Abstract
Purpose: :
To evaluate the effect of increased corneal thickness after Descemet stripping automated endothelial keratoplasty (DSAEK) or non-Descemet stripping automated endothelial keratoplasty (nDSAEK) on intraocular pressure (IOP) as measured with four different techniques.
Methods: :
Twenty four eyes (22 patients; mean age, 74.0 years) with successful DSAEK (11 eyes) or nDSAEK (13 eyes) treatment at least three months prior to testing.IOP was measured with Goldmann applanation tonometry (GAT), dynamic contour tonometry (DCT), pneumatonometry and Tono-pen XL® (Tonopen). Central corneal thickness (CCT) was measured by ultrasonic pachymetry.IOP and CCT data for all eyes were used for statistical analysis prospectively.
Results: :
Mean IOP measured by GAT, DCT, pneumatonometry, and Tonopen were 14.4, 13.9, 11.2, and 13.2 mmHg, respectively, in the DSAEK group; and 15.0, 14.4, 12.5, and 14.4mmHg, respectively, in the nDSAEK group. In the DSAEK group, all six pairs of measurement techniques correlated significantly. In contrast, in the nDSAEK group, three pairs (GAT vs Tonopen, GAT vs pneumatonometry, pneumatonometry vs Tonopen) were significantly correlated, whereas the remaining three pairs (GAT vs DCT, DCT vs Tonopen, and DCT vs pneumatonometry) were not statistically correlated. In both groups, IOP measurements by pneumatonometry were significantly lower than the other devices. Correlations between IOP and CCT were not statistically significant in either procedure group.
Conclusions: :
For both DSAEK and nDSAEK, IOP readings by the four techniques were unaffected by artificially thickened corneas. Readings by GAT, DCT, and Tonopen were comparable; however, pneumatonometry readings were lower than readings for the other three techniques.
Keywords: cornea: clinical science • transplantation • intraocular pressure