Macular Ganglion Cell Complex Reduction Preceding Visual Field Loss in a Patient With Chiasmal Compression With a 21-Month Follow-Up: Comment
In Dr. Horton's comments about our article, he stated that conventional visual field testing may not be sensitive enough to detect functional changes associated with ganglion cell damage (3). We agree, but we also have been impressed with the possibility that, despite what seems to be significant GCC loss, there are enough ganglion cells remaining, especially in the macula, for patients to retain excellent visual function. In other words, the GCC loss may not have reached a “tipping point” as suggested by Dr. Costello, who also commented on our study (4). This seems to occur in other conditions, including Leber hereditary optic neuropathy in which, despite what seems to be almost complete loss of macular ganglion cells, some patients, over time, may regain excellent visual acuity and visual fields.