Revised classification of corneas with Fuchs endothelial corneal dystrophy (FECD) (reproduced from Sun et al with permission from Elsevier35)
| Classification*† | Required findings | |
| Slit-lamp examination | Scheimpflug tomography‡ | |
| FECD with clinically definite oedema | Guttae present and typically confluent§; clinically visible corneal oedema¶ present | Not required; classification made by slit-lamp examination alone If obtained, tomography would typically show all three features of corneal oedema,** possibly with focal anterior elevation associated with any area of focal posterior depression |
| FECD with subclinical oedema | Guttae present and typically confluent,§ without clinically definite oedema | Required Shows the features of corneal oedema**; frequently all three features are present, and typically at least two features are present |
| FECD without oedema | Guttae present and could be non-confluent or confluent§ without clinically definite oedema | Required Shows no features consistent with corneal oedema, that is, appears consistent with a normal cornea |
| No FECD | No guttae | Not required |
*Slit-lamp examination is required first to diagnose FECD by the presence of guttae and to determine if clinically definite edema is present. Tomography is only required for FECD without clinically definite edema.
†This classification is independent of central corneal thickness, traditional morphologic grading, and patients’ visual dysfunction; however, the afore-mentioned characteristics may be considered as adjunctive information.
‡Assessment of the pachymetry and posterior corneal elevation maps (Pentacam HR; Oculus, Lynnwood, Washington, USA), typically found in the ‘4-Maps Refractive’ display.
§Authors recommend that confluence be confirmed by specular reflection at slit-lamp examination; visible cells between guttae by this method indicates non-confluent guttae in that region of examination.
¶Clinically definite oedema is oedema that is obviously visible by slit-lamp examination based on thickening of the stroma (with a visible change in corneal contour of the anterior or posterior surface), Descemet or deep stromal folds, microcystic epithelial oedema or bedewing, or subepithelial bullae. The specific finding should be documented to support this classification.
**Specific features of tomographic corneal oedema are (1) loss of parallel isopachs, (2) displacement of the thinnest point of the cornea and (3) presence of focal posterior corneal depression.