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Simulate pattern dystrophy — a clinically and genetically heterogeneous group of autosomal dominant macular dystrophies united by characteristic bilateral, roughly symmetrical deposits of pigment and lipofuscin-like material at the level of the retinal pigment epithelium (RPE) around or at the macula, producing distinctive geometric "patterns" visible on fundus examination, fundus autofluorescence (FAF), and OCT. The most frequently implicated gene is PRPH2 (peripherin-2, also known as RDS — retinal degeneration slow — chromosome 6p21.1), which encodes the photoreceptor outer segment transmembrane glycoprotein peripherin-2, a tetraspanin superfamily member essential for the structural integrity and morphogenesis of the rod and cone outer segment disc edges. Peripherin-2 forms obligate non-covalent dimers with ROM1 (rod outer segment membrane protein 1) at the disc rim — the highly stable peripherin-2/ROM1 complexes keep the outer segment discs from collapsing or fusing aberrantly. PRPH2 haploinsufficiency or dominant-negative mutations destabilise outer segment disc morphology, impairing RPE phagocytosis of shed outer segment tips, leading to progressive lipofuscin and bisretinoid (A2E, all-trans retinal dimers) accumulation in RPE lysosomes. This excess lipofuscin accumulation — visible as hyperautofluorescence on FAF imaging in patterns corresponding to the deposit distribution — eventually causes focal and then diffuse RPE atrophy, underlying photoreceptor degeneration, and progressive central visual loss in the 4th–6th decade. Four major clinical patterns are recognised: (1) Butterfly-shaped pigment dystrophy (Byer, 1950; Deutman, 1970) — the most recognised PRPH2 phenotype, showing bilateral triradiate (three-winged) pigmented macular deposits resembling a butterfly; (2) Macroreticular (spider) pattern dystrophy — a coarse, irregular net-like pigment network extending from the fovea to the mid-periphery; (3) Fundus pulverulentus — fine granular dust-like pigment throughout the posterior pole; (4) Adult-onset foveomacular vitelliform dystrophy (AFVD) — small (0.5–2 disc diameters), round, dull yellow-grey subfoveal vitelliform deposits resembling a miniature Best disease lesion, arising in adults aged 40–70 years without the electro-oculogram (EOG) abnormality that defines Best disease. Model these three major pattern subtypes with ΔE colour shift, CIE xy chromaticity, and image simulation.

Pattern dystrophy colour science simulation by Auric Artisan.

Base color
Pattern subtype & settings
RPE lipofuscin / atrophy progression 50%
Image simulation
Upload JPG/PNG (max 1200 × 1200). See how a scene appears through butterfly-shaped macular lipofuscin deposits (paracentral metamorphopsia with early foveal sparing), macroreticular pattern (broader diffuse macular involvement with perifoveal pigment-induced distortion), or adult-onset foveomacular vitelliform dystrophy (central subfoveal deposit causing mild-to-moderate central blurring with preserved peripheral field).
Research notes
Pattern dystrophy clinical spectrum: Pattern dystrophies are among the most phenotypically variable inherited retinal diseases — different PRPH2 mutations (missense, frameshift, splice-site, large deletions) in the same family often produce different pattern subtypes, and within an individual the pattern can evolve or transition over decades. The key diagnostic challenge is distinguishing pattern dystrophy from age-related macular degeneration (AMD): both conditions present in the 4th–7th decade with central visual changes, macular drusen-like deposits, and RPE changes. Fundus autofluorescence (FAF) is the single most useful differentiating test — pattern dystrophy produces characteristic geometric hyperautofluorescent deposit patterns, while AMD produces diffuse patchy hypo- and hyper-AF without the geometric symmetry. Genetic testing of PRPH2 confirms the diagnosis. Visual prognosis is generally better than AMD — many pattern dystrophy patients maintain driving vision until the 6th–7th decade; CNV is less common than in AMD but can occur.
Swatches
Normal
HEX: — • RGB: — • xy: —
PD affected
HEX: — • RGB: — • xy: —
ΔE (CIE76)
—
ΔE (CIEDE2000)
—
Deep preview
Normal
PD (deep)
Chromaticity (CIE xy)
RPE lipofuscin deposit chromaticity shift
D65 white point: 0.313, 0.329
Image simulation

Pattern dystrophy simulations model the RPE lipofuscin accumulation and progressive cone-photoreceptor dysfunction using subtype-specific PRPH2 outer segment disc pathology models in the sRGB colour space. Butterfly-shaped pattern: models predominantly paracentral RPE lipofuscin accumulation as mild central L/M/S cone signal disruption with preserved foveal function until late stages — consistent with the clinical pattern of good central acuity (often 6/9 or better) maintained until RPE atrophy reaches the fovea. Macroreticular pattern: models broader perimacular RPE involvement as more diffuse macular cone signal reduction with greater chroma loss. AFVD: models subfoveal vitelliform material as a central "blur source" with mild-to-moderate foveal cone attenuation and a mild warm chromaticity bias (from the yellow vitelliform material absorbing short-wave light). ΔE2000 per Sharma et al. (2005). Not for clinical diagnosis — pattern dystrophy requires FAF imaging, SD-OCT, EOG, and PRPH2 genetic testing.

Multi-condition comparison
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Compare butterfly-shaped macular deposits, macroreticular/spider perimacular pigmentation, and adult-onset foveomacular vitelliform dystrophy (AFVD). Observe the distinct pattern-specific central visual signatures from PRPH2-driven RPE lipofuscin accumulation.