Comments and Conclusions
- Retinitis pigmentosa is a hereditary retinal degeneration that can be inherited as an autosomal-recessive(50-60%), autosomal dominant (30-40%), or Winked disorder. Over 45 different genes have been identified for retinitis pigmentosa, which accounts for approximately 60% of all cases.l The prevalence of RP worldwide is 1 in 4000.1
- The majority Of RP cases occur isolated (nonsyndromic RP) and approximately 25% occur as part Of a syndrome (syndromic RP).8 Approximately Of all RP cases occur as a part Of Usher syndrome.8 Other syndromic forms Of RP occur in Bardet-Biedl syndrome, Refsum disease, and other metabolic, renal, skeletal or neurological diseases.8
- Symptoms in RP patients can vary from vision loss in childhood to patients remaining asymptomatic until adulthood.l Classical progression Of RP begins with night blindness and poor dark adaptation in childhood, mid-peripheral visual field defects in young adulthood, far-peripheral visual field defects as an adult leading to tunnel Vision, and finally central vision loss leading to blindness by the age of 60.L
- Studies have shown that an abnormally thick or thin retina and the absence of the PIL (IS/OS junction) under the foveal pit is highly correlated with low visual acuity in RP patients.9’LO Another study suggested the grade and length of the PIL was strongly correlated to the visual acuity and retinal sensitivity in RP patients.L1