The relationship between central corneal thickness and optic disc size in patients with primary open-angle glaucoma in a hospital-based population.

PURPOSE: To investigate the relationship between central corneal thickness (CCT) and optic disc size in patients with primary open-angle glaucoma (POAG) in a hospital-based population. METHODS: Data for the right eyes of 1435 White patients with POAG were included in a retrospective hospital-based study. All eyes underwent optic nerve head imaging using Heidelberg Retina Tomograph II (HRT II; Heidelberg Engineering, Heidelberg, Germany) and CCT measurement by ultrasound corneal pachymetry. Eyes with prior intraocular or corneal surgery were excluded. Low-quality HRT II images were also excluded. The impact of age, gender, CCT, intraocular pressure, cylindrical and spherical refractive error as independent factors on optic disc size was investigated in a multiple linear regression analysis. RESULTS: The data for 1104 right eyes qualified for participation in the study. The median age of these patients was 65 years. The median CCT was 547 µm (25th-75th percentile 522-575 µm). The median optic disc size was 2.21 mm(2) (25th-75th percentile 1.89-2.60 mm(2)). Multiple linear regression analysis revealed that age (p = 0.001), CCT (p = 0.001) and spherical equivalent (p = 0.049) were correlated to disc size according to the following formula: disc area = -0.004 × age - 0.001 × CCT - 0.014 × spherical equivalent +3.290. R(2) of the whole model was 0.021. Univariate regression analysis between age and disc area provided R(2) = 0.008 with p = 0.002. Univariate regression analysis between disc area and CCT provided R(2) = 0.005 with p = 0.02. CONCLUSION: In this retrospective hospital-based study we could not detect a clinically relevant correlation between optic disc size and CCT. The correlation between CCT and disc size and between age and disc size were statistically significant, but the R(2) values were very low. The results of the study are biased because of its hospital-based design, so the results of the study need to be confirmed in a large population-based study.

A defined change of polarization axis is detected by variable corneal compensation of the GDxVCC.

PURPOSE: The aim of the study was to examine whether a defined change of polarization axis (PA) is detected by the variable cornea compensation (VCC) of the GDxVCC. The idea behind was to induce a change of PA by a rotation of the eye and to determine whether the rotation affects the magnitude of retardation and retinal nerve fiber layer measurements. METHODS: Fifteen normal eyes were examined with the GDxVCC. First scans (cornea and optic nerve head) of the right eye in regular position (0 degree) were performed. These scans are recognized and saved regularly as a right eye by the instrument. Then a second scan set of the same eye was taken: the subjects turned their head upside-down (180 degrees). These scans were recognized and saved as a left eye. For each scan, the instrument calculates the polarization parameter axis and magnitude. RESULTS: The difference of magnitude was 4.3+/-3.7 nm (0 to 12 nm) and difference of axis was 3.5+/-2.4 degrees (0.1 to 8.1 degrees). There were no significant differences in all measured parameters between the "normal" and the turned eye (all P>0.2; paired t tests). DISCUSSION: A defined change of PA was detected by the VCC of the GDx and the instrument was able to reproduce the polarization parameters of the anterior segment and retinal nerve fiber layer parameters of the same eye in 2 different positions with adequate accuracy.

Charles Bonnet Syndrome: successful treatment of visual hallucinations due to vision loss with selective serotonin reuptake inhibitors.

Visual hallucinations are a common and often distressing consequence of vision loss, particularly in age-related macular degeneration. Charles Bonnet Syndrome (CBS) is defined by the triad of complex visual hallucinations, ocular pathology causing visual deterioration and preserved cognitive status. So far, although this condition is frequent, no established treatment for CBS has been stated. We report here the case of a 78-year-old woman, who came in our hospital because of a 4-week long mild depressive symptomatology. For 1 year she experienced daily sudden, unexpected, vivid and elaborate hallucinations. Insight was completely present, so the patient stated that the hallucinations were unreal and that the faces, geometrical figures and animals she saw every day were possibly due to her vision loss. The Mini Mental State Examination, digit span and verbal fluency were administered and no cognitive impairment was reported. The visual acuity was hand motion. After 4 days of treatment with venlafaxine the hallucinations completely disappeared. This is the first case to show that selective serotonin (and noradrenalin) reuptake inhibitors may be an effective and well-tolerated treatment for visual hallucinations associated with vision loss, and it adds to evidence implicating serotonergic pathways in the pathogenesis of visual hallucinations.