Abstract
Purpose: :
Ocular pulse amplitude (OPA) as measured by dynamic contour tonometry (DCT) may reflect ocular blood flow as well as ocular rigidity. Clinical utility of OPA is being investigated. The relationship of OPA and anterior segment characteristics has been reported in normal eyes but has not been examined in eyes that have undergone successful Descemet stripping endothelial keratoplasty (DSEK). We examined the relationship of OPA to intraocular pressure (IOP) and corneal thickness in eyes after DSEK.
Methods: :
A prospective, cross-sectional study of patients who had undergone successful DSEK at one tertiary referral center with at least three months of follow-up was performed. Patients with corneal edema or other acute corneal pathology were excluded. Measurements performed included OPA and IOP by DCT; IOP by Goldmann applanation tonometry (GAT); and IOP by pneumotonometry (PT). Total corneal thickness (CCT) was measured by ultrasonic pachymetry, and thickness of the donor and the recipient cornea was measured by anterior segment optical coherence tomography. Pearson’s correlations between OPA and other anterior segment parameters were performed.
Results: :
Fifty eyes of 38 patients were included. Indications for DSEK included Fuch’s corneal dystrophy (40 eyes; 80%), corneal edema (8 eyes; 16%), and repeat DSEK (2 eyes; 4%). Mean OPA was 2.53 ± 1.24 mm Hg. Mean IOP was 19.8 ± 4.4 mm Hg by DCT, 15.9 ± 4.9 mm Hg by GAT and 20.3 ± 4.6 mm Hg by PT. Mean total CCT was 701 ± 68 µ. Mean thickness of the donor and recipient was 175 ± 42 µ and 502 ± 47 µ, respectively. OPA was modestly correlated with GAT (r=0.36; p=0.01) and PT (r=0.32; p=0.03). The correlation of OPA with DCT approached significance (r=0.27; p=0.06). OPA was not associated with CCT or the thickness of donor and the recipient (p>0.05).
Conclusions: :
The mean OPA in DSEK eyes was comparable to that of normal eyes reported previously. Similar to prior reports in healthy eyes, we found an association between OPA and IOP but not CCT. Our data suggest that corneal changes induced by DSEK do not significantly alter OPA readings.
Keywords: intraocular pressure • cornea: clinical science