Mortality and causes of death in a population with blindness in Korea: A longitudinal follow-up study using a national sample cohort

Development of Cell Culture Platforms for Study of Trabecular Meshwork Cells and Glaucoma Development

BACKGROUND

Various cell culture platforms that could display native environmental cue-mimicking stimuli were developed, and effects of environmental cues on cell behaviors were studied with the cell culture platforms. Likewise, various cell culture platforms mimicking native trabecular meshwork (TM) composed of juxtacanalicular, corneoscleral and uveal meshwork located in internal scleral sulcus were used to study effects of environmental cues and/or drug treatments on TM cells and glaucoma development. Glaucoma is a disease that could cause blindness, and cause of glaucoma is not clearly identified yet. It appears that aqueous humor (AH) outflow resistance increased by damages on pathway of AH outflow can elevate intraocular pressure (IOP). These overall possibly contribute to development of glaucoma.

METHODS

For the study of glaucoma, static and dynamic cell culture platforms were developed. Particularly, the dynamic platforms exploiting AH outflow-mimicking perfusion or increased IOP-mimicking increased pressure were used to study how perfusion or increased pressure could affect TM cells. Overall, potential mechanisms of glaucoma development, TM structures and compositions, TM cell culture platform types and researches on TM cells and glaucoma development with the platforms were described in this review.

RESULTS AND CONCLUSION

This will be useful to improve researches on TM cells and develop enhanced therapies targeting glaucoma.

Re-hospitalizations within 30-days and mortality outcomes among severely visually impaired and blind patients: analysis of the National Readmission Database

BACKGROUND

Readmissions and in-hospital mortality among patients with severe vision impairment or blindness (SVI/B) has not been fully studied. We investigated hospital outcomes for adults with SVI/B in the United States.

METHODS

Using the Nationwide Readmission Database year 2017, we analyzed primary outcomes for thirty-day readmission rates for patients with and without SVI/B. Secondary outcomes were in-hospital mortality rates for readmitted patients, in-hospital mortality rates for index patients, the five most common principal diagnoses for readmission, and resource utilization.

RESULTS

34,558 patients had an index admission for SVI/B vs. 24,600,000 who did not. Patients with SVI/B had a 13.3% [4,383] readmission rate within 30 days compared to 8.4% [2,033,329] without SVI/B. Compared to readmitted patients without SVI/B patients, those with SVI/B were older (mean [SD] age: 64.4 [SD ± 19] vs. 61.4 [SD ± 20] years) and had more comorbidities (Charlson comorbidity score ≥ 3: 79.2% [ 3,471] vs. 60.9% [1,238,299]). The mortality rate among patients readmitted with SVI/B was 5.38% [236] vs. 4.02% [81,740] for patients without SVI/B, p-value = 0.016. Top reasons for readmissions among patients with SVI/B included sepsis 12% [526], heart failure 10.5% [460)], acute renal failure 4.4% [193], complications due to type II diabetes mellitus 4.1% [178], and pneumonia 2.7% [118]. The mean length of stay for readmitted patients with SVI/B was 6.3 days (confidence interval [CI]: 6.0-6.7 days), vs. 5.6 days for patients without SVI/B (CI: 5.5-5.8 days), p-value < 0.01. The mean hospital charges for readmitted patients with SVI/B was $57,202 (CI: $53,712-$61,292) vs. $51,582 (CI: $49,966-$53,198), p-value < 0.01.

CONCLUSION

Patients with SVI/B had higher readmission rates and greater mortality on readmissions than those without SVI/B. Interventional studies for optimal discharge strategies are critically needed to improve clinical and resource utilization outcomes in patients with SVI/B.

