randomised trial designed to emulate a parallel group design. SETTING: A virtual internet-based clinical assessment, conducted at community optometry practices, and hospital ophthalmology clinics. PARTICIPANTS: Ophthalmologists with experience in the age-related macular degeneration service; fully qualified optometrists not participating in nAMD shared care schemes. INTERVENTIONS: The participating optometrists and ophthalmologists classified lesions from vignettes and were asked to judge whether any retreatment was required. Vignettes comprised clinical information, colour fundus photographs and optical coherence tomography images. Participants' classifications were validated against experts' classifications (reference standard). Resource use and cost information were attributed to these retreatment decisions. MAIN OUTCOME MEASURES: Correct classification of whether further treatment is needed, compared with a reference standard. RESULTS: The mean cost per assessment, including the subsequent care pathway, was £411 for optometrists and £397 for ophthalmologists: a cost difference of £13 (95% CI -£18 to £45). Optometrists were non-inferior to ophthalmologists with respect to the overall percentage of lesions correctly assessed (difference -1.0%; 95% CI -4.5% to 2.5%). CONCLUSIONS: In the base case analysis, the slightly larger number of incorrect retreatment decisions by optometrists led to marginally and non-significantly higher costs. Sensitivity analyses that reflected different practices across eye hospitals indicate that shared care pathways between optometrists and ophthalmologists can be identified which may reduce demands on scant hospital resources, although in light of the uncertainty around differences in outcome and cost it remains unclear whether the differences between the 2 care pathways are significant in economic terms. TRIAL REGISTRATION NUMBER: ISRCTN07479761; Pre-results.

The design and implementation of a study to investigate the effectiveness of community vs hospital eye service follow-up for patients with neovascular age-related macular degeneration with quiescent disease.

IntroductionStandard treatment for neovascular age-related macular degeneration (nAMD) is intravitreal injections of anti-VEGF drugs. Following multiple injections, nAMD lesions often become quiescent but there is a high risk of reactivation, and regular review by hospital ophthalmologists is the norm. The present trial examines the feasibility of community optometrists making lesion reactivation decisions.MethodsThe Effectiveness of Community vs Hospital Eye Service (ECHoES) trial is a virtual trial; lesion reactivation decisions were made about vignettes that comprised clinical data, colour fundus photographs, and optical coherence tomograms displayed on a web-based platform. Participants were either hospital ophthalmologists or community optometrists. All participants were provided with webinar training on the disease, its management, and assessment of the retinal imaging outputs. In a balanced design, 96 participants each assessed 42 vignettes; a total of 288 vignettes were assessed seven times by each professional group.The primary outcome is a participant's judgement of lesion reactivation compared with a reference standard. Secondary outcomes are the frequency of sight threatening errors; judgements about specific lesion components; participant-rated confidence in their decisions about the primary outcome; cost effectiveness of follow-up by optometrists rather than ophthalmologists.DiscussionThis trial addresses an important question for the NHS, namely whether, with appropriate training, community optometrists can make retreatment decisions for patients with nAMD to the same standard as hospital ophthalmologists. The trial employed a novel approach as participation was entirely through a web-based application; the trial required very few resources compared with those that would have been needed for a conventional randomised controlled clinical trial.

Verteporfin photodynamic therapy of choroidal neovascularization in angioid streaks: one-year results of a prospective case series.

