Parent and Teacher Perspectives on Factors Decreasing Participation in School-Based Vision Programs.

Purpose: To examine factors decreasing participation in school-based vision programs from parent and teacher perspectives.Methods: We conducted 41 semi-structured focus groups (20 parent groups, 21 teacher/staff groups), at 10 Baltimore and 11 Chicago public elementary and middle schools offering school-based vision programs. School-based vision programs provided vision screening, eye exams, and eyeglasses if needed. Focus groups ranged in size from 2-9 participants (median = 5). Sessions were recorded, transcribed, and coded through an iterative process to develop themes using inductive analysis.Results: Ninety parents and 117 teachers/staff participated. Participants identified five major factors decreasing participation in school-based vision programs: (1) challenges with the consent form, including distribution, collection, and literacy and language barriers; (2) having existing eye care; (3) misunderstandings about the program, especially related to cost and insurance; (4) difficulty raising parental awareness of the program; and (5) certain attitudes towards vision, eye care, and school-based programs, including low prioritization of eye care, mistrust of the program, fear of sharing private information, not believing their child needs glasses, and reluctance accepting 'subsidized' services.Conclusion: Parents and teachers identified important structural barriers to participation (i.e., consent form challenges and low parental awareness) and specific reasons for non-participation (i.e., attitudes, misunderstanding of the program, existing eye care) in school-based vision programs. Effective strategies are needed to facilitate return of consent forms and promote awareness of school-based vision programs among parents. Programs should also target services towards those currently without access to eye care and increase awareness about paediatric vision needs.

Vascular tone pathway polymorphisms in relation to primary open-angle glaucoma.

AIMS: Vascular perfusion may be impaired in primary open-angle glaucoma (POAG); thus, we evaluated a panel of markers in vascular tone-regulating genes in relation to POAG. METHODS: We used Illumina 660W-Quad array genotype data and pooled P-values from 3108 POAG cases and 3430 controls from the combined National Eye Institute Glaucoma Human Genetics Collaboration consortium and Glaucoma Genes and Environment studies. Using information from previous literature and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, we compiled single-nucleotide polymorphisms (SNPs) in 186 vascular tone-regulating genes. We used the 'Pathway Analysis by Randomization Incorporating Structure' analysis software, which performed 1000 permutations to compare the overall pathway and selected genes with comparable randomly generated pathways and genes in their association with POAG. RESULTS: The vascular tone pathway was not associated with POAG overall or POAG subtypes, defined by the type of visual field loss (early paracentral loss (n=224 cases) or only peripheral loss (n=993 cases)) (permuted P≥0.20). In gene-based analyses, eight were associated with POAG overall at permuted P<0.001: PRKAA1, CAV1, ITPR3, EDNRB, GNB2, DNM2, HFE, and MYL9. Notably, six of these eight (the first six listed) code for factors involved in the endothelial nitric oxide synthase activity, and three of these six (CAV1, ITPR3, and EDNRB) were also associated with early paracentral loss at P<0.001, whereas none of the six genes reached P<0.001 for peripheral loss only. DISCUSSION: Although the assembled vascular tone SNP set was not associated with POAG, genes that code for local factors involved in setting vascular tone were associated with POAG.

Comparing approaches to screening for angle closure in older Chinese adults.

AIMS: Primary angle-closure glaucoma is expected to account for nearly 50% of bilateral glaucoma blindness by 2020. This study was conducted to assess the performance of the scanning peripheral anterior chamber depth analyzer (SPAC) and limbal anterior chamber depth (LACD) as screening methods for angle closure. METHODS: This study assessed two clinical populations to compare SPAC, LACD, and gonioscopy: the Zhongshan Angle-closure Prevention Trial, from which 370 patients were eligible as closed-angle participants and the Liwan Eye Study, from which 72 patients were selected as open-angle controls. Eligible participants were assessed by SPAC, LACD, and gonioscopy. RESULTS: Angle status was defined by gonioscopy. Area under the receiver operating characteristic curve (AUROC) for SPAC was 0.92 (0.89-0.95) whereas AUROC for LACD was 0.94 (0.92-0.97). Using conventional cutoff points, sensitivity/specificity was 93.0%/70.8% for SPAC and 94.1%/87.5% for LACD. Sequential testing using both SPAC and LACD increased the specificity to 94.4% and decreased the sensitivity to 87.0%. CONCLUSION: SPAC has significantly lower specificity than LACD measurement using conventional cutoffs but interpretation of the findings can be performed by modestly trained personnel.

