Therapy glaucoma
The goal of glaucoma therapy must be the individual optimal adjustment of the intraocular pressure. This means that the pressure must be lowered. This is achieved by three different methods: Eye drops: Several groups of drugs are available for the treatment of glaucoma.
The following table gives a brief overview of the substances and their effects. Beta-blockers: The production of aqueous humor is reduced. Sympathomimetics: Carboanhydrase inhibitors: Reduction of aqueous humor production Prostaglandin derivatives: Improvement of uveoscleral outflow (see above) Parasympathomimetics: Improvement of the outflow of aqueous humor by increased muscle contraction and the resulting opening of the chamber angle
- Eye drops (medication)
- Laser treatment
- Operation
The eye doctor will determine which of the eye drops are suitable.
In addition to the desired effect, the side effects and other diseases that may be influenced by the medication must also be considered. Typical side effects of parasympathomimetics are, for example, deterioration of vision, especially in older people with pre-existing lens opacity (cataract). Caution is also advised with beta blockers. They can intensify asthma or aggravate heart rhythm disorders. In some cases, they lower blood pressure, which is desirable in the treatment of high blood pressure.
Glaucoma laser treatment
There are two ways to treat glaucoma with laser therapy. One variant is called trabeculoplasty. In this procedure, 80-100 “laser shots” are delivered into the area of the chamber angle, thus improving the outflow of the aqueous humor. The other variant is the so-called cyclophotocoagulation, in which the ciliary epithelium, i.e. the region in the eye that produces the aqueous humor, is targeted. The aim is to achieve partial destruction (sclerotherapy) and thus to reduce the production of aqueous humor.
Operation glaucoma
To improve the outflow of aqueous humor, several surgical procedures have been developed for glaucoma. Ultimately, however, an additional, artificial outflow for the aqueous humor is always created. Most procedures aim to create a rectangular opening (trabeculectomy) or a round opening (goniotrepanation) in the eyeball in the area of the anterior chamber of the eye, through which the aqueous humor can then be absorbed by veins and lymph vessels.
These so-called filtration operations are often more effective than drug therapy. On the other hand, they naturally also involve the usual risks associated with surgery. Inflammation, unpredictable bleeding and other damage can occur.
As a rule, however, these risks can be considered rather low. However, postoperative wound healing disorders occur much more frequently (about a quarter of all cases). These lead to scarring with subsequent closure of the artificial opening and again impaired aqueous humor drainage.
The result is an increase in intraocular pressure. Other similar, but not as deeply penetrating (invasive) surgical procedures are deep sclerectomy and viscocanalostomy. In deep sclerectomy, an extremely thin layer of Schlemm’s canal is left over the artificially created opening to prevent excessive outflow of aqueous humor.
In viscocanalostomy, the Schlemm canal is widened with the aim of restoring the normal outflow path. However, these procedures are usually not as effective as filtration operations. The acute glaucoma attack is an emergency.
First, the intraocular pressure should be lowered as quickly as possible. This is achieved by medication (see above). An iridectomy can be performed surgically.
In an iridectomy, a gap is created in the iris either surgically or by laser. This allows the aqueous humor to flow easily from the posterior chamber into the anterior chamber and then drain off in the aqueous humor. Congenital glaucoma is always treated by surgery.
A goniotomy is performed. This is an operation in which remaining remnants of the embryonic tissue are cut out in the chamber angle. Then, Schlemm’s canal is free again and the aqueous humor can drain off.In contrast to adults, it is possible for newborns and infants that a depression in the papilla may partially recede after surgical treatment.
The therapy for secondary glaucoma depends on the underlying disease (e.g. diabetes mellitus). The treatment options in the eye are essentially the same as those described above. However, the primary focus is always on the underlying disease and its treatment (in the case of diabetes, for example, the correct setting of sugar and fat levels).