PURPOSE: To report the 12-month results on the use of verteporfin photodynamic therapy (PDT) in the treatment of choroidal neovascularization (CNV) secondary to angioid streaks. STUDY DESIGN: Five-center prospective case series. METHODS: Patients with CNV secondary to angioid streaks who were treated with PDT were recruited and followed up at 3-month intervals for 12 months, with the addition of visits at 1.5 and 4.5 months if deemed appropriate by the investigator. Best-corrected visual acuity (BCVA) was measured at each visit after full refraction or with their current distance spectacles using Early Treatment Diabetic Retinopathy Study logarithm of the minimum angle of resolution charts. Stereoscopic fundus fluorescein angiography was used to determine baseline lesion characteristics and location. RESULTS: Twenty-two patients were recruited (23 eyes, 16 with subfoveal CNV and 7 with juxtafoveal; all classic no occult). Seventeen patients (77%) had angioid streaks secondary to pseudoxanthoma elasticum. In the subfoveal group, median BCVA at baseline was 49 letters (approximate Snellen equivalent, 20/100) and was 46 at 12 months (approximate Snellen equivalent, 20/125). Twelve of 16 eyes (75%) lost fewer than 8 letters, whereas 14 of 16 eyes (88%) lost fewer than 15 letters. The mean CNV greatest linear dimension (GLD) was 2520 microm at baseline. At 12 months, 7 of 16 eyes with subfoveal CNV at baseline were leaking (GLD = 3220 microm; P = 0.62). The mean number of treatments in the first 12 months was 2.9. In the juxtafoveal group, the median BCVA at baseline was 66 letters (approximate Snellen equivalent, 20/50) and was 51 letters at 12 months (approximate Snellen equivalent, 20/100). Two of 7 eyes (29%) gained 8 or more letters at the 12-month examination, whereas 4 of 7 eyes (57%) lost more than 15 letters. The mean CNV GLD at baseline was 1890 microm. At 12 months, 1 of 7 eyes with juxtafoveal CNV at baseline was leaking. Choroidal neovascularization progressed from juxtafoveal to subfoveal location during the follow-up period in 4 of 7 eyes. The mean number of treatments in the first 12 months was 3.4. No side effects were noted in either patient group. CONCLUSIONS: This small series suggests that treatment of CNV secondary to angioid streaks with verteporfin PDT seems to limit visual loss in most patients through the first 12 months of follow-up, particularly in those with subfoveal lesions at baseline.

Early electroretinography in unilateral central retinal vein occlusion as a predictor of rubeosis iridis.

Twenty-six patients with clinically nonischemic unilateral central retinal vein occlusion and four in whom clinical categorization was unclear were recruited. The scotopic electroretinogram (ERG) was recorded at presentation to a range of six different luminances. Patients were followed up for six months to assess the correlation between initial ERG response and subsequent outcome. Seven patients developed rubeosis iridis. The b-wave implicit time was the parameter most significantly associated with subsequent rubeosis, followed by b-wave/a-wave amplitude ratio and then b-wave amplitude. Neither a-wave amplitude nor implicit time was a valuable predictor. The b-wave implicit times were equally predictive of rubeosis at each of the luminances used. In individually affected eyes, a b-wave implicit time at presentation, averaged across the range of luminances used, of greater than 47.17 ms was strongly associated with later rubeosis, as was an intereye difference of greater than 7.39 ms.

Photographic and angiographic characterization of the retina of Kenyan children with severe malaria.

OBJECTIVE: To investigate retinal lesions in children with severe falciparum malaria. METHODS: Color photography and fluorescein angiography were performed in consecutive children admitted to a pediatric high-dependency unit in Kenya during 1 malaria season. The presence and category of retinal lesion was compared with disease severity, clinical outcome, anemia, lactic acidosis, and parasite count. RESULTS: Twenty-six patients with cerebral malaria and 14 patients who were prostrate were studied. Thirty-one of the patients had clinical features of ocular disease, including round, flame-shaped, and white-centered hemorrhages; peripheral and foveal retinal opacification; peripheral vascular occlusion; venous dilation; disc edema with hyperemia; and arterial pulsatility. Of 8 patients with retinal opacification, only 2 showed small, infrequent zones of capillary nonperfusion on fluorescein angiography; the leakage of dye at sites of opacification was not seen. Retinal opacification was significantly associated with a higher parasite count (P < .02). White-centered hemorrhages were significantly associated with a higher parasite count (P < .05), severe disease (p < .05), and severe anemia (P < .02). CONCLUSIONS: The blood-retina barrier and retinal vascular flow remain substantially normal despite widespread pathological features. Retinal features in children with severe malaria are consistent with cellular hypoxia, nutritional deficiency, or both rather than with vascular occlusion; they support the concept of metabolic steal by parasites.

