Age-Related Changes of Intraocular Pressure in Elderly People in Southern China: Lingtou Eye Cohort Study

Age-specific distribution of intraocular pressure in elderly Iranian population and its associated factors

Background

The purpose of this study was to determine the distribution of intraocular pressure (IOP) and assess its association with age, sex, systemic blood pressure, diabetes mellitus, body mass index (BMI) and tobacco smoking in Iranian elderly population.

Methods

This cohort-based, cross-sectional study assessed elderly individuals aged 60-90 years in Amirkola, northern Iran, in 2016-2017. Past medical history, blood pressure, diabetes mellitus, BMI and tobacco smoking were recorded through an interview and physical examination. IOP was assessed using non-contact tonometry.

Results

Total of 1377 individuals participated in this study, out of which 1346 IOP measurements were included for the final analysis. The mean age of participants was 69.4 ± 7.1 years and mean IOP was determined to be 16.7 ± 3.2 mmHg. Majority of the participants were males (56.1% vs 43.1%), 73.8% of participants were overweight or obese, 6.1% smoked tobacco, 28.9% had diabetes mellitus and 84.9% had higher than normal blood pressure. Through multiple regression analysis, it was determined that age (β=-0.132, p<0.001) was negatively associated with IOP, and the presence of diabetes mellitus (β=0.118, p<0.001), systolic blood pressure (β=0.101, p<0.001), and BMI (β=0.020, P=0.020) were positively associated with IOP.

Conclusion

Mean IOP of individuals in this study was higher than average based on other studies. Age, was negatively and systemic blood pressure, BMI and presence of diabetes mellitus were positively associated with mean IOP of elderly Iranian population. Sex and tobacco smoking were not correlated with IOP.

Age-Related Changes in Intraocular Pressure: Japan Ningen Dock Study

PRCIS

The analysis of intraocular pressure by age using a mega database showed a consistent age-related intraocular pressure decrease.

PURPOSE

To clarify the association between age and intraocular pressure (IOP), the IOP value by age was assessed using a large IOP database.

MATERIALS AND METHODS

This cross-sectional study was conducted among 103 health checkup institutions registered to the Japan Society of Ningen Dock, and included participants who underwent annual health checkups between April 2014 and March 2015. The inclusion criteria were as follows: complete data for IOP in eyes, body mass index, waist circumference, blood pressure, hemoglobin A1c, and a self-administered health questionnaire. A total of 655,818 participants were enrolled. The mean age was 51.5±10.5 years (range, 20-96 y), and 40.1% were women. IOP was measured using a noncontact tonometer. Multiple linear regression analysis was conducted to explore factors associated with IOP, including age, and analyses stratified by age group: <40, 40-69, and ≥70 years.

RESULTS

A consistent negative association between IOP and age [β=-0.353 (95% confidence interval: -0.360--0.346)] was observed. In the age groups of <40 and ≥70 years, the age-related IOP decline was more pronounced [β=-0.502 (95% CI: -0.566 to -0.439); β=-0.674 (95% CI: -0.753 to -0.595)], with it being 14.21±2.95 and 11.18±2.52 mm Hg in the 20-24 and 90-96 year age groups, respectively. The middle-aged (aged 40-69 y) population showed gradual decline [β=-0.313 (95% CI: -0.323 to -0.303)].

CONCLUSION

Age was strongly and negatively associated with IOP. The magnitude of IOP decline across lifespans was ∼3 mmHg. Age-related decreases in IOP were nonlinear and phasic.

