eMedicine Specialties > Ophthalmology > Cornea

Posterior Polymorphous Corneal Dystrophy

Author: Dustin J Coupal, MD, FRCSC, Eye Specialist and Surgeon, Private Practice
Coauthor(s): W Keith Hamilton, MD, Clinical Assistant Professor, Department of Ophthalmology, Saskatoon City Hospital Eye Centre
Contributor Information and Disclosures

Updated: Feb 1, 2007

Introduction

Background

First described by Koeppe in 1892, posterior polymorphous corneal dystrophy (PPMD) is a dominantly inherited condition characterized by particular alterations of the Descemet membrane and the corneal endothelium. Typically, the corneal changes are either slowly progressive or nonprogressive. In severe cases, corneal decompensation and edema can occur. Although PPMD is most often a bilateral condition, marked asymmetry in the degree of involvement may be seen. Most persons with PPMD are asymptomatic.

Pathophysiology

Three main abnormalities are described: vesicular changes, endothelial band lesions, and irregular opacities of the posterior corneal surface. The corneal endothelium undergoes a transformation and demonstrates many epithelial characteristics on examination with electron microscopy and immunohistochemical analysis. Often, the endothelium is found to be multilayered.

Frequency

United States

The frequency of PPMD is not well documented. Although it is considered to be uncommon, PPMD may be recognized and diagnosed more often in recent years than in the past.

Mortality/Morbidity

The effect of PPMD on patients is highly variable, with a broad clinical spectrum of findings, ranging from nonprogressive asymptomatic disease to progressive or advanced debilitating corneal disease with corneal decompensation and glaucoma.

Race

No racial predilection exists.

Sex

No sexual predilection exists.

Age

Although PPMD is an inherited corneal dystrophy, the age at diagnosis is highly variable because of the broad spectrum of disease severity. Findings may be present at birth. Most patients are first identified at age 30-50 years; however, this is likely only indicative of a more common age for ocular examinations.

  • Some patients may present at birth with congenital disease, exhibiting advanced disease with corneal edema.
  • Presentation in adulthood is indicative of a more stable disease state with a decreased probability of progression to corneal decompensation.
  • Most patients with significant symptoms present at age 25-50 years.

Clinical

History

  • The clinical findings in patients with PPMD are highly variable, with a broad clinical spectrum of findings, ranging from only occasional Descemet membrane vesicles to progressive debilitating corneal disease with corneal decompensation and glaucoma.
  • A family history of PPMD should be assessed.
  • Although most patients with PPMD are asymptomatic, the most common symptoms in those with more significant involvement are as follows:
    • Photophobia
    • Decreased visual acuity
    • Foreign body sensation

Physical

  • The most characteristic finding on slit lamp biomicroscopy is multiple vesicles or blisters, either isolated or grouped in clusters, on the posterior corneal surface. The vesicles often have identifiable surrounding halos.
  • Slit lamp biomicroscopy may also identify all or some of the following characteristics depending on the extent of the disease:
    • Posterior corneal opacities occurring in linear bands or other polymorphous configurations with irregular scalloped edges
    • Areas of more diffuse posterior corneal opacity
    • Focal excrescents of the Descemet membrane
    • Iridocorneal adhesions
    • Pupillary ectropion
    • Corectopia
    • Stromal and epithelial edema (advanced cases)

Causes

  • The precise etiology of PPMD remains unknown. PPMD is a congenital inherited dystrophy involving abnormalities of the corneal endothelium and the Descemet membrane.
    • Most cases of PPMD are transmitted in an autosomal dominant fashion with variable expression, although autosomal recessive transmission has also been reported.
    • A number of autosomal dominant cases of PPMD have been linked to a mutation in an unidentified gene located at band 20q11, whereas other cases have reported a mutation in a gene encoding for collagen VIII located on chromosome 1 (COL8A2) as the cause of PPMD.
    • In other cases, the genetic locus remains unknown.
  • PPMD has been associated with other conditions, including the following:
    • Alport syndrome
    • Keratoconus

More on Posterior Polymorphous Corneal Dystrophy

Overview: Posterior Polymorphous Corneal Dystrophy
Differential Diagnoses & Workup: Posterior Polymorphous Corneal Dystrophy
Treatment & Medication: Posterior Polymorphous Corneal Dystrophy
Follow-up: Posterior Polymorphous Corneal Dystrophy
Multimedia: Posterior Polymorphous Corneal Dystrophy
References
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References

  1. Anderson NJ, Badawi DY, Grossniklaus HE, Stulting RD. Posterior polymorphous membranous dystrophy with overlapping features of iridocorneal endothelial syndrome. Arch Ophthalmol. Apr 2001;119(4):624-5. [Medline].

  2. Bechara SJ, Grossniklaus HE, Waring GO, Wells JA 3rd. Keratoconus associated with posterior polymorphous dystrophy. Am J Ophthalmol. Dec 15 1991;112(6):729-31. [Medline].

  3. Boruchoff SA, Weiner MJ, Albert DM. Recurrence of posterior polymorphous corneal dystrophy after penetrating keratoplasty. Am J Ophthalmol. Mar 15 1990;109(3):323-8. [Medline].

