EVALUATION OF COEXISTING OPTIC-NERVE HEAD DRUSEN AND GLAUCOMA WITH OPTICAL COHERENCE TOMOGRAPHY

Objective: Optic nerve head drusen often make evaluation of the nerve head difficult to interpret, In addition, visual field defects are kno wn to occur in patients with optic disk drusen, resembling glaucomatou s damage. The authors report two cases of coincident optic nerve head drusen and glaucoma, in which the use of optical coherence tomography (OCT) in evaluating the nerve fiber layer was beneficial. Participants : Two patients with both optic nerve head drusen and glaucoma, one wit h primary open angle glaucoma, the other with pseudoexfoliation glauco ma were evaluated, Both patients had asymmetric optic disk drusen, wit h clinically visible drusen only in one eye. Intervention: Ophthalmolo gic examination, color and red-free photography, automated Humphrey vi sual field testing and OCT were performed, Results: Nerve fiber layer loss as measured by OCT was found to be greater than expected by the a ppearance of the optic nerve head and red-free photography, with visua l fields consistent with findings in case 1. In case 2, visual fields were full, despite nerve fiber layer thinning seen by OCT and red-free photography. Conclusions: There can be significant nerve fiber layer thinning in patients with both glaucoma and optic disk drusen, despite the appearance of the optic nerve head in these patients. The cup mar gin may be obscured by the drusen, giving rise to a falsely full-appea ring disk. In such cases, OCT may provide a useful means to quantitati vely measure the nerve fiber layer thickness and to aid in the managem ent of these patients by detecting nerve fiber layer thinning earlier than would otherwise be possible.