IOP Fluctuation Effects on Scanning Laser Polarimetry with Variable Corneal Compensator, Optical Coherence Tomography and Confocal Scanning Laser Ophthalmoscopy.

Abstract

Abstract: : Purpose: To verify intra–ocular pressure (IOP) fluctuation correlation with anatomical evaluation obtained by scanning laser polarimetry (GDx Access) with Variable Corneal Compesator (VCC), optical coherence tomography (OCT III) and confocal scanning laser ophthalmoscopy (Heidelberg Retina Tomography – HRT II). Methods: Seventeen patients with clinically controlled primary open–angle glaucoma, best corrected visual acuity better than 20/60 and cup/disk ratio equal or less than 0.8 were evaluated. Patients were asked not to use the glaucoma eye drops twenty–four hours before the exams. Baseline IOP was accessed by Goldmann aplanation tonometer and optic disk topography (HRT II), nerve fiber layer analysis (GDx Access – VCC) and optical coherence tomography (OCT III) were performed. Afterwards, 250 mg oral acetazolamide was administered to every patient. Two hours later, all patients underwent IOP measurement and the same examination sequence listed before. Difference for all standard steriometric parameters of these three devices entered as dependent variable in a linear regression model, with delta IOP and %delta IOP as independent variables. Results: Mean delta IOP was –3.35 ± 3.37 mmHg (ranging from –13 to 0) and mean %delta IOP was –16.84 ± 14.66 % (ranging from –52 to 0 %). There were no statistically significant correlation between the difference in IOP (delta IOP and %delta IOP) and all stereometric parameters (P>0.05). Conclusions: Small differences in IOP did not correlate with GDx VCC, OCT III and HRT II standard stereometric parameters fluctuation.

Keywords: optic disc • nerve fiber layer • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)