A longitudinal study of the association between visual impairment and income change using a national health screening cohort

We evaluated the influence of visual impairment (VI) on income change using the longitudinal database of a Korean National Health Insurance Service cohort. A total of 5292 participants ≥ 40 years old and registered as visually impaired persons were selected at a 1:4 ratio with 45,081 non-VI participants matched for age, sex, and income level. The income level of both the VI and non-VI groups increased over time. In the VI group, the income levels 3, 4 and 5 years were higher than the initial value, while the income levels from 1 through 5 years were increased each year in the non-VI group. The rate of change in income between time and VI were significant. In the subgroup analysis considering age, sex, and severity of VI, the rate of change in income were significant in < 65 years old subgroups. Regarding the severity of VI, a significant interaction was found for the mild-to-moderate VI subgroup. Although both the VI and non-VI groups showed increased income levels over 5 years, the degree of income increase in the VI group was relatively lower than that in the non-VI group. This finding was prominent in the middle-age subgroup. These results strongly suggested that VI induced an income inequality.

Association between glaucoma surgery and all-cause and cause-specific mortality among elderly patients with glaucoma: a nationwide population-based cohort study

This population-based, retrospective cohort study aimed to evaluate the association between glaucoma surgery and all-cause and cause-specific mortality among Korean elderly patients with glaucoma. A total of 16210 elderly patients (aged ≥ 60 years) diagnosed with glaucoma between 2003 and 2012 were included, and their insurance data were analyzed. The participants were categorized into a glaucoma surgery cohort (n = 487), which included individuals who had diagnostic codes for open angle glaucoma (OAG) or angle closure glaucoma (ACG) and codes for glaucoma surgery, and a glaucoma diagnosis cohort (n = 15,723), which included patients who had codes for OAG and ACG but not for glaucoma surgery. Sociodemographic factors, Charlson Comorbidity Index score, and ocular comorbidities were included as covariates. Cox regression models were used to assess the association between glaucoma surgery and mortality. The incidence of all-cause mortality was 34.76/1,000 person-years and 27.88/1,000 person-years in the glaucoma surgery and diagnosis groups, respectively. The adjusted hazard ratio (HR) for all-cause mortality associated with glaucoma surgery was 1.31 (95% confidence interval [CI], 1.05–1.62, P = 0.014). The adjusted HR for mortality due to a neurologic cause was significant (HR = 2.66, 95% CI 1.18–6.00, P = 0.018). The adjusted HRs for mortality due to cancer (HR = 2.03, 95% CI 1.07–3.83, P = 0.029) and accident or trauma (HR = 4.00, 95% CI 1.55–10.34, P = 0.004) associated with glaucoma surgery for ACG were significant as well. Glaucoma surgery was associated with an increase of mortality in elderly patients with glaucoma. In particular, the risk of mortality associated with glaucoma surgery due to neurologic causes was significant.

Severe vision impairment and blindness in hospitalized patients: a retrospective nationwide study

Background

Outcomes among hospitalized patients with severe vision impairment or blindness have not been extensively explored. This study sought to determine clinical and resource utilization outcomes in patients with severe vision impairment/blindness (SVI/B). Because obesity is very common among those who are hospitalized, we also sought to understand its impact among patients with SVI/B.

Methods

We conducted a retrospective study using the National Inpatient Sample for the year 2017; hospitalized adults with and without SVI/B were compared. In addition, for all patients with SVI/B, we compared those with and without obesity. Multiple logistic regression and linear analysis were used to evaluate mortality, disposition, length of stay, and hospital charges; the analyses were adjusted for multiple variables including age, sex, and race.

