Purpose:
To compare how scanning laser polarimetry (GDx), spectral optical coherence tomography (OCT) and automated visual field (VF) testing classify glaucoma suspect patients.
Methods:
We examined both eyes of 88 subjects with suspect glaucoma (intraocular pressure (IOP) repeatedly > 21 mmHg, or optic nerve head (ONH) cup/disc (C/D) ratio 0.6 or more, disobedience of the ISNT-rule, or C/D ratio asymmetry between eyes of > 0.2). The subjects’ retinal nerve fiber layer (RNFL) around the ONH was examined with GDx and Cirrhus OCT. The VF was examined with Humphrey automatic perimeter (HAP). The GDx result was considered glaucomatous if the acquired RNFL thickness was less than the lower 1% limit of the normal population in the mean, superior, or inferior average, or the nerve fiber index (NFI) was > 50, and borderline if acquired RNFL thickness was less than the lower 5% limit of the normal population, or the NFI was 35-50. OCT was considered glaucomatous if the mean or any quadrant RNFL thickness was less than the lower 1% limit of the normal population, and borderline if it was less than the lower 5% limit. HAP was considered glaucomatous if the Glaucoma Hemi-field Test (GHT) was out of limits, or the mean deviation (MD) or pattern standard deviation (PSD) values were abnormal with a probability of p<0.01. Borderline HAP was defined as a borderline GHT, or MD or PSD values abnormal with a probability p<0.05.
Results:
Normal results with all three methods were found in 18 subjects. Fifteen subjects had abnormal results with all three methods, with five being classified as glaucomatous with all the methods and 10 as borderline. In the remaining 55 subjects, the methods gave differing results. Further classification is shown in Figure 1.
Conclusions:
Different methods classified most subjects differently in regard of glaucoma in this population of glaucoma suspects.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)