Orbital floor fracture repair: the endonasal approach.

To avoid the dangers associated with lower eyelid approaches to the orbital floor and to improve visualization, we propose an endoscopic procedure for orbital floor fracture reduction and osteosynthesis using endonasal access via the medial maxillary sinus wall. The technique of endoscopic, endonasal transantral surgery is described, together with a retrospective analysis of 17 patients who had undergone this surgical procedure in the Department of Otorhinolaryngology, University of Regensburg, between July 2013 and June 2016. Fractures without infraorbital margin involvement were successfully repaired and enophthalmos and/or diplopia were corrected in all cases. The endonasal approach described here allows orbital floor fractures to be repaired without injury to the eyelid apparatus. Visualization, in particular across the orbital floor as far as the palatine process, appears to be superior to that achieved with other approaches. The increased time required for the procedure and the difficulties of manipulation within a confined space are offset by rapid wound healing without ocular swelling and a minimal risk of complications.

[Muscular Dystrophies Involving the Retinal Function]. / Netzhautbeteiligung bei Muskeldystrophien.

Muscular dystrophies are rare disorders, with an incidence of approx. 20 in 100 000. Some dystrophies also affect retinal or optic nerve function. In such cases, the ophthalmological findings may be critical for differential diagnosis or patient counseling. For example in Duchenne muscular dystrophy, where the alteration in retinal function seems to reflect cerebral involvement. Other important forms are mitochondrial and metabolic disorders, such as the Kearns-Sayre syndrome and the Refsum syndrome. Molecular genetic analysis has become a major tool for differential diagnosis, but may be complex and demanding. This article gives an overview of major muscular dystrophies involving retinal function and their genetic origin, in order to guide differential diagnosis.

Total colourblindness is caused by mutations in the gene encoding the alpha-subunit of the cone photoreceptor cGMP-gated cation channel.

Total colourblindness (OMIM 216900), also referred to as rod monochromacy (RM) or complete achromatopsia, is a rare, autosomal recessive inherited and congenital disorder characterized by photophobia, reduced visual acuity, nystagmus and the complete inability to discriminate between colours. Electroretinographic recordings show that in RM, rod photoreceptor function is normal, whereas cone photoreceptor responses are absent. The locus for RM has been mapped to chromosome 2q11 (ref. 2), however the gene underlying RM has not yet been identified. Recently, a suitable candidate gene, CNGA3, encoding the alpha-subunit of the cone photoreceptor cGMP-gated cation channel, a key component of the phototransduction pathway, has been cloned and assigned to human chromosome 2q11 (refs 3,4). We report the identification of missense mutations in CNGA3 in five families with RM. Homozygous mutations are present in two families, whereas the remaining families show compound heterozygous mutations. In all cases, the segregation pattern of the mutations is consistent with the autosomal recessive inheritance of the disease and all mutations affect amino acids that are highly conserved among cyclic nucleotide gated channels (CNG) in various species. This is the first report of a colour vision disorder caused by defects other than mutations in the cone pigment genes, and implies at least in this instance a common genetic basis for phototransduction in the three different cone photoreceptors of the human retina.

[Hereditary macular dystrophies in differential diagnosis of AMD]. / Hereditäre Makuladystrophien in der Differenzialdiagnose der AMD.

The onset of hereditary macular dystrophies may occur at all ages and may be the origin of visual disturbances even after the age of 50 years. During the disease course, many macular dystrophies change their fundus appearance, finally leading to a geographic chorioretinal atrophy making it difficult to distinguish the disease form dry AMD. Furthermore, a macular dystrophy associated CNV may be misleading to the diagnosis of wet AMD. Additional fundus autofluorescence and optical coherence tomography imaging are very valuable for delineating macular dystrophies from AMD. In this paper we provide an overview of the important hereditary macular dystrophies which should be considered as differential diagnoses for AMD.

[Unilateral retinal hemorrhage in infants-two cases of shaken baby syndrome?] / Unilaterale Netzhautblutungen bei Säuglingen ­ 2 Fälle von Schütteltrauma?

A 2.5-month-old boy and a 2-month-old girl were admitted to a pediatric intensive care unit with impaired consciousness. Both infants had subdural hemorrhages. Because of presumed non-accidental head injury (NAHI) funduscopy was performed, which revealed unilateral hemorrhage in both children. After intensive differential diagnostics NAHI was suspected in both cases and a forensic medical examination was initiated. This case series is important because it shows that unilateral retinal bleeding does not exclude NAHI.

