Development and evaluation of an intervention to promote the use of eyeglasses among Romani families in Bulgaria

Objective

Uncorrected refractive error (i.e., lack of eyeglasses for the treatment of refractive error) is one of the leading causes of visual impairment in Eastern Europe. Limited information is available on how to promote the use of eyeglasses among Romani families in Bulgaria. In step 1, the objective was to obtain suggestions by Romani mothers on how to promote the use of eyeglasses among children. In step 2, the objective was to evaluate an intervention to promote the use of eyeglasses based on suggestions received during step 1.

Methods

During step 1, 5 focus groups with Romani mothers took place in one neighborhood in Bulgaria. During step 2, the intervention used a one-group pre-test, post-test design. Families received eye examinations. Those who needed eyeglasses chose attractive eyeglasses. Parents received education on how to encourage their children to wear eyeglasses.

Results

During step 1, 54 mothers participated. Mothers suggested that the whole family should receive eye examinations and eyeglasses. During step 2, of 33 family members, 14 did not have refractive errors and 19 did. Of the 19 family members with refractive error, none had eyeglasses at pre-test. Approximately 6 months following the end of the intervention, 11 of the 19 family members (57.9%) wore eyeglasses and the remaining 8 (42.1%) did not.

Conclusion

Romani family members needed eyeglasses but did not have any at pre-test of the intervention. Future interventions that offer education on the importance of eye examinations may increase receipt of eye examinations and adherence to wearing eyeglasses.

Hierarchical Censored Bayesian Analysis of Visual Field Progression

Purpose

To develop a Bayesian model (BM) for visual field (VF) progression accounting for the hierarchical, censored and heteroskedastic nature of the data.

Methods

Three versions of a hierarchical BM were developed: a simple linear (Hi-linear); censored at 0 dB (Hi-censored); heteroskedastic censored (Hi-HSK). For the latter, we modeled the test variability according to VF sensitivity using a large test-retest cohort (1396 VFs, 146 eyes with glaucoma). We analyzed a large cohort of 44,371 VF tests from 3352 eyes from five glaucoma clinics. We quantified the bias in the estimated rate-of-progression, the detection of progression (Hit-rate [HR]), the median time-to-progression and the prediction error of future observations (mean absolute error [MAE]). HR and time-to-progression were compared at matched false-positive-rate (FPR), quantified using permutations of a separate test-retest cohort (360 tests, 30 eyes with glaucoma). BMs were compared to simple linear regression and Permutation-Analyses-of Pointwise-Linear-Regression. Differences in time-to-progression were tested using survival analysis.

Results

Censored models showed the smallest bias in the rate-of-progression. The three BMs performed very similarly in terms of HR and time-to-progression and always better than the other methods. The average reduction in time-to-progression was 37% with the BMs (P < 0.001) at 5% FPR. MAE for prediction was very similar among methods.

Conclusions

Bayesian hierarchical models improved the detection of VF progression. Accounting for censoring improves the precision of the estimates, but minimal effect is provided by accounting for heteroskedasticity.

Translational Relevance

These results are relevant for quantification of VF progression in practice and for clinical trials.

Improving the Power of Glaucoma Neuroprotection Trials Using Existing Visual Field Data

PURPOSE

Selecting reliable visual field (VF) test takers could improve the power of randomized clinical trials in glaucoma. We test this hypothesis via simulations using a large real world data set.

DESIGN

Methodology analysis: assessment of how improving reliability affects sample size estimates.

METHODS

A variability index (VI) estimating intertest variability was calculated for each subject using the residuals of the regression of the mean deviation over time for the first 6 tests in a series of at least 10 examinations for 2,804 patients. Using data from the rest of the series, we simulate VFs at regular intervals for 2 years. To simulate the neuroprotective effect (NE), we reduced the observed progression rate by 20%, 30%, or 50%. The main outcome measure was the sample size to detect a significant difference (P < .05) at 80% power.

RESULTS

In the first experiment, we simulated a trial including one eye per subject, either selecting randomly from the database or prioritizing patients with low VI. We could not reach 80% power for the low NE with the available patients, but the sample size was reduced by 38% and 49% for the 30% and 50% NE, respectively. In the second experiment, we simulated 2 eyes per subject, one of which was the control eye. The sample size (smaller overall) was reduced by 26% and 38% for the 30% and 50% NE by prioritizing patients with low VI.

