Fuchs Endothelial Dystrophy Workup

Updated: May 04, 2018
  • Author: Vikas Mittal, MBBS, MS; Chief Editor: Hampton Roy, Sr, MD  more...
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Other Tests

Perform specular endothelial microscopy examinations of all siblings of patients with Fuchs endothelial dystrophy. The photographs of the affected corneas may be kept for future reference. Endothelial cell density, hexagonality, and polymegethism may be recorded. The following 5 stages may be seen, as described by Laing et al: [6]

  • Stage 1: The guttate excrescences are in the form of dark structures with sharply defined single bright spots at their center. The structures are considerably smaller in size than a single endothelial cell. Such an excrescence does not lie near the boundary wall of the cell.
  • Stage 2: The excrescence is almost the size of the endothelial cell. The surrounding cells have a stretched appearance.
  • Stage 3: The excrescence is considerably larger, and many cells are involved in one lesion. The dark structure is 5-10 times the size of an endothelial cell. The adjacent cells are abnormal and have missing boundaries. Many lesions are seen close to each other, but they do not coalesce. The excrescences are of 2 types, a smooth round shape or a rough excrescence.
  • Stage 4: The individual excrescences have coalesced. The net result is multilobed, rather than a round outline. The dark areas have many bright spots. The multilobulated structures cover considerable area. The cells between the excrescence masses tend to become abnormal. Coalesced areas contain both the smooth and the rough variety of excrescences.
  • Stage 5: An organized mosaic of endothelial cells is difficult to see. Many stages may be observed in the different areas of the same eye.

Pachymetry is a good way of gauging the increase in corneal edema. The thickness can be compared with the new readings on subsequent visits. Increasing thickness of the cornea means increasing corneal endothelial decompensation. Presence of Descemet folds, epithelial bedewing, and corneal thickness of greater than 0.62 mm indicates potential decompensation. This also affects clinical decisions regarding surgery.

Confocal microscopy can aid in demonstrating corneal endothelial cell polymorphism and pleomorphism, as well as in measuring endothelial cell density in significant stromal edema setting to a certain extent.


Histologic Findings

In the early stages, the focal thickening of the Descemet membrane is similar to those seen in the Hassall-Henle warts of the peripheral cornea. The corneal endothelium appears stretched and thinned over the dome of the excrescences.

In advanced cases, a generalized thickening of the Descemet membrane is observed. This thickening appears to bury the cornea guttata that formed in the earlier stages.

In normal corneas, histologic preparations show lamellar separation as an artifact. In the cases of corneal edema, the artifactitious lamellar separation of the lamellae is reduced. Subepithelial bullae formation is seen at the anterior corneal surface. In the periphery of the cornea, subepithelial fibrous tissue is usually seen. Intraepithelial cysts filled with cellular debris are also seen. Intraepithelial basement membrane formation may occur due to the misdirection of the epithelial cells. The Bowman membrane is normal, unless it has been involved in ulcer formation and keratitis, after the rupture of a bulla.