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Object. Age-related macular degeneration (AMD) is the leading cause of severe vision loss in people older than age 65 years in the western world. The visual acuity loss usually results from the ingrowth of new vessels from the choroid capillaries, so called choroidal neovascularization (CNV). The aim of this pilot study was to investigate the effect of a single-fraction gamma knife radiosurgery (GKS) on visual acuity and the growth pattern of CNV in patients with AMD. Methods. Ten patients with a mean age of 75 years and with a subfoveal, classic CNV due to AMD were enrolled in this study. All patients were treated with GKS in one fraction with a prescription dose of 10 Gy. The treatment target was the CNV located in the macula. Computerized tomography scans of the globe were obtained. After a follow up of 1 year visual acuity was stable in six patients and decreased in four. The size of the CNV could be stabilized in four patients, and in six an enlargement of these neovascular complexes was shown. No side effects, such as cataract formation, development of radiation-induced retinopathy, or optic neuropathy, have been observed so far. Conclusions. Gamma knife radiosurgery seemed to have a beneficial effect on visual acuity in patients with AMD, but it failed to control growth of CNV in six patients. A longer follow up, a larger study population, and a randomized and controlled study are necessary for a final conclusion.

Repetitive, short-pulse laser can coagulate the retinal pigment epithelium selectively, while sparing the adjacent outer neuroretina and the choroid. Therefore the functional defects caused by panretinal photocoagulation with conventional laser delivery systems may be reduced or even avoided using a micropulsed diode laser. A panretinal laser treatment was performed in 6 patients with proliferative diabetic retinopathy using an argon laser on one and a micropulsed diode laser on the fellow eye. Pre- and posttreatment examination consisted besides of a complete ophthalmological status, a fluorescein angiography, visual fields and of electrophysiological tests. The argon laser eyes showed a profound loss of response in the scotopic ERG and more absolut scotomas in the peripheral visual fields compared to the micropulsed eyes. Most of the laser burns caused by the micropulsed diode laser could not be detected neither ophthalmoscopically nor angiographically. Some lesions were visible as small laser scars. No regression of the proliferations could be achieved with the diode laser after a follow-up of at least 5 months. The functional damage after panretinal photocoagulation can be reduced using a micropulsed diode laser, but no stabilisation of the proliferative retinopathy could be obtained at the energy levels used.

Frequency-Doubling-Perimetry (FDP) is based on the frequency-doubling effect, which is a psychophysiological phenomenon. This effect mainly concerns the magnocellular system and is recommended by the manufacturer as a simple and user-friendly screening instrument for visual field defects. We studied visual field results of FDP and compared them to conventional white on white perimetry (W/W perimetry). Patients and methods: We investigated a total of 214 eyes. 170 eyes of 85 patients had various eye diseases and 44 eyes of 22 were normal. W/W perimetry was performed with the Octopus- perimeter using different programs (32, G2, M2, 07) depending on the cause of the disease. Normal FDP with pathological W/W was rated as better and pathological FDP with normal W/W was valued as a worse result. Results: 35% of the patients showed better results in FDP than in W/W perimetry, whereas 65% had the same results in both investigations. 21% of the normal patients presented better results in FDP than in W/W perimetry, whereas 73% had the same results in both investigations. Conclusion: Considering that 35% of the patients had better result ('false positive') in FDP-perimetry it appears to us that the specifity is too low for using FDP as a screening method.

By way of an extracorporeal circulation, the HELP-system (Heparin- induced extracorporeal LDL-precipitation) selectively eliminates fibrinogen, LDL-cholesterol, cholesterol, triglycerides and LP(a) from the blood plasma achieving, an immediate improvement of the hemorheological situation. HELP- treatment were administered to 56 (mean age 65.3 ± 9.5 years) with retinal artery or vein occlusions or with nonarteritic anterior ischemic optic neuropathy (AION). The patients received 8 single treatments over a period of 7 weeks. A 40-50% reduction of fibrinogen and LDL after the first procedure significantly lowered whole blood and plasma viscosity as well as RCTT of about 15-20%. Visual acuity increased by two or more Snellen lines in all 4 patients with retinal artery occlusion, in 73.9% of the patients with nonischemic retinal vein occlusion and in 52.6% in the patients with AION after 3 months. Compared to a hemodiluted control group, patients with AION treated with HELP obained a statistically significant improvement of the mean sensitivity of the visual fields. The development of iris neovascularization in ischemic central retinal vein occlusion, was not influenced by HELP- therapy compared to the untreated group. Our studies showed a beneficial influence of HELP-treatment on the hemorheological situation, significant functional improvements were achieved only in patients with nonarteritic AION.

