Ganglion cell layer complex measurements in compressive optic neuropathy

Purpose of review Neuroophthalmologists and neurosurgeons are often asked by their patients what their visual prognosis will be after decompression of an optic chiasm lesion. Previous methods have been studied but have not provided consistent guidance. However, a recent algorithm which allows for retinal ganglion cell analysis from optical coherence tomography (OCT) may be more helpful. Recent findings Recent studies have shown that ganglion cell layer complex (GCC) measurements from OCT strongly correlate with the visual field loss associated with compressive optic neuropathies. For example, GCC measurements show corresponding binasal thinning with bitemporal hemianopia. Some investigators have also shown that more preserved GCC thickness is preoperatively associated with better postsurgical outcome. Interestingly, some patients experience almost complete recovery of visual fields despite considerable GCC thinning, and others may have GCC loss before they develop demonstrable visual field defects. Summary GCC measurements on OCT strongly correlate with visual field defects from optic chiasm compressive lesions and may help with regard to prognosis following treatment. However, considerable visual recovery is possible despite persistent GCC loss.