Reticular drusen linked to AMD progression

Jul 1 2014

By Afsaneh Gray, medwireNews Reporter

Four percent of individuals aged 49 years and above will develop reticular drusen over 15 years of follow-up, Australian study findings suggest, with the incidence higher in those with age-related macular degeneration (AMD) risk factors.

The findings also showed that patients with reticular drusen were four times more likely than those without the condition to go on to develop late AMD, but increased fish consumption lowered this risk.

According to study author Jie Jin Wang (University of Sydney, New South Wales) and colleagues, reticular drusen has been relatively under-researched, and has often been grouped together with other lesions in previous studies. Their research aimed to rectify this, and to assess possible links between common AMD risk factors and other early AMD lesion characteristics and the incidence of reticular drusen and its progression to late AMD.

The researchers recruited 3654 participants to the Blue Mountains Eye Study, of whom 75.8% of survivors attended 5-year follow-up examinations, and 76.7% and 56.1% attended 10- and 15-year follow-ups, respectively.

At baseline, colour retinal photographs confirmed the presence of reticular drusen in 118 eyes. Genotyping of DNA samples indicated that the presence of two risk alleles, one in the CFH gene (rs1061170) and one in the ARMS2 gene (rs10490924) were associated with a 1.8-fold and 3.0-fold higher incidence of reticular drusen, respectively. Furthermore, each decade of increasing age, led to a 3.4-fold increase in reticular drusen incidence, and being female, rather than male, doubled the incidence. Being a current smoker was also found to be a significant independent risk factor, after accounting for the other factors.

In all, 40, or 33.9%, of people with reticular drusen at baseline went on to develop late AMD over 5 years. Progression to late AMD was more likely to occur in patients with reticular drusen located outside rather than inside the macular area (50.0 vs 37.8%).

Dietary lutein–zeaxanthin intake, which is found in fish, was associated with a decreased likelihood of progression from reticular drusen to late AMD. Nonetheless, the authors caution that “this observation was based on a relatively small sample of eyes of participants who had dietary intake information available.”

Writing in Ophthalmology, they conclude: “The proportion of eyes that progressed from reticular drusen to late AMD over 5 years was 4-fold that in eyes without reticular drusen, suggesting that this sign portends a higher risk.”

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