MRI findings of globe and optic nerves in tilted disk syndrome.

We assessed the anatomical variations of the globe and optic nerve in tilted disk (TD) syndrome using magnetic resonance imaging (MRI) findings and compared them with a control group. Eleven patients diagnosed with TD syndrome during eye examination were referred for MRI of the sella and chiasm to exclude intracranial mass lesions. The shape of the globe, the chiasmal angle, the insertion angles of the optic nerve in axial and parasagittal planes determined by lines parallel to the optic nerve and tangent to the globe in TD syndrome were compared with a control group consisting of 53 cases. Gender ratios were 7/4 (F/M) for the TD group and 35/18 for the control group (p>0.05). The insertion angle of the optic disk to the globe was wider in the temporal quadrant (p<0.05) and narrower in the nasal quadrant (p<0.05) in TD syndrome than in the control group. There was no significant difference in the superior and inferior insertion angles between the groups. The anterior-posterior (AP) diameter of the globe was significantly longer in patients with TD (p<0.05). There was no significant difference between the optic chiasm angles. The relationships of the optic disk and the globe were significantly different in patients with TD syndrome in comparison to the control group. TD syndrome is related to the malalignment of optic nerve and globe in the horizontal plane.

Fluorescein dye disappearance test in patients with different degrees of epiphora.

PURPOSE: To assess the diagnostic efficacy of a modification of the fluorescein dye disappearance test (DDT) in patients with different degrees of epiphora. METHODS: DDT was performed by instilling a drop of 2% fluorescein in the eye. Schirmer tear test strips were placed in the lower conjunctival fornix, after 3 and 10 minutes. The colour dilution on the strips was compared to a scale with known standards and the most closely comparable colour dilution was chosen and recorded as the visual scale test (VST) grade of the strip. The grey-scale value (GV) of each strip was calculated by computer image analysis. The control group comprised 44 patients, mean age 44.8 years (SD 7.5, range 30-60). There were 13 patients in group 1 with moderate epiphora; mean age was 44.2 years (SD 9.5, range 30-60). There were 17 patients in group 2 with severe epiphora; mean age was 48.3 years (SD 7.7, range 37- 60). RESULTS: VST and GV differed significantly between controls and group 1 patients at 3 minutes (p=0.002, p=0.001), and between controls and group 2 patients at 3 minutes (p<0.001, p<0.001). There was no difference between groups 1 and 2 patients in VST and GV at 3 minutes. The differences were highly significant between controls and group 1 at 10 minutes (p=0.001, p=0.007), and between controls and group 2 at 10 minutes (p<0.001, p<0.001). The differences in GV and VST between groups 1 and 2 were significant at 10 minutes (p=0.026, p=0.018). CONCLUSIONS: This modified DDT permits identification of different degrees of epiphora in a non-invasive manner, it can therefore be used to evaluate the outcome of different treatment strategies.

Relation of optic disc topography and age to thickness of retinal nerve fibre layer as measured using scanning laser polarimetry, in normal subjects.

AIMS: To evaluate the relation of the optic nerve head topographic measurements and age with the thickness of the retinal nerve fibre layer (RNFL) in normal Caucasoid subjects by means of scanning laser polarimetry and tomography. METHODS: Topographic optic disc measurements and RNFL thickness values of 38 normal Caucasoid subjects of both sexes aged 20 to 78 were measured using a confocal scanning laser ophthalmoscope and a confocal scanning laser polarimeter. One eye was randomly selected for statistical analysis. The effects of optic disc size, age, and optic disc head topographic measurements of total and regional RNFL thickness were evaluated. RESULTS: Age showed a significant correlation with the integral of the total RNFL thickness (R=-0.341, p<0.05). The optic disc size showed a significant correlation with the integral of the total, superior, and inferior quadrant RNFL thickness (R=0.425, p<0.01), (R=0.361, p<0.05), (R=0.468, p<0.05). Neuroretinal rim area (NRA) had a correlation with the superior and inferior quadrant RNFL thickness values (R=0.339, p<0.05) (R=0.393, p<0.05). There was no significant correlation between the other optic disc topographic measurements and RNFL thickness values (p>0.05). CONCLUSION: The thickness of total as well as superior and inferior quadrant peripapillary RNFL as measured by scanning laser polarimetry increased significantly with an increase in optic disc size. The cross sectional area occupied by superior and inferior polar RNFL increased significantly with an increase in NRA. The total cross sectional area occupied by RNFL decreased significantly with an increase in age. The effects of optic disc size, age, and NRA should be considered when the peripapillary RNFL thickness is evaluated.