title: Ocular pulse amplitude before and after cataract surgery.
abstract: OBJECTIVE
  To investigate the impact of cataract surgery on the association of the ocular pulse amplitude (OPA) and intraocular pressure (IOP) with respect to the interpretation of OPA as an estimate of ocular blood flow.
  
  
  METHODS
  Twenty-four patients with cataract were included in a clinical study. OPA was measured using dynamic contour tonometry (DCT, Pascal(®), SMT Swiss Microtechnology AG, Switzerland). IOP was measured by means of Goldmann applanation tonometry (IOP GAT) and DCT (IOP DCT). All measurements were performed before and one day after cataract surgery.
  
  
  RESULTS
  At baseline, OPA was correlated to IOP GAT (r = 0.67, P = 0.0002) and IOP DCT (r = 0.82, P < 0.0001), but not to age or axial length. Postoperative OPA was correlated to IOP GAT (r = 0.67, P = 0.0002) and IOP DCT (r = 0.65, P = 0.0004). In 17 patients, IOP GAT decreased after surgery (IOP DCT n = 14), whereas an increase was apparent in seven patients (IOP DCT n = 10). The mean absolute deviation of IOP GAT pre- to post-surgery was 4.54 mmHg ± 2.47 (range 1-10 mmHg) and 5.4 mmHg ± 3.2 (range 1.1-13.1 mmHg) for IOP DCT. The changes of OPA were significantly correlated to changes in IOP GAT (r = 0.48, P = 0.017) and IOP DCT (r = 0.60, P = 0.001). IOP GAT and IOP DCT changes were not correlated to changes in corneal thickness.
  
  
  CONCLUSIONS
  The OPA measured with the Pascal(®) device seems to be dependent on IOP changes. Particular caution should be taken in the interpretation of OPA in estimating pulsatile ocular blood flow.
authors: Department of Ophthalmology, RWTH Aachen University, Aachen, Germany. nplange@ukaachen.de
authors: Niklas
authors: N
authors: Plange
authors: Corinna
authors: C
authors: Rennings
authors: Anne
authors: A
authors: Herr
authors: Anke
authors: A
authors: Weber
authors: Gernot F
authors: GF
authors: Roessler
authors: Babac E
authors: BE
authors: Mazinani
authors: Marion
authors: M
authors: Kaup
authors: Andreas
authors: A
authors: Remky
mesh_terms: D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D005123:Eye / Q000098:blood supply*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D019654:Lens Implantation, Intraocular; D008297:Male; D018918:Phacoemulsification; D014065:Tonometry, Ocular