Xen gel stent occlusion with iris pigment epithelium

Abstract

directed to examine the entire course of this slender nerve. The majority of affected patients are oligosymptomatic with diplopia only and can be observed with serial contrastenhanced MRIs coupled with symptomatic management such as prism glasses or strabismus surgery. It is important to periodically monitor these patients as there is a potential for haemorrhage or growth resulting in brainstem compression. Concerning symptoms include sensory changes, paresis, ataxia and other cranial nerve palsies. Surgical resection is almost always associated with persistence or worsening of superior oblique weakness and carries the risk of stroke, intracranial haemorrhage and damage to surrounding cranial nerves. Therefore, surgery is not recommended as initial treatment of an isolated CNIV schwannoma, but may be necessary if the tumour rapidly enlarges causing mass effect. In slowly progressive cases, radiotherapy may be considered as an alternative treatment modality. In particular, gamma knife stereotactic radiosurgery has recently delivered promising results with small case series reporting reduced tumour volume and improvement of diplopia. This is the longest published follow-up period for a presumed CNIV schwannoma, demonstrating its typical extremely slow-growing nature. Clinical and radiologic observation is favoured over neurosurgical intervention in such cases.