Purpose: To investigate the correlation between ocular pulse amplitude and visual field defects in patients with glaucoma, ocular hypertension, and glaucoma suspicion when measured with the Pascal Dynamic Contour Tonometer, and to verify if the ocular pulse amplitude is an independent predictor for visual field parameters.
Methods: Seventy-seven eyes (42 patients) with glaucoma, ocular hypertension or glaucoma suspicion were examined. Ocular pulse amplitude was measured with the dynamic contour tonometer by one investigator masked to the visual field data. Visual fields were performed within three months of ocular pulse amplitude measurement by the Octopus or Humphrey Field Analyser, and were analysed with Peridata Software. Mean defect, pattern standard deviation ( radical Loss Variance) and regression analysis of those parameters (Trend Indices) were correlated with the ocular pulse amplitude for each eye.
Results: Forty-nine eyes had glaucoma, 14 had ocular hypertension, and 14 were glaucoma suspects. The mean follow-up was 46.5 (range 6-96) months. There was a significant correlation between OPA and MD and OPA and PSD, even after correction for IOP (and diagnostic group and eye): the estimated slope equals 2.68 (S.E. = 0.82, p = 0.003) and -0.86 (S.E. = 0.33, p = 0.014), respectively. There was even a weak correlation between OPA and the evolution of MD (dB/year). The slope estimate for OPA equals 0.070 (S.E. = 0.033), p = 0.037. However, after correction for IOP (and diagnostic group and eye), the strength of the relationship is reduced and the evidence disappears: the slope estimate for OPA now equals 0.039 (S.E. = 0.041), p = 0.34. There is no evidence for an association between OPA and the evolution of Trend-PSD.
Conclusion: A small ocular pulse amplitude, as measured with a dynamic contour tonometer, is correlated with moderate to severe glaucomatous visual field loss and might be a risk factor for the development of glaucomatous visual field defects.