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A 71-year-old patient died 4 weeks after the occurrence of incomplete occlusion of the central retinal vein. Histology of the two bulbi was compared with the photographic and fluorescenceangiographic findings of the fundus. Histologic evaluation showed that the occlusion had been caused by a thickening of the vein wall due to proliferation of fibrocytes and histiocytes just behind the lamina cribrosa. There were no signs of phlebitis or thrombosis.

The retinal blood vessels serve for nutrition of the retinal ganglion cells and their axons. This study was undertaken to evaluate the vessel diameter in normal and glaucoma eyes. The calibers of the superior temporal and inferior temporal retinal artery and vein were measured at the optic disc border and at a distance of 2 mm from the optic disc center; 473 eyes of 281 patients suffering from chronic primary open-angle glaucoma and 275 eyes of 173 normal subjects were examined. Fifteen-degree, color stereo optic disc photographs were used. In the normal eyes the inferior temporal vessels were significantly larger than the superior temporal vessels. This corresponds with: (1) the configuration of the normal neuroretinal rim, which is significantly broader in the inferior disc region than in the superior disc area; (2) the visibility of the retinal nerve fibers, which are better detectable in the inferior temporal area than in the superior temporal one; and (3) the foveola location 0.53 +/- 0.34 mm inferior to the optic disc center. The retinal vessel diameter was independent of the patients' age and optic disc and parapapillary chorioretinal atrophy size. In the glaucoma group the vessel caliber was significantly smaller than in the normal eyes. The differences were more marked for the arteries and the inferior temporal vessels, respectively. The vessel diameters decreased significantly with increasing glaucoma stage independently of the patients' age. The parapapillary retinal vessel diameter may reflect the need of vascular supply in the corresponding superficial retinal area. It may be correlated with the local ganglion cell density and retinal nerve fiber layer thickness.

A study of 70 ophthalmologically asymptomatic patients with abnormal hemoglobinopathy (AS, SS, S Thal) is presented. A significant number of SS and S Thal group patients had visual acuity of less than 20/20. Retinal vein dilation and tortuosity was observed in 54% of S Thal and 83% of SS patients. Early stages of proliferative retinopathy were encountered in 7% of SS and S Thal patients in the study. The importance of routine ocular examination including meticulous binocular indirect ophthalmoscopy with scleral depression in asymptomatic patients with abnormal hemoglobin is stressed.

Retinal sensitivity is examined by projecting the aiming beam of an argon krypton laser photocoagulator onto the fundus through a contact lens. Even at normal intensity the brightness of the projected aiming on the retina is much greater than the maximum-intensity light target in ordinary scotometry. The discrepancy between scotomata when comparing the results of ordinary and laser scotometry suggests a potential for recovery of visual function, especially in macular diseases. This examination is practicable even if there is slight opacity of the media. By setting the laser beam at sufficiently low intensity, relative scotomata can be detected.

We conducted a detailed investigation into retinal hemorrhages in renovascular malignant arterial hypertension experimentally produced in rhesus monkeys. The hypertension was produced by modified Goldblatt's procedures in 60 rhesus monkeys and hypertensive fundus changes were studied by ophthalmoscopy, stereoscopic color fundus photography and fluorescein fundus angiography. Our study revealed that, in hypertensive retinopathy due to malignant hypertension, retinal hemorrhages usually did not constitute either one of the earliest or one of the most conspicuous retinal lesions, but, on the contrary, were a minor feature of the retinopathy. Neither the time of onset of retinal hemorrhages nor their peak severity showed any significant correlation with the level of the arterial hypertension. The hemorrhages were usually situated in the nerve fiber layer, and could be located anywhere in the fundus but were usually found in the distribution of the radial peripapillary retinal capillaries. There was no association between the presence of retinal hemorrhages and retinal venous changes; the latter were seen only in a minority of animals and consisted of retinal venous stasis, venous collaterals and arteriovenous shunts.