No abstract

Glaucomatous neuroretinal rim loss can occur in a sequence of sectors with the temporal inferior disc sector as the first and the nasal superior disc sector as the last to be affected. This study evaluated whether the position of the central retinal vessel trunk is correlated with this pattern of glaucomatous rim loss. Morphometrically stereo colour optic disc photographs of 157 glaucomatous eyes and 67 normal eyes were checked. In the normal and glaucomatous eyes, the central retinal vessel trunk was located eccentrically in the upper nasal quadrant of the optic disc. Taking into account the vertically oval disc shape, the distance to the central vessel trunk was largest for the temporal inferior disc region and shortest for the nasal superior disc area. An abnormal form ofthe glaucomatous neuroretinal rim was found in eyes with an atypical location of the retinal vessel trunk. Also in these glaucomatous eyes, the rim loss was usually most and least marked in that sector with the longest and shortest distance, respectively, to the central retinal vessel trunk. One could infer that the sequence of rim loss in glaucoma is dependent upon the distance of the region to the central retinal vessel trunk; the further away the region from the retinal vessel trunk, the more likely it is to be affected by rim loss. This suggests that the distance from the central retinal vessels is one factor among others that is correlated with the regional vulnerability of the neuroretinal rim to the glaucomatous process. (BrJ Ophthalmol 1994; 78: -2-25 to 4-0 dioptres) were included in the study.These were randomly selected eyes out of a set of normal and glaucomatous eyes in which the exit of the retinal vessel trunk on the lamina cribrosa surface was clearly visible. Eyes with a myopic refractive error exceeding -8 dioptres were excluded because of a different optic disc morphology.7 Additionally, 53 glaucomatous eyes with tilted discs were evaluated. They were defined by a horizontally oval optic disc shape with the horizontal disc diameter being at least 10% longer than the vertical one. The ratio of the minimal disc diameter to the maximal disc diameter was at maximum 0 90.Criteria for the diagnosis of glaucoma were an elevated intraocular pressure to readings of more than 21 mm Hg, glaucomatous changes of the optic nerve head such as an abnormally small neuroretinal rim area in relation to the optic disc size, larger vertical than horizontal cup to disc ratios, splinter-shaped optic disc haemorrhages, reduced visibility of the retinal nerve fibre bundles including localised defects, and glaucomatous visual field defects.For all eyes, 15 degree colour stereo optic disc photographs had been taken using a telecentric Zeiss fundus camera equipped with an Allen stereo separator. The disc transparencies were projected in a scale of 1 to 15. The outlines of the optic disc and optic cup were plotted on paper and morphometrically analysed. We measured area and horizontal, vertical, minimal, and maximal diameters of the disc and ...

No abstract

No abstract

No abstract