Purpose: The aim of the present paper is to describe the variations in intraocular pressure (IOP) during the day in normals, in patients with primary open-angle glaucoma (POAG) and in patients with normal-tension glaucoma (NTG). IOP represents one of the most important risk factors for glaucoma. However the IOP value is not constant during the day and IOP fluctuation could influence the diagnostic and prognostic evaluation of the glaucomatous disease. Methods: For this purpose IOP was evaluated every 2 h from 8 a.m. to 8 p.m. in one randomized eye of 33 normal subjects, 95 POAG and 50 NTG patients. Results: The results show that the highest IOP values were detectable in the morning in all three groups. The lowest values were found in the early afternoon hours. These variations were most evident in POAG patients. The daily IOP fluctuations were directly proportional to IOP level. Conclusion: The study evidents that a single tonometric evaluation, especially if done in the first hours of the afternoon, is not sufficient to correctly evaluate the IOP-related risk in glaucoma patients. If the pressure peaks are important in determining the extent of glaucomatous damage in NTG patients IOP should not have an important role in optic nerve head damage. The use of diurnal curves seems to be mandatory for the assessment of IOP-related risk and of efficiency of the therapeutic approach.

The examination findings of the fellow eye of 534 patients affected by a unilateral retinal detachment are reported. Nearly 90% of these eyes showed degenerative areas and about 20% showed one or more retinal breaks. These findings are quite different from those reported in examinations of 'random eyes' and suggest that fellow eyes are 'high risks' that often need prompt prophylactic treatment.

This study is aimed at establishing the efficacy of the therapeutic agent, betaxolol, in diurnal control of IOP (intraocular pressure). Therapy was performed on 32 eyes affected by POAG (primary open-angle glaucoma) and 16 eyes affected by NTG (normal-tension glaucoma). Two preparations of betaxolol were utilized: betaxolol hydrochloride 0.50% (Betoptic) was administered to 15 POAG and 7 NTG eyes; betaxolol hydrochloride 0.25% ophthalmic suspension (Betoptic S) was administered to 17 POAG and 9 NTG eyes. IOP measurements were taken every two hours from 8 a.m. to 8 p.m. IOP was measured before therapy and at 12 hours, 30 days, and 3 months of therapy. Betaxolol hydrochloride 0.50% was more effective at lowering IOP during the day. Diurnal pressure peaks, which are a risk factor concerning the maintenance of visual field in glaucoma patients, were also reduced using 0.50% betaxolol hydrochloride.

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The perceptual alternation of the Necker cube, in its stationary phase, is studied as a function of the stimulus luminance down to the extreme condition in which the cones are completely inactivated so that the pattern of neural excitation reaching the primary visual cortex is very different from the normal one. No evident effect of luminance was found under passive observation either on the reversal rate or on the features of data distributions. Moreover, the complementary situation in which perception is based only on the cones does not affect the phenomenon either. These results permit the assumption that the perceptual alternation in its stationary phase, is a passive and automatic process, that is affected neither by a satiation of the first levels of the visual system nor by the psychological attitude of the subject consequent on dazzling the retina.