Understanding Glaucoma

Glaucoma encompasses a collection of eye diseases that damage the optic nerve, leading to vision loss and potential blindness. It ranks as a primary cause of visual impairment and blindness in the United States, affecting individuals across all age groups. Often called the “sneak thief of sight,” many people with glaucoma may not show symptoms until significant vision loss has occurred.

How Glaucoma Develops

The eye continuously generates a watery fluid known as aqueous humor, which maintains the eye’s shape by balancing production and drainage. This fluid exits through a delicate meshwork. When the drainage system becomes compromised, it increases eye pressure, known as glaucoma. This elevated pressure can harm your vision, making early detection and treatment vital. Eye Associates of South Texas specialists are proficient in treating glaucoma through medical, laser, and surgical methods. Our services are available at various locations, including San Antonio, Seguin, New Braunfels, La Vernia, Castroville, Hondo, Luling, Lockhart, and Gonzales.

Types of Glaucoma

Open-Angle Glaucoma

Open-angle glaucoma is the most prevalent form, where the eye’s fluid drains too slowly through the trabecular meshwork. This slow drainage leads to increased pressure as fluid accumulates. Vision loss in open-angle glaucoma progresses gradually and often goes unnoticed until it becomes irreversible. This type accounts for about 95% of glaucoma cases.

Angle-Closure Glaucoma

Angle-closure glaucoma is a condition where the trabecular meshwork in the eye becomes blocked, resulting in a sudden increase in intraocular pressure. This rise in pressure can lead to severe symptoms like eye pain, blurred vision, halos around lights, and even nausea or vomiting. Despite being less prevalent than other forms of glaucoma, angle-closure glaucoma demands prompt medical intervention to prevent potential vision loss and complications.

Understanding Glaucoma Symptoms

Many individuals may not notice any signs during the initial stages of glaucoma. This often means no pain or vision loss, making it challenging to detect early on. However, as the condition advances, some common symptoms may begin to appear:

Early and Advanced Symptoms

  • Peripheral Vision Loss: Difficulty seeing objects on the side.
  • Sudden Eye Pain: Intense pain in one or both eyes.
  • Headache: Persistent headaches not linked to other causes.
  • Blurred Vision: Difficulty seeing clearly.
  • Halos Around Lights: Rings or halos seen around lights.
  • Tunnel Vision: Narrowing of the visual field.
  • Nausea: Feeling queasy without a clear cause.
  • Vomiting: Accompanying nausea, often due to severe eye pain.
  • Red Eyes: Noticeable redness in the eyes.

How Glaucoma is Diagnosed

Specific individuals may remain unaware of their glaucoma condition until they receive a standard eye examination. There are various diagnostic tests used to identify glaucoma:

Key Diagnostic Tests

  • Visual Field Test: Measures peripheral vision.
  • Dilated Eye Examination: Allows a detailed view of the optic nerve.
  • Retinal Evaluation: Assesses the health of the retina.
  • Gonioscopy: Examines the drainage angle of the eye.
  • Visual Acuity Test: Tests clarity of vision.
  • Tonometry: Measures intraocular pressure.
  • Pachymetry: Assesses corneal thickness.

At Eye Associates of South Texas, our board-certified ophthalmologists and optometrists utilize advanced diagnostic tools and extensive clinical training to determine the presence of glaucoma.

Advanced Diagnostic Tools

  • Spectral Domain OCT: Offers precise optic nerve analysis without dilation using Zeiss, Optovue, Optos, or Nidek technology.
  • Automated Threshold Perimeter: This tool examines the visual field. It is also a Visual Field Analyzer (Humphrey, Heidelberg, Welch Allyn).
  • Color Photography: Documents the condition of the optic nerve.
  • Ultrasonic Pachymetry: Utilizes Accutome technology to measure corneal thickness.

