[Characteristics of pupil function in patients with dissociated vertical divergence]. / Bestehen Besonderheiten der Pupillomotorik bei dissoziiertem Höhenschielen?

Dissociated vertical divergence (DVD) is frequently associated with the infantile strabismus syndrome. There are different theories on the pathomechanism of this disorder, but none of them is generally accepted. Some authors believe that the slow upward movement of the covered eye is due to a different illumination of both retinae and consequently an unequal activity of the oculomotor nerve's nuclei. In one hypothesis a predominance of crossing pupillary tract fibres from the pretectal area to motor and parasympathetic nuclei of the oculomotor nerve was supposed. The consequence of this abnormal pathway in the midbrain would be a pronounced contraction anisocoria in patients with DVD. In contraction anisocoria the directly illuminated pupil contracts more strongly than the contralateral pupil without any efferent defect. In a small study we compared direct and indirect pupillary light reflexes in 11 DVD patients and 10 normal subjects. We found no significant differences of contraction anisocoria between the two groups. The results do not support the hypothesis of a different pupillary tract pathway in the midbrain of patients with DVD.

[Optic neuritis]. / Die Neuritis nervi optici.

The diagnosis of optic neuritis (ON) is made clinically based on typical signs and symptoms such as reduced vision and painful eye movements. Very often, ON is part of or associated with a systemic disease, in particular, multiple sclerosis (MS). Differential diagnosis is necessary in untypical cases with bilateral involvement, unusual age at manifestation or associated systemic and/or neurological symptoms. Neurological examination and cerebral MRI are standard in ON work-up. CSF analysis together with MRI scans allows MS risk assessment in ON patients. Further work-up is necessary in suspected systemic autoimmune disorders, sarcoidosis or infectious causes of ON such as borreliosis.

[Pupillary disorders - diagnosis, diseases, consequences]. / Pupillenstörungen - Diagnostik, Erkrankungen, Konsequenz.

Examination of the pupil offers an objective evaluation of visual function as well as the vegetative pathways to the eye. Essential information is gathered within a short time. This makes pupillary inspection a valuable part of the routine ophthalmological, neurological and general medical examinations. Due to the proximity of pupillary pathways to various anatomic structures, pupillary dysfunction can be caused by a variety of disorders, some of which may be life threatening. The ophthalmologist plays a key role in detecting pupillary disorders and in directing further investigations. Therefore, one should have a good knowledge of the diagnostic significance of pupillary function and dysfunction.

[Ocular neuromyotonia--clinical appearance and thoughts on pathogenesis]. / Die okuläre Neuromyotonie--klinisches Bild und Gedanken zur Pathogenese.

Ocular neuromyotonia (ONM) is a rare neurogenic disorder of ocular motility. The affected patients complain of recurrent transient diplopia secondary to a sudden, painless deviation of one eye. This deviation occurs in the direction of action of an extraocular muscle, which is being stimulated at high frequency. ONM is usually seen after radiation therapy, but may also be caused by compression of the affected cranial nerve. The pathophysiology of ONM is incompletely understood, potential mechanisms include 1) ephaptic transmission along the affected nerve, 2) disturbances of potassium channels in the neuronal cell membrane, and 3) central neural re-organisation. The diagnosis of ONM is made based on clinical findings and can be supported by electrophysiological characteristics. Neuroimaging with attention to the affected cranial nerve should be obtained in order to exclude a compressive cause. Therapy of ONM with carbamazepine is usually effective.

[The problem of glaucoma in Africa--progress report from Cameroon]. / Zur Problematik des Glaukoms in Afrika -- ein Erfahrungsbericht aus Kamerun.

BACKGROUND: Glaucoma is one of the most common causes of blindness in the world. This aspect is well known for the developed countries, however in Africa blindness mainly occurs due to cataract, trachoma and onchocercosis. Glaucoma is not mentioned enough. Patients present with severe findings after a long-lasting history of disease. PATIENTS AND METHODS: In our project experienced surgeons and young medical doctors have been practising regularly in Cameroon since 2001. By means of support from the "Komitee zur Verhütung von Blindheit" and medical industries we keep in contact with a local ophthalmologist. During the consultation of hundreds of patients we have often seen highly advanced glaucoma cases. RESULTS: The medical therapy of glaucoma and also the surgical procedures are limited -- modern antiglaucomatosa are not available. We achieved sufficient regulation of intraocular pressure after trabeculectomy with or without cataract surgery in many cases. The success rate was decreased by severe scar reactions especially in young black people. In advanced glaucoma cases and oculus ultimus we also used the old techniques of iridencleisis. There was a good postoperative regulation of eye pressure, but sometimes we saw a giant filtering bleb after this iris-mutilating procedure. CONCLUSIONS: Glaucoma is a very complex problem, also in Cameroon. Although the diagnostic possibilities are limited, the therapeutic spectrum is differentiated. The introduction of a robust laser for cyclophotocoagulation would be a useful alternative.