Abstract
Purpose: :
To evaluate the corneal parameters after Descemet’s stripping automated endothelial keratoplasty (DSAEK) using a rotating Scheimpflug camera.
Methods: :
Thirty-two eyes of 28 patients who underwent DSAEK were evaluated with a Pentacam Scheimpflug camera (Pentacam, Oculus, Wetzlar, Germany) at 3 months post-operatively. The following parameters were obtained: mean anterior keratometry (Ka), anterior astigmatism, mean anterior radius of curvature (Ra), mean posterior keratometry (Kp), posterior astigmatism, mean posterior radius of curvature (Rp), central corneal thickness, true net power, corneal volume, keratometric power deviation (KPD) and mean zonal equivalent K readings (EKR) at 2mm, 4mm and 6mm. These values were compared with 32 non-surgical eyes of 32 age-matched controls.
Results: :
The Ka, Rp and true net power were lower in DSAEK group (42.60±1.57 D, 5.91± 0.47mm and 40.55±1.79 D) as compared to controls (43.59±1.62 D, 6.46±0.32mm and 42.48±1.57 D). On the other hand, Ra, central pachymetry, cornea volume and KPD were higher in the DSAEK group (7.93± 0.3mm, 627.75± 46.41µm, 72.9± 7.77mm3 and 1.89± 0.78 D respectively) as compared to the controls (7.73± 0.27mm, 552.53± 34.53µm, 58.19± 4.42 mm3 and 1.22 ± 0.27 D respectively). The mean Kp had higher negative value (-6.8± 0.54 D) in DSAEK eyes as compared to (-6.22± 0.3D) controls, suggesting increased posterior curvature due to the endothelial graft. EKR values increased towards the periphery in both groups and were lower in DSAEK group as compared to controls in all the zones. The difference was found to be statistically significant (p<0.01) for all the parameters except Ra and anterior surface astigmatism between the two groups.
Conclusions: :
The true net power of cornea shows statistically significant lower values as compared to age matched controls and is likely due to combined effect of increase in posterior curvature (increased minus lens effect) and decrease in anterior corneal curvature (decreased plus lens effect) after DSAEK surgery.
Keywords: cornea: endothelium • transplantation • aberrations