[Perforating keratoplasty versus Descemet stripping automated endothelial keratoplasty in the partner eye: Functional results and patient satisfaction]

[Pathogenesis and diagnostic evaluation of Fuchs' endothelial corneal dystrophy]

BACKGROUND

Following new treatment options for Fuchs' endothelial corneal dystrophy, our understanding of optical and structural changes in the patient's cornea is also starting to improve.

OBJECTIVE

To provide an update on clinical evaluation of Fuchs' dystrophy.

MATERIAL AND METHODS

Standardized approaches to evaluate patients with Fuchs dystrophy in routine practice and research are discussed, accounting for the progressive and partially irreversible structural changes in all corneal layers.

RESULTS

Early structural changes in the cornea can be detected before clinical edema becomes visible on slit-lamp exam. Optical limitations resulting from these structural changes can be quantified not only with high-contrast acuity but also with glare or contrast sensitivity tests. Characteristic vision-related limitations of patients with Fuchs dystrophy can, e.g., be assessed with V-FUCHS, a Fuchs dystrophy-specific "Visual Function and Corneal Health Status" instrument for patient-reported outcomes.

CONCLUSION

Clinical grading of Fuchs dystrophy in an edematous and a non-edematous stage is outdated. Better therapy options and our improved understanding of progressive changes in the entire cornea require a standardized assessment of optical and structural changes and patient-reported limitations.

Scrolling Characteristics of Pre-Descemet Endothelial Keratoplasty Tissue: An Ex Vivo Study

PURPOSE

To evaluate the scrolling propensity of pre-Descemet endothelial keratoplasty (PDEK) tissue and to compare it with each component of the PDEK tissue, namely the pre-Descemet layer (Dua's layer [PDL]) and the Descemet membrane (DM).

DESIGN

Experimental laboratory investigation.

METHODS

Fourteen human donor sclerocorneal discs in which a type 1 big bubble was obtained by stromal injection of air were studied. The wall of the type 1 big bubble was excised and its grade of scrolling noted. The components of the wall (ie, the DM and PDL) were then separated and the scrolling of each was individually graded. Statistical comparison of the grade of scrolling of each layer and correlation with age was carried out; 25-μm slices of anterior and posterior stroma obtained with the femtosecond laser from 4 control samples were used for comparison. The main outcome measure was the grade of scrolling of PDEK tissue in comparison with PDL and DM.

RESULTS

Mean donor age was 67 years. The mean grade of the scroll formed by PDEK tissue was1.6 compared to 0.64 for PDL alone and 3.6 for DM alone. The difference was statistically significant. No correlation between donor age and degree of scrolling for any of the tissues tested was found.

CONCLUSION

PDEK tissue scrolls less than DM. PDL scrolls the least. This demonstrates that PDL tissue splints the DM and reduces its scrolling in PDEK. This feature has relevance to tissue preparation, handling, and unscrolling in the eye during endothelial keratoplasty.