Your comprehensive glaucoma assessment will include measuring intraocular pressure, testing peripheral vision, checking for optic nerve damage, and examining the eye’s drainage angle. If a second opinion is needed, Dr. J.T. Kavanagh, MD, a fellowship-trained glaucoma specialist with over 20 years of experience, can provide his expertise.

Effective Glaucoma Treatments

Initiating treatment as soon as glaucoma is diagnosed is crucial to minimizing the risk of permanent vision loss. Glaucoma currently has no cure, but treatments are available to alleviate symptoms and prevent further damage. Each treatment plan is tailored to the type and severity of glaucoma, which can be discussed with your healthcare provider. Below are some standard treatment options for glaucoma:

Medication for Glaucoma

Medications, either eye drops or oral tablets, decrease fluid production in the eye or enhance drainage. Side effects may include redness, stinging, irritation, or blurry vision. You must inform your doctor about any other medications or allergies to minimize the risk of adverse reactions. Consistent use of these medications is essential to maintaining controlled eye pressure.

Surgical Options for Glaucoma

When medication alone isn’t sufficient, surgical intervention may be necessary to lower eye pressure. Here are some standard surgical procedures for glaucoma:

Laser Peripheral Iridotomy (LPI)

This procedure is ideal for patients with narrow-angle glaucoma. It involves creating a small hole in the iris to increase the angle between the iris and cornea, facilitating better fluid drainage.

Argon Laser Trabeculoplasty (ALT) and Selective Laser Trabeculoplasty (SLT)

Both methods are designed for patients with primary open-angle glaucoma (POAG). These procedures involve opening the trabecular passages to improve fluid drainage. ALT is effective for approximately 75% of patients, while SLT can be repeated if necessary.

MicroInvasive Glaucoma Surgery (MIGS)

Suitable for patients with mild to moderate glaucoma, MIGS offers better control without the need for additional medications. It is also beneficial for those undergoing cataract surgery who wish to reduce reliance on glaucoma medications.

Filtering Microsurgery (Trabeculectomy)

This procedure, recommended for patients who haven’t responded to laser surgery or medications, creates a new drainage passage by making a small incision in the sclera and forming a collection pouch between the sclera and conjunctiva.

Tube Shunt Surgery

This procedure is often recommended for patients with neovascular glaucoma, failed trabeculectomy, or a high risk of developing scar tissue. A thin, flexible tube (shunt) with a silicone pouch is inserted into the eye to facilitate fluid drainage.

We are committed to providing the most effective treatments for our glaucoma patients at the Eye Associates of South Texas. We offer a comprehensive range of options, including minimally invasive glaucoma surgeries (MIGS) and traditional procedures such as trabeculectomies and aqueous shunts.

Minimally Invasive Glaucoma Surgery (MIGS) Types

iStent Inject®

The iStent Inject® is a revolutionary micro-implant designed to lower intraocular pressure in glaucoma patients. Known as a minor medical implant used in the human body, it helps restore the eye’s natural fluid outflow, maintaining safe pressure levels. This can reduce or even eliminate the need for glaucoma medications. Implanted during cataract surgery through a small incision, the iStent Inject® is invisible and undetectable once in place. Patients typically experience a quick recovery and can return home the same day. Eye Associates of South Texas pioneered the post-FDA approval procedure in San Antonio in August 2018.

Hydrus microstent

The Hydrus Microstent, made by Ivantis, is a highly flexible implant designed to treat open-angle glaucoma. Composed of a nickel and titanium alloy, this eight mm-long device acts as a scaffold within Schlemm’s canal to enhance fluid outflow and reduce eye pressure by approximately 20%. While mild complications such as temporary hemorrhages can occur, they typically resolve within a week. Eye Associates of South Texas was the first practice in the region to utilize this innovative technology.

XEN® Gel Stent

The XEN® Gel Stent offers a surgical solution for patients with open-angle glaucoma who have not succeeded with other treatments. This soft, flexible tube creates a new drainage channel to lower intraocular pressure effectively. Dr. Kavanagh, a certified Xen Gel Stent implanter and fellowship-trained glaucoma specialist, uses this device as part of his comprehensive approach to treating severe glaucoma.

