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Purpose: To evaluate the effect of transpalpebral electrotherapy on patients with dry age-related macular degeneration (AMD). Methods: 22 patients were randomized in two groups to either receive therapy (n = 12) or placebo (n = 10). There was no statistically significant difference for age and initial visual acuity (VA) between the two groups (p = 0.6; ANOVA). Treatment was performed on 5 consecutive days. On each day two sessions were applied. Every session included 8 spots (40 sec/spot) around the eye globe. The current applied (changing frequency 5-80 Hz) varied individually between 150 and 220 A. Patients were examined before treatment, at the end of the 5-day treatment period, after 4 weeks and at 6 months. Examinations included a standardized VA testing, using ETDRS letters, contrast sensitivity, macular sensitivity and fixation stability using microperimetry and measurements with SD-OCT. Results: At the end of week 1, mean VA improved markedly (p = 0.001; T test), with 7 out of 12 patients showing an improvement of more than 5 letters. After 4 weeks, there was an improvement of more than 10 letters in 3 patients (mean + 5.7 letters; p = 0.001; T test) whereas at 6 months a loss of 1.6 letters was observed. Only 4 (33%) of our patients did not show any improvement at all. Contrast sensitivity displayed a similar pattern. Within one week after treatment, there was a rapid improvement (+4.4 optotypes; p = 0.006; T test). After 6 months, contrast sensitivity declined again (+1.5 optotypes; p = 0.2; T test). Compared to the placebo group changes on VA failed statistical significance (p = 0.1 at 4 week; T test) whereas changes on contrast sensitivity were statistically significant (p = 0.01 at week 4; T test). No adverse events were seen or reported during the study period. Conclusions: To the best of our knowledge, this is the first report of a transpalpebral electrostimulation in patients with dry AMD that demonstrates a temporary increase in visual function in some of these patients; results that seem to justify further research on this potential treatment option for dry AMD.

To find out whether, and which type of, adrenoceptors mediate prejunctional inhibition of sensory neurotransmitter release from trigeminal fibres, the modulation of twitch response to electrical field stimulation on rabbit isolated iris was investigated. Evoked iris sphincter contractions consisted of a minor fast cholinergic and a large slow component. The latter was unaffected by atropine and guanethidine, hence nonadrenergic noncholinergic in nature (NANC), but nearly completely abolished by capsaicin pretreatment and by the neurokinin receptor antagonist spantide. The response was probably not mediated by NK2 receptors as SR 48,968, an NK2 selective nonpeptide antagonist, failed to reduce the response to the release of the endogenous neurokinin(s) (and exogenous substance P), but in part due to NK1 receptor activation as shown by a reduction of response by CP 96,345, an NK1 selective non-peptide antagonist, and in part perhaps mediated by NK3 receptors. A small neurokinin receptor antagonist- and capsaicin-insensitive NANC contraction is probably not mediated by CGRP receptors. The alpha 2-adrenoceptor agonist oxymetazoline inhibited the evoked NANC response (22 nmol/l, IC20; about 40%, maximum inhibition) without affecting the cholinergic response (up to 1 mumol/l) or the postjunctional iris sensitivity to exogenous substance P. The inhibition was antagonized by rauwolscine (apparent -log KB 8.04) and by the relatively alpha 2B-adrenoceptor selective antagonist ARC-239 (-log KB 8.51). The alpha 2- and imidazoline receptor agonist aganodine inhibited the evoked NANC response (0.25 mumol/l, IC20; about 30%, maximum inhibition) without affecting the postjunctional substance P responses. Rauwolscine 0.3 mumol/l failed to antagonize this effect. It is concluded that the release of sensory neurotransmitter(s) from trigeminal fibres in the rabbit eye may be inhibited by alpha 2B-adrenoceptors and by a non-alpha 2-receptor, perhaps an imidazoline receptor.

Purpose: To determine the correlations and strength of association between different imaging systems in analyzing the retinal nerve fiber layer (RNFL) of glaucoma patients: optical coherence tomography (OCT), scanning laser polarimetry (SLP) and confocal scanning laser ophthalmoscopy (CSLO).Materials and Methodology: 114 eyes of patients with moderate open angle glaucoma underwent spectral domain OCT (Topcon SD-OCT 2000 and Zeiss Cirrus HD-OCT), SLP (GDx VCC and GDx Pro) and CSLO (Heidelberg Retina Tomograph, HRT 3). Correlation coefficients were calculated between the structural parameters yielded by these examinations. The quantitative relationship between the measured RNFL thickness globally and for the four regions (superior, inferior, nasal, temporal) were evaluated with different regression models for all used imaging systems.Results: The strongest correlation of RNFL measurements was found between devices using the same technology like GDx VCC and GDx Pro as well as Topcon OCT and Cirrus OCT. In glaucoma patients, the strongest associations (R²) were found between RNFL measurements of the two optical coherence tomography devices Topcon OCT and Cirrus OCT (R² = 0.513) and between GDx VCC and GDx Pro (R² = 0.451). The results of the OCTs and GDX Pro also had a strong quantitative relationship (Topcon OCT R² = 0.339 and Cirrus OCT R² = 0.347). GDx VCC and the OCTs showed a mild to moderate association (Topcon OCT R² = 0.207 and Cirrus OCT R² = 0.258). The confocal scanning laser ophthalmoscopy (HRT 3) had the lowest association to all other devices (Topcon OCT R² = 0.254, Cirrus OCT R² = 0.158, GDx Pro R² = 0.086 and GDx VCC R² = 0.1).Conclusion: The measurements of the RNFL in glaucoma patients reveal a high correlation of OCT and GDx devices because OCTs can measure all major retinal layers and SLP can detect nerve fibers allowing a comparison between the results of this devices. However, CSLO by means of HRT topography can only measure height values of the retinal surface but it cannot distinguish between different retinal layers.This may explain the rather poor correlations and associations between CSLO measurements and those of all other imaging devices which makes it difficult to compare HRT 3 nerve fiber data.These correlations are important in clinical routine especially when different techniques are used in the follow-up of glaucoma patients.

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