ISSN 2398-2969      

Nictitating membrane: cartilage abnormality


David L Williams

Synonym(s): Third eyelid scrolling, everted haw, everted nictitating membrane.


  • Cause: abnormal curvature or 'scrolling' of bar of T-shaped third eyelid cartilage Nictitating membrane cartilage deformity German Shepherd Dog 7 months often seen in young dogs of large breeds.
  • Signs: everted free margin of membrane ( or less commonly inverted) , maybe tear overflow and conjunctivitis.
  • Diagnosis: clinical signs.
  • Treatment: subconjunctival resection (from bulbar surface) of deformed portion of cartilage.
  • Prognosis: good.



  • Loose attachments of nictitating membrane; may be due to abnormal cartilage shape.



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Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Gelatt K N (1972) Surgical correction of everted nictitating membrane in the dog. Vet Med Small Anim Clin 67 (3), 291-2 PubMed.

Other sources of information

  • Gelatt K N (1972)Vet Med/SAC67. pp 271.

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