Kahook Dual Blade Goniotomy

The Kahook Dual Blade Goniotomy effectively reduces intraocular pressure by creating a drainage channel in the eye’s trabecular meshwork. This procedure can be performed during cataract surgery or as a stand-alone treatment. The dual blade makes an incision in the trabecular meshwork to facilitate better fluid drainage, ultimately lowering eye pressure.

Omni Sight Sciences Canaloplasty

Canaloplasty using the OMNI Surgical System is an advanced procedure designed to decrease resistance to aqueous outflow, lowering intraocular pressure. This treatment can be carried out independently or alongside cataract surgery. Dr. Kavanagh regularly performs canaloplasty using this state-of-the-art device.

Interested in MIGS (Minimally Invasive Glaucoma Surgery)?

If glaucoma medications or previous treatments haven’t sufficiently lowered your intraocular pressure, consider exploring MIGS. These innovative treatments offer safe and effective options for managing glaucoma. Early detection and timely intervention can make a significant difference.

Contact Eye Associates of South Texas today to schedule your eye exam and discuss your suitability for MIGS.

Glaucoma Lasers

Selective Laser Trabeculoplasty (SLT)

Selective Laser Trabeculoplasty (SLT) is a proven method for reducing intraocular pressure (IOP). This laser treatment uses short, gentle light pulses targeting pigmented cells within the eye’s drainage system. Applying the lowest possible laser energy minimizes any visible change to the target tissue. These energy bursts stimulate a natural healing response, enlarging the fluid outflow pores and lowering eye pressure.

In-office SLT treatments use the same equipment as regular eye exams. After numbing the eye with drops, the procedure involves around 80 laser pulses delivered through a unique mirrored lens. Patients usually experience mild discomfort, such as a slight pinch or burning sensation. While the treatment takes only a few minutes, the process lasts about an hour, including preparation and follow-up measures to ensure patient safety. Typically, only one eye is treated at a time. Patients continue their usual eye drops and receive a prescription for an additional drop if there is any post-procedure discomfort, though most find it unnecessary.

Side Effects of SLT

Post-treatment side effects are rare but can include soreness, redness, and temporary vision blurring. These are generally short-lived and easily managed with eye drops. Sometimes, eye pressure may increase, typically temporary and treatable with additional medication. Rarely can this pressure increase persist, requiring more invasive surgical intervention. Another rare complication is anterior peripheral synechiae, where the iris adheres to the cornea. Persistent inflammation and swelling can also occur but are uncommon.

These potential complications are infrequent and can be appropriately managed if they occur. SLT outcomes vary by individual, and continuous glaucoma monitoring is essential. Depending on the results, SLT can be safely repeated if necessary.

Ready to explore your options? Contact us today to schedule your consultation.

Cyclo G6™ Glaucoma Laser System with MicroPulse P3™ Glaucoma Probe Device

The Cyclo G6™ Glaucoma Laser System, featuring the MicroPulse P3™ Glaucoma Probe Device, offers a safer ciliary body treatment method than traditional G-Probe cyclodestruction lasers. Instead of a prolonged laser pulse, it uses micro-pulses of energy to perform transscleral cyclophotocoagulation, preventing ocular tissue from heating and burning. This method can reduce intraocular pressure by up to 30% in some patients.

Classic Procedures


Trabeculectomy is a long-standing surgical procedure, first described by Cairns in the late 1960s, that creates a “trap door” into the eye’s anterior chamber. This operation has a proven track record spanning over 50 years. Dr. Kavanagh, who is fellowship-trained in glaucoma, routinely performs this surgery when less invasive methods are needed.

Tube Shunt (Ahmed)

An aqueous tube shunt may be necessary for severe glaucoma cases. This involves implanting a device with a tube entering the eye and an external reservoir sutured to the sclera. It is typically required for conditions like rubeotic or uveitic glaucoma. The doctors at Eye