H. Thieme

Correlation of Endothelin-1 Concentration in Aqueous Humor with Intraocular Pressure in Primary Open Angle and Pseudoexfoliation Glaucoma

PURPOSE Endothelin-1 (ET-1) has been found in elevated concentrations in the aqueous humor of glaucoma patients. Indirect evidence from animal studies suggests that ET-1 might directly influence intraocular pressure (IOP). The aim of this study was to determine whether ET-1 concentrations in aqueous humor of cataract and glaucoma patients correlate with IOP. METHODS Aqueous humor and blood samples from patients with either cataract (control, n = 38), primary open angle glaucoma (POAG, n = 35), or pseudoexfoliation glaucoma (PEXG, n = 21), without other ocular or systemic disease, were collected during routine cataract surgery or trabeculectomy. ET-1 concentration was determined by an ET-1 ELISA kit. IOP was measured preoperatively by standard Goldmann applanation tonometry. All statistical analysis was performed using commercial predictive analytics software. RESULTS Both IOP and ET-1 concentration in aqueous humor were significantly increased in POAG (23.4 ± 6.8 mm Hg, 5.9 ± 2.9 pg/mL) and PEXG (24.3 ± 8.8 mm Hg, 7.7 ± 2.1 pg/mL) compared with control (15.0 ± 2.9 mm Hg, 4.3 ± 2.4 pg/mL). No difference was detected for plasma ET-1 concentrations. IOP and ET-1 in the aqueous humor were significantly correlated (R = 0.394, R² = 0.155, P < 0.001), although no correlation was found between IOP and ET-1 in blood plasma or between ET-1 in aqueous humor and ET-1 in plasma. CONCLUSIONS In this study, a small but highly significant correlation between IOP and the ET-1 concentration in the aqueous humor was found. Although no causative relationship can be deduced from this, ocular ET-1 effects on IOP control may merit further investigation.

Clinical results of encapsulated bleb removal after Ahmed glaucoma valve implants

In refractory glaucoma, surgical intervention is required which in most cases aims at artificially increasing the drainage of aqueous humor from the eye. One surgical option used with increasing frequency is the implantation of episcleral glaucoma drainage devices (GDD). The clinical success of such devices is often limited by excessive wound healing and scar formation around the base plate of the implant. In severe cases, which seem to occur most frequently in pediatric patients, the rapid formation of a thick, water-impervious fibrotic capsule within months after initial implantation leads to diminished aqueous resorption and an increase in intraocular pressure to presurgical values. Often additional surgical interventions become necessary. Excision of the fibrotic tissue around the implant may help to salvage function and might be an alternative to the more commonly practiced implantation of an additional GDD. In the case series presented here the surgical method of capsular revision is described and the clinical outcome in 11 eyes from 10 patients is reported.

Prediction of higher visual function in macular degeneration with multifocal electroretinogram and multifocal visual evoked potential

Visual search can be guided by past experience of regularities in our visual environment. This search guidance by contextual memory cues is impaired by foveal vision loss. Here we compared retinal and cortical visually evoked responses in their predictive value for contextual cueing impairment and visual acuity.

Klinische Ergebnisse von Kapselausschneidungen nach Ahmed-Implantaten

In refractory glaucoma, surgical intervention is required which in most cases aims at artificially increasing the drainage of aqueous humor from the eye. One surgical option used with increasing frequency is the implantation of episcleral glaucoma drainage devices (GDD). The clinical success of such devices is often limited by excessive wound healing and scar formation around the base plate of the implant. In severe cases, which seem to occur most frequently in pediatric patients, the rapid formation of a thick, water-impervious fibrotic capsule within months after initial implantation leads to diminished aqueous resorption and an increase in intraocular pressure to presurgical values. Often additional surgical interventions become necessary. Excision of the fibrotic tissue around the implant may help to salvage function and might be an alternative to the more commonly practiced implantation of an additional GDD. In the case series presented here the surgical method of capsular revision is described and the clinical outcome in 11 eyes from 10 patients is reported.

Visual Pathways in Humans With Ephrin-B1 Deficiency Associated With the Cranio-Fronto-Nasal Syndrome.

