Inherited Retinal Dystrophies: RP, Stargardt, Best and More
Last updated: November 2026
Inherited retinal dystrophies (IRDs) are a large group of genetic diseases of the photoreceptors and RPE. Each is rare, but together they are a major cause of blindness in young people. Recognising the pattern, using electrophysiology, and offering genetic testing are now part of routine care.
The main conditions
| Condition | Inheritance and gene | Key features | Investigations |
|---|---|---|---|
| Retinitis pigmentosa (rod-cone dystrophy) | AD, AR or X-linked (X-linked is most severe) | Night blindness, constricted fields (ring scotoma), bone-spicule pigment, attenuated vessels, waxy disc pallor; CMO and posterior subcapsular cataract | Reduced or extinguished scotopic ERG; OCT for CMO |
| Stargardt disease | AR, ABCA4 | Childhood or teenage central vision loss, yellow flecks, beaten-bronze macula | Dark (silent) choroid on FFA, FAF flecks; avoid high-dose vitamin A supplements |
| Best vitelliform dystrophy | AD, BEST1 | Egg-yolk macular lesion in childhood, vision often good early | Abnormal EOG with normal full-field ERG |
| Cone and cone-rod dystrophy | Various | Photophobia, poor central and colour vision, bull's eye maculopathy | Reduced photopic and flicker ERG |
| X-linked retinoschisis | X-linked, RS1 | Boys with spoke-wheel foveal schisis, peripheral schisis | Negative ERG (b-wave smaller than a-wave) |
| Choroideremia | X-linked, CHM | Night blindness, progressive choroidal atrophy in men | Carrier females show patchy pigment |
| Leber congenital amaurosis | AR (for example RPE65, CEP290) | Severe visual loss from infancy, nystagmus, oculodigital sign | Extinguished ERG; RPE65 disease treatable with voretigene neparvovec (gene therapy, FDA 2017) |
Syndromic retinitis pigmentosa
- Usher syndrome: RP with deafness (the commonest).
- Bardet-Biedl: RP, obesity, polydactyly, renal and learning problems.
- Refsum disease: high phytanic acid (treatable with diet).
- Kearns-Sayre: RP-like pigmentation, ptosis, ophthalmoplegia, heart block (check ECG).
- Abetalipoproteinaemia (vitamin E and A treatment).
Management
- Genetic testing and counselling, family examination.
- Treat complications: CMO in RP with oral or topical carbonic anhydrase inhibitors; cataract surgery (with care, CMO risk).
- Low vision aids, mobility training, certificates and education support.
- Sunglasses and UV protection; avoid smoking. Discuss clinical trials and gene therapy where available.
Where residents slip
- Missing Kearns-Sayre: always check the ECG.
- Advising high-dose vitamin A in Stargardt.
- Forgetting that Best disease can have a normal ERG.
Test yourself: flip cards
Related: ERG, EOG and VEP Made Easy: One Test per Level, Retinal Layers and OCT Made Easy: Where Every Lesion Sits, Low Vision Aids Calculator: Kestenbaum Rule and Magnification.
Key sources
- Hartong DT, Berson EL, Dryja TP. Retinitis pigmentosa. Lancet. 2006;368:1795-1809
- Russell S, et al. Efficacy and safety of voretigene neparvovec in RPE65-mediated inherited retinal dystrophy. Lancet. 2017;390:849-860
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