A new genetic test can predict the presence of glaucoma, a disease that is the second leading cause of blindness in western countries and usually causes no symptoms to alert of their presence.
Much progress has been made since in 1794 a physicist, chemist and naturalist Englishman named Dalton, describe his own blindness and his brother with regard to colors, because at the moment we already know the molecular genetic mechanisms involved in the development of many eye diseases including glaucoma.
The idea that some of the factors causing glaucoma can be inherited was suggested for the first time 150 years ago.
As shown by various studies, the role of inheritance seems to be determinant in glaucoma. They show that the 13-50% of glaucoma patients, have at least one family member with the disease, individuals with a family history of glaucoma are 10 times more likely to suffer than those who have not.
The high prevalence in African Americans compared with that observed in Caucasians, could likewise reflect this underlying genetic factor.
Therefore, as soon as possible to know that a person could develop the disease, especially in populations at risk and to calculate the forward and visual impairment that may cause, is essential for it’s therapeutic. In this sense, genetic diagnosis allows treatment to be individualized and take steps to minimize the chance of blindness in high-risk patients.
At present the results simply indicate chances of suffering the disease or not, to be more precise in some special types of glaucoma as pseuexfoliative, one of the most frequent and more complex glaucoma to be treated, because it causes the release of a substance which is deposited in the trabecular meshwork, blocking the aqueous humor outflow and increasing the intraocular pressure, as shown in Figures 1 and 2.
Figure 1. – Pseudoexfoliative glaucoma with signs of the PSX material in crystalline, white line marked with arrows (A) and in the rim of the pupil, white spots marked with arrows (B).
Figure 2. – Aqueous humor outflow (A) to the drainage area of the trabecular meshwork, green circle (B) and deposits of pseudoexfoliation material in the trabecular meshwork, marked with an asterisk in a piece of trabecular view with electron microscopy (C).
We believe it is highly recommended this type of genetic analysis to those patients with a family history of glaucoma or ocular hypertension with unknown origin. The visit to the ophthalmologist, glaucoma specialist, and genetic testing can prevent the onset of glaucoma and the possible loss of vision.