Cuticular Drusen Volume May Help Predict Progression of Age-Related Macular Degeneration 

The presence of numerous cuticular drusen may confer risk for disease progression in patients with age-related macular degeneration (AMD), according to research published in Retina. Multimodal imaging datasets which include fluorescein angiography (FA) may confirm if solitary nodular drusen progresses to high-risk soft drusen, according to the report.   

Researchers histologically determined median and interquartile range (IQR) of base widths of single (non-confluent) nodular drusen from 3 sources: 43 eyes from 43 clinically undocumented donors with AMD histopathology in an online resource, 1 eye from a 90-year-old woman with bilateral AMD who underwent FA at presentation at age 79, and 2 eyes of a 61-year-old man with cuticular drusen with “starry sky” FA. The research team processed all tissues for high-resolution epoxy-resin histology and for cuticular drusen, transmission electron microscopy.

The researchers observed that all drusen localized between the retinal pigment epithelium basal lamina and inner collagenous layer of Bruch’s membrane. They also observed that all of the drusen were solid, globular, homogeneously stained with toluidine blue, and uncovered through basal laminar deposit and basal mounds. 

The median base widths were 13.0 µm (Source 1; n=128 drusen; IQR 7.7, 20.0 µm), 15.3 µm (Source 2, n=87, IQR 10.6, 20.5 µm), and 7.3 µm (Source 3; n=78; IQR 3.9, 14.1 µm), the report shows.  

“We find that both isolated nodular drusen and cuticular drusen are hyperfluorescent on FA and have similar morphology and dimensions. For cuticular drusen we additionally observed an apparent transition in internal composition. These data support several concepts elaborated below: nodular and cuticular drusen are the same entity, cuticular drusen are numerous due to predisposing factors in people who have them, and numerous cuticular drusen may confer progression risk using principles learned for other AMD deposits,” according to the researchers.

Study limitations include the lack of drusen overall, lack of ultrastructural studies, and failure to exclude other mechanisms for lipid release that may occur during specific phases of health and disease. 

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. This research was supported by multiple sources. Please see the original reference for a full list of disclosures.