Analysis of factors influencing refractive error in Fuchs eyes undergoing Descemet membrane endothelial keratoplasty triple procedure.

PURPOSE: To evaluate the accuracy of current intraocular lens (IOL) formulas and identify factors influencing mean error in eyes undergoing Descemet membrane endothelial keratoplasty (DMEK) triple procedure, that is, DMEK combined with cataract extraction and IOL placement for concurrent Fuchs endothelial corneal dystrophy (FECD) and cataracts.

DESIGN

Retrospective cohort study.

SUBJECTS: 90 eyes with FECD undergoing uncomplicated DMEK triple procedure at Wilmer Eye Institute.

METHODS

We analysed tomographic features of oedema, including loss of regular isopachs, displacement of the thinnest point of the cornea and the presence of posterior surface depression, and assessed the correlation with the prediction error.

MAIN OUTCOME MEASURES: We compared the mean error (±SD) for the Barrett Universal II (BU2), Hoffer QST, Haigis-L (HL) and Barrett True K (BTK) formulas and the percentage of eyes within 0.25, 0.5 and 1 diopter (D) of error.

RESULTS

All formulas resulted in a mean hyperopic error, with the HL having the lowest mean error of 0.24 D (±0.97 D) and BU2 having the highest ME of 0.94 D (±0.97 D). For each additional tomographic feature of corneal oedema in the BU2 and Hoffer QST formulas, the mean hyperopic error increased by 0.38 D. For the BTK and HL formulas, the mean error increased by 0.35 D (p<0.001).

CONCLUSION

The number of tomographic features of oedema can be useful in identifying eyes with higher errors in IOL calculation when performing the DMEK triple procedure for FECD.