Comparison of optical coherence tomography and scanning laser polarimetry in glaucoma, ocular hypertension, and suspected glaucoma

BACKGROUND AND OBJECTIVE: To compare the performance of the newest generation optical coherence topography (OCT) and scanning laser polarimetry with variable corneal compensation (SLP-VCC) in eyes with glaucoma, ocular hypertension, and suspected glaucoma. PATIENTS AND METHODS: One eye each of 84 patients (30 with glaucoma, 26 with suspected glaucoma, and 28 with ocular hypertension) was included in the study. Retinal nerve fiber layer (RNFL) thickness was measured with both technologies and thickness parameters were compared in the three groups of eyes. The correspondence of RNFL thickness measurements with visual field function was also studied. RESULTS: Average OCT-RNFL thickness was found to have a statistically significant difference between patients with glaucoma and either suspected glaucoma or ocular hypertension. A statistically significant correlation between the average RNFL thicknesses measured by the two different technologies was shown only in the glaucoma group. A significant correlation with visual field mean deviation was found for superior average RNFL thickness as measured by SLP and for nerve fiber indicator and average and inferior average RNFL thickness as measured by OCT in glaucomatous eyes. Regression analysis indicated nerve fiber indicator to be the most valuable factor in predicting mean deviation. CONCLUSION: RNFL thickness measurements obtained with OCT and SLP-VCC correlate well only in eyes with more advanced glaucomatous damage. The nerve fiber indicator parameter derived by SLP correlated best with mean deviation.