CONCLUSIONS

Selecting patients with low intertest variability can significantly improve the power and reduce the sample size needed in a trial.

Ophthalmic Emergency Department Visits: Factors Associated With Loss to Follow-up

PURPOSE

To describe follow-up rates for patients referred for outpatient ophthalmic care after emergency department (ED) discharge and identify patient and visit characteristics associated with loss to follow-up (LTFU).

DESIGN

Single-institution retrospective cohort study.

METHODS

We analyzed the medical records of 2,206 patients seen in the ED for an eye-related issue who were subsequently scheduled for ophthalmology follow-up between 2013 and 2019 at a single tertiary health system. The main outcome measures were the frequency of and risk factors for LTFU and ED revisits.

RESULTS

In total, 1,649 (74.8%) patients completed follow-up within 2 months of an index ED visit. In multivariable analysis, younger age (P < .001), a nonurgent ophthalmic condition or nonophthalmic primary diagnosis (P < .001), scheduled follow-up >5 days after the ED visit (P < .001), additional follow-up appointments (<.001), no prior history of ophthalmology appointments (P = .045), a visual acuity of 20/40 or better (P = .027), and having Medicaid or being uninsured (P < .001) were significantly associated with LTFU. The presence of an interpreter significantly increased the likelihood of follow-up among non-English speaking patients (P < .001). LTFU was significantly associated with an ED revisit within 4 months of an index visit, and the ED revisit rate was significantly higher for patients LTFU vs those who completed follow-up (5.7% vs 1.1%; P < .001).

CONCLUSIONS

A quarter of patients referred for ophthalmic care after an ED presentation were LTFU. We identified numerous factors associated with LTFU that could be used to develop interventions to enhance follow-up. In addition, patients who were LTFU were more likely to revisit the ED for the same ophthalmic condition.

Changes in Class I and IIb HDACs by δ-Opioid in Chronic Rat Glaucoma Model

Purpose

This study determines if δ-opioid receptor agonist (i.e. SNC-121)-induced epigenetic changes via regulation of histone deacetylases (HDACs) for retinal ganglion cell (RGC) neuroprotection in glaucoma model.

Methods

Intraocular pressure was raised in rat eyes by injecting 2M hypertonic saline into the limbal veins. SNC-121 (1 mg/kg; i.p.) was administered to the animals for 7 days. Retinas were collected at days 7 and 42, post-injury followed by measurement of HDAC activities, mRNA, and protein expression by enzyme assay, quantitative real-time PCR (qRT-PCR), Western blotting, and immunohistochemistry.

Results

The visual acuity, contrast sensitivity, and pattern electroretinograms (ERGs) were declined in ocular hypertensive animals, which were significantly improved by SNC-121 treatment. Class I and IIb HDACs activities were significantly increased at days 7 and 42 in ocular hypertensive animals. The mRNA and protein expression of HDAC 1 was increased by 1.33 ± 0.07-fold and 20.2 ± 2.7%, HDAC 2 by 1.4 ± 0.05-fold and 17.0 ± 2.4%, HDAC 3 by 1.4 ± 0.06-fold and 17.4 ± 3.4%, and HDAC 6 by 1.5 ± 0.09-fold and 15.1 ± 3.3% at day 7, post-injury. Both the mRNA and protein expression of HDACs were potentiated further at day 42 in ocular hypertensive animals. HDAC activities, mRNA, and protein expression were blocked by SNC-121 treatment at days 7 and 42 in ocular hypertensive animals.

Conclusions

Data suggests that class I and IIb HDACs are activated and upregulated during early stages of glaucoma. Early intervention with δ-opioid receptor activation resulted in the prolonged suppression of class I and IIb HDACs activities and expression, which may, in part, play a crucial role in RGC neuroprotection.

Unaltered Perception of Suprathreshold Contrast in Early Glaucoma Despite Sensitivity Loss

Purpose

Glaucoma raises contrast detection thresholds, but our natural visual environment is dominated by high contrast that may remain suprathreshold in early to moderate glaucoma. This study investigates the effect of glaucoma on the apparent contrast of visible stimuli.

