Impact of Repeat Number on Resolution of Corneal Edema after Descemet's Stripping Only in Fuchs Dystrophy: A Pilot Study.

PURPOSE

To investigate whether Fuchs endothelial corneal dystrophy (FECD) genotype, specifically transcription factor 4 ( CTG triplet repeat "load" predicts time to clearance following Descemet's Stripping Only (DSO).

METHODS

This prospective, interventional trial was conducted on consecutive FECD patients undergoing DSO. Genetic analysis using patients' saliva was performed to assess the extent of CTG expansion using short tandem repeat analysis, corroborated gel electrophoresis and Sanger sequencing. Polymerase chain reaction and bidirectional Sanger sequencing was undertaken. Partial least square regression and logistic regression modelling was used to evaluate the predictive power of repeats on corneal clearance.

RESULTS

Of 11 eyes of 11 patients, 8 showed complete corneal clearance. For these 8 patients, mean allele repeat was 24.8 (SD: 23.7, range: 11-63) and 63.4 (SD: 30.3; range: 11-97), respectively. In total, 9/11 (81.8%) had expanded CTG repeats (>40) in one allele. In cases with an allele repeat ≥80, there was a significantly increased risk of corneal non-clearance (odds ratio 18.2, = 0.009).

CONCLUSION

Whilst it was not possible to predict time to corneal clearance based on CTG repeats, there is a significant correlation between allele repeats and achievement of corneal clearance.