Drusen: Types, Fundus Appearance and Multimodal Imaging
Learn how to recognise different drusen patterns, localise them on OCT, and understand their clinical significance.
Start by Describing the Lesion
Before naming a yellow-white retinal deposit, first describe what you see.
- Is it single or multiple?
- Is it unilateral or bilateral?
- Is the distribution macular, peripapillary or widespread?
- Are the deposits discrete or confluent?
- Are the margins sharp or indistinct?
- Are they yellow-white, pale yellow or grey?
- Are they flat, elevated or refractile?
- Where are they in relation to the RPE and outer retina?
- Is there associated pigmentary change, atrophy, fluid or haemorrhage?
Once the lesion appears drusen-like, OCT location and morphology become particularly useful for narrowing the diagnosis.
What Is a Druse?
Conventional drusen are extracellular deposits located beneath the retinal pigment epithelium (RPE), within the RPE–Bruch membrane complex. They contain a mixture of lipid, protein, mineral and other extracellular components. [3]
Photoreceptors
RPE
Conventional drusen — located beneath the RPE and above Bruch membrane
Bruch membrane
| Small / drupelets | Medium | Large |
|---|---|---|
| <63 μm | 63 to <125 μm | ≥125 μm |
These size categories are used in clinical AMD classification. [1] [2]
Small discrete drusen, traditionally called hard drusen, are usually yellow-white, sharply defined and separate from one another. On OCT they produce small focal elevations or irregularities of the RPE–Bruch membrane complex.
Larger or “soft” drusen are typically paler, less sharply defined and broader on OCT. They are also more likely to become confluent.
The distinction between hard and soft drusen is therefore primarily morphological and should not be reduced to a single size cut-off. [1] [2] [3]
Size matters, but size, morphology and anatomical location should always be interpreted together.
Drusen, Drusenoid PED and AMD Risk
Larger drusen are more likely to become confluent. When several large drusen merge beneath the RPE, they can produce a broad elevation called a drusenoid pigment epithelial detachment (drusenoid PED).
On OCT, a drusenoid PED appears as a relatively smooth, broad elevation of the RPE containing drusenoid material.
Drusen become more clinically significant as their size increases and when they are accompanied by AMD-related pigmentary abnormalities. [1] [2]
| Macular finding | Clinical interpretation |
|---|---|
| Small drusen / drupelets only | Usually an ageing change |
| Medium drusen | Early AMD |
| Large drusen and/or AMD-associated pigmentary abnormalities | Intermediate AMD |
| Macular atrophy or macular neovascularisation | Late AMD |
Drusen should therefore not be assessed in isolation. Associated RPE hyperpigmentation or hypopigmentary abnormalities also contribute to AMD staging and progression risk. [1] [2]
A drusenoid PED represents a higher-risk AMD phenotype.
In the AREDS natural-history cohort, 42% of eyes with drusenoid PED and without advanced AMD at baseline progressed to advanced AMD within 5 years: 19% developed central geographic atrophy and 23% developed neovascular AMD. [4]
Cuticular Drusen
Cuticular drusen, historically also called basal laminar drusen, form a distinctive phenotype that may appear at a relatively younger age than typical age-related soft drusen. [5]
| Imaging | Typical finding |
|---|---|
| Fundus | Numerous small, fairly uniform, round or punctate yellow deposits. They may be densely packed and involve the macular, paramacular and more widespread retina. |
| Fluorescein angiography | Multiple pinpoint areas of hyperfluorescence producing the classic “starry-sky” appearance. |
| OCT | Multiple small triangular RPE elevations, producing a characteristic saw-tooth appearance. |
An acquired vitelliform lesion may occur in association with cuticular drusen. In older patients or more diffuse phenotypes, they may also be associated with macular atrophy or macular neovascularisation. [5]
Numerous uniform drusen + starry-sky FA + saw-tooth OCT → think cuticular drusen.
Other Distinct Drusen Patterns
Some drusen do not fit neatly into the usual age-related small-to-large spectrum. Their appearance, age of presentation or distribution can provide the clue to the diagnosis.
| Pattern | Key clinical clues | OCT / significance |
|---|---|---|
| Large colloid drusen | Large yellow deposits, often bilateral and relatively symmetrical. They may present at a younger age than conventional AMD-associated drusen. | Prominent dome-shaped RPE elevations on OCT. Some lesions may regress over time, although outer-retinal atrophy can occasionally develop. [8] |
| Calcified / refractile drusen | Bright, glistening or refractile deposits produced by mineralisation within drusen. | OCT may show heterogeneous internal reflectivity with hyperreflective components. They may be associated with surrounding RPE and outer-retinal degeneration. [9] |
Because calcified or refractile drusen can appear strikingly bright on fundoscopy, they may occasionally be mistaken for hard exudates.
