Intraocular pressure and corneal biomechanics in Fuchs’ endothelial dystrophy and after posterior lamellar keratoplasty

Abstract

. Purpose: To evaluate the precision of techniques for measuring intraocular pressure (IOP) in corneas with presumably altered biomechanical properties. Methods: Intraocular pressure was measured with a Goldmann applanation tonometer (GAT), ocular response analyzer (ORA) and dynamic contour tonometer (DCT) in 70 eyes. Thirty‐five eyes were normal corneas, 18 eyes had Fuchs’ endothelial dystrophy, and 17 eyes had undergone Descemet’s stripping automated endothelial keratoplasty (DSAEK) surgery. Corneal hysteresis (CH), corneal resistance factor (CRF) as well as central corneal thickness (CCT) were recorded with the ORA. Results: The measured cornea‐corrected IOP using ORA was significantly higher than GAT in all three groups (p < 0.001). The DCT differed significantly from the Goldmann only in the Fuchs’ group (p = 0.04). The Goldmann and DCT showed no significant between‐group differences, whereas IOP measured with the ORA was different between groups (p < 0.001). CH in the DSEAK group differed significantly from the controls (p < 0.001), but there was no significant difference between the DSEAK and Fuchs’ groups (p = 0.21). CCT did not differ significantly between the DSAEK and Fuchs’ group (p = 0.47). However, both these groups differed significantly from the controls (p < 0.001). Conclusion: Corneal hysteresis and CRF are reduced in Fuchs’ endothelial dystrophy as well as after posterior lamellar keratoplasty. GAT and DCT seem to measure IOP correctly in patients with Fuchs’ endothelial dystrophy as well as after posterior lamellar keratoplasty. Corneal‐corrected IOP as measured with the ORA appears to overestimate IOP in patients with Fuchs’ endothelial dystrophy as well as after posterior lamellar keratoplasty.

Changes in Corneal Biomechanical Properties After Descemet Stripping Automated Endothelial Keratoplasty for Pseudophakic Bullous Keratopathy

“…IOP g was almost identical between case and control eyes both pre-and postoperatively, which is in line with the results of a previous study. 10 In the present study, IOP cc yielded the highest pressure values in patients with PBK as well as after DSAEK. This measurement is intended to compensate for biomechanical properties and be less affected by CCT than by GAT in corneas with abnormal thickness.…”

“…This is in accordance with the results of other studies demonstrating that corneal biomechanical parameters are significantly lower in other causes of corneal edema such as Fuchs endothelial dystrophy. 9,10 This reduced corneal rigidity is attributable to slacking of stromal fibres in the posterior corneal layers because of edema. 12 The results of the present study demonstrated that CH and CRF are significantly improved after DSAEK and become comparable to those of the normal fellow eye.…”

“…6 A few studies have investigated biomechanical properties of corneas thickened by stromal edema or DSAEK. [7][8][9][10][11] To the best of our knowledge, however, no studies have characterized these metrics in pseudophakic bullous keratopathy (PBK) before and after DSAEK. The purpose of the present study was to determine the extent to which DSAEK can alter these parameters in PBK.…”

Elevated Intraocular Pressure in Patients Undergoing Penetrating Keratoplasty and Descemet Stripping Endothelial Keratoplasty

“…Similar findings were reported by Yi et al 15 and Clemmensen and Hjortdal. 29 Yi et al 15 also showed that patients with preexisting glaucoma are much more likely to develop a steroid response after DSEK as compared with unaffected individuals. Lower rates of graft rejection in DSEK 2 could potentially allow earlier tapering of steroids, leading to a lower risk of steroid-induced glaucomatous optic nerve damage.…”

Incidence of Intraocular Pressure Elevation and Glaucoma after Lamellar versus Full-Thickness Penetrating Keratoplasty

“…In addition, previous studies have shown that the increased corneal thickness after DSEK does not significantly influence IOP measurement, making correction of IOP according to corneal thickness unnecessary. 18,19 In a recent retrospective study by Sandhu et al 9 that included 61 eyes with a 12month follow-up, elevated IOP was found to be a serious aftereffect of both PK and DSEK, with at least 30% pressure elevation from baseline within 1 year in 39% of cases. However, given the low number of eyes included and the short follow-up of patients in that study, the similar incidences observed do not necessarily indicate an absence of differences between the 2 groups.…”