No beneficial effect was obtained on neither functional nor on morphological results in patients with age-related macular degeneration after radiation treatment with 14.4 Gy in our previous study. In the present prospective study 40 patients - 8 males and 32 females - with a mean age of 75 years and exudative AMD with involvement of the fovea were radiated with a dosage of 25.2 Gy. Visual acuity, visual fields, fluorescein (FA) and indocyaningreen angiography (ICGA) were investigated prior to treatment and 3, 6, 9 and 12 months after treatment. Radiation was administered to the posterior pole with a 8 MV-photon beam from a linear accelerator A dose of 25.5 Gy, 1.8 Gy per day, 5 fractions per week was delivered through a single lateral port. Five patients had classic, well-defined CNV, 35 had occult lesions. After the follow-up period (6 months all patients, 9 months 21, 12 months 12 patients) the visual acuity improved in 1 patient, was stable in 13 and deteriorated three or more lines in 26 patients. A stabilisation or regression of the neovascular complex was not observed in any of the patients. Although the follow-up period of this study is to short to make a final conclusion, the functional results are no different compared to those of our previous study with 14.4 Gy.

The Susac syndrome, firstly described by Susac in 1979 is a very rare microangiopathy of the retina, the inner car and the brain affecting predominantly young women. The pathogenesis is not known, however it is thought to be due to an autoimmune disease. The authors report about a 34- years-old woman showing visual field defects in both eyes. In the history of recurrent tinnitus for three years was found. Apart from a short episode of headache, vertigo, dysarthria and ataxia the patient was otherwise neurologically intact. On fundus examination both eyes revealed extremely attenuated arterioles with irregular contours as well as some totally occluded arterial vessels and sporadic cotton wool spots. Fluorescein- angiography resulted in some hyperfluorescences of the vessel walls and leakages. Magnetic resonance imaging showed punctate hyperintense white matter lesions of the brain similar to those observed after minimal vascular damage. Laboratory tests were unremarkable. Finally, the treatment with oral steroids led to a stabilisation of the functional and morphological changes.

The effect of two practices adopted by settlers (abandoned pasture and fallow land) on soil fertility of two deforested Amazonian regions (Belém-Pará and Ariquemes-Rondônia) was studied. Whenever possible, cultivated pasture, over similar time periods in both cases and in natural forest, were employed as soil fertility reference standards. Nutrient dynamics was studied using the electroultra-filtration technique. In general, deforestation, as practiced in these areas, has a degrading effect on soil fertility. The effect of burning normally leads to a pH rise caused by ash. This usually yields a favorable transitory effect, improving soil fertility conditions, however not sufficient for plant needs, as inferred from the low P and K levels. Cattle excrements, improved the K level for cultivated pastures. Qualitative differences related to N were observed between cultivated pasture and both, fallow land or abandoned pasture. In the first, a certain recovery of available N levels was detected, mainly affecting the EUF-Norg fraction. On the other hand, a regeneration of organic compounds, in the fallow land and the abandoned pasture, closely related to those existing in the natural forest, was verified. This is mainly due to the presence of a higher proportion of NO3- - N and, consequently, a EUF-Norg/EUF-NO3- ratio close to 1.

Lyme borreliosis is an emerging tickborne spirochetal infection characterized by a broad variety of symptoms, ranging from neurologic disorders and different skin manifestations to cardiac symptoms. Many ocular and neuro-ophthalmic symptoms have recently been attributed to Lyme disease. Especially in endemic areas ophthalmologists need to be aware of Borrelia burgdorferi as a possible causal agent. The aim of this paper is to present a short review of the literature of ophthalmic disorders resulting from Borrelia burgdorferi infections.