Methods

Twenty participants with glaucoma with partial visual field defects (mean age, 72 ± 7 years) and 20 age‐similar healthy controls (mean age, 70 ± 7 years) took part. Contrast detection thresholds for Gabor stimuli (SD, 0.75°) of four spatial frequencies (0.5, 1.0, 2.0, and 4.0 c/deg) were first measured at 10° eccentricity, both within and outside of visual field defects for participants with glaucoma. Subsequently, the contrast of a central Gabor was matched to that of a peripheral Gabor with contrast fixed at two times or four times the detection threshold. Data were analyzed by linear mixed modelling.

Results

Compared with controls, detection thresholds for participants with glaucoma were raised by 0.05 ± 0.025 (Michelson units, ± SE; P = 0.12) and by 0.141 ± 0.026 (P < 0.001) outside and within visual field defects, respectively. For reference stimuli at two times the detection contrast, matched contrast ratios (matched/reference contrast) were 0.16 ± 0.039 (P < 0.001) higher outside compared with within visual field defects in participants with glaucoma. Matched contrast ratios within visual field defects were similar to controls (mean 0.033 ± 0.066 lower; P = 0.87). For reference stimuli at four times the detection contrast, matched contrast ratios were similar across all three groups (P = 0.58). Spatial frequency had a minimal effect on matched contrast ratios.

Conclusions

Despite decreased contrast sensitivity, people with glaucoma perceive the contrast of visible suprathreshold stimuli similarly to healthy controls. These results suggest possible compensation for sensitivity loss in the visual system.

Auditing service delivery in glaucoma clinics using visual field records: a feasibility study

Objective

This study aimed to demonstrate that large-scale visual field (VF) data can be extracted from electronic medical records (EMRs) and to assess the feasibility of calculating metrics from these data that could be used to audit aspects of service delivery of glaucoma care.

Method and analysis

Humphrey visual field analyser (HFA) data were extracted from Medisoft EMRs from five regionally different clinics in England in November 2015, resulting in 602 439 records from 73 994 people. Target patients were defined as people in glaucoma clinics with measurable and sustained VF loss in at least one eye (HFA mean deviation (MD) outside normal limits ≥2 VFs). Metrics for VF reliability, stage of VF loss at presentation, speed of MD loss, predicted loss of sight years (bilateral VF impairment) and frequency of VFs were calculated.

Results

One-third of people (34.8%) in the EMRs had measurable and repeatable VF loss and were subject to analyses (n=25 760 patients). Median (IQR) age and presenting MD in these patients were 71 (61, 78) years and −6 (–10, –4) dB, respectively. In 19 264 patients with >4 years follow-up, median (IQR) MD loss was −0.2 (−0.8, 0.3) dB/year and median (IQR) intervals between VF examinations was 11 (8, 16) months. Metrics predicting loss of sight years and reliability of examinations varied between centres (p<0.001).

Conclusion

This study illustrates the feasibility of assessing aspects of health service delivery in glaucoma clinics through analysis of VF databases. Proposed metrics could be useful for blindness prevention from glaucoma in secondary care centres.

Severity of Visual Field Loss at First Presentation to Glaucoma Clinics in England and Tanzania

Purpose: To compare severity of visual field (VF) loss at first presentation in glaucoma clinics in England and Tanzania.Methods: Large archives of VF records from automated perimetry were used to retrospectively examine vision loss at first presentation in glaucoma clinics in Tanzania (N = 1,502) and England (N = 9,264). Mean deviation (MD) of the worse eye at the first hospital visit was used as an estimate of detectable VF loss severity.Results: In Tanzania, 44.7% {CI_95%: 42.2, 47.2} of patients presented with severe VF loss (< -20 dB), versus 4.6% {4.1, 5.0} in England. If we consider late presentation to also include cases of advanced loss (-12.01 dB to -20 dB), then the proportion of patients presenting late was 58.1% {55.6, 60.6} and 14.0% {13.3, 14.7}, respectively. The proportion of late presentations was greater in Tanzania at all ages, but the difference was particularly pronounced among working-age adults, with 50.3% {46.9, 53.7} of 18-65-year-olds presenting with advanced or severe VF loss, versus 10.2% {9.3, 11.3} in England. In both countries, men were more likely to present late than women.Conclusions: Late presentation of glaucoma is a problem in England, and an even greater challenge in Tanzania. Possible solutions are discussed, including increased community eye-care, and a more proactive approach to case finding through the use of disruptive new technologies, such as low-cost, portable diagnostic aids.

