Doyne Honeycomb Retinal Dystrophy (Familial Drusen)

A 38-year-old woman with a family history of early macular dystrophy presents with mild metamorphopsia and paracentral scotomas. Visual acuity is 6/9 OU. Fundus examination reveals numerous, discrete, round, yellow-white drusen-like deposits arranged in a radial honeycomb pattern at the macula and extending around the optic disc. OCT shows sub-RPE hyperreflective deposits with overlying RPE and outer retinal preservation. Genetic testing confirms an autosomal dominant R345W mutation in the EFEMP1 gene encoding fibulin-3. The structure marked **A** in the diagram represents the confluent honeycomb drusen pattern characteristic of this condition. Which of the following best describes the biochemical nature and clinical significance of these deposits?