Retinitis Pigmentosa & Inherited Retinal Dystrophies
An inherited retinal dystrophy causing progressive degeneration of rod and cone photoreceptors, manifesting as night blindness and tunnel vision.
Article Table of Contents
1. Comprehensive Overview
Retinitis Pigmentosa (RP) comprises a genetically heterogeneous group of inherited retinal dystrophies characterized by progressive apoptosis of rod and cone photoreceptors.
Genetics & Pathophysiology: Over 100 identified causative genes (e.g., RHO, USH2A, RPGR, RPE65) inherited via autosomal dominant (30-40%), autosomal recessive (50-60%), X-linked (10-15%), or mitochondrial modes. Primary degeneration of rod photoreceptors induces nyctalopia and peripheral constriction, followed by non-cell-autonomous secondary cone loss.
The Classic Diagnostic Triad: 1. Bone-spicule intraretinal hyperpigmentation in the mid-periphery. 2. Marked retinal arteriolar attenuation. 3. Waxy pallor of the optic nerve head.
Therapeutic Milestone: Gene Therapy: FDA/EMA approval of Voretigene Neparvovec (Luxturna) for confirmed biallelic RPE65-mutation dystrophy represents the world's first approved in-vivo human gene replacement therapy, restoring functional rod sensitivity via subretinal AAV vector delivery.
2. Symptoms & Warning Signs
If you observe any of the following symptoms repeatedly, an eye exam is strongly recommended:
- Nyctalopia (night blindness): Marked difficulty seeing in dim light or navigating at dusk, typically emerging in childhood or adolescence
- Progressive concentric peripheral visual field loss, causing patients to trip over low obstacles or bump into furniture
- Advanced 'Tunnel Vision' (tubular central island sparing foveal acuity for decades)
- Severely delayed dark adaptation when transitioning from sunlight to dim interiors
- Glare sensitivity and photophobia
- Late-stage central visual decline and impaired color perception
3. Causes & Risk Factors
- 1Pathogenic mutations in photoreceptor and RPE structural/phototransduction genes (RHO, USH2A, RPE65, RPGR)
- 2Consanguinity markedly elevating prevalence of autosomal recessive inheritance
- 3Syndromic associations: Usher syndrome (sensorineural hearing loss + RP), Bardet-Biedl syndrome, Kearns-Sayre syndrome
4. Treatments & Medical Management
5. Prevention & Daily Eye Care Advice
- Pre-marital genetic counseling and carrier screening in families with established inherited retinal disease history
- Consistent lifetime UV-protective sunglasses to reduce photo-oxidative stress on surviving photoreceptors
- Annual visual field perimetry and full-field electroretinography (ffERG) monitoring
6. When to Seek Emergency Eye Care
Visit an immediate eye emergency center if you experience any of the following critical indicators:
- ⚠Parental observation of a child stumbling, hesitating, or struggling in dark environments
- ⚠Progressive narrowing of peripheral visual boundaries
- ⚠Inquiry regarding comprehensive retinal genetic panel testing for gene therapy eligibility
7. Frequently Asked Questions
Q:What is Luxturna gene therapy and who is eligible?
Luxturna (Voretigene Neparvovec) is an adeno-associated viral (AAV2) vector delivering a normal copy of the human RPE65 gene into viable retinal pigment epithelial cells, approved for patients with confirmed biallelic RPE65 mutations to significantly enhance functional vision and light sensitivity.