Comparison of dynamic contour tonometry and goldmann applanation tonometry in deep lamellar and penetrating keratoplasties.
OBJECTIVE
To compare the measurements of intraocular pressure (IOP) with dynamic contour tonometry (DCT) and Goldmann applanation tonometry (GAT) in eyes with corneal graft and to evaluate the influence of corneal thickness (CCT), corneal curvature (CC), and astigmatism on these methods.


METHODS
Prospective, observational cross-sectional study.


METHODS
Eighteen eyes of 18 patients after penetrating keratoplasty (PKP) and 14 eyes of 14 patients after deep lamellar keratoplasty (DLKP) underwent IOP evaluation with DCT and GAT, and measurements of CCT, CC, and astigmatism. Bland-Altman plots were used to evaluate the agreement between tonometers. Multivariate regression analysis was used to evaluate the influence of ocular structural factors and running suture on IOP measurements obtained with both tonometers.


RESULTS
IOP values obtained by DCT and GAT were strongly correlated in all eyes (r = .91; P < .001). DCT values measured 2.5 +/- 1.7 mm Hg higher than GAT readings (P < .001). A reduction of the mean IOP difference between DCT and GAT with an increase in IOP values (P < .001) was found. Regression analysis showed no effect of CCT, CC, astigmatism, and running suture on both DCT and GAT readings, either in DLKP or in PKP eyes.


CONCLUSIONS
We found a good overall correlation between both tonometers but the agreement between instruments differs in high or low IOP ranges. The wide and varying 95% limits of agreement between DCT and GAT indicates that DCT provides IOP measurements on deep lamellar and penetrating keratoplasties which can be used in the clinical practice.
Ceruti
Piero
P
Eye Clinic, Department of Neurological and Visual Sciences, University of Verona, Borgo Trento Hospital, Piazzale Stefani 1, Verona, Italy. pierre77@libero.it
Morbio
Roberta
R
Marraffa
Michele
M
Marchini
Giorgio
G
D000328:Adult; D001251:Astigmatism; D003315:Cornea / Q000473:pathology; D003316:Corneal Diseases / Q000601:surgery; D016039:Corneal Transplantation; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D015948:Keratoplasty, Penetrating; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D013536:Suture Techniques; D014065:Tonometry, Ocular / Q000379:methods*