Retinal venous sheathing and the blood-retinal barrier in multiple sclerosis.

OBJECTIVE: To assess the temporal relations among retinal appearance, disruption of the blood-retinal barrier, clinical subgroup, disease course, and disruption of the blood-brain barrier in multiple sclerosis. DESIGN: A 6-month prospective study involving monthly clinical ocular examinations, color fundus photography, fundus fluorescein angiograms, and magnetic resonance brain scans with gadolinium-diethylenetriamine-pentaacetic acid (Gd-DPTA) enhancement. SETTING: University-based ophthalmology and neurology departments. PATIENTS: Twenty-three patients with relapsing-remitting, primary-progressive, or secondary-progressive multiple sclerosis. RESULTS: Retinal venous sheathing was seen in six patients. The appearances observed included focal venous sheathing, diffuse venous sheathing, sheathing centered on sites of arteriovenous crossover, and focal perivenous hemorrhage. Arteriolar sheathing was also observed in one patient. Venous leakage on fundus fluorescein angiogram was detected in three patients, all of whom also had sheathing. The following three patterns of disruption of the blood-retinal barrier were seen on fundus fluorescein angiogram: focal leakage, extensive leakage, and very late wall staining. In one patient, the leakage was transitory. No correlations were observed between ophthalmologic features and multiple sclerosis clinical subgroup, disease course, or the number of new (Gd-DTPA-enhancing) lesions on magnetic resonance imaging. CONCLUSIONS: Disruption of the blood-retinal barrier, like the more frequent disruption of the blood-brain barrier seen on magnetic resonance imaging, is often unrelated to clinical neurologic relapses and occurs with apparently similar frequency in different patients independent of clinical disease course.

A review of the spectrum of clinical ocular fundus findings in P. falciparum malaria in African children with a proposed classification and grading system.

Ocular fundus pathology in Plasmodium falciparum malaria is common and has prognostic significance. We have made a collaborative effort to document the ocular features in several populations. Based on examination of 735 patients in Malawi, Kenya and The Gambia by direct and indirect ophthalmoscopy with dilated pupils, we have determined that the 5 distinct clinical features (in order of frequency) include retinal whitening, haemorrhages, unique vessel abnormalities, papilloedema, and cotton wool spots. Photographs and descriptions of these are presented, along with a proposed grading scheme.

Natural history of herpes zoster ophthalmicus: predictors of postherpetic neuralgia and ocular involvement.

Seventy-one patients presenting with acute herpes zoster ophthalmicus were followed up for six months for a prospective analysis of the natural history of the disease. Acute and chronic ocular complications, nasociliary nerve involvement, age, sex, rash, and pain were assessed, and the results are presented. Acute pain was measured by a visual analogue scale. Postherpetic neuralgia (PHN) was more likely in patients over 80 and in those who scored their pain highly at presentation. Duration of rash was longer in patients who developed PHN. No other associations between the parameters studied were found. Nasociliary nerve involvement was associated with subsequent ocular disease.

Visual outcomes in children in Malawi following retinopathy of severe malaria.

AIM: To investigate whether retinal changes in children with severe malaria affect visual acuity 1 month after systemic recovery. METHODS: All children with severe malaria admitted to a research ward in Malawi during one malaria season were examined by direct and indirect ophthalmoscopy. Visual acuity was tested in those attending follow up by Cardiff cards, Sheridan-Gardiner single letters, or Snellen chart. RESULTS: 96 (68%) children attended follow up, of whom 83 (86%) had visual acuity measured. Cardiff cards were used in 47 (57%) children, and Sheridan-Gardiner letters or Snellen chart in 29 (35%). There was no significant difference in the mean logMAR visual acuity between groups with or without macular whitening (0.14 versus 0.16, p = 0.55). There was no trend for worse visual acuity with increasing severity of macular whitening (p = 0.52) including patients in whom the fovea was involved (p = 0.32). Six (4.2%) children had cortical blindness after cerebral malaria, and all six had other neurological sequelae. Ophthalmoscopy during the acute illness revealed no abnormalities in four of these children. CONCLUSION: Retinal changes in severe malaria, in particular macular whitening, do not appear to affect visual acuity at 1 month. This supports the hypothesis that retinal whitening is due to reversible intracellular oedema in response to relative hypoxia, caused by sequestered erythrocytes infected by Plasmodium falciparum. Impaired visual functioning after cerebral malaria is not attributable to retinal changes and appears to be a cortical phenomenon.