[New DIN and ISO norms for determination of visual acuity]. / Neue DIN- und ISO-Normen zur Sehschärfebestimmung.

Recently, three international norms (ISO) for visual acuity assessment were revised. The DIN EN ISO 8596:2018 stipulates the Landolt C eye chart as the standard optotype and specifies display characteristics. An informative annex lists clinical optotypes for the first time. These include the ETDRS chart, Snellen chart and pediatric optotypes; however, these clinical optotypes do not have the same status as the Landolt C chart, since even with identical font size and stroke width they may differ in recognizability. The technical report ISO/TR 19498:2015 complements DIN EN ISO 8596. A scientifically appropriate procedure is described, which enables a quantitative correlation of clinical optotypes with the Landolt C chart. The DIN EN ISO 10938:2016 describes the required optical quality of optotypes. For the first time, electronic devices are explicitly approved for standardized visual acuity tests. Consequently, according to this amendment electronic devices may be used for acuity assessment for ophthalmological expert opinions according to DIN 58220, part 3.

[How to distinguish between autosomal dominant optic atrophy and Leber's hereditary optic neuropathy]. / Autosomal-dominant erbliche Optikusatrophie vs. Lebersche Optikusneuropathie. Wie kann man sie unterscheiden?

BACKGROUND: Patients with long-lasting bilateral optic atrophy showed typical clinical features of autosomal dominant optic atrophy (ADOA). Molecular genetic analysis identified them as atypical cases of Leber's hereditary optic neuropathy (LHON). METHOD: Three patients with bilateral optic atrophy and central scotomas of their visual fields were clinically diagnosed with ADOA. Samples of lymphocytic genomic DNA were amplified with polymerase chain reaction, and analysis of the coding exons including the flanking intron/UTR sequences of the OPA-1 gene was performed. However, no ADOA-associated mutations were found. We therefore analysed the total lymphocyte mitochondrial DNA for all common LHON mutations in these patients. RESULTS: Three patients from three unrelated pedigrees (two men, one woman) who were clinically diagnosed as suffering from ADOA did not harbor any typical mutation of the OPA-1 gene. However, analysis of their mitochondrial DNA showed that they harbored the 3460, 11778, and 14484 LHON mutations. The patients were identified as atypical cases of LHON. The pedigrees of the patients fulfilled the criteria for both dominant and mitochondrial-maternal transmission in all cases. The clinical picture of LHON differed remarkably from the classic course of LHON. CONCLUSIONS: To identify atypical LHON patients with bilateral optic atrophy and central scotomas in the visual field and to distinguish them from ADOA patients, careful molecular genetic analysis is necessary. In these rare cases, only double examinations of both the genomic and the mitochondrial DNA will allow these patients to be adequately advised.

[Contrast vision-definitions, conversions, and equivalence tables]. / Kontrastsehen ­ Definitionen, Umrechnungen und Äquivalenztabelle.

Human contrast vision and its quantitative assessment are gaining more attention. Publications on this topic can be confusing due to the overabundance of differing definitions and quantification of contrast vision. As a case in point, in Germany, contrast ratios as required for certain driving licenses and the DIN-defined contrast ratio are reciprocal. In this article, the five most important definitions of luminance contrast and contrast vision (Michelson, Weber, contrast ratios, logCS) are presented. We detail the specific domains for them, give formulae to convert between all of them and provide a table with equivalent values. We recommend the unit logCS wherever possible.

Cre recombinase expression or topical tamoxifen treatment do not affect retinal structure and function, neuronal vulnerability or glial reactivity in the mouse eye.

Mice with a constitutive or tamoxifen-induced Cre recombinase (Cre) expression are frequently used research tools to allow the conditional deletion of target genes via the Cre-loxP system. Here we analyzed for the first time in a comprehensive and comparative way, whether retinal Cre expression or topical tamoxifen treatment itself would cause structural or functional changes, including changes in the expression profiles of molecular markers, glial reactivity and photoreceptor vulnerability. To this end, we characterized the transgenic α-Cre, Lmop-Cre and the tamoxifen-inducible CAGG-CreER™ mouse lines, all having robust Cre expression in the neuronal retina. In addition, we characterized the effects of topical tamoxifen treatment itself in wildtype mice. We performed morphometric analyses, immunohistochemical staining, in vivo ERG and angiography analyses and realtime RT-PCR analyses. Furthermore, the influence of Cre recombinase or topical tamoxifen exposure on neuronal vulnerability was studied by using light damage as a model for photoreceptor degeneration. Taken together, neither the expression of Cre, nor topical tamoxifen treatment caused detectable changes in retinal structure and function, the expression profiles of investigated molecular markers, glial reactivity and photoreceptor vulnerability. We conclude that the Cre-loxP system and its induction through tamoxifen is a safe and reliable method to delete desired target genes in the neural retina.

