Most Read Articles
Jairia Dela Cruz, 04 Jul 2016
The risk of band keratopathy may be greatly increased in patients with end-stage renal disease (ESRD), and significant risk factors are iridocyclitis and degenerated eye, according to a Taiwan-based cohort study billed as the largest to ever be conducted on the relationship between the two conditions.
Audrey Abella, 26 Apr 2017
Intravitreous administration of the vascular endothelial growth factor (VEGF) inhibitor ranibizumab does not increase the risk of cardiovascular and cerebrovascular events in patients with diabetic macular edema (DME), according to a recent study.
4 days ago
A number of clinical tumour and treatment parameters, most of which are shown to reflect initial tumour size, appear to contribute to the regression of choroidal melanoma after brachytherapy, a recent study has shown.
Tristan Manalac, 01 May 2018
Eating dark chocolates may have short-term beneficial impacts on vision, according to a recent study, which reports significant improvements in contrast sensitivity and visual acuity following dark vs milk chocolate consumption.

Elevated urinary F2-isoprostanes tied to age-related macular degeneration

Tristan Manalac
24 Jul 2017

Elevated level of F2-isoprostanes in the urine is independently associated with age-related macular degeneration (AMD) in Chinese adults in Singapore, a new case-control study has found.

“We demonstrated that urinary [F2-isoprostanes] were positively associated with any AMD independent of age, sex, smoking, body mass index (BMI), systolic blood pressure (BP), total and high-density lipoprotein (HDL) cholesterol, and cardiovascular disease (CVD),” said researchers.

“The positive association was not linear, with a ceiling effect observed with higher levels, which implied conversely that lower levels of [F2-isoprostanes] were protectively associated with AMD,” they added.

The study included 238 patients with AMD (mean age 66.2±9.4 years; 63.0 percent male) and 390 controls (mean age 67.1±9.2; 64.4 percent male) distributed across four quartiles of urinary F2-isoprostane concentrations.

Compared to the first quartile, those in the second (odds ratio [OR], 1.96; 95 percent CI, 1.21 to 3.19), third (OR, 1.76; 1.08 to 2.88) and fourth (OR, 1.72; 1.03 to 2.88) quartiles had significant correlations with any AMD after adjusting for age, sex, smoking, BMI and other confounders. The trend was not linear (p=0.6 for trend). [Invest Ophthalmol Vis Sci 2017;58:2538-2543]

Repeated analysis showed that those in the second (OR, 2.32; 1.40 to 3.85), third (OR, 1.98; 1.19 to 3.31) and fourth (OR, 1.81; 1.06 to 3.09) also showed significant associations with early AMD (p=0.3 for trend).

While subgroup analysis showed that those with hypertension (OR, 1.84; 1.04 to 3.27), with BMI <25 kg/m2 (OR, 2.38; 1.24 to 4.57) and females (OR, 2.45; 1.04 to 5.76) had higher risks of any AMD, none of the associations were statistically significant.

Urinary F2-isoprostane levels were associated with drusen (OR, 2.06; 1.26 to 337) but not pigmentary lesions (OR, 1.41; 0.86 to 2.33).

“Several potential mechanisms have been postulated to explain the association between [F2-isoprostanes] and AMD,” investigators explained. Previous studies have established the relationship between F2-isoprostanes and atherosclerosis and inflammation, both of which are key drivers of AMD.

”In addition, [F2-isoprostanes] have also been shown to be associated with several proatherogenic factors including smoking, diabetes and hypertension,” they said.

Participants were recruited from thee Singapore Chinese Eye Study. Those with either early or late AMD were designated as cases while age- and sex-matched individuals without any AMD were recruited as controls. AMD was confirmed through fundus photography.

Concentrations of F2-isoprostanes and creatinine were measured from frozen urine samples. Logistic regression models were used to evaluate the association between F2-isoprostanes and AMD.

“[The findings] provide further evidence of a link between oxidative stress and AMD pathogenesis. If confirmed in prospective studies and diverse populations, [F2-isoprostanes] may serve as a potential systemic biomarker for predicting AMD,” said researchers.

Editor's Recommendations
Most Read Articles
Jairia Dela Cruz, 04 Jul 2016
The risk of band keratopathy may be greatly increased in patients with end-stage renal disease (ESRD), and significant risk factors are iridocyclitis and degenerated eye, according to a Taiwan-based cohort study billed as the largest to ever be conducted on the relationship between the two conditions.
Audrey Abella, 26 Apr 2017
Intravitreous administration of the vascular endothelial growth factor (VEGF) inhibitor ranibizumab does not increase the risk of cardiovascular and cerebrovascular events in patients with diabetic macular edema (DME), according to a recent study.
4 days ago
A number of clinical tumour and treatment parameters, most of which are shown to reflect initial tumour size, appear to contribute to the regression of choroidal melanoma after brachytherapy, a recent study has shown.
Tristan Manalac, 01 May 2018
Eating dark chocolates may have short-term beneficial impacts on vision, according to a recent study, which reports significant improvements in contrast sensitivity and visual acuity following dark vs milk chocolate consumption.