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Posterior polymorphous corneal dystrophy

Disease definition

A rare mild subtype of posterior corneal dystrophy characterized by small aggregates of apparent vesicles bordered by a gray haze at the level of Descemet membrane, generally with no effect on vision.

ORPHA:98973

Classification level: Disorder
  • Synonym(s):
    • PPCD
    • Posterior polymorphous dystrophy
    • Schlichting dystrophy
  • Prevalence: Unknown
  • Inheritance: Autosomal dominant 
  • Age of onset: Childhood
  • ICD-10: H18.5
  • ICD-11: LA11.5
  • OMIM: 609140  609141  618031
  • UMLS: C0339284
  • MeSH: -
  • GARD: -
  • MedDRA: -

Summary

Epidemiology

Prevalence of this form of corneal dystrophy is unknown.

Clinical description

Lesions generally develop in early childhood and are mostly bilateral but may be asymmetrical or unilateral in some cases. Most patients are asymptomatic with no corneal edema, but progressive visual impairment due to stromal clouding may rarely occur.

Etiology

PPCD is a genetically heterogenous condition with extremely variable expression. Three genes have been implicated: VSX1 (20p11.21), COL8A2 (1p34.2-p32.3), and ZEB1 (10p11.22), but the evidence implicating VSX1 and COL8A2 is questionable.

Diagnostic methods

Multiple layers of collagen manifesting as focal fusiform or nodular excrescences are found on the posterior surface of Descemet membrane.

Differential diagnosis

PPCD should be distinguished from congenital endothelial dystrophy type 1 (CHED1, see this term), since the two conditions share certain morphological and clinical features.

Genetic counseling

An autosomal dominant pattern of inheritance has been reported.

Management and treatment

Most patients with PPCD do not require therapy, but some may eventually require a penetrating keratoplasty or a procedure for repairing the posterior surface of the cornea, such as a deep lamellar endothelial keratoplasty (DLEK), Descemet stripping endothelial keratoplasty (DSEK), or Descemet stripping automated endothelial keratoplasty (DSAEK).

Expert reviewer(s):  Dr Gordon KLINTWORTH - Last update: May 2012

  A summary on this disease is available in Deutsch (2012) Español (2012) Français (2012) Italiano (2012) Nederlands (2012) Greek (2012, pdf) Polski (2012, pdf) Polski (2012)

Detailed information

Disease review articles

Genetic Testing

ERN : produced/endorsed by ERN(s)
FSMR : produced/endorsed by FSMR(s)

Additional information

Further information on this disease

Patient-centred resources for this disease

Research activities on this disease

Specialised Social Services

The documents contained in this web site are presented for information purposes only. The material is in no way intended to replace professional medical care by a qualified specialist and should not be used as a basis for diagnosis or treatment.