Following are some of the potential side effects of the most commonly prescribed types of glaucoma medications.
Prostaglandin Analogs: help to increase aqueous outflow with once a day application.
Side effects: possible changes in eye color and eyelid skin, stinging, blurred vision, eye redness, itching, burning.
Beta-Blockers: help to reduce aqueous production and used in combination with carbonic anhydrase inhibitors and alpha agonists.
Side effects: low blood pressure, reduced pulse rate, fatigue, shortness of breath; rarely: reduced libido, depression.
Carbonic Anhydrase Inhibitors: help to reduce aqueous production
Side effects: in eye drop form: stinging, burning, eye discomfort; in pill form: tingling hands and feet, fatigue, stomach upset, memory problems, frequent urination.
Alpha Agonists: Neuroprotection and help to reduce aqueous production
Side effects: burning or stinging, fatigue, headache, drowsiness, dry mouth and nose, relatively higher likelihood of an allergic reaction.
Side effects of combined medications may include any of the side effects of the drug types they contain.
Selective Laser Trabeculoplasty (SLT) is a safe, quick, simple, and non-invasive treatment option used to treat glaucoma. It works by reducing the pressure inside the eye. The eye pressure is known as intraocular pressure (IOP). The procedure does not require admission to the hospital and is carried out in the outpatient department.
This laser treatment uses a YAG laser to make a microscopic hole in the peripheral iris to help the passage of fluid resulting in a structural improvement in the access to the trabecular meshwork which are the drains of the eye helping the fluid to pass and reducing the risk of angle-closure glaucoma. The procedure does not require admission to the hospital and is carried out in the outpatient department.
The diode laser is a highly concentrated beam of light, which can be used to target and treat a selected area. Sometimes, laser treatment is recommended in order to avoid or delay the need for more invasive surgery. The diode laser is used to produce very small burns in the ciliary body, which produces the watery fluid called aqueous humor, and is situated behind the iris (colored part of your eye). The reduced production of aqueous humor causes eye pressure to fall.
The recent most increased interest in glaucoma surgery has been in Minimally Invasive Glaucoma Surgery (MIGS) with formidable results in mild to moderate glaucoma. These are designed to improve the safety of surgical intervention for glaucoma. Although initially coined minimally invasive, the term micro seems more appropriate because it truly differentiates these microscopic ophthalmic procedures from other minimally invasive surgical procedures (i.e., general surgery). Most MIGS procedures enhance physiologic outflow and are aimed at a different patient population than traditional filtration surgery. As opposed to competing with traditional filtering surgery, MIGS seems to be more of an alternative to medical therapy in an effort to address adherence challenges, adverse events, and qualityof-life (QOL) issues with topical medications.
The iStent Trabecular Micro-Bypass Stent (Glaukos, Laguna Hills, CA) received FDA approval in 2012. The device is a heparin-coated, non-ferromagnetic titanium stent with a snorkel shape to facilitate implantation. The device is placed using a singleuse, sterile inserter through a 1.5mm corneal incision. The iStent itself is the smallest FDA approved device, measuring at 0.3mm in height and 1mm in length. The iStent is a safe minimally invasive glaucoma surgery (MIGS) procedure that can reduce the need for daily use of glaucoma eye drops. A small (1mm) titanium drainage stent is inserted into the eye’s natural drainage channel to lower intraocular pressure. Most clinical trials concluded that iStent implantation with phacoemulsification resulted in a significantly lower, long-term decrease in IOP and number of medications used compared to phacoemulsification alone. No major complications have been reported.
The XEN Glaucoma Implant (AqueSys Implant) was created by AqueSys Inc acquired by Allergan. The implant itself is made out of a soft, collagen-derived, gelatin that is known to be noninflammatory. The Xen Gel Stent aims to reduce intraocular pressure by inserting a small drainage tube into the eye. The stent allows fluid to drain from the anterior chamber into a reservoir (bleb) under the conjunctiva. The goal of implantation is to create an aqueous humor outflow path from the anterior chamber to the subconjunctival space. The implant is injected through a small corneal incision with the use of an inserter similar to those used for IOLs. Similar to other implants, it can be performed in conjunction with cataract surgery.
All shunts perform approximately the same function of lowering the eye pressure. It’s important to note that no treatment is guaranteed to completely eliminate the need for eye drops, but the strong results seen in the use of either the Istent or XEN Gel Stent give the right patients a very strong choice for eliminating the need for them.
Trabeculectomy is a surgical operation that creates an alternative drainage channel, to help aqueous fluid (natural fluid of the eye) drain from your eye. This operation creates a bypass for the blocked natural drain (trabecular meshwork) of your eye. Your eye pressure is reduced because fluid can now drain more easily through the newly created drainage channel.
Aqueous shunts are devices that are used to reduce the eye pressure in glaucoma by draining the aqueous humor (natural fluid of the eye) from inside the eye to a small blister or bleb behind the eyelid. Draining the aqueous humor, using a shunt, reduces the pressure on the optic nerve that causes loss of vision in glaucoma. The purpose of lowering the eye pressure is to prevent further loss of vision. Control of the eye pressure with an aqueous shunt will not restore vision already lost from glaucoma. Aqueous shunts have various other names such as tube implants, glaucoma tube shunts, glaucoma drainage devices, and glaucoma drainage implants. These all refer to the same thing. Although there are many types of shunts available, two main types are in use at Moorfields Eye Hospital Dubai and they function in a similar fashion.
These are called the Ahmed Glaucoma Valve and The Baerveldt Glaucoma Implant.
In certain eye conditions, a third type, known as the Molteno Implant, might also be used.