Ultrabiomicroscopic study of the effects of brimonidine, apraclonidine, latanoprost and ibopamine on the chamber angle and ciliary body.

The authors used the Zeiss Humphrey (Mod840, 50 MHz) ultrabiomicroscope to evaluate the changes that Brimonidine, Apraclonidine, Latanoprost and Ibopamine cause in the anterior chamber and on the ciliary body of healthy subjects. The eyes of 60 volunteers, separated into 4 groups according to drug instilled, were studied and the parameters analyzed were: anterior chamber depth (ACD), pupillary diameter (PD), angle opening at 500 microns from the scleral spur (AOD500), trabecular iris angle (TIA) and iris thicknesses (ID1 and ID3). The study showed the miotic effect of Brimonidine (S) that was accompanied by an angle opening (S). Apraclonidine and Latanoprost caused no statistically significant changes in the angle or in the ciliary body. Ibopamine caused mydriasis (S). The UBM, therefore, showed itself to be useful also in the study of the mechanism of action of drugs on the angular structures and on the ciliary body.

Glaucoma, lighting and color vision. An investigation into their interrelationship.

The results of a study on color vision capacity performed with a view to further analyzing glaucomatous dyschromatopsia are reported. The Farnsworth-Munsell 100-hue test was used in a population of 52 subjects (104 eyes) with daylight fluorescent lighting and low-tension halogen lighting. Photocolorimetric observations with each type of lighting were made. It was found that halogen lighting increased the glaucomatous subjects' mean score, the number of dyschromatopsia and the number of blue-yellow dyschromatopsia axes. The authors conclude that halogen lighting is preferable for the Farnsworth-Munsell 100-hue test in glaucoma and confirm the predominance of blue-yellow dyschromatopsia axes in glaucoma.

[Importance of ocular blood flow in glaucoma]. / Die Wichtigkeit des Augenblutflusses beim Glaukom.

BACKGROUND: The vascular factor is becoming increasingly important in the pathogenesis of primary open-angle glaucoma. Ocular hypotonia, which is indubitably a risk factor in the development of glaucoma, cannot be regarded as the sole pathogenic factor. Clinical experience leaves no doubt that some patients tolerate a high IOP for prolonged periods of time without ocular damage. In others, however, severe glaucoma-related lesions result from slight hypertonia or critically low pressure. METHODS: The authors analyze the general factors which influence ocular blood flow and increase the deleterious effect of ocular hypertonia, and report results relating to the hemodynamic status of a group of glaucoma patients prior to and after one year of therapy with beta-blockers. The results are analyzed and discussed.

Differences in the longterm effect of timolol and betaxolol on the pulsatile ocular blood flow.

In the past several years the effect of longterm glaucoma therapy on ocular hemodynamics has taken on increased interest. This interest has been sparked by studies demonstrating differential effects of various beta-blockers on visual function, and the possible contributory role of ocular blood flow. In the present study, the pulsatile ocular blood flow (POBF), as derived by the Langham OBF system, was measured prior to treatment and then tracked throughout a one-year period of beta-blocker therapy (betaxolol 0.5% or timolol 0.5%) in 25 glaucoma patients. Results of the two treatments were compared, and indicated that, whereas both betaxolol- and timolol-treated patients had similar significant reductions in the IOP, the effect of the two treatments on the POBF differed. In timolol-treated patients, the POBF decreased significantly over the 12-month observation period, whereas in betaxolol-treated patients it remained stable.

The Pulsair-Keeler non-contact tonometer in self-tonometry: preliminary results.

The authors considered the possibility of using the Pulsair-Keeler non-contact tonometer in self-tonometry. For this reason, 45 patients have been trained to use the instrument and, after a reasonable trial period, were able to self-measure their IOP. The results have been compared to the tonometric values measured with Goldmann tonometer to evaluate statistically the limits and the dependability of this method of measurement. The results shows that self-tonometry with the Pulsair-Keeler tonometer can be used in monitoring glaucomatous patients at home.