Increased iris thickness and association with primary angle closure glaucoma.

AIMS: To investigate the relationship between quantitative iris parameters and angle closure disease. methods: Participants with angle closure were recruited prospectively from glaucoma clinics. Anterior segment optical coherence tomography (AS-OCT) was performed under standardised dark conditions. Customised software was used on horizontal AS-OCT scans to measure iris thickness at 750 um (IT750) and 2000 um (IT2000) from the sclera spur, maximal iris thickness (ITM) and cross-sectional area of the iris (I-Area). RESULTS: 167 Angle closure (consisting of 50 primary angle-closure (PAC), 73 primary angle closure glaucoma (PACG) and 44 fellow eyes of acute PAC) and 1153 normal participants were examined. After adjusting for age, sex, pupil size and anterior chamber depth, mean IT750 (0.499 vs 0.451 mm, p<0.001), IT2000 (0.543 vs 0.479 mm, p<0.001), ITM (0.660 vs 0.602 mm, p<0.001) and I-Area (1.645 vs 1.570 mm(2), p=0.014) were significantly greater in angle closure (combined groups) versus normal eyes. Multivariate adjusted odd ratios (OR) of each parameter for the angle closure as compared with normal eyes were: IT750 OR1.7 (95% CI 1.1 to 2.7, p=0.032); IT2000 OR2.2 (95% CI 1.3 to 3.8, p=0.006) and ITM OR2.2 (95% CI 1.3 to 3.6, p=0.003), respectively, per 0.1 unit increase. CONCLUSIONS: Increased iris thickness is associated with angle closure.

Quantitative analysis of anterior segment optical coherence tomography images: the Zhongshan Angle Assessment Program.

AIM: To describe a new image analysis method and software for anterior chamber images obtained by the anterior-segment optical coherence tomography (AS-OCT) and to assess its intraobserver and interobserver measurement reproducibility. METHODS: Twenty 8-bit greyscale 600x300 AS-OCT images with apparent wide angles and 20 images with apparent narrow angles were consecutively selected from a database. Two glaucoma fellowship-trained ophthalmologists used proprietary image analysis software to analyse the images twice. Algorithms defined the borders and curvatures of anterior chamber (AC) structures and measured AC parameters using scleral spur location as the only observer input. The intraobserver and interobserver reproducibility of scleral spur location and angle parameters was calculated in terms of limits of agreement (LOA; mean of differences+/-1.96 SD of differences) and coefficient of variation (CV; SD of differences/overall mean). RESULTS: The analysis software successfully measured all parameters in all images. When the same image was assessed twice by the same grader, the mean differences ranged from 0 to 0.010 mm in linear measurements and 0.001 to 0.006 mm2 in angle area measurements. LOA tended to be greater in the wider angles. The upper and lower limit values of LOAs were approximately 1/5 to 1/4 of the overall mean. Measurements between two graders had a higher variance. Reproducibility in terms of CV was better in wide angles when compared with narrow angles. The reproducibility of scleral spur placement between observers was poorer in narrow angles (p = 0.001). About 50% of the interobserver variance in angle-area measurements was attributable to the variance of scleral spur placement, while this proportion was only 10-20% in linear measurements. CONCLUSIONS: Determination of angle parameters using semiautomated software leads to variability in measurement. Variability increases when more than one observer identifies the scleral spur. Variability differs in narrow and open angles, and so including both types is essential when evaluating angle-assessment software. A fully automated analysis and higher image resolution would likely improve quantification of Visante AS-OCT images.

Degree of angle closure and extent of peripheral anterior synechiae: an anterior segment OCT study.

