[Multifocal ERG with confocal scanning laser ophthalmoscope. Comparison with monitor simulation]. / Multifokales ERG mittels konfokalem Scanning Laser Ophthalmoskop. Vergleich mit Monitorsimulation.

BACKGROUND: Multifocal electroretinograms (mfERG) were recorded using a confocal scanning laser ophthalmoscope (cSLO) and compared to the results from conventional monitor stimulation. METHODS: Single and repeated measurements were recorded from 23 normal subjects using the cSLO (Heidelberg Retina Angiograph, Heidelberg Engineering, Heidelberg) as well as a conventional monitor as stimulation devices. Laser power output was modified by various optical filters. The reliability of the method and agreement with the conventional monitor stimulation were determined. RESULTS: CSLO recordings showed a high degree of variability. Reduction of laser power output improved the retinal response topography and characteristically modified response variations with each filter. Differences in amplitude size between cSLO and monitor recordings decreased with increasing amplitude levels. The results of repeated measurements showed considerable variation. CONCLUSION: It is possible to use a cSLO as a stimulator for mfERG recordings. However, a relatively high degree of variability represents a significant limitation of this method. Appropriate reduction of laser power decreases variations and serves to obtain photopic response topographies.

[Pharmacological concepts to treat hereditary retinal degenerations]. / Pharmakologische Ansätze in der Therapie erblicher Netzhautdegenerationen.

This article reviews the current pharmacological strategies to treat inherited retinal degeneration. To date there is no causal therapy despite growing knowledge of the particular pathomechanisms. However, treatment is available for complications, such as cystic macular changes and cystoid macular edema. To reduce retinal thickness systemic or topical carboanhydrase inhibitors can be applied and in rare cases combined with steroids when indicated, however reduction of retinal thickness is not always accompanied by improvement of visual acuity. Regular follow-up with optical coherence tomography is required. In some cases, potentially neuroprotective agents (valproic acid, ciliary neurotrophic factor and Ca(2+ ) channel inhibitors) or food supplementation (vitamin A, lutein, synthetic retinoids and decosahexaenoic acid) may have a positive impact on disease progression (e.g. reduction in progression of visual field loss or individual electrophysiological parameters). However, beneficial effects and side effects, e.g. of vitamin A substitution, depend not only on the disease phenotype (such as retinitis pigmentosa) but also on the actual genotype. Furthermore, no data are available regarding the application of pharmaceuticals in the pediatric population.

[Electrophysiological examination methods in glaucoma diagnostics]. / Elektrophysiologische Untersuchungsmethoden in der Glaukomdiagnostik.

The two currently used most successful techniques for early detection of glaucoma are described. (1) The pattern electroretinogram (PERG) allows detection of incipient glaucomatous damage in eyes with ocular hypertension up to 4 years ahead of manifest glaucoma with a sensitivity and specificity of approximately 75%. This is achieved by selecting optimized stimulation (check size and stimulation frequency) and analysis protocols (amplitude ratio to different check sizes). The major disadvantage is the requirement for best corrected visual acuity to be at least 0.8(decimal) to avoid false positive results. (2) The photopic negative response (PhNR), a component of the Ganzfeld ERG, does not suffer from optical factors reducing visual acuity. It is also affected in early glaucoma but so far has not achieved the same sensitivity and specificity as the PERG.

[Importance of flicker contrast tests in functional glaucoma diagnostics]. / Bedeutung der Flimmer-Kontrasttests in der funktionellen Glaukomdiagnostik.

One of the many unsolved problems concerning glaucoma is early detection and many different methodologies have been developed. This article concentrates on methodologies belonging to the class of flicker contrast tests which present dynamic stimuli (with temporal frequencies generally above 10 Hz) and assess the perceptual thresholds for contrast, be it global or locally resolved. The tests include global flicker sensitivity, flicker perimetry (current embodiment: Pulsar), Rauschfeld campimetry, frequency doubling perimetry and flicker-defined edge perimetry. These different approaches are placed into historical perspective and are critically assessed.

[Clinical and neuroradiological diagnostics of orbital tumors]. / Klinische und neuroradiologische Diagnostik bei Orbitatumoren.

