Purpose:The aim of the study was to evaluate the influence of optic disc size on the variables of laser scanning polarimetry(GDx).Patients and methods:One hundred and nineteen healthy controls and 161 patients with ocular hypertension(OHT)received detailed ophthalmologic investigation with respect to glaucoma including retinal nerve fiber analysis with GDx(Version 3.0.05× 1;Laser Diagnostic Technologies Europe).Optic disc size was measured with planimetry using 15° optic disc photographs.With respect to frequency of optic disc size in the normal population patients were divided in quartiles of equal sample size.Results:The ratio between retinal nerve fiber layer thickness in the superior and inferior areas in relation to the nasal and temporal regions decreases significantly with increasing optic disc size and the difference between the highest and lowest retinal nerve fiber layer thickness decreases significantly with increasing optic disc size.The results of multivariate neural network analysis increased with larger optic disc size in controls as well as in patients with OHT.Linear regression analysis showed an increase of 9 units(the Number)per 1 mm2 of optic disc size.A Number above 30,which indicates suspected glaucoma,was detected in more than a third of the normal population investigated if the optic disc area was larger than 3.5 mm2.Overall,patients with OHT had a higher Number than controls(20.5± 11.5 vs.18.1± 10.4;p >0.05),but the difference between the two groups did not reach a significant level.Conclusions:Retinal nerve fiber analysis in patients with an optic disc size larger than 3.5mm2 should be interpreted carefully;the Number in particular requires corrections for optic disc size. Purpose: The aim of the study was to evaluate the influence of optical disc size on the variables of laser scanning polarimetry (GDx). Pats and methods: One hundred and nineteen healthy controls and 161 patients with ocular hypertension (OHT) received detailed ophthalmologic investigation with respect to glaucoma including retinal nerve fiber analysis with GDx (Version 3.0.05 × 1; Laser Diagnostic Technologies Europe). Optically disc size was measured with planimetry using 15 ° optic disc photograph .With respect to frequency of optic disc size in the normal population patients were divided in quartiles of equal sample size. Results: The ratio between retinal nerve fiber layer thickness in the superior and inferior areas in relation to the nasal and temporal regions decreased significantly with increasing optic disc size and the difference between the highest and lowest retinal nerve fiber layer thickness decreases significantly with increasing optic disc size. The results of multivariate neural net work analysis increased with larger optic disc size in controls as well as in patients with OHT.Linear regression analysis showed an increase of 9 units (the Number) per 1 mm2 of optic disc size .A Number above 30, which indicates suspended glaucoma, was detected in more than a third of the normal population investigated if the optic disc area was larger than 3.5 mm 2. Overall, patients with OHT had a higher number than controls (20.5 ± 11.5 vs.18.1 ± 10.4; p> 0.05), but the difference between the two groups did not reach a significant level. Conclusions: Retinal nerve fiber analysis in patients with an optic disc size larger than 3.5 mm2 should be interpreted carefully; the Number in particular required corrections for optic disc size.