PURPOSE Numerous animal studies demonstrated the importance of components of the ephrin/Eph system for correct visual system development. Analogous investigations in humans are entirely missing. Here, we examined the visual system in humans with ephrin-B1 deficiency, which is x-linked and associated with the cranio-fronto-nasal syndrome (CFNS) in heterozygous females. METHODS For one male hemizygous for ephrin-B1 deficiency and three affected heterozygous females with molecular-genetically confirmed mutations, the integrity of the partial decussation of the optic nerves was assessed with visual evoked potentials (VEPs) and compared with albinotic, achiasmic, and control participants with healthy vision. Further, retinal morphology and function and the gross-retinotopic representation of the primary visual cortex were examined with spectral-domain optical coherence tomography (SD-OCT), ERG, and multifocal (mf) VEPs for the male participant and part of the carriers. RESULTS Strabismus and lack of stereovision was evident in the male and two of the females. Other characteristics of the visual system organization and function were normal: (1) retina: SD-OCT and funduscopy indicated normal foveal and optic nerve head morphology. Electroretinograms indicated normal retinal function, (2) optic chiasm: conventional (c)VEP showed no evidence for misrouting and mfVEPs were only suggestive of, if any, very minor local misrouting, and (3) visual cortex: mfVEP characteristics indicated normal retinotopic gross-representations of the contralateral visual hemifield in each hemisphere. CONCLUSIONS While ephrin-B1 deficiency leads to abnormal visual pathways in mice, it leaves the human visual system, apart from deficits in binocular vision, largely normal. We presume that other components of the ephrin-system can substitute the lack of ephrin-B1 in humans.

Differential effects of optic media opacities on simultaneous multifocal pattern electroretinograms and visual evoked potentials

OBJECTIVE To identify potential confounds in the comparison of simultaneously acquired multifocal electroretinograms (mfPERGs) and visual evoked potentials (mfVEPs) to pattern reversal stimulation. METHODS With VERIS Science 5.1.10X monocular mfPERGs and mfVEPs were recorded simultaneously to optimised pattern-reversal stimulation for a reference condition and two filter conditions, i.e. blur and 8% luminance transmission, in two separate experiments in participants with normal vision. The impact of the filter conditions on mfPERG amplitude (P50 and N95 peaks), mfVEP-magnitude (root-mean-squares and signal-to-noise-ratios), and on the response timing was assessed. RESULTS Blur reduced mfPERG P50 and N95 amplitudes to 16%, 21%, and mfVEP magnitude to 82%. Decreasing stimulus luminance to 8% reduced only the mfPERG (P50 to 72% and N95 to 74%), but delayed both mfPERG and mfVEP responses by 5.3 and 4.6ms, respectively. CONCLUSIONS Comparatively minor stimulus manipulations, mimicking optic media opacities, had a differential effect on mfPERGs and mfVEPs magnitudes. SIGNIFICANCE Simultaneous mfPERG/mfVEP recordings are a promising approach to compare retinal and cortical function, but caution must be exerted in the interpretation of response differences due to incongruent response characteristics.

Konservierungsmittel aus Sicht der Glaukomchirurgie

Trabeculectomy is still the gold standard in the surgical treatment of glaucoma patients. Development of a bleb is the primary goal of this procedure and the conjunctival status is therefore decisive. Only a good functioning bleb renders good intraocular pressure (IOP) control. Scar tissue formation leads to bleb failure which is quite common despite the use of antiproliferative agents, such as mitomycin C and 5 fluoruracil. Wound healing is important and is influenced and impaired by the chronic use of topical antiglaucoma drugs. Therefore, complete abstinence is recommended from 4-6 weeks prior to a planned trabeculectomy; however, it seems mandatory to completely abolish preservatives such as drops containing benzalkonium chloride to enhance trabeculectomy success rates.

Vergrößerter blinder Fleck

Fletcher et al. [1] beschrieben das „Acute Idiopathic Blind Spot Enlargement Syndrome“ erstmals 1988 als Symptomkomplex mit plotzlich auftretendem, monokularem Gesichtsfelddefekt im Bereich des blinden Flecks ohne Papillenschwellung bei regelrechten Befunden bezuglich Visus, Farbwahrnehmung, Pupillenreaktion und Fundusbefund. Das Syndrom betrifft vor allem Frauen im mittleren Lebensalter [2, 3]. Die Atiologie ist bisher ungeklart. Es zeigen sich jedoch Parallelen zu anderen Krankheitsbildern wie dem „Multiple Evanescent White Dot Syndrome“, das eine entzundliche Genese vermuten lasst [7]. Shinoda et al. [4] zeigten, dass eine morphologische Storung im Bereich der Ausensegmente der Photorezeptoren vorliegt.

