Ex vivo VK-X3000 analysis reveals higher Descemet's membrane roughness in Fuchs endothelial corneal dystrophy compared to healthy controls.

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medRxiv Published April 9, 2026 Medically reviewed April 25, 2026 Study authors: Maurin, C.; Poinard, S.; Travers, G.; Gontier, E.; Karpathiou, G.; Decoeur, F.; He, Z.; Gain, P.; TH… DOI ↗ By Dr. Lars van Dijk, PhD · Surgical, Procedural & Diagnostic

Key Takeaway

Note higher Descemet's membrane roughness in FECD vs controls via ex vivo VK-X3000 analysis.

This observational study utilized ex vivo analysis of corneal specimens to evaluate the VK-X3000 system, which combines laser scanning confocal imaging and white-light interferometry. The population consisted of 38 patients with Fuchs endothelial corneal dystrophy (FECD) undergoing endothelial keratoplasty and 4 healthy donors. The primary outcome was quantitative topographic characterization of Descemet's membrane, specifically assessing surface roughness and guttae features.

The analysis identified significant differences in surface roughness (Sa) between the FECD group and controls. Median surface roughness was 0.571 m for FECD patients compared to 0.239 m for controls (p = 0.0018). Spatial organization of guttae varied by zone: the central zone showed buried guttae in the posterior fibrillar layer with a median roughness of 0.442 m. The paracentral zone exhibited large uncovered guttae with a median roughness of 0.562 m (p = 0.0423).

In the outer zone, no confluent guttae were observed, with a median roughness of 0.261 m (p < 0.0001). No adverse events, discontinuations, or safety data were reported as the analysis was performed on excised specimens. The study did not report funding sources, conflicts of interest, or specific limitations regarding generalizability to in vivo settings.

These findings demonstrate distinct roughness parameters and guttae features across three zones in FECD. While the VK-X3000 system effectively characterizes Descemet's membrane topography in this ex vivo context, the observational nature of the study and lack of in vivo data limit immediate clinical recommendations for routine diagnostic use.

Study Details

EvidenceLevel 5

PublishedApr 2026

View Original Abstract ↓

Aim: To evaluate the potential of a three-dimensional microscope combining Laser scanning confocal imaging and white-light interferometry for quantitative topographic characterisation of Descemet's membrane (DM) in Fuchs endothelial corneal dystrophy (FECD). Methods: Descemet's membranes were collected from 38 FECD patients undergoing endothelial keratoplasty and 4 healthy donors. After flat-mounting on glass slide and drying, specimens were analysed using the VK-X3000 system (KEYENCE). Entire samples were reconstructed by image stitching at low magnification (x10) in white-light interferometry mode (0.01nm axial resolution). Higher magnifications (x20-x150) in confocal mode (12nm axial resolution) enabled detailed structural analysis. Three-dimensional height maps were generated to calculate standardised surface roughness parameters. Guttae and other DM features were classified according to spatial organisation and elevation profiles. Results: White-light interferometry enabled full-field mapping of whole 8mm diameter DMs with nanometric vertical resolution (~2 hours/sample). Surface roughness (Sa) was higher in FECD than in controls (median{+/-}IQR: 0.571{+/-}0.259 m vs 0.239{+/-}0.161 m ; p = 0.0018). In FECD, three zones were identified: central (guttae buried in the posterior fibrillar layer; Sa 0.442 {+/-} 0.112 m), paracentral (large uncovered guttae; Sa 0.562{+/-}0.170 m ; p = 0.0423), and outer zone (no confluent guttae; Sa 0.261{+/-}0.143 m ; p < 0.0001). Confocal 3D imaging revealed radial striae, embossments and furrows in the DM, confluent central guttae, and fused or buried structures. Conclusions: Combining white-light interferometry and confocal microscopy enables label-free, high-resolution surface characterisation of DM in FECD, providing quantitative metrics to compare histological subtypes and supporting the predominance of radial structural organisation.