What is glaucoma?

Glaucoma is chronic, progressive eye disease which leads to irreversible damage to the optic nerve. Glaucoma can be associated with elevated eye pressures. Regular eye exams and appropriate testing to assess for glaucoma are critical to prevent vision loss and maintain good eye health.

Glaucoma is a leading cause of blindness worldwide, but if diagnosed and treated early, vision can be maintained.

There are different types of glaucoma, the most common of which are described below:

• Primary open-angle glaucoma
  • This type is most common and develops over time due to improper drainage of the fluid within the eye. This leads to optic nerve damage. POAG is painless and visual problems often occur late in the course of the disease.
  • One subtype of POAG is normal tension glaucoma, in which glaucoma develops despite normal pressures in the eye.
• Closed-angle glaucoma/Narrow-angle glaucoma
  • If the internal drainage system of the eye begins to narrow or close off, this can result in improper drainage of fluid and resultant raised eye pressure. If the drainage system gets blocked completely and suddenly, an emergency called Acute Angle Closure results. This is rare but vision threatening, so if any of the following symptoms occur, call Eye Surgeons Associates or visit the nearest emergency room immediately:
    • sudden blurred vision
    • severe eye pain
    • halos around lights
    • headache
    • nausea/vomiting
  • Secondary Glaucoma  
    • This can result from trauma, diabetes, steroid use, stroke-like events in the eye, infection, and inflammation

Signs and Symptoms of glaucoma

Glaucoma is generally a silent disease, meaning patients usually do not notice any visual changes until the advanced stage of the disease. Having regular eye examinations by an ophthalmologist can detect this disease in its early stages.

While evaluating patients for glaucoma, an ophthalmologist may enquire about the following:

• History of any ocular disease
• Previous ocular surgery
• Trauma to head or eye
• Past medical history
• History of medication use, particularly steroid use
• Any family history of glaucoma

What are the risk factors for glaucoma?

Some people tend to develop glaucoma more often as compared to normal individuals due to the following factors:

• High eye pressure
• Age more than 40 years
• Family history of glaucoma
• African American race
• Thin central corneal thickness
• Hypertension
• Diabetes
• Migraine
• Previous head injury
• Steroid use

How is glaucoma diagnosed?

The following eye examinations are performed when evaluating a patient for glaucoma:

• Slit-lamp examination
• Fundoscopy
• Tonometry
• Gonioscopy
• Pachymetry

Diagnostic tests performed in the evaluation for glaucoma may include:

• Fundus photography
• Retinal nerve fiber layer imaging
• Automated perimetry (visual field testing)
• Optical coherence tomography
• Fluorescein angiography
• Color vision measurements
• Ultrasound biomicroscopy

How is glaucoma managed?

Glaucoma may be managed with medical and surgical techniques. There are many medications and procedures available all designed to lower the intraocular pressure and stabilize glaucoma.

1. Pharmacological management

All medications used in the management of glaucoma aim to lower the intraocular pressure. The following classes of medications are commonly prescribed. Talk to your ophthalmologist about which medication may be right for you. Be sure to discuss any medication allergies you may have, other medical conditions for which you take medicine, and expected side effects of the various drop therapies.

• Beta-blockers
• Adrenergic agonists
• Carbonic anhydrase inhibitors
• Prostaglandin analogs
• Alpha agonists
• RHO kinase inhibitors

If you develop red-eye, pain, blurred vision, a change in heart rate, dry mouth, or any other adverse events, consult your doctor promptly.

1. Laser surgery

Laser surgery, or selective laser trabeculoplasty, is also indicated as a primary or secondary therapy for glaucoma. This is a safe and effective way to lower the eye pressure, and may be used in conjunction with eye drops or in place of eye drops to help control glaucoma. Ask your ophthalmologist if you are a good candidate for laser.

1. Surgical management

If eye pressure is uncontrolled with more conservative techniques, or if glaucoma is progressing despite medical therapy, surgery may be indicated. The following are common surgical procedures that may be used to treat primary open-angle glaucoma.

• Trabeculectomy
  • In this surgery, the surgeon makes a trap door in the eye, under which a channel is made allowing fluid to drain from the inside of the eye to the outside, forming a bleb.
• Drainage implant
  • In this surgery, a tube shunt is implanted in the eye to improve drainage of fluid from within the eye. This implant sends fluid to a reservoir which gets absorbed by blood vessels.
• Minimal invasive glaucoma surgeries (MIGS)

These are newer surgical techniques that may be used to treat open-angle glaucoma, alone or in conjunction with cataract surgery. Some of these procedures commonly performed at ESA include:

• Istent Implant
• Kahook dual blade goniotomy
• Hydrus microstent
• GATT/Trabeculotomy
• Xen gel stent

Prevention

The following steps may help you to detect glaucoma early which is critical for maintaining good vision:

• Regular detailed eye examinations
• If you have a family history of glaucoma then recommend screening to all immediate family members
• Wear eye protection.

REFERENCES

1. What Is Glaucoma? (2021, June 15). American Academy of Ophthalmology. https://www.aao.org/eye-health/diseases/what-is-glaucoma
2. Biggerstaff, K. S., MD. (2021, June 3). Primary Open-Angle Glaucoma (POAG): Practice Essentials, Background, Pathophysiology. Medscape. https://emedicine.medscape.com/article/1206147-overview#:%7E:text=Glaucoma%20is%20currently%20defined%20as,of%20intraocular%20pressure%20(IOP).
3. Glaucoma - Symptoms and causes. (2020, October 23). Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/glaucoma/symptoms-causes/syc-20372839
4. Who Is at Risk for Glaucoma? (2020, September 30). American Academy of Ophthalmology. https://www.aao.org/eye-health/diseases/glaucoma-risk
5. Weinreb, R. N., Aung, T., & Medeiros, F. A. (2014). The pathophysiology and treatment of glaucoma: a review. JAMA, 311(18), 1901–1911. https://doi.org/10.1001/jama.2014.3192

Author

Eye Surgeons Associates Drs. Zuhair H. Peracha, Manal H. Peracha-Riyaz, Eric Zuckerman, Matthew Pieters, and Leila Siblani are dedicated to excellence in eye care and service. We utilize the latest treatment methods and procedures, including routine eye care, cataract surgery, glaucoma treatment, retinal disease management, diabetic eye treatment, and eyelid surgery.