Allgemeine Substanzklassen und Pharmakologie bei Glaukom

The pharmaceutical therapy of glaucoma dates back to 1875 when Weber introduced pilocarpine into the medicinal treatment of glaucoma. Since then there has been a continuous development of topical antiglaucoma therapy whereby the main developments date back to the 1980s and 1990s. All forms of medicinal therapy aim at lowering the intraocular pressure and achieve this either by inhibiting aqueous humor secretion into the ciliary body or by enhancing physiological drainage routes along Schlemms canal. This article gives an overview over the most important classes of antiglaucoma drugs, the indications and contraindications as well as pharmacological characteristics. The focus lies on the market of combination and generic drug preparations that is currently rapidly developing and therefore needs to be discussed in detail.ZusammenfassungDie medikamentöse Therapie der Glaukome datiert zurück auf das Jahr 1875. Weber führte in diesem Jahr das Pilocarpin in die medikamentöse Behandlung der Glaukome ein. Seitdem hat es eine beständige Weiterentwicklung lokaler Antiglaukomatosa gegeben, wobei der Schwerpunkt der Entwicklung in den 80er/90er-Jahren des letzten Jahrhunderts lag. Grundsätzlich zielen alle Medikamente in der Glaukomtherapie darauf ab, den Augeninnendruck zu senken. Sie tun dies entweder durch die Verbesserung des Kammerwasserabflusses über die physiologischen Drainagewege oder aber durch Hemmung der Kammerwassersekretion im Ziliarkörper. Der Beitrag verschafft einen Überblick über die wichtigsten Substanzklassen, ihre Indikationen und Kontraindikationen sowie die pharmakologischen Besonderheiten. Auf den immer unübersichtlicher werdenden Markt der Kombinations- und Generikapräparate soll gesondert eingegangen werden.AbstractThe pharmaceutical therapy of glaucoma dates back to 1875 when Weber introduced pilocarpine into the medicinal treatment of glaucoma. Since then there has been a continuous development of topical antiglaucoma therapy whereby the main developments date back to the 1980s and 1990s. All forms of medicinal therapy aim at lowering the intraocular pressure and achieve this either by inhibiting aqueous humor secretion into the ciliary body or by enhancing physiological drainage routes along Schlemm’s canal. This article gives an overview over the most important classes of antiglaucoma drugs, the indications and contraindications as well as pharmacological characteristics. The focus lies on the market of combination and generic drug preparations that is currently rapidly developing and therefore needs to be discussed in detail.

General substance classification and pharmacology of glaucoma

The pharmaceutical therapy of glaucoma dates back to 1875 when Weber introduced pilocarpine into the medicinal treatment of glaucoma. Since then there has been a continuous development of topical antiglaucoma therapy whereby the main developments date back to the 1980s and 1990s. All forms of medicinal therapy aim at lowering the intraocular pressure and achieve this either by inhibiting aqueous humor secretion into the ciliary body or by enhancing physiological drainage routes along Schlemms canal. This article gives an overview over the most important classes of antiglaucoma drugs, the indications and contraindications as well as pharmacological characteristics. The focus lies on the market of combination and generic drug preparations that is currently rapidly developing and therefore needs to be discussed in detail.ZusammenfassungDie medikamentöse Therapie der Glaukome datiert zurück auf das Jahr 1875. Weber führte in diesem Jahr das Pilocarpin in die medikamentöse Behandlung der Glaukome ein. Seitdem hat es eine beständige Weiterentwicklung lokaler Antiglaukomatosa gegeben, wobei der Schwerpunkt der Entwicklung in den 80er/90er-Jahren des letzten Jahrhunderts lag. Grundsätzlich zielen alle Medikamente in der Glaukomtherapie darauf ab, den Augeninnendruck zu senken. Sie tun dies entweder durch die Verbesserung des Kammerwasserabflusses über die physiologischen Drainagewege oder aber durch Hemmung der Kammerwassersekretion im Ziliarkörper. Der Beitrag verschafft einen Überblick über die wichtigsten Substanzklassen, ihre Indikationen und Kontraindikationen sowie die pharmakologischen Besonderheiten. Auf den immer unübersichtlicher werdenden Markt der Kombinations- und Generikapräparate soll gesondert eingegangen werden.AbstractThe pharmaceutical therapy of glaucoma dates back to 1875 when Weber introduced pilocarpine into the medicinal treatment of glaucoma. Since then there has been a continuous development of topical antiglaucoma therapy whereby the main developments date back to the 1980s and 1990s. All forms of medicinal therapy aim at lowering the intraocular pressure and achieve this either by inhibiting aqueous humor secretion into the ciliary body or by enhancing physiological drainage routes along Schlemm’s canal. This article gives an overview over the most important classes of antiglaucoma drugs, the indications and contraindications as well as pharmacological characteristics. The focus lies on the market of combination and generic drug preparations that is currently rapidly developing and therefore needs to be discussed in detail.