AIMS: To evaluate the relationship between angle width as determined by anterior segment optical coherence tomography (AS-OCT) and the presence of peripheral anterior synechiae (PAS). METHODS: This was a prospective observational case series in which 203 subjects with primary angle closure or open angles were recruited. Images of the nasal, temporal and inferior angles were obtained with AS-OCT in dark conditions. Subjects then underwent gonioscopy by an independent examiner who was masked to the AS-OCT findings. PAS were identified by gonioscopy and defined as abnormal adhesions of the iris to the angle that were at least half a clock hour in width and present to the level of the anterior trabecular meshwork or higher. The total clock hours of PAS were recorded. RESULTS: Sixty-eight subjects (33.5%) were PACS, 76 subjects (37.4%) had PAC/PACG, 14 (6.9%) had primary open angle glaucoma, and 45 (22.2%) subjects were normal with open angles. There was a weak but significant correlation between the angle opening distance (AOD), trabecular iris space area (TISA) and angle recess area (ARA) with clock hours of PAS (Spearman's correlation coefficients = -0.30, -0.32 and -0.32, respectively, p<0.001). The mean values of the AOD, TISA and ARA in the nasal, temporal and inferior quadrants were significantly less in eyes with PAS compared with those without (p<0.001, Mann-Whitney U test). Analysis by quadrant showed that these parameters were smaller in the nasal and temporal quadrants in eyes with PAS (p<0.01). CONCLUSIONS: Angle width determined by AS-OCT and the extent of PAS were weakly correlated, and angle width was significantly smaller in eyes with PAS.

Lens extraction for chronic angle-closure glaucoma.

BACKGROUND: Angle-closure glaucoma is characterized by obstruction to the outflow of aqueous humor and consequent rise in intraocular pressure. The obstruction may result from an anatomical predisposition of the eye or may be due to pathophysiologic processes in any part of the eye. The former is considered the primary form and the latter a secondary form of angle closure. Relative pupillary block obstructing free flow of aqueous from the posterior chamber of the eye to the anterior chamber is considered to be the most common mechanism of angle closure. Crowding of the angle is another mechanism, which often coexists with pupillary block. This can result from an anterior placement of the lens due to an increase in the thickness of the lens (as occurs with aging), anterior displacement by a posterior force (for example choroidal effusion), or laxity of the zonules. OBJECTIVES: The objective of this review was to assess the effectiveness of lens extraction for chronic primary angle-closure glaucoma compared with other interventions for the condition in people without past history of acute-angle closure attacks. SEARCH STRATEGY: We searched CENTRAL (2005, Issue 3), MEDLINE (1950 to April 2006), EMBASE (1980 to April 2006), and LILACS (to August 2005). We searched the reference lists of included studies and used the Science Citation Index database. SELECTION CRITERIA: In the absence of any randomized trials we included non-randomized studies comparing lens extraction with other treatment modalities for chronic primary angle-closure glaucoma including, but not limited to, laser iridotomy, medications, and laser iridoplasty. We excluded studies with a case-series design. DATA COLLECTION AND ANALYSIS: Two authors independently extracted data on methodological quality of the included studies, outcomes for the review, and study characteristics including participant characteristics, interventions, and sources of funding. Differences were resolved through discussion. MAIN RESULTS: We found no randomized trials evaluating the effects of lens extraction as a treatment for chronic primary angle-closure glaucoma. Two non-randomized comparative studies included in the review have several methodological flaws including selection bias. While these studies and other non-comparative studies provide information on biological plausibility and treatment effect they do not provide proof of effectiveness. Also, they do not address the question of how primary lens extraction compares with other treatments for chronic primary angle-closure glaucoma. AUTHORS' CONCLUSIONS: There is no evidence from good quality randomized trials or non-randomized studies of the effectiveness of lens extraction for chronic primary angle-closure glaucoma.

An outbreak of norovirus gastroenteritis associated with wedding cakes.

We sought to determine the source of a norovirus outbreak among attendees of 46 weddings taking place during a single weekend. Norovirus-compatible illness was experienced by 332 (39%) of wedding guests surveyed; the outbreak affected up to 2700 persons. Illness was associated with eating wedding cake provided by a bakery common to the weddings (adjusted RR 4.5, P<0.001). A cake requiring direct hand contact during its preparation accounted for the majority of illness. At least two bakery employees experienced norovirus-compatible illness during the week preceding the weddings. Identical sequence types of norovirus were detected in stool specimens submitted by two wedding guests, a wedding hall employee, and one of the ill bakery employees. It is likely that one or more food workers at the bakery contaminated the wedding cakes through direct and indirect contact. These findings reinforce the necessity of proper food-handling practices and of policies that discourage food handlers from working while ill.