A distinct inherited drusen phenotype is associated with EFEMP1.
Doyne honeycomb retinal dystrophy, Malattia Leventinese and familial dominant drusen belong to this inherited disease spectrum. [7]
Visual function may remain good for many years, but later disease can be complicated by RPE atrophy or macular neovascularisation. [7]
EFEMP1-associated dominant drusen are not simply “AMD in a young patient.” They represent an inherited retinal dystrophy with a characteristic distribution and phenotype.
Subretinal Drusenoid Deposits
Subretinal drusenoid deposits (SDD), also called reticular pseudodrusen, are a distinct drusen-like phenotype. [3] [6]
Deposits are located below the RPE, within the RPE–Bruch membrane complex.
Deposits are located above the RPE, between the RPE and photoreceptors.
| Feature | Typical appearance |
|---|---|
| Colour | Often yellow-grey rather than bright yellow. |
| Pattern | Frequently arranged in an interconnecting or reticular pattern. |
| Distribution | Often prominent in the superior macular region. |
| Colour fundus photography | May be relatively subtle and therefore easy to underestimate clinically. |
| OCT | Demonstrates deposits above the RPE in the subretinal space. |
SDDs are dynamic and may enlarge, coalesce or regress. However, apparent regression should not automatically be interpreted as restoration of normal retinal anatomy because it may accompany outer-retinal degeneration. [6]
Their presence is associated with increased risk of late AMD, particularly macular atrophy and type 3 macular neovascularisation. [6]
One-Glance Comparison
| Feature | Small discrete drusen | Soft / large drusen | Cuticular drusen | SDD |
|---|---|---|---|---|
| Colour | Yellow-white | Pale yellow | Numerous small yellow deposits | Yellow-grey |
| Margins | Sharp and discrete | Less distinct | Fairly discrete and uniform | Reticular / interconnected |
| Location | Below RPE | Below RPE | Below RPE | Above RPE |
| OCT clue | Small focal RPE elevation | Broader RPE elevation | Triangular / saw-tooth RPE elevations | Subretinal deposits above RPE |
| Pattern clue | Small + discrete | Large / may become confluent | Starry-sky FA | Reticular pseudodrusen |
| Main significance | May represent an ageing change | Important in AMD risk assessment | Distinct multimodal phenotype | High-risk AMD phenotype |
References
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1.Ferris FL III, Wilkinson CP, Bird A, et al.; Beckman Initiative for Macular Research Classification Committee. Clinical classification of age-related macular degeneration. Ophthalmology. 2013;120(4):844–851.
doi:10.1016/j.ophtha.2012.10.036 -
2.Vemulakonda GA, Bailey ST, Kim SJ, et al.; American Academy of Ophthalmology Preferred Practice Pattern Retina/Vitreous Committee. Age-Related Macular Degeneration Preferred Practice Pattern®. Ophthalmology. 2025;132(4):P1–P74.
doi:10.1016/j.ophtha.2024.12.018 -
3.Fleckenstein M, Keenan TDL, Guymer RH, et al. Age-related macular degeneration. Nature Reviews Disease Primers. 2021;7:31.
doi:10.1038/s41572-021-00265-2 -
4.Cukras C, Agrón E, Klein ML, et al. Natural history of drusenoid pigment epithelial detachment in age-related macular degeneration: Age-Related Eye Disease Study Report No. 28. Ophthalmology. 2010;117(3):489–499.
doi:10.1016/j.ophtha.2009.12.002 -
5.Fragiotta S, Fernández-Avellaneda P, Breazzano MP, Scuderi G. Clinical manifestations of cuticular drusen: Current perspectives. Clinical Ophthalmology. 2021;15:3877–3887.
doi:10.2147/OPTH.S272345 -
6.Monge M, Araya A, Wu L. Subretinal drusenoid deposits: An update. Taiwan Journal of Ophthalmology. 2022;12(2):138–146.
doi:10.4103/tjo.tjo_18_22 -
7.Zhang K, Sun X, Chen Y, et al. Doyne honeycomb retinal dystrophy/Malattia Leventinese induced by EFEMP1 mutation in a Chinese family. BMC Ophthalmology. 2018;18:318.
doi:10.1186/s12886-018-0988-7 -
8.Sassi H, Miere A, Amoroso F, et al. Insight into large colloid drusen: A decade-long follow-up. European Journal of Ophthalmology. 2025;35(6):2213–2221.
doi:10.1177/11206721251351495 -
9.Tan ACS, Pilgrim MG, Fearn S, et al. Calcified nodules in retinal drusen are associated with disease progression in age-related macular degeneration. Science Translational Medicine. 2018;10(466):eaat4544.
doi:10.1126/scitranslmed.aat4544
