Extramacular Drusen Commonly Observed in Eyes with AMD

February 23, 2023

Article

An analysis of data from AREDS2 suggests extramacular drusen in eyes with AMD are more frequent with an increased drusen burden within the macula.

Emily Y. Chew, MD

Credit: National Eye Institute

Key Highlights

Extramacular drusen are commonly observed in eyes with age-related macular degeneration (AMD).
Data from AREDS2 suggest extramacular drusen are more frequent with an increased drusen burden observed within the macula.
Extramacular drusen may not have additional risk in the progression from intermediate AMD to late AMD.
Investigators observed extramacular drusen represented a small area (< 0.5 mm2) in approximately half of eyes.
Eyes with extramacular drusen exhibited larger macular drusen size and area compared to eyes without extramacular drusen (P <.001).
Extramacular drusen were not associated with progression to late AMD.

Extramacular drusen were commonly observed in eyes with age-related macular degeneration (AMD), according to a retrospective analysis of the Age-Related Eye Disease Study 2 (AREDS2).¹

The analysis suggests extramcular drusen in eyes with AMD are more frequent with an increased drusen burden within the macula, but may not indicate additional risk in the progression from intermediate AMD to late AMD.

“In eyes with intermediate AMD, extramacular drusen do not confer additional risk to previously identified risk factors in progression to late AMD,” wrote the investigative team.

The investigative team, led by Emily Y. Chew, MD, set out to identify the prevalence of extramacular drusen and their role in the progression of AMD, using 4168 eyes (2998 participants) with AMD in one of both eyes enrolled in AREDS2. AREDS2 was a 5-year multicenter study of nutritional supplements.

The team evaluated baseline 3-field 30-degree color photpgrahs for drusen characteristics outside the macular grid, including size, area, and location. Then, the characteristics of extramacular drusen were compared with those of drusen within the macula. Main outcomes for the study were progression rates to late AMD.

In their results, investigators observed extramacular drusen represented a small area (< 0.5 mm²) in approximately half of eyes. Although extramacular drusen were observed in 3624 (86.9%) eyes, data showed they represented that small area in 50.3% of eyes and only 17.5% of eyes exhibited an area of >1 disc area.

Investigators additionally found eyes with extramacular drusen exhibited larger macular drusen size and area compared to eyes without extramacular drusen (P <.001). They noted extramacular drusen were not associated with progression to late AMD.

In further analysis, the hazard ratio adjusted for baselien age, sex, smoking, AMD severity level, and reticular pseudodrusen for the 4043 eyes at risk of developing late AMD over 5 years was 1.17 (95% confidence interval [CI], 0.88 – 1.54; P = .27) for geographic atrophy. In addition, the hazard ratio for neovascular AMD was 0.96 (95% CI, 0.76 - 1.2; P = .7).

References

Domalpally A, Xing B, Pak JW, et al. Extramacular Drusen and progression of age-related macular degeneration. Ophthalmology Retina. 2023;7(2). doi:10.1016/j.oret.2022.08.001