  4. Brooks AM, Grant G, Gillies WE. Differentiation of posterior polymorphous dystrophy from other posterior corneal opacities by specular microscopy. Ophthalmology. Nov 1989;96(11):1639-45. [Medline].

  5. Chiou AG, Kaufman SC, Beuerman RW, et al. Confocal microscopy in posterior polymorphous corneal dystrophy. Ophthalmologica. 1999;213(4):211-3. [Medline].

  6. Colville DJ, Savige J. Alport syndrome. A review of the ocular manifestations. Ophthalmic Genet. Dec 1997;18(4):161-73. [Medline].

  7. Grupcheva CN, Chew GS, Edwards M, et al. Imaging posterior polymorphous corneal dystrophy by in vivo confocal microscopy. Clin Experiment Ophthalmol. Aug 2001;29(4):256-9. [Medline].

  8. Henriquez AS, Kenyon KR, Dohlman CH, et al. Morphologic characteristics of posterior polymorphous dystrophy. A study of nine corneas and review of the literature. Surv Ophthalmol. Sep-Oct 1984;29(2):139-47. [Medline].

  9. Klintworth GK. The molecular genetics of the corneal dystrophies--current status. Front Biosci. May 1 2003;8:d687-713. [Medline].

  10. Koeppe L. Klinische Beobachtungen mit der Nerstspaltlampe und dem Hornhautmikroskop. Albrecht von Graefe's Arch Klin Exp Ophthalmol. 1916;91:375-379.

  11. Krachmer JH. Posterior polymorphous corneal dystrophy: a disease characterized by epithelial-like endothelial cells which influence management and prognosis. Trans Am Ophthalmol Soc. 1985;83:413-75. [Medline].

  12. Laganowski HC, Sherrard ES, Muir MG, Buckley RJ. Distinguishing features of the iridocorneal endothelial syndrome and posterior polymorphous dystrophy: value of endothelial specular microscopy. Br J Ophthalmol. Apr 1991;75(4):212-6. [Medline].

  13. Moroi SE, Gokhale PA, Schteingart MT, et al. Clinicopathologic correlation and genetic analysis in a case of posterior polymorphous corneal dystrophy. Am J Ophthalmol. Apr 2003;135(4):461-70. [Medline].

  14. Presberg SE, Quigley HA, Forster RK, Green WR. Posterior polymorphous corneal dystrophy. Cornea. 1985-86;4(4):239-48. [Medline].

  15. Teekhasaenee C, Nimmanit S, Wutthiphan S, et al. Posterior polymorphous dystrophy and Alport syndrome. Ophthalmology. Aug 1991;98(8):1207-15. [Medline].

  16. Weissman BA, Ehrlich M, Levenson JE, Pettit TH. Four cases of keratoconus and posterior polymorphous corneal dystrophy. Optom Vis Sci. Apr 1989;66(4):243-6. [Medline].

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Further Reading

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Keywords

PPMD, posterior polymorphous dystrophy, posterior endothelial dystrophy, hereditary deep dystrophy, PPCD

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Contributor Information and Disclosures

Author

Dustin J Coupal, MD, FRCSC, Eye Specialist and Surgeon, Private Practice
Dustin J Coupal, MD, FRCSC is a member of the following medical societies: American Academy of Ophthalmology, Canadian Medical Association, Canadian Medical Protective Association, and Canadian Ophthalmological Society
Disclosure: Nothing to disclose.

Coauthor(s)

W Keith Hamilton, MD, Clinical Assistant Professor, Department of Ophthalmology, Saskatoon City Hospital Eye Centre
Disclosure: Nothing to disclose.

Medical Editor

Fernando H Murillo-Lopez, MD, Senior Surgeon, Unidad Privada de Oftalmologia CEMES
Fernando H Murillo-Lopez, MD is a member of the following medical societies: American Academy of Ophthalmology
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Christopher J Rapuano, MD, Professor, Department of Ophthalmology, Jefferson Medical College; Co-Chairman of the Cornea Service, Co-Chairman of Refractive Surgery Department, Wills Eye Hospital
Christopher J Rapuano, MD is a member of the following medical societies: American Academy of Ophthalmology, American Society of Cataract and Refractive Surgery, Eye Bank Association of America, Pennsylvania Medical Society, and Philadelphia County Medical Society
Disclosure: Allergan Honoraria Speaking and teaching; Allergan Consulting fee Consulting; Alcon Honoraria Speaking and teaching; Inspire Honoraria Speaking and teaching; RPS Ownership interest Other

CME Editor

Ralph Garzia, OD, Assistant Dean for Clinical Programs, Associate Professor, School of Optometry, University of Missouri at St Louis
Ralph Garzia, OD is a member of the following medical societies: American Academy of Optometry and American Optometric Association
Disclosure: Nothing to disclose.

Chief Editor

Hampton Roy Sr, MD, Associate Clinical Professor, Department of Ophthalmology, University of Arkansas for Medical Sciences
Hampton Roy Sr, MD is a member of the following medical societies: American Academy of Ophthalmology, American College of Surgeons, and Pan-American Association of Ophthalmology
Disclosure: Nothing to disclose.

 
 
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