Primary and secondary glaucoma
Glaucoma is the term used in ophthalmology to refer to a group of diseases that increase intraocular pressure (IOP) and cause progressive damage to the optic nerve.
The types of glaucoma They are classified into primary and secondary glaucoma and within these classifications are the different types of open-angle and angle-closure glaucoma.
Primary and secondary glaucoma
Glaucoma is the term used in ophthalmology to refer to a group of diseases that increase intraocular pressure (IOP) and cause progressive damage to the optic nerve.
The types of glaucoma They are classified into primary and secondary glaucoma and within these classifications are the different types of open-angle and angle-closure glaucoma.
What is primary and secondary glaucoma?
We speak of primary and secondary glaucoma to classify the different types of glaucoma.
El primary glaucoma, unlike the secondary, is caused by a physiological eye problem which blocks the aqueous humor outflow system, triggering an increase in intraocular pressure (IOP).
El secondary glaucoma is characterized in that its origin is not associated with the ocular structure, but with other conditions or diseases such as inflammatory processes, diabetes mellitus or trauma, among others, that secondarily cause a problem in the drainage system of the eye.
Primary glaucoma
Primary glaucoma is one whose origin is caused by an eye problem and affects the drainage system of the internal fluid of the eye, better known as aqueous humor.
The fluidity and reabsorption of aqueous humor are very important to maintain balanced intraocular pressure levels. The structures that form the drainage system are located right at the angle formed by the iris and the cornea (iridocorneal angle). These drainage structures are called Schlemm's canal and trabecular meshwork and occupy the 360º of the iridocorneal angle.
When there is a failure in the drainage system of the eye, the aqueous humor can neither be released nor absorbed correctly and, as a consequence, the level of intraocular pressure increases. In turn, the constant increase in IOP or its fluctuations damage the optic nerve and wreak irreversible havoc on vision.
Open angle
El primary open angle glaucoma It is the most common among the different types of glaucoma, in fact, 90% of glaucoma cases are primary open-angle. This type of glaucoma is caused by the obstruction of the drainage channels, but it is characterized by the iridocorneal angle is open and is amplio, as it should be.
This glaucoma develops slowly, is lifelong, and rarely has symptoms. Primary open-angle glaucoma is usually diagnosed during a routine eye exam.
Closed angle
El angle-closure glaucoma it is less frequent and is caused by the obstruction of the drainage channels that increases the intraocular pressure suddenly. In this type of glaucoma the iridocorneal angle is narrow and it is closed, this being the main cause of glaucoma since it is impossible for the aqueous humor to drain properly.
Angle closure glaucoma is a lot more aggressive than the rest of the glaucomas, since it considerably affects the intraocular pressure and, therefore, is more damaging to the optic nerve. The progress of this disease is rapid and presents very noticeable symptoms such as blurred vision, colored halos around the lights or vomiting, among others.
Causes
Primary glaucoma originates from a physiological condition y not associated with any other pathology. The difference between primary open-angle and closed-angle glaucoma lies in the iridocorneal angle (angle formed by the iris and the cornea). As everyone infers, the causes of open angle glaucoma may be present in Schlemm's canal or in the trabecular meshwork since the iridocorneal angle is open, while in closed-angle glaucoma the problem lies specifically in the narrowness of the iridocorneal angle.
Symptom
El primary open angle glaucoma is a silent disease that does not usually present symptoms until the condition is chronic and is in an advanced stage.
Instead, angle-closure glaucoma It is a disease that starts suddenly and causes symptoms from the start. Most patients with this type of glaucoma have blurred vision and even loss of vision. Angle-closure glaucoma is a medical emergency and must be treated immediately.
secondary glaucoma
Secondary glaucoma is less common and, as the name suggests, is secondary or consequence of a disease, Trauma or inflammatory process in the organism. Heart failure, respiratory diseases, cysts, uveitis and / or some medications can be triggers for secondary glaucoma.
Secondary open-angle glaucomas can include, but are not limited to:
- pigmentary glaucoma: It is caused by pigment dispersion syndrome. It is produced by the detachment of melanin from the iris that travels to the drainage system and is deposited in the trabecular meshwork, in the aqueous humor or in Schlemm's canal.
- Pseudoexfoliative glaucoma: It is caused by pseudoexfoliative syndrome, a condition characterized by the accumulation of extracellular material in the ocular structure, including the drainage structures of the aqueous humor.
- Normotensive or normotensive: associated with cardiovascular problems or intermittent closures of the drainage angle.
- Traumatic glaucoma: caused by a blow or trauma that affects the ocular structure or the iridocorneal angle.
- Glaucoma due to iridocorneal syndrome: it is characterized by symptoms such as holes in the iris, atrophy and papillary distortion, among others.
- neovascular: it is associated with the growth of new blood vessels in the iris
Treatment of primary glaucoma
Treatment of primary open-angle glaucoma aims to monitor intraocular pressure levels. In general, the treatment is carried out on a scale according to the evolutionary state of the disease, starting with the eye drop administration and evaluating the option of carrying out a glaucoma surgery when the disease is in an advanced stage.
Treatment of secondary glaucoma
Treatment of secondary glaucoma, like that of primary glaucoma, has the main objective of controlling the IOP when the angle is open. The treatment options contemplated are the same, use of eye drops for intraocular pressure and, when necessary or when the disease is more advanced, we perform a drainage surgery for glaucoma.
Angle-closure glaucomas must be treated immediately, as they progress so quickly that they are considered a medical emergency. In these cases the treatment aims lower IOP levels to stop optic nerve damage and preserve the patient's vision. Glaucoma surgery cannot reverse the damage caused to the nerve of the eye, hence the importance of acting quickly when faced with closed-angle glaucoma.
