Medial transconjunctival intrinsic optic nerve biopsy: Surgical technique and indications

Aim: To describe a method of intrinsic optic nerve biopsy and its indications. Methods: Retrospective case series. Results: We report four cases that required intrinsic optic nerve biopsy for progressive optic neuropathy with uncertain diagnosis after negative systemic investigations. In all cases, a medial transconjunctival approach was used. There were no complications noted with this technique in the series, specifically there was no reported deterioration in vision. One case of neurosarcoidosis was confirmed. In the other three cases, the pathology results were non-diagnostic but ruled out serious causes such as central nervous system leukaemia relapse. Conclusion: Medial transconjunctival intrinsic optic nerve biopsy is a minimally invasive and safe technique. The technique is suitable for sampling pathology in the distal portion of the optic nerve. Optic nerve biopsy is indicated when there is significant loss of vision from an isolated optic nerve disease and all systemic investigations have failed to identify the cause, or where the clinical course of a presumed diagnosis is atypical.