Can eye growth be manipulated pharmocologically?
There is significant incentive to come up with a drug that could be used to either prevent the development or slow the progression of human myopia. Attention to date has been mostly directed at two drug groups, dopamine analogs, and antimuscarinic drugs. That dopamine analogs influence eye growth is perhaps not surprising as in the retina, DA modulates contrast sensitivity and image contrast is altered by defocus. However, the data are not overly promising. There is also the added problem with this drug group in terms of efficacy for treating human myopia, in that any drug mediating its effects through changes in retinal function is likely to be problematic in terms of side-effects. Antimuscarinic drugs hold more promise as they appear to directly inhibit scleral growth. The selective drug, pirenzepine, is now in clinical trial. However, there are many other possible candidates including retinoic acid analogs.