Purpose: To investigate optic nerve head (ONH) microvascular changes secondary to transsynaptic retrograde degeneration (TRD), comperatively with direct retrograde degeneration and healthy controls. Methods: Patients with hemianopia due to intracranial lesion included in the study. Intracranial lesion was categorized by location: postgeniculate (causing TRD), chiasmal (causing direct retrograde degeneration). For the postgeniculate lesions, the eye on the same side of the lesion was defined as the ipsilateral eye and the eye on the opposite side as the contralateral eye. Optic disc microvasculature was evaluated with the help of optic coherence tomography angiography. Results: Sixteen eyes of 16 patients with chiasmal lesion, 28 eyes of 14 patients with postgeniculate lesion, and 30 eyes of 30 healthy subjects were included in the study. Ipsilateral eyes of the patients with postgeniculate lesion had decreased vessel density at the temporal sectors compatible with the affected nasal side of the visual field. Contralateral eyes showed no reduction of the vessel density at the affected nasal sectors. The eyes with chiasmal lesions had decreased vessel density at the peripapillary region and nasal half of the ONH compatible with temporal hemianopia. Vascular changes in the chiasmal lesion were more prominent than those of the postgeniculate lesion. Retinal nerve fiber layer and ganglion cell complex thickness were reduced. Conclusion: Vessel density of ONH was reduced in patients with homonymous hemianopia, providing evidence for TRD secondary to acquired postgeniculate lesion. Direct retrograde degeneration was more prominent in affected sectors when compared to TRD.
Meningiomas are mostly benign tumors of the central nervous system. Recurrence can be seen in clinoidal meningiomas especially extending into optic canal. We present a patient with a history of left clinoidal meningioma excision via pterional approach and recurrence purely in left optic canal. Optic canal drilling is necessary for complete removal of these type of tumors. Contralateral subfrontal approach with an eyebrow incision and a keyhole supraorbital craniotomy was used for this patient. Contralateral viewing of the surgical area provided direct angles and created better workspace for the surgeon. Total excision was achieved with no additional neurological deficits in the postoperative period. This approach can be used with its wide exposure of surgical site, potential space usage without need of retraction and better postoperative scar healing.
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