Sclera, Scleral Icterus, Yellow Sclera, Episclera

  • Physiology
  1. Sclera
    1. Thick, protective outer coat of the eye underlying the Conjunctiva
    2. Poorly vascularized
    3. Normally white (with possible bluish discoloration) and opaque
    4. Scleral inflammation is very painful, and associated with Vision Loss
  2. Episclera
    1. Covers the anterior Sclera and lacks the Scleral bluish discoloration
    2. Continuous with the Cornea
    3. Episcleral inflammation is not typically painful, and does not cause Vision change
  • Findings
  • Normal
  1. Normally white and opaque
  • Causes
  • Scleral Inflammation
  • Causes
  • Scleral Discoloration
  1. Blue Sclera suggests Osteogenesis Imperfecta
  2. Yellow Sclera Causes
    1. Carotenemia does not involve the Sclera
    2. Scleral Icterus
      1. Hyperbilirubinemia (associated with Jaundice)
      2. Bilirubin uniformly deposits throughout Sclera
    3. Quinacrine
      1. Yellow discoloration near limbus
    4. Yellow subscleral fat (normal)
      1. Involves only the area farthest from the limbus
  • Reference
  1. Degowin (1987) Bedside Diagnostic Exam, p. 480