Relationship between diastolic perfusion pressure and progressive optic neuropathy as determined by Heidelberg...

To determine through retrospective file analysis which clinical factors best predict glaucomatous optic neuropathy as evaluated by Heidelberg retinal tomography (HRT II) imaging.

One HUNDRED twenty-two records from patients referred for HRT imaging at the University of Waterloo Ocular Heath Clinic met inclusion criteria for this study and were reviewed. Topographic change analysis (TCA) data generated by HRT were examined in addition to the following clinical information: diastolic blood pressure, right arm sitting, intraocular pressure, and central corneal thickness. All HRT scans included were required to have 20 μm or better standard deviation (SD) on acquisition and deemed "very good" quality or "excellent" by HRT software. Based on previously defined published HRT TCA change criteria, each patient was allocated to one of the following groups: stable, borderline, or progressive.

Diastolic perfusion pressure (DPP) was found to be significantly lower in the borderline and progressive groups compared with the stable group (P < 0.001). DPP was also lower significantly lower in the progressive group compared with the borderline group (P < 0.001).

Low DPP appears to be a reasonable predictor of progressive optic neuropathy as determined using scans of <20 μm SD on the HRT TCA platform. DPP of 56 mm Hg or lower appears to be a clinically useful threshold to identify patients at increased risk of progressive optic neuropathy.