Abstract
Purpose :
Opacification of the human lens is irreversible, age-dependent, and inevitably results in cataract formation. The opacification process is modified by lifestyle factors, including smoking and anti-oxidant intake, ultraviolet light exposure, as well as ocular and systemic comorbidities and their treatments such as corticosteroid therapy. Assessment of lens opacification (LO) may contribute to a better understanding of ageing processes. To elucidate whether and to what extent chronic inflammation could contribute to age-associated LO, we assessed the relation between a range of inflammatory markers and LO in a population-based study.
Methods :
In the population-based Rhineland Study (www.rheinland-studie.de) we performed objective densitometry of the lens using Scheimpflug imaging (Pentacam AXL, Oculus). We assessed associations between blood markers of systemic inflammation, in particular interleukins (IL) – 6, 8, 10, and tumor necrosis factor-alpha (TNF-a) and LO (in % grey value) using multivariable linear regression. We adjusted for potential confounders (age, sex, body-mass-index (BMI), spherical equivalent (SE), smoking, history of diabetes, hypertension and stroke, use of corticosteroids, and leukocyte count) and excluded participants who reported pseudophakia.
Results :
Complete data on lens densitometry and inflammatory markers were available from 3,518 individuals whose age ranged from 30 to 90 years (mean (SD) 53.2 ± 12.5) with a mean LO of 9.6% ± 1.0 (range 7.6 to 13.1). LO increased with age (0.07% per year, p<0.001) and with more hyperopic SE (0.03% per diopter, p<0.001). Moreover, higher serum levels of IL-8 (0.003% per pg/ml, p=0.005) and leukocyte count (0.01% per G/l, p=0.09) were independently associated with increased LO, the latter borderline statistically significant. We found no association with IL-6, IL-10 and TNF-a.
Conclusions :
Our results suggest a potential role of chronic systemic inflammation in the pathogenesis of LO. IL-8 is a pro-inflammatory cytokine and activates leukocytes, resulting in the release of oxygen radicals, which may contribute to age-associated LO. The potential of LO to be used as a biomarker for biological ageing or systemic inflammation needs to be explored further in longitudinal studies.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.