OCT Circle Scans Can Be Used to Study Many Eyes with Advanced Glaucoma

Purpose

To examine the utility of optical coherence tomography (OCT) for studying eyes with advanced glaucoma [i.e., eyes with a 24-2 visual field (VF) mean deviation (MD) worse than -15 dB], we tested the hypothesis that if these eyes had a 10-2 total deviation (TD) map with points better than -8 dB, then the topographically corresponding regions on the circumpapillary retinal nerve fiber layer (cpRNFL) should show a preserved region.

Design

Evaluation of technology study.

Participants

39 eyes from 33 patients (mean: 68.8 ± 9.2 years) with a diagnosis of glaucoma had a 24-2 VF with a MD ≤ -15 dB (mean: -18.94 ± 2.95 dB). All eyes additionally had a 10-2 VF and an averaged OCT circle scan.

Methods

Each scan was inspected, and preserved cpRNFL regions of the disc associated with the macula (central ±8° were delin eated.

Main Outcome Measures

The number of eyes with preserved cpRNFL regions and their association with preserved VF locations (i.e. better than -8 dB) shown in the 10-2 VF TD map.

Results

38 of the 39 eyes had one or more points on the 10-2 VF with TD values that were better than -8 dB (mean: 25.7 ± 12.6 points). For all 39 eyes, there was a preserved portion of the cpRNFL on the circle scan within the disc region associated with the macula. However, for 3 of these eyes, this region was hypodense and could be a challenge for the clinician to identify.

Conclusion

OCT scans can be used to assess and potentially follow the preserved regions of cpRNFL associated with the macula in eyes with advanced glaucoma if there is a preserved region on the 10-2 VF better than -8 dB.

Portable Perimetry Using Eye-Tracking on a Tablet Computer-A Feasibility Assessment

Purpose

Visual field (VF) examination by standard automated perimetry (SAP) is an important method of clinical assessment. However, the complexity of the test, and its use of bulky, expensive equipment makes it impractical for case-finding. We propose and evaluate a new approach to paracentral VF assessment that combines an inexpensive eye-tracker with a portable tablet computer (“Eyecatcher”).

Methods

Twenty-four eyes from 12 glaucoma patients, and 12 eyes from six age-similar controls were examined. Participants were tested monocularly (once per eye), with both the novel Eyecatcher test and traditional SAP (HFA SITA standard 24-2). For Eyecatcher, the participant's task was to simply to look at a sequence of fixed-luminance dots, presented relative to the current point of fixation. Start and end fixations were used to determine locations where stimuli were seen/unseen, and to build a continuous map of sensitivity loss across a VF of approximately 20°.

Results

Eyecatcher was able to clearly separate patients from controls, and the results were consistent with those from traditional SAP. In particular, mean Eyecatcher scores were strongly correlated with mean deviation scores (r² = 0.64, P < 0.001), and there was good concordance between corresponding VF locations (∼84%). Participants reported that Eyecatcher was more enjoyable, easier to perform, and less tiring than SAP (all P < 0.001).

Conclusions

Portable perimetry using an inexpensive eye-tracker and a tablet computer is feasible, although possible means of improvement are suggested.

Translational Relevance

Such a test could have significant utility as a case finding device.

The Effect of Gender on Visual Field Sensitivity: The Singapore Chinese Eye Study

PURPOSE

Visual field (VF) sensitivity is known to be age-dependent, but there is a paucity of evidence on whether it is gender-dependent. We therefore investigated the effect of gender on VF sensitivity.

METHODS

An observational study involving 491 adults from the population-based Singapore Chinese Eye Study (SCES). Study participants underwent a comprehensive and standardised ocular examination and VF assessment on the Humphrey Field Analyzer II (Carl Zeiss Meditec, Inc., Dublin, CA, USA). The effect of gender on the mean deviation (MD) and pattern standard deviation (PSD) was analysed with linear regression models.