Exophthalmus is the leading sign of space-occupying lesions of the orbit. Patients may further present with lid swelling, impaired ocular motility and optic neuropathy including a relative afferent pupillary defect, compressive optic disc edema or optic atrophy. Orbital tumors can be classified into various categories depending on the etiology, as lymphoproliferative lesions (in particular non-Hodgkin's lymphoma as the most common malignant orbital tumor of adulthood), optic nerve and meningeal lesions, lacrimal gland lesions, secondary orbital tumors which extend to the orbit from neighboring structures and metastases. Slightly less common are vasculogenic and cystic lesions including cavernous hemangioma as the most common benign orbital tumor of adulthood and dermoid cysts as the most common benign orbital tumor of childhood. Rhabdomyosarcoma is the most common malignant orbital tumor of childhood but has a low total incidence. Orbital tumors might not only cause symptoms like pain, diplopia and loss of visual acuity but may also lead to esthetically disfiguring changes. Particular attention should be paid to underlying systemic diseases and generalized tumor diseases. This article illustrates the approach to a detailed clinical and neuroradiological assessment which is mandatory for the care of orbital tumor patients.

[Achromatopsia]. / Achromatopsie.

Hereditary cone diseases manifest as progressive or stationary disorders. Among the stationary cone disorders autosomal recessive achromatopsia occurs most frequently and begins within the first months of life with nystagmus and photophobia. Color discrimination is not possible, and visual acuity is severely reduced. In addition to a thorough ophthalmic examination, color vision tests and electrophysiology are prerequisites to establish a diagnosis of achromatopsia. A genetic examination is very helpful to distinguish achromatopsia from other stationary cone disorders like X-linked recessive blue cone monochromatism and from progressive cone and cone-rod dystrophies. It is the correct clinical and genetic diagnosis that eventually will allow an individual prognosis, accurate genetic counseling, and the optimal choice of low vision aids.

[Intensive intracorneal keloid formation in a case of Peters plus syndrome and in Peters anomaly with maximum manifestation]. / Ausgeprägte intrakorneale Keloidbildung bei Peters-Plus-Syndrom und bei einer Maximalvariante der Peters-Anomalie.

We present two cases of Peters anomaly (Peters plus syndrome and a maximum manifestation variant) with abnormally thickened cornea and corneal staphyloma. Both patients presented to our hospital shortly after birth and were treated with perforating keratoplasty and lensectomy. Histological analysis showed marked thickening of the corneal stroma due to abnormal stromal connective tissue deposition. Additionally, both eyes showed the characteristic changes of Peters anomaly with corneal opacity, adherence of the iris stroma and anterior lens surface to the posterior corneal surface, absence of the corneal endothelium, Descemet and Bowmans layers. Peters anomaly with abnormally thick intracorneal fibrosis with or without congenital corneal staphyloma is a very rare manifestation.

[Hereditary optic atrophies]. / Hereditäre Optikusneuropathien.

Hereditary optic neuropathies are caused by mutations either in the nuclear or mitochondrial genome and lead to retinal ganglion cell death mediated by reduced oxidative phosphorylation, fragmentation of the mitochondrial network, and increased sensitivity to apoptosis. Nuclear mutations result in autosomal dominant optic atrophy, autosomal recessive optic atrophy, or X-linked recessive optic atrophy, whereas mitochondrial mutations result in Leber's hereditary optic neuropathy, which is maternally inherited. A tentative diagnosis of a hereditary optic neuropathy can usually be made on the grounds of a thorough patient and family history, visual field and color vision tests, and a detailed assessment of the optic nerve head. The rarity of hereditary optic neuropathies makes it difficult to include these disorders in the differential diagnosis. Molecular genetic testing of a blood DNA sample should be performed on every patient, with implications for future genetic counseling and prediction of the disease course.

Multifocal ERG recording with simultaneous fundus monitoring using a confocal scanning laser ophthalmoscope.

PURPOSE: To assess the general feasibility of recording multifocal electroretinograms (mfERGs) with simultaneous fundus monitoring in a clinical setting. METHODS: An mfERG system (RETIscan) and a confocal scanning laser ophthalmoscope (Heidelberg Retina Angiograph) were connected to record mfERGs elicited by a pseudorandom binary m-sequence stimulus generated by a 514 nm laser source. Recordings were compared to a conventional mfERG system using monitor stimulation. A total of five subjects (two normal subjects and three patients) were examined. RESULTS: In normal volunteers records obtained by the fundus-monitored mfERG showed highest response densities in the central fundus area and a decrease of response amplitudes towards the periphery paralleling cone receptor density. However, compared to the monitor stimulation, the drop-off of amplitudes as a function of eccentricity was not as clearly defined. The responses obtained from patients with retinal diseases were diminished in the areas of retinal dysfunction. CONCLUSIONS: These preliminary findings indicate that the technique of laser stimulation in principle allows for topographic retinal recording. This method might be useful, for example if the retinal position of the stimulus array is not centred onto the fovea but deviates due to fixation problems. However, further improvement of the technique appears necessary before considering routine clinical application.