Why is geographic atrophy more common in Iceland than in other white populations.

• Published in: Acta Ophthalmologica Scandinavica
• Main Author: JONASSON, F
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2007
• Subjects: Iceland
• Online Access: http://dx.doi.org/10.1111/j.1600-0420.2007.01063_3230.x; http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1600-0420.2007.01063_3230.x; http://onlinelibrary.wiley.com/wol1/doi/10.1111/j.1600-0420.2007.01063_3230.x/fullpdf

Abstract Purpose: Studies have shown geographic atrophy to be more common in Iceland than elsewhere. Several possible causes for this are explored. Methods: We use fundus photographs and standardized grading and classification of age‐related maculopathy and age‐related macular degeneration to establish prevalence and 5‐year incidence. We use a questionnaire regarding lifestyle and diet. We genotyped 581 Icelandic patients with advanced AMD (278 neovascular AMD, 203 GA & 100 with mixed neovascular AMD/GA). We examined CFH and closely related genes CFHR1‐4 and HTRA1. Results: Reykjavik Eye Study includes 1045 participants born 1890 – 1946. Those better nourished than the average seemed to have a protective effect against late AMD. Iris colour was not associated with AMD. Smoking may confer similarly increased risk for GA and wet AMD. CFH confers similar risk for drusen, GA and wet AMD. Changes in the promoter region of HtrA serine peptidase1 (HTRA1) confer slightly higher risk to wet AMD than GA though this difference is not statistically significant. Conclusions: Smoking lead to increased risk of prevalent AMD and to increased 5‐year mortality. Genetic risk for wet AMD and GA appeared similar suggesting that at least in part they share the same genetic pathway. The generation under consideration consumed hardly ever vegetables containing lutein and zeaxanthin, did however have a very high intake of Omega‐3 from fish and fish‐oil the latter with high doses of Vitamin A added. High Vitamin A itake over a lifespan may have increased the lipofuscine content in the retinal pigment epithelium and lack of lutein and zeaxanthin intake over the same lifespan may have lead to serious deficit and both may have increased the risk of geographic atrophy in this population.