Contents
Inherited retinal dystrophy caused by the loss of photoreceptors and characterized by retinal pigment deposits visible on fundus examination.
- Type of pigmentary retinopathy
- M/C hereditary fundus dystrophy
Clinical hallmarks:
- Abnormal fundus with bone-spicule deposits and attenuated retinal vessels
- Anormal, diminished or absent a- and b-waves in the electroretinogram (ERG)
- Reduced visual field
Classification
Non-syndromic RP:
- Autosomal dominant RPÂ (adRP) (best prognosis)
- Autosomal recessive RP (arRP) (M/C)
- X-Linked RPÂ (xlRP) (rarest, worst prognosis)
- Leber congenital amaurosisÂ
- Digenic RP (very rare)
Syndromic and systemic RP (20-30% cases):
Atypical RP with associated non-ocular disease
- Usher syndrome (USH)Â (M/C syndromic RP, 10%): Autosomal recessive disease characterized by the association of hearing loss, retinitis pigmentosa (RP), and, in some cases, vestibular dysfunction.
- Bardet-Biedl syndrome (BBS) (5%): Characterized by rod-cone dystrophy (>90%), truncal obesity (72%), postaxial polydactyly, cognitive impairment, male hypogonadotrophic hypogonadism, complex female genitourinary malformations, and renal abnormalities.
- Kearn-Sayre syndrome
- Refsum syndrome
- Bassen-Kornzweig syndrome
- Neuropathy, ataxia & retinitis pigmentosa (NARP)
Presentation
Loss of vision (due to photoreceptor apoptosis):
Night blindness → ↓ Visual fields → Tunnel vision → Legal blindness → Complete blindness
Case study:
Diagnosis
Functional signs:
- Night blindness (nyctalopia) (earliest symptom)
- Photophobia (appears later)
- Visual acuity (preserved in early and mid stages)
Visual field:
- Patchy losses of peripheral vision evolving to:
- Ring shape scotoma → Tunnel vision
Fundus:
- Classic triad:
- Bony-spicule retinal pigmentation
- Arteriolar attenuation
- Optic disc pallor
- Other findings: Subscapular cataracts, macular edema



Electroretinogram (ERG):
- Dramatic diminution in a- and b-wave’s amplitudes
- Scotopic system (rods) predominates over photopic (cones) system

Management
No standard treatments for patients with retinitis pigmentosa (RP)
High-dose Vitamin A supplementation + LFT monitoring:
Slow the rate of retinal deterioration
Voretigene
Gene therapy approved for RPE-65 gene associated RP