Staphyloma

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Staphyloma (scleral ectasia) is a scleral genetic defect that is lined with uveal tissue.

Secondary staphyloma can also occur secondary to trauma, particularly penetrating scleral injuries which results in uveal extension into scleral defect[1].

Because of the bulging size of these lesions, secondary strabismus may develop.

A tentative diagnosis can be obtained with gonioscopy but a definitive diagnosis requires scleral biopsy and histological assessment of tissue samples.

A differential diagnosis would include limbal melanocytoma and extension of a diffuse iris melanoma through the sclera.

Corrective debridement of the lesion is usually curative, with the deficit filled with a flap taken from Tenon’s capsule and conjunctiva.

Unusual surgical techniques have been reported, such as an homologous peritoneal graft[2].

References

  1. Grahn BH et al (2004) Veterinary Ophthalmology Essentials. Philadelphia: Butterworth Heinemann. pp:117–122
  2. Barros PS & Safatle AM (2000) Congenital scleral staphyloma in a dog repaired with preserved homologous peritoneum. Vet Ophthalmol 3(1):27-29