Patient preferences for anaesthesia management during cataract surgery.

BACKGROUND/AIMS: To assess patient preferences for different anaesthesia management strategies during cataract surgery. METHODS: Cross sectional clinic based study of patient preferences for anaesthesia management strategies. Patients rated their preferences using a linear rating scale from 0 to 100. RESULTS: Subjects tended to prefer block to topical anaesthesia and oral to intravenous sedation. On a scale from 0 to 100, subjects preferred oral to intravenous sedation and block to topical anaesthesia by about 8 points. CONCLUSIONS: When given the choice of four different anaesthesia management strategies, 72% of the study subjects preferred block anaesthesia to topical anaesthesia. More patients chose to have oral sedation than intravenous sedation. These findings indicate that patients may prefer anaesthesia management approaches other than the ones they are currently being offered.

VF-14 item specific responses in patients undergoing first eye cataract surgery: can the length of the VF-14 be reduced?

AIMS: To report the item specific responses of the VF-14 in a population of patients undergoing cataract surgery in their first eye and to determine whether or not the VF-14 can be reduced without compromising its performance as an index of cataract related visual impairment. METHODS: The item specific responses to the VF-14 were analysed before (771 patients) and 4 months after (552 patients) cataract surgery in one eye to determine if the VF-14 index can be reduced without compromising its performance. Patients studied were selected from a cross sectional longitudinal study of patients undergoing cataract surgery in 72 ophthalmologist's offices located in three metropolitan regions of the United States. RESULTS: Pairwise correlations between items in the VF-14 were all less than 0.6, indicating that no items could be removed solely on the basis of redundancy. 10 items correlated moderately with change in trouble, and 11 correlated moderately with change in satisfaction (r >0.15) at 4 months after cataract extraction. Eleven items demonstrated an effect size >0.4 at 4 months. These 11 items were either important for detecting cataract related functional disability or for quantifying the extent to which cataract impaired function. Additionally, 11 items were needed to detect adequately individuals with functional impairment. Three items (recognising people, cooking, and reading large print) were less responsive to cataract extraction and were more strongly associated with ocular comorbidities. CONCLUSIONS: While previous reports indicate that the VF-14 can be significantly shortened, our analysis only justifies removing three items. While the resulting VF-11 has properties similar to the VF-14, the limited time savings do not justify altering this already validated instrument.

A decision analysis of anesthesia management for cataract surgery.

PURPOSE: To compare the trade-offs in cost and preference of various anesthesia management strategies for cataract surgery. METHODS: Six strategies, differing in sedation, local anesthetic, and monitoring approach, were chosen for comparison. For each strategy, potential complications, and conversions to different anesthesia approaches were modeled. A panel of physicians and anesthetists, well versed in the literature and practice of the anesthesia management of cataract surgery, assigned preference values to the strategies and potential outcomes (0 to 1 scale). Probability estimates were obtained from a study of 19,557 cataract surgeries and from the panel. Cost estimates were derived from several sources. The model was analyzed to determine the strategies associated with the highest expected preference and lowest expected cost. RESULTS: The strategy associated with the highest net preference was intravenous sedation with block anesthesia and an anesthesiologist present throughout the case. The expected net preference for this strategy was 19% greater than the net preference for the next most preferred strategy, oral sedation with block anesthesia and an anesthesiologist on call (0.88 versus 0.74), but the expected anesthesia costs per case were much greater ($324 versus $42). Results were sensitive to plausible variation in the preference values assigned to the six initial management strategies and to the cost of topical versus block anesthesia. CONCLUSION: This analysis emphasizes that cost and preference are important considerations when choosing an anesthesia management strategy for cataract surgery. For some surgeries, substantial cost savings may be available for a small change in preference.

Activity restrictions as part of the discharge management for children with a traumatic head injury.

This article describes a proactive management strategy that is currently part of the discharge protocol for children seeking care for a head injury (HI) at a pediatric and adolescent trauma center. The strategy consists of setting activity restrictions for children hospitalized and those seen in the emergency department after a HI that may or not have been sports related. It was developed based on extensive clinical experience with families of children with a HI and existing guidelines for returning athletes to sports. Possible merits and pitfalls of the strategy are discussed.