Corneoscleral burn during phacoemulsification surgery.

We report a case in which a severe corneoscleral burn occurred during phacoemulsification surgery. The equipment-tuning process was uneventful and routine surgery was expected. Severe tissue injury occurred because the anterior chamber collapsed momentarily and the phaco tip touched corneoscleral tissue. We discuss mechanisms by which this type of injury may occur and the likely cause in our case. We also suggest methods to reduce the incidence.

Emboli observed with use of transesophageal echocardiography immediately after tourniquet release during total knee arthroplasty with cement.

The right atrium and the right ventricle of fifty-five patients were imaged with transesophageal echocardiography during fifty-nine total knee arthroplasties performed with cement and the use of general anesthesia. The patients ranged in age from thirty-two to eighty-three years (mean, 65.5 years). Cardiopulmonary parameters were measured with use of hemodynamic monitoring systems, such as pulse oximeters, pulmonary artery catheters, and radial artery catheters. In addition, a femoral vein catheter was inserted on the side of the operation in ten of the fifty-five patients. Showers of echogenic material traversing the right atrium, the right ventricle, and the pulmonary artery after the tourniquet was deflated were observed to various degrees in all patients and lasted three to fifteen minutes. The mean peak intensity occurred within thirty seconds (range, twenty-four to forty-five seconds) after the tourniquet was released. The mean mixed venous oxygen saturation (and standard error of the mean) decreased (from 83+/-0.9 to 72+/-1.5 per cent) and the mean pulmonary arterial pressure increased (from 20+/-1.0 to 27+/-1.0 millimeters of mercury [2.67+/-0.13 to 3.60+/-0.13 kilopascals]), compared with the values before the tourniquet was released, in all patients. The pulmonary vascular resistance index increased after release of the tourniquet (to a maximum of 328+/-29 dyne.s.cm(-5).m2; p = 0.00002) only in the patients who had echogenic material that was at least 0.5 centimeter in diameter. Clinical pulmonary embolism developed postoperatively in three patients; all three had had echogenic particles that were more than 0.5 centimeter in maximum diameter on imaging. Blood aspirated from one of the pulmonary artery catheters and from five of the ten femoral vein catheters demonstrated fresh venous thrombus. Histological evaluation of the aspirates failed to demonstrate fat, marrow, or particles of polymethylmethacrylate. Surgeons should consider acute pulmonary embolism as a diagnosis when evaluating a patient who has hemodynamic collapse during total knee arthroplasty performed with cement.

Oral acyclovir in herpes zoster ophthalmicus.

46 patients with acute herpes zoster ophthalmicus of less than 72 hours duration were recruited into a placebo controlled trial to assess the efficacy of oral acyclovir, 800 mg 5 times daily, in preventing or modifying ocular complications and pain. Fewer acyclovir recipients developed intraocular complications and these were less severe but neither difference was statistically significant. However, active ocular disease was significantly less common in the acyclovir group (p = 0.01) at 6 months. Pain was significantly less severe in the acyclovir group between 2 and 6 months. The proportion of patients with pain scores greater than 0 was significantly lower in the acyclovir group between 2 and 3 months. Oral acyclovir appears to modify the disease process in herpes zoster ophthalmicus, to reduce the severity and incidence of postherpetic pain and especially to protect against long-term ocular complications.

Percutaneous stabilization of U-shaped sacral fractures using iliosacral screws: technique and early results.

