by LasikExpert » Sat Feb 24, 2007 9:00 pm
Whether or not corneal nerve density returning to preoperative levels is an important factor in dry eye is not very clear. It is only one measurement of healing. What we know helps resolve Lasik induced dry eye is corneal nerve sensitivity returning. The system needs these signals to keep a balance of tear quality and quantity. The possibility that nerve sensitivity is damaged forever exists, but the probability is relatively low. Some would say very, very low. We may, however, be chasing a red herring.
The success of Restasis in treating Lasik related dry eye indicates that much of the problem relates to inflammation. Inflammation is a natural consequence of wound healing and in this scenario would close the channels that carry the fluids that become tears. It may be that the initial wound response causes inflammation and the lack of sensitivity in the first few weeks/months fails to tell the system that the need for inflammation has passed. Dry eyes is a very complex problem, and surgery related dry eyes is even more complex.
For purposes of reporting complication rates we look at what remains unresolved at six months postop. That does not mean that all healing stops at six months. Many people report improvement in vision quality and resolution of complications after the six-month point. We could report on one-year postop results, but in an environment where advertisements imply the 20-Minute Miracle, we felt that six months was appropriate.