Diagnostic capabilities of frequency-doubling technology, scanning laser polarimetry, and nerve fiber layer photographs to distinguish glaucomatous damage.

PURPOSE: To investigate the ability of three diagnostic tests: frequency-doubling technology (FDT), scanning laser polarimetry (GDx), and nerve fiber layer (NFL) photographs to distinguish normal from glaucomatous eyes. METHODS: Data were obtained in a cross-sectional, hospital clinic-based study, including one eye from each of 253 persons older than 40 years (68 normal, 94 glaucoma suspects and 91 glaucoma patients). We performed a comprehensive ocular examination, as well as static automated perimetry (Humphrey 24-2), screening FDT, GDx, optic nerve stereoscopic photographs and high-contrast NFL photographs. RESULTS: The following were significantly different for glaucomatous patients compared with suspects and normals: mean values of mean deviation (MD, Humphrey 24-2) and corrected pattern standard deviation (CPSD), 11 GDx indices, mean FDT testing time and missed points, and NFL graded defects (ANOVA, Mantel-Haenszel test; p = 0.0001). Using Humphrey 24-2 test results and clinical assessment as the defining features of glaucoma, we found that the optimal mix of sensitivity and specificity values were 84% and 100% for FDT (presence of any defect); 62% and 96% for GDx (The Number, cut-off value of 27); and, 95% and 82% for NFL photographs (presence of any abnormality). FDT testing took the least time to be administered. CONCLUSIONS: The FDT had the best diagnostic performance. Neural network analysis of GDx data outperformed other elements of its software.

Synthesis of the literature on the effectiveness of regional anesthesia for cataract surgery.

OBJECTIVE: To synthesize the findings of the randomized trials of regional anesthesia management strategies for cataract surgery. DESIGN: Literature review and analysis. METHOD: The authors performed a systematic search of the literature to identify all articles pertaining to regional anesthesia during cataract surgery on adults. One investigator abstracted the content of each article onto a custom-designed form. A second investigator corroborated the findings. The evidence supporting the anesthesia approaches was graded by consensus as good, fair, poor, or insufficient. MAIN OUTCOME MEASURES: Evidence supporting the effectiveness of different forms of regional anesthesia. RESULTS: There was good evidence that retrobulbar and peribulbar blocks provide equivalent akinesia and pain control during cataract surgery. Additionally, sub-Tenon's blocks were at least as effective as retrobulbar and peribulbar blocks. There was good evidence that retrobulbar block provides better pain control during surgery than topical anesthesia, and there was fair evidence that peribulbar block provides better pain control than topical anesthesia. CONCLUSIONS: This synthesis of the literature demonstrates that currently used approaches to anesthesia management provide adequate pain control for successful cataract surgery, but there is some variation in the effectiveness of the most commonly used techniques. Data are needed on patient preferences to determine the optimal strategies for anesthesia management during cataract surgery.

The methodologic quality of clinical trials on regional anesthesia for cataract surgery.

OBJECTIVE: To assess the methodologic quality of published randomized trials of regional anesthesia management strategies for cataract surgery. DESIGN: Literature review and analysis. METHOD: We performed a systematic search of the literature to identify all articles pertaining to regional anesthesia for cataract surgery on adults. Overall quality scores and scores for individual methodologic domains were based on the evaluations of two investigators experienced in methodologic research who independently reviewed all relevant articles using a quality abstraction form. MAIN OUTCOME MEASURES: Study quality in each of five domains: representativeness, bias and confounding, intervention description, outcomes and follow-up, and statistical quality and interpretation. RESULTS: Eighty-two randomized clinical trials were identified with a mean overall quality score of 44%. The mean domain scores ranged from 37% for representativeness to 58% for outcomes and follow-up. Forty percent or fewer studies received the maximum score for reporting the setting, the population, and the start and end dates; describing the inclusion and exclusion criteria; adequately randomizing subjects; and adequately masking individuals participating in the study. Key outcomes were often inadequately reported, including the distribution of patient-reported pain scores and the mean surgical time. CONCLUSIONS: Greater attention to methodologic quality and detailed reporting of study results will improve the ability of readers to interpret the results of clinical trials assessing regional anesthesia for cataract surgery.