Results

30,420,907 adults were hospitalized, of whom 37,200 had SVI/B. Patients with SVI/B were older (mean age ± SEM: 66.4 ± 0.24 vs. 57.9 ± 0.09 years, p < 0.01), less likely to be female (50 % vs. 57.7 %, p < 0.01), more frequently insured by Medicare (75.7 % vs. 49.2 %, p < 0.01), and had more comorbidities (Charlson comorbidity score ≥ 3: 53.2 % vs. 27.8 %, p < 0.01). Patients with SVI/B had a higher in-hospital mortality rate (3.9 % vs. 2.2 %; p < 0.01), and had lower odds to be discharged home after hospital discharge (adjusted Odds Ratio {aOR} =0.54, [Confidence Interval (CI) 0.51–0.58]; p < 0.01) compared to those without SVI/B. Hospital charges were not significantly different (adjusted Mean Difference {aMD} = $247 CI [-$2,474-2,929]; p = 0.85) but length of stay was longer (aMD = 0.5 days CI [0.3–0.7]; p < 0.01) for those with SVI/B. Patients with vision impariment who were also obese had higher total hospital charges compared to those without obesity (mean difference: $9,821 [CI $1,375-$18,268]; p = 0.02).

Conclusions

Patients admitted to American hospitals in 2017 who had SVI/B had worse clinical outcomes and greater resources utilization than those without SVI/B. Hospital-based healthcare providers who understand that those with SVI/B may be at risk for worse outcomes may be optimally positioned to help them to receive the best possible care.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-02021-2.

Blindness increases the risk for hip fracture and vertebral fracture but not the risk for distal radius fracture: a longitudinal follow-up study using a national sample cohort

The risks for hip fracture and vertebral fracture, but not the risk for distal radius fracture, were significantly higher in the blindness group than in the control group with a maximum 12-year follow-up.

PURPOSE

To evaluate the influence of visual impairment on the risk for osteoporotic fractures at common sites: hip, thoracic/lumbar vertebra, and distal radius.

METHODS

This longitudinal follow-up study used a database of a national sample cohort from 2002 to 2013 provided by the Korean National Health Insurance Service. Of a total of 1,125,691 subjects, 3918 patients with visual impairment and age ≥ 50 years were enrolled in a 1:4 ratio; 15,672 control participants were matched for age, sex, income, and region of residence. Stratified Cox proportional-hazards models were used to evaluate the crude and adjusted (for steroid medication, rheumatoid arthritis, depression, osteoporosis, diabetes mellitus, and stroke history) hazard ratios (HRs) for each fracture site. Fracture diagnoses were based on the ICD-10 codes: hip fracture (S720, S721, S722), vertebral fracture (S220, S320), and distal radius fracture (S525).

RESULTS

The HRs for hip and vertebral fracture were significantly higher in the blindness group (adjusted HR = 2.46, p < 0.001 for hip fracture; adjusted HR = 1.42, p = 0.020 for thoracic/lumbar vertebral fracture) than in the matched control group. However, the HR for distal radius fracture was not higher in the blindness group. The HRs for all three fracture sites were not significantly higher in the non-blindness visual impairment group after adjustment.

CONCLUSION

The risks for hip fracture and vertebral fracture were significantly higher in the blindness group. However, the risk for distal radius fracture was not related to visual impairment including blindness.

Is septal deviation associated with headache?: A nationwide 10-year follow-up cohort study

To investigate the potential relationship between septal deviation (SD) and headache using nationwide representative cohort sample data.This study used a nationwide cohort sample from the Korean National Health Insurance Service database. The cohort sample was composed of 1 million patients, which is obtained by propensity score matching from 2002 to 2013. There were 9171 individuals in the SD group and 28243 in the control or no SD group. The Kaplan-Meier survival analysis, the log-rank test, and Cox proportional hazard regression analysis were used to calculate the incidence, survival curve, and hazard ratio of headache for each group.There were no statistically significant differences in sex (P = .7708), age (P = .991), residential area (P = .9626), or socioeconomic status (P = .9982) between the 2 groups. The survival curve between SD and control or no SD showed a statistically significant difference. The adjusted hazard ratio for headache incidence during the 10-year follow-up period of the SD group was 1.37 (95% CI: 1.31-1.43).This cohort study suggests that SD is associated with headache. Therefore, these findings suggest that septoplasty can be considered as 1 of the treatment option in SD patients with headache.