Q28 - Dystrophies of retina and choroidea

Question 1

Dystrophies

Answer 1

Are the degeneration of tissues, often hereditary.

• Retinal/Macular dystrophies= Stargardt disease and Best’s Vitelliform dystrophy.
• Choroidal dystrophies = choroideremia, central areolar choroidal dystrophy or diffuse choroidal atrophy
• Macular dystrophies lead to loss of central vision, Choroidal dystrophies can lead to retinal detachment and total vision loss.

Question 2

Macular dystrophies

Answer 2

A) Stargardt disease:
- macular dystrophy that proceed from RPE -> gradual macular degeneration. Autosomal recessive defective ATP-binding cassette -> toxic Vit A dimer formation that accumulate within Lipofuscin in RPE.
- Loss of central vision and scotomas. White lesions in macula. No treatment.
B) Best’s Vitelliform dystrophy:
- Autosomal dominant defective chloride channel -> accumulation of lipofuscin with loss of central vision.
C) Retinitis Pigmentosa:
- Group of disorders involving pigment deposits in retina leading to progressive loss of visual acuity, nightblindness etc. Many forms, including Rod-Cone dystrophy (most common) and Cone-Rod dystrophy.