PURPOSE: To present the technique and early results of percutaneous stabilization of U-shaped sacral fractures with attention to neurologic recovery and maintenance of fracture reduction of the sacrum. DESIGN: Retrospective clinical study. SETTING: Level I trauma center. PATIENTS: During a thirty-eight-month period, 442 patients with pelvic ring disruptions were treated at a Level I trauma center. Thirteen (2.9 percent) of these patients had displaced U-shaped sacral fractures treated with percutaneous stabilization. INTERVENTION: Fracture stabilization was accomplished using fluoroscopically guided iliosacral screws inserted percutaneously with the patient positioned supine. Neurodiagnostic monitoring was not used during screw insertions. This technique was limited to patients with sacral kyphotic deformities, which allowed in situ fixation. Sacral neurologic decompression was not performed. MAIN OUTCOME MEASUREMENTS: Fracture healing and the stability of fixation were assessed on inlet and outlet radiographs and a lateral sacral view. Detailed neurologic examinations were performed at injury and at follow-up. RESULTS: The sacral fractures were classified based on plain pelvic radiographs and computed tomography scans and included one Type 1, eight Type 2, and four Type 3 fracture patterns. Twenty-five fully threaded cancellous 7.0-millimeter cannulated screws were used. Eleven patients had bilateral screw fixations; one patient had unilateral double screw fixation; and one patient had unilateral single screw fixation. Operative time for screw insertion averaged forty-eight minutes, with 2.1 minutes of fluoroscopy per screw. Accurate screw insertions without neuroforaminal or sacral spinal canal violations were confirmed in all patients with postoperative pelvic plain radiographs and computed tomography scans. A paradoxical inlet view of the upper sacral segments on the injury anteroposterior pelvis was seen in twelve of thirteen patients (92.3 percent), and the diagnosis was confirmed with the lateral sacral view in all thirteen (100 percent) patients. Preoperatively, sacral kyphosis averaged 29 degrees, whereas postoperative sacral kyphosis averaged 28 degrees. Screw disengagement occurred without a change in position of the sacral fracture in the only patient treated with a single unilateral screw. All fractures healed clinically and radiographically. Of the nine patients with preoperative neurologic abnormalities, two (22 percent) patients had residual neurologic deficits. Both patients had associated multiple level lumbar burst fractures, which required decompression and instrumented stabilization. CONCLUSIONS: These sacral fractures are rare and occur after significant spinal axial loading. A paradoxic inlet view of the upper sacrum on the anteroposterior plain pelvic radiograph heralds the diagnosis. Delayed diagnosis is avoided by a high clinical suspicion, early lateral sacral radiographs, and pelvic computed tomography scans. Surgical stabilization may assist in early mobilization of the patient from recumbency and prevents progressive deformity with associated nerve root injury. Percutaneous fixation diminishes potential blood loss and operative times, yet still allows subsequent sacral decompression of the local neural elements using open techniques when necessary. Early percutaneous iliosacral screw fixation is effective treatment for these injuries.

Cost effectiveness analysis of screening for sight threatening diabetic eye disease.

OBJECTIVE: To measure the cost effectiveness of systematic photographic screening for sight threatening diabetic eye disease compared with existing practice. DESIGN: Cost effectiveness analysis. SETTING: Liverpool. SUBJECTS: A target population of 5000 diabetic patients invited for screening. MAIN OUTCOME MEASURES: Cost effectiveness (cost per true positive) of systematic and opportunistic programmes; incremental cost effectiveness of replacing opportunistic with systematic screening. RESULTS: Baseline prevalence of sight threatening eye disease was 14.1%. The cost effectiveness of the systematic programme was 209 pound sterling (sensitivity 89%, specificity 86%, compliance 80%, annual cost 104996 pound sterling) and of the opportunistic programme was 289 pound sterling (combined sensitivity 63%, specificity 92%, compliance 78%, annual cost 99 981 pound sterling). The incremental cost effectiveness of completely replacing the opportunistic programme was 32 pound sterling. Absolute values of cost effectiveness were highly sensitive to varying prevalence, sensitivity and specificity, compliance, and programme size. CONCLUSION: Replacing existing programmes with systematic screening for diabetic eye disease is justified.