RESULTS

The mean age was 52.9 ± 5.9 years, and 229 (46.6%) participants were women. A total of 800 reliable VFs from 655 healthy eyes without visual impairment, glaucoma and significant cataract were included. The mean (± standard deviation) MD was -0.45 ± 1.01 dB in men, and -0.84 ± 1.20 dB in women. The MD [95% confidence interval] was 0.28 [-0.44 to -0.12] dB lower in females compared to males (P = 0.001) after adjusting for reliability indices, degree of lens opacity, and other potential confounders. The PSD was not significantly different between the genders.

CONCLUSIONS

In the SCES, the population-average of the central VF sensitivity was significantly lower in women compared to men by a small amount (0.28 dB). This effect was observed in healthy eyes, and was not explained by multiple potential confounders. Hence, this likely represents a physiological gender-based difference that is unaccounted for in standard automated perimetry. Further studies in other populations would be needed to corroborate our findings.

Peripheral Endothelial Cell Count Is a Predictor of Disease Severity in Advanced Fuchs Endothelial Corneal Dystrophy

PURPOSE

In advanced Fuchs endothelial corneal dystrophy (FECD), central endothelial changes do not correlate with disease severity. The peripheral endothelial cell count (ECC) has not been studied as a marker of FECD severity. The goal of this study was to determine the relationship between the peripheral ECC and known clinical markers of FECD in advanced cases.

METHODS

Patients with FECD examined between January 1, 2013, and September 1, 2016, by 1 cornea specialist were identified. Medical records from all previous visits were reviewed to include eyes with high-quality central and peripheral in vivo confocal microscopy images performed on the same day as a clinical evaluation. Endothelial photographs were used to perform manual cell counts centrally and peripherally. Clinical grading of FECD from 1 to 4 was performed at the slit-lamp.

RESULTS

We identified 154 eyes of 126 patients that met criteria for inclusion. With higher disease grades, central ECC and peripheral ECC decreased, visual acuity worsened, and central corneal thickness (CCT) increased (all P < 0.05). In patients with advanced disease (defined as either grade 3 or 4, CCT >700, or central ECC <350), the peripheral ECC was the best predictor of disease severity and had the highest number of statistically significant correlations with other clinical markers compared with competing variables.

CONCLUSIONS

In advanced FECD, severity is best determined by the peripheral ECC compared with the central ECC, visual acuity, clinical disease grade, and CCT. The peripheral ECC should be added to the clinical parameters used to evaluate FECD severity.

Physiologic and psychological gender differences in bariatric surgery

BACKGROUND

Bariatric surgery is a safe and effective treatment for clinically severe obesity, but inequity in male and female utilization is well recognized. Approximately 20% of patients undergoing bariatric surgery are male. This paper aims to describe differences in outcomes by gender and to understand the physiologic and psychological differences that may explain this gender gap.

METHODS

We examined 61,708 patients from the Michigan Bariatric Surgery Collaborative (MBSC) undergoing primary bariatric surgery between 2006 and 2016. Clinical data regarding demographics, comorbidities, and outcomes were compared by gender. Preoperative and 1-year postoperative surveys gathered psychological outcomes.

RESULTS

This cohort was consistent with the national population with approximately 22% male patients. There were several significant differences between males and females at the time of surgery. Males tended to be older, have a higher BMI, be married, have lower self-reported depression scores, and have more comorbidities (all p < 0.05). Postoperatively, males suffered more serious complications than women (2.67 vs. 2.12, respectively, p < 0.05). At 1 year postoperatively, males were significantly more satisfied with their operation despite increased complications, decreased weight loss, and decreased rates of comorbidity resolution as compared to females (all p < 0.05).

CONCLUSIONS

Despite significantly lower weight loss and increased complication rates, males tend to have markedly higher satisfaction and psychological well-being scores than females. To improve outcomes in males, earlier referral to surgery may help to significantly reduce their risk. Conversely, increased attention to psychological support in the perioperative period for females may lead to improved psychological outcomes (i.e., body image, depression, psychological well-being).