Novel rhodopsin mutations and genotype-phenotype correlation in patients with autosomal dominant retinitis pigmentosa.

AIM: To identify novel or rare rhodopsin gene mutations in patients with autosomal dominant retinitis pigmentosa and description of their clinical phenotype. METHODS: The complete rhodopsin gene was screened for mutations by DNA sequencing in index patients. Mutation specific assays were used for segregation analysis and screening for controls. Eight patients from five families and their relatives were diagnosed with autosomal dominant retinitis pigmentosa (adRP) by means of clinical evaluation. RESULTS: Mutation screening identified five different rhodopsin mutations including three novel mutations: Ser176Phe, Arg314fs16, and Val20Gly and two missense mutations, Pro215Leu and Thr289Pro, that were only reported once in a mutation report. Electrophysiological and psychophysical testings provide evidence of an impaired rod system with additionally affected cone system in subjects from each genotype group. Visual function tended to be less affected in subjects with the Arg314fs16 and Val20Gly mutations than in the Ser176Phe phenotype. In contrast, Pro215Leu and Thr289Pro mutations caused a remarkably severe phenotype. CONCLUSION: The ophthalmic findings support a correlation between disease expression and structural alteration: (1) extracellular/intradiscal Val20Gly and cytoplasmic Arg314fs16 mutation-mild adRP phenotype; (2) Ser176Phe mutation-"mostly type 1" disease; (3) predicted alteration of transmembrane domains TM V and TM VII induced by Pro215Leu and Thr289Pro-severe phenotype. However, variation of phenotype expression in identical genotypes may still be a typical feature of RHO mutations.

[Ophthalmomyiasis externa]. / Ophthalmomyiasis externa.

Ophthalmomyiasis refers to infestation of the eye by fly larvae. Although rare, cases have been reported from all over the world. Patients with ophthalmomyiasis suffer from itching, foreign body sensation and epiphora. Ophthalmomyiasis is mostly caused by larvae of Oestrus ovis, the common sheep botfly. Larvae of Oestrus ovis are photophobic and hide in the upper and lower fornix. First line treatment consists of mechanical removal of the larvae.

Macular pigment densities derived from central and peripheral spectral sensitivity differences.

Estimates of the density spectrum of the macular pigment (Wyszecki G, Stiles WS. Color Science: Concepts and Methods. Quantitative Data and Formulas. 1st ed. New York: Wiley, 1967); (Vos JJ. Literature review of human macular absorption in the visible and its consequences for the cone receptor primaries. Institute for Perception. Soesterberg, The Netherlands, 1972) are partially based on the difference between central and peripheral spectral sensitivities, measured under conditions chosen to isolate a single cone class (Stiles WS. Madrid: Union Internationale de Physique Pure et Appliquée, 1953;1:65-103). Such derivations assume that the isolated spectral sensitivity is the same at both retinal locations, save for the intervening macular pigment. If this is true, then the type of cone class mediating detection should not influence the calculated difference spectrum. To test this assumption, we measured central and peripheral spectral sensitivities in a deuteranope, a protanope and a normal trichromat observer: (a) for short-wave sensitive (S-) cone detection; and (b) for long-wave sensitive (L-) cone detection (deuteranope), for middle-wave sensitive (M-) cone detection (protanope) or for both L- and M-cone detection (normal trichromat). The difference spectra determined for L- or M-cone detection deviate significantly from those measured for S-cone detection, at wavelengths below 450 nm. A theoretical analysis suggests that the discrepancies are owing, in part, to regional variation in the optical density of the cone pigments; and that such receptor variation cannot be ignored when deriving the standard density spectrum of the macular pigment.

L, M and L-M hybrid cone photopigments in man: deriving lambda max from flicker photometric spectral sensitivities.

