What Really Causes Glaucoma?

Abstract

Glaucoma can be defined in many different ways, as evidenced in this text. The most common definition is based on anatomy and pressure, with open angle glaucoma being most common among Caucasians in North America, low or normal tension glaucoma being most common among the Japanese, and angle closure being most common among other Asians. (Such clear delineations are not currently recognized in other ethnic groups.) Certain regions of the world give rise to the special circumstances of exfoliation. In the U.S., I am continually surprised with the discovery of new geographic foci of exfoliation. Regionally, it has been recognized for decades that exfoliation has a higher than normal prevalence in the greater Minneapolis area and around Minnesota - it is likely that this is due to the large number of individuals of Scandinavian descent. A week before writing this, I found out that exfoliation was also very common in the Salt Lake City area, where again northern European heritage is considered the causal factor. The genetics of exfoliation may eventually be studied more extensively in the geographic areas that are most highly affected. Ultimately, what really causes glaucoma is likely to be defined in genetic terms, just as exfoliation (but not necessarily exfoliative glaucoma) has been. Risk factors and “environmental factors,” as enumerated in the first chapters of this text, will always be important and have an impact upon the susceptible eye.