Gut Microbiota of Individuals Could Be Balanced by a 14-Day Supplementation With Laminaria japonica and Differed in Metabolizing Alginate and Galactofucan

Laminaria japonica is rich in alginate (Alg) and galactofucan (GF) which have both been reported to regulate gut microbiota composition. To reveal the effect of L. japonica on human gut microbiota, the fecal microbiota of 12 volunteers before and after 14-day L. japonica intake was sequenced and compared, and the capabilities of the gut microbiota to utilize Alg and GF were also investigated. The 16S rRNA gene sequencing results demonstrated that Firmicutes/Bacteroidetes ratio could be balanced by L. japonica supplementation. The ability of gut microbiota to utilize Alg was significantly enhanced by L. japonica supplementation. Furthermore, the multiple linear regression analysis suggested that bacteria from Bacteroidaceae and Ruminococcaceae were positively correlated with Alg utilization while those from Erysipelotrichaceae, Bacteroidaceae, and Prevotellaceae participated in GF degradation. Moreover, the production of acetic acid and the total short-chain fatty acids (SCFAs) in fermentation were consistent with the consumption of Alg or GF, and propionic acid content was positively correlated with Alg consumption. In addition, the percentage of monosaccharides in the consumed GF after the fermentation suggested that gut microbiota from individuals could consume GF with different monosaccharide preferences. These findings shed a light on the impacts of dietary L. japonica on human health.

Serum Calcium Level as a Useful Surrogate for Risk of Elevated Intraocular Pressure

BACKGROUND

Uncontrolled intraocular pressure (IOP) plays a principal role in the deterioration of glaucoma, and the intraocular pressure is also accepted as the most important modifiable factor. Calcium ion has been found to play a vital role in regulating the resistance of the trabecular meshwork in humans. However, the relationship between serum total calcium and IOP has not been well-established.

METHODS

We investigated the association between serum total calcium and the IOP in a large population (14,037 eligible participants, consisting of 7712 men and 6325 women, were included) at the Tri-Service General Hospital from 2010 to 2016. Several models of covariate adjustments associated with IOP were designed. Univariate and multivariate regression analysis was performed for gender differences in the association between the serum total calcium level and IOP.

RESULTS

There was a significant relationship between serum total calcium levels and IOP in women and men with a β coefficient of 0.050 (95% confidence interval (CI), 0.030-0.069) and 0.025 (95%CI, 0.007-0.043). Notably, participants in the highest tertiles of serum total calcium levels had significantly higher IOP, in both the male and female participants.

CONCLUSIONS

Our study shows that IOP is significantly associated with serum total calcium levels in a large Asian population. This study supports the notion that serum total calcium may play an important role in groups at high risk for elevated IOP.

Gender-Specific Association Between Serum Uric Acid and Incident High Intraocular Pressure in Chinese Population: A Cross-Sectional Study

Purpose

The purpose of this study was to investigate the relationship between high intraocular pressure (IOP) and uric acid.

Methods

In a retrospective cross-sectional study, 19,147 participants were included in 2018. Serum uric acid (SUA) was cut to four groups as Q1 to Q4, according to the quartiles. The odds ratio (OR) and 95% confidence interval (CI) of different SUA levels were estimated by a binomial logistic regression model in men and women. A restrictive cubic spline method was used to estimate the dose-response relationship between uric acid and high IOP. Subgroup analysis was performed to find the gender-specific association between uric acid and high IOP.

Results

In women, after adjusting for confounding factors, the Q3 and Q4 of SUA levels were significantly associated with the risk of high IOP. The OR with 95% CI for Q3 and Q4 were 1.77 (1.22, 2.57) and 1.51 (1.01, 2.26), respectively, Q1 as a reference. For men, SUA levels were not associated with the incidence of high IOP. Moreover, the spline analysis found an inverted U‐shaped relationship between uric acid and high IOP in women (P = 0.0171).

Conclusions

Elevated levels of SUAwere independently associated with an increased risk of high IOP in women, but not in men. In addition, uric acid had an inverse U-shaped nonlinear dose-response relationship with high IOP in women.

Ocular biometric parameters are associated with non-contact tonometry measured intraocular pressure in non-pathologic myopic patients

PURPOSES

This research aimed to investigate effects and risk factors on non-contact tonometer (NCT) readings in healthy myopic subjects by employing cross-sectional study design.

METHODS

Totally, sixty otherwise healthy myopic volunteers (mean 28.4 years old) with 90% female were recruited in ophthalmic clinic. The routine ophthalmic tests, refractive evaluation, examination central corneal thickness (CCT), depth of anterior chamber, axial length, corneal curvature, white-to-white and NCT were assessed at baseline. The linear-mixed model was utilized to evaluate correlation between the readings and ocular biometric parameters.

RESULTS

For population in this study, mean spherical equivalents were - 4.85 ± 1.79 diopters in right eyes and - 4.63 ± 1.95 diopters in left eyes. Meanwhile, 28.3% of the eyes had a refractive error exceeding - 6.0 diopters. The mean NCT reading was 15.02 ± 3.02 mmHg in left eyes and 15.33 ± 2.96 mmHg in right eyes. Among the factors analyzed, CCT was the most significant parameter associated with NCT readings. After adjusting for the other factors, per one standard deviation increase of central corneal thickness (36.11 μm) was associated a 1.14 (95% confidence interval 0.53-1.77) mmHg elevated NCT reading. The average central corneal curvature, age and spherical equivalence were also significantly and independently associated with NCT readings.

CONCLUSIONS

Central corneal thickness, age, corneal curvature and degree of myopia were independently associated with NCT measured intraocular pressure. Central corneal thickness is one of the most influential factors.

Intraocular Pressure in General and Diabetic Populations From Southern China: the Dongguan Eye Study

Purpose

To investigate the distribution and risk factors for intraocular pressure (IOP) among general and diabetic populations in Southern China.

Methods

The study participants aged 40 years or older were enrolled from the Dongguan Eye Study, a population-based cross-sectional study from September 2011 to February 2012. Systemic and ophthalmic examinations were performed, and diabetes status was screened based on the American Diabetes Association diagnostic criteria (2010). IOP was measured by a noncontact tonometer per standardized protocol. Regression analyses were used to assess the association between potential risk factors and IOP.

Results

A total of 2112 subjects were included with a median age of 55 years. IOP for general population showed a near normal distribution with an average of 15.58 ± 3.27 mm Hg. Multiple regression analyses revealed that higher IOP was significantly correlated with younger age, higher body mass index (BMI), shorter height, higher blood pressure (BP), higher fasting blood glucose (FBG), higher low-density lipoprotein cholesterol (LDL-C), lower high-density lipoprotein cholesterol (HDL-C), and thicker central corneal thickness (CCT). There was no association between diabetes status and IOP after adjusting for possible confounders. IOP for diabetic participants showed a right-skewed distribution. Risk factors for IOP elevation in diabetes included female, younger age, higher BP, higher LDL-C, lower HDL-C, and thicker CCT.

Conclusions

The present study identifies risk factors for elevated IOP in general and diabetic populations. Younger age and lower HDL-C, as well as higher BP, LDL-C, and CCT were significant factors contributing to higher IOP, especially in the female diabetic population.

Ten-year changes of intraocular pressure in adults: the Liwan Eye Study

IMPORTANCE

Understanding the longitudinal intraocular pressure (IOP) changes and potential risk factors in adults is important for future glaucoma control in the aging society.

BACKGROUND

Limited longitudinal studies exist in Asia investigating the longitudinal IOP changes and with varying results.

DESIGN

Population-based cohort study.

PARTICIPANTS

1405 baseline participants from the Liwan Eye Study.

METHODS

All baseline participants were invited for the 10-year follow-up examination in 2013. IOP (by Tonopen), central corneal thickness (CCT; by ultrasound), refractive error (by autorefractor), blood pressure, height and weight were measured per standardized protocol and the presence of hypertension or diabetes was collected by questionnaire. Follow-up examinations were conducted using the same equipment with proper calibration. Linear regression analysis was used to assess the association between IOP change and potential risk factors.

MAIN OUTCOME MEASURES

10-year IOP change.

RESULTS

Of the 791 participants at the 10-year follow-up, IOP data were available for 602 participants with a mean age of 60.9 years (55.5% female). The average IOP change over 10 years was an increase of 1.44 mmHg (95% confidence interval, 1.12-1.75). Linear regression showed that 10-year IOP change was not associated with baseline age, gender, body mass index (BMI), CCT, spherical equivalence (SE), hypertension or diabetes. However, it was positively associated with longitudinal increase of BMI when longitudinal changes of BMI and SE were included in the model (P < 0.001).

CONCLUSIONS AND RELEVANCE

We observed a small increase in IOP over 10 years in this adult Chinese population, which was positively related to the longitudinal change in BMI.

Inter-relationship between ageing, body mass index, diabetes, systemic blood pressure and intraocular pressure in Asians: 6-year longitudinal study

Background

To investigate the biological effect of ageing on intraocular pressure (IOP) and risk factors in a population-based cohort study of Malay and Indian adults.

Methods

Participants aged 40–80 years were recruited for baseline and 6-year follow-up visits between 2004–2009 and 2010–2015, respectively. Blood pressure (BP) was measured with an automatic BP monitor and IOP were obtained by Goldmann applanation tonometry. Main outcome was change in IOP, defined as the difference between the 6-year IOP and the baseline IOP. Linear regression models were used to investigate the association of changes in IOP with risk factors.

Results

 Participants without a history of glaucoma or cataract surgery at baseline were included (n = 3188; mean age: 54±9 years) . Their average IOP was reduced (−0.5±3.1 mm Hg), except for those who developed hypertension at follow-up (0.0±3.1 mm Hg). After adjusting for covariates, changes in IOP were negatively associated with age (β=−0.07, 95% CI −0.13 to −0.01) and positively associated with body mass index, diabetes, hypertension (normotensive as reference group; newly developed hypertensive (β=0.67, 95% CI 0.39 to 0.95) and chronic hypertensive (β=0.46, 95% CI 0.22 to 0.70)), baseline systolic BP (SBP) (β=0.20, 95% CI 0.14 to 0.26) and diastolic BP (DBP) (β=0.33, 95% CI 0.22 to 0.44), as well as with 6-year increases in SBP (β=0.27, 95% CI 0.21 to 0.33) and DBP (β=0.52, 95% CI 0.41 to 0.63).

Conclusions

Normal ageing and reduced systemic BP are associated with reduced IOP in Malay and Indian adults. Given that high IOP is a risk factor for glaucoma, our finding highlights the importance of controlling hypertension in older adults, where hypertension and glaucoma incidences are on a rise.

Longitudinal changes in intraocular pressure and association with systemic factors and refractive error: Lingtou Eye Cohort Study

OBJECTIVES

To investigate the longitudinal changes in intraocular pressure (IOP) and its associations with refractive error and systemic determinants in a Chinese geriatric population.

DESIGN

Prospective cohort study.

SETTING

Guangzhou Government Servant Physical Check-up Center, Guangzhou, China.

PARTICIPANTS

4413 government employees aged no less than 40 years (41.9% female) attending annual physical and eye examinations were included in this study. The inclusion criterion was having attended the 2010 follow-up examination. The exclusion criteria include glaucoma or intraocular surgery history, IOP >21 mm Hg at any visit or without available IOP data at all visits from 2010 to 2014.

PRIMARY AND SECONDARY OUTCOME MEASURES

The outcome measure was IOP at each follow-up visit from 2010 to 2014. Mixed-effect model was used to assess the relationship between longitudinal changes in IOP and potential risk factors.

RESULTS

For the 2653 participants who had available IOP data at both the 2010 and 2014 follow-up visits, the average change in IOP was an increase of 0.43 (95% CI 0.36 to 0.50) mm Hg. For the whole study population and in the optimised mixed model, there was a non-linear increase of IOP with age (P<0.001), with greater changes in younger subjects and in women (P<0.001 and P=0.002, respectively). Elevations in systolic blood pressure, diastolic blood pressure, body mass index (BMI) and fasting plasma glucose (FPG), as well as a myopic shift (all with P<0.001), during the follow-up were associated with an increasing trend of IOP, while serum lipids were found to be not significantly associated.

CONCLUSIONS

In this cohort of elderly Chinese adults, IOP increases non-linearly with ageing. People with increasing blood pressure, BMI, FPG and myopic progression are more likely to have IOP elevation over time.