Systemic, Ocular and Genetic Risk Factors for Age-related Macular Degeneration and Polypoidal Choroidal Vasculopathy in Singaporeans

Abstract

To examine the association of systemic, ocular and genetic risk factors in neovascular age-related macular degeneration (nAMD) in a large cohort of Asian patients, and to further compare risk factors between those with typical AMD and polypoidal choroidal vasculoapthy (PCV) subtypes. We recruited 456 cases and 1,824 controls matched for age, gender and ethnicity. Data on systemic and ocular risk factors were collected on questionnaires. In a subgroup of subjects, we included genetic data on four AMD-associated single nucleotide polymorphisms (SNPs). Risk factors for nAMD and subtypes were analyzed. Systemic risk factors for nAMD included older age, male gender, higher BMI and higher HDL-cholesterol. Ocular risk factors included pseudophakic and shorter axial length. Risk factors common to both typical AMD and PCV subtypes included age, BMI and HDL-cholesterol. Shorter axial length was only associated with PCV, while male gender and pseudophakia were only associated with typical AMD. In the subgroup with genotype data, ARMS2 rs10490924 and CFH rs800292 were associated with nAMD. None of the risk factors were significantly different between PCV and typical AMD. Systemic, ocular and genetic risk factors were largely similar for typical AMD and PCV subtypes in this Asian population based in Singapore.

Polypoidal Choroidal Vasculopathy in Congolese Patients

“…It is unlikely that such an association existed in our cohort, where only one patient was diabetic. [45], but the association was not observed with either PCV or AMD in another investigation [51]. Serum total cholesterol was within normal range in all 14 patients, which may be consistent with the lack of its association with PCV reported by Fujiwara et al [52] and Li et al [54].…”

“…e Beijing Study [30] also reported a lack of such an association, contrasting with findings of a Singaporean study where smoking conferred a 4.2-fold greater risk for PVC [37]. In the Singapore Epidemiology of Eye Diseases Program [51], subjects with higher BMI were more likely to have PCV, contrasting with findings of two Japanese studies [45,52]. Because of the design of the present study, we cannot say with certainty whether higher BMI (57.1%) is a risk factor for PCV.…”

“…While 2 of our patients had lower serum levels of HDLcholesterol, studies on the association of PCV with HDLcholesterol levels have produced inconsistent findings. Fujiwara et al [52] as well as Li et al [54] failed to find an association, whereas Cheung et al [51] and Fan et al [55] reported that higher levels of HDL-cholesterol were significant risk factors for PCV. PCV classically presents on fundus examination as an orange-red nodule in the macula or peripapillary region, associated with serosanguineous PED without drusen [1,12].…”

“…A specific reason to our population may be the high prevalence of HTN and uncontrolled HTN in Kinshasa [50]. However, it is worth noting that two studies in Singapore, a large hospital-based case-control study [37] and a population-based case-control study among participants of the Singapore Epidemiology of Eye Diseases Program and the Asian AMD Phenotyping Study [51], the Beijing Eye Study [30], and two other studies in Japan [38,52] failed to find a significant association between HTN and PCV, thereby contributing to the ongoing debate on the putative role of HTN in PCV development. On the contrary, Kikuchi et al [45] reported a significantly higher proportion of people with HTN among PCV patients than among controls.…”

Asian age-related macular degeneration: from basic science research perspective

“…Interestingly Asian specific CETP D442G mutation is known to impair CETP function and increase serum high-density lipoprotein (HDL) cholesterol levels. In Asian population, higher HDL was an independent risk factor for neovascular AMD including typical AMD and PCV [62]. Similarly, genome-wide association studies conducted in Western countries have shown an association between AMD and hepatic lipase (LIPC), which also affects serum HDL cholesterol levels.…”