Using heterochromatic flicker photometry, we have measured the corneal spectral sensitivities of the X-chromosome-linked photopigments in 40 dichromats, 37 of whom have a single opsin gene in their tandem array. The photopigments encoded by their genes include: the alanine variant of the normal middle-wavelength sensitive photopigment, M(A180); the alanine and serine variants of the normal long-wavelength sensitive photopigment, L(A180) and L(S180); four different L-M hybrid or anomalous photopigments, L2M3(A180), L3M4(S180), L4M5(A180) and L4M5(S180); and two variants of the L-cone photopigment, encoded by genes with embedded M-cone exon two sequences, L(M2; A180) and L(M2; S180). The peak absorbances (lambda max) of the underlying photopigment spectra associated with each genotype were estimated by correcting the corneal spectral sensitivities back to the retinal level, after removing the effects of the macular and lens pigments and fitting a template of fixed shape to the dilute photopigment spectrum. Details of the genotype-phenotype correlations are summarized elsewhere (Sharpe, L. T., Stockman, A., Jägle, H., Knau, H., Klausen, G., Reitner, A. et al. (1998). J. Neuroscience, 18, 10053-10069). Here, we present the individual corneal spectral sensitivities for the first time as well as details and a comparison of three analyses used to estimate the lambda max values, including one in which the lens and macular pigment densities of each observer were individually measured.

[Bilateral anterior ischemic optic neuropathy following EHEC sepsis and hemolytic-uremic syndrome]. / Bilaterale anteriore ischämische Optikusneuropathie nach EHEC-Sepsis und hämolytisch-urämischem Syndrom.

After emerging from a coma caused by enterohemorrhagic Escherichia coli (EHEC) sepsis with severe neurological and renal involvement a 53-year-old female patient complained of blurred vision. Due to hemolytic-uremic syndrome (HUS) the patient also suffered from dialysis-dependent acute kidney failure. Horizontal visual field defects of the lower hemifield and corresponding segmental optic disc pallor were found in both eyes. Bilateral anterior ischemic optic neuropathy (AION) was diagnosed presumably caused by high volume shifting and hypotonia due to sepsis and dialysis. The literature revealed that bilateral AION is often seen after complex surgical procedures or in patients with severe metabolic disorders. This ophthalmologic complication should always be taken into consideration because of the serious permanent visual damage.

[Acute bilateral loss of vision in posterior reversible encephalopathy syndrome]. / Plötzlicher beidseitiger Visusverlust bei posteriorem reversiblem Enzephalopathiesyndrom.

We describe the case of a patient from the emergency ophthalmic clinic who presented with sudden, bilateral visual loss, headache and dizziness. The magnetic resonance imaging (MRI) showed bilateral parieto-occipital vasogenic edema of the white and grey brain matter consistent with the diagnosis of posterior reversible encephalopathy syndrome (PRES). This is a rare cause of sudden bilateral visual loss which describes a condition with bilateral edema of primarily the white but also the grey matter. The edema is usually detectable with MRI but not always with the less sensitive computed tomography (CT). Further clinical signs may be headache, seizure, nausea, character changes and reduced consciousness. Arterial hypertension, drugs inducing hypertension or drug side effects may cause PRES but sometimes the reason remains unknown. In most cases the symptoms resolve simultaneously with the edema but may also lead to severe complications. In suspected cases of PRES the blood pressure should be measured and a MRI performed, followed by intensive care and treatment of the hypertension, other symptoms and complications.

[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.

An integrated domain specific language for post-processing and visualizing electrophysiological signals in Java.

Electrophysiology of vision - especially the electroretinogram (ERG) - is used as a non-invasive way for functional testing of the visual system. The ERG is a combined electrical response generated by neural and non-neuronal cells in the retina in response to light stimulation. This response can be recorded and used for diagnosis of numerous disorders. For both clinical practice and clinical trials it is important to process those signals in an accurate and fast way and to provide the results as structured, consistent reports. Therefore, we developed a freely available and open-source framework in Java (http://www.eye.uni-tuebingen.de/project/idsI4sigproc). The framework is focused on an easy integration with existing applications. By leveraging well-established software patterns like pipes-and-filters and fluent interfaces as well as by designing the application programming interfaces (API) as an integrated domain specific language (DSL) the overall framework provides a smooth learning curve. Additionally, it already contains several processing methods and visualization features and can be extended easily by implementing the provided interfaces. In this way, not only can new processing methods be added but the framework can also be adopted for other areas of signal processing. This article describes in detail the structure and implementation of the framework and demonstrate its application through the software package used in clinical practice and clinical trials at the University Eye Hospital Tuebingen one of the largest departments in the field of visual electrophysiology in Europe.

[Intermittent elevation deficiency]. / Intermittierendes Hebungsdefizit.

A 7-year-old boy presented with vertical double images. A paediatric examination and magnetic resonance imaging of the head did not show any pathological findings. The diagnosis was an acquired click syndrome of the superior oblique muscle. In cases with inflammatory and systemic origin the underlying disease should be treated. Local steroid therapy can be carried out for improvement of inflammation in the region of the superior oblique muscle with a high degree of suffering.