A large-scale longitudinal investigation has shed new light on the effects that age and systemic factors have on intraocular pressure (IOP) – an important clinical risk factor for many ophthalmological diseases, including glaucoma.
While further research is necessary, the study suggests lifestyle changes may be useful to suppress IOP. If proven, this could reduce the heavy global burden of medications, laser treatment, and surgeries currently used to achieve IOP targets.
Published in Investigative Ophthalmology & Visual Science, the study found that a combination of age and systemic factors, including gender and several serum values, were significantly associated with a longitudinal change in IOP.
a combination of age and systemic factors, including gender and several serum values, were significantly associated with a longitudinal change in IOP
To undertake the study, Prof Ryo Asaoka and colleagues from the Department of Ophthalmology at the University of Tokyo, analysed 20,909 eyes from 10,471 participants (mean age, 52.7 years; 65.9% men) without glaucoma from a large-scale health screening cohort at Seirei Center for Health Promotion and Prevention Medicine in Japan.
With age and sex noted at baseline, systemic factors of participants were then reported annually for at least eight years noting: time series body mass index (BMI), time series smoking habits, time series systolic and diastolic blood pressures (SBP and DBP), and time series 19 blood examinations.
Prof Asaoka and colleagues reported that IOP significantly decreased by −0.084mmHg/year.
“BMI, SBP, DBP, smoking habits, total triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and glycosylated haemoglobin A1c were not significantly associated with the change of IOP.
“Higher values of age, aspartate aminotransferase, haemoglobin, platelet, and calcium were suggested to be significantly associated with the decrease of IOP, whereas higher alanine aminotransferase, guanosine triphosphate, white blood cell count, red blood cell count, and female gender were significantly associated with the increase of IOP.”
The researchers reported that there were several limitations of this study, including noncontact tonometry readings, and an absence of central corneal thickness measurements that are known to induce measurement errors during tonometry. Of 10,471 subjects, 1,494 were taking systemic hypertension medication(s), which lower IOP and are related to many of the factors included in the study – the contents of the medication (for example, beta-blockers) were not collected.
Additionally, the 10,471 subjects were just 27.6% of the 37,989 subjects who attended the screening program in the initial three years (meaning over 72% of participants dropped out for various reasons). Finally, significant differences were observed in age, gender, height, BMI, DBP, and smoking habitat between the two groups.
Despite these limitations, Prof Asaoka and colleagues wrote, “The current results suggested that IOP might be suppressed by changing life habitat, such as increasing the intake of foods containing calcium and maintaining good biliary tract functions, however, these are not the results of intervention. A further study would be needed to investigate the effect of changing life habitat on IOP trend.”
Reference Asaoka, R., Obana A., Murata, H., et al., The Association Between Age and Systemic Variables and the Longitudinal Trend of Intraocular Pressure in a Large-Scale Health Examination Cohort. Invest. Ophthalmol. Vis. Sci. 2022;63(11):22. doi:https://doi.org/10.1167/iovs.63.11.22.
