Retinitis Pigmentosa:

Definition

The most common retinal dystrophy; Incidence 1/5000.

Inheritance

Autosomal Recessive, Dominant or Xlinked recessive.

Clinical

May be first noticed at any age but frequently in teenage; reduced night vision; constricted visual fields, commonly loss of central vision occurring later in life.

Associated syndromes

Signs

Scattered retinal pigmentation (bone spicule shape); optic disc waxy appearance; Attenuated vessels;

Genetic

Multiple genetic abnormalities

Diagnosis: Electrophysiology

  • EOG abnormal;
  • ERG – Early abnormal scotopic progressing to
    • abnormal photopic- delayed + reduced
    • Extinguished ERG
  • Abnormal pattern ERG
  • Multifocal ERG –central responses retained initially while peripheral responses are reduced at an early stage

Examples of Visual electrophysiology in Retinitis Pigmentosa

Treatment

No effective therapy available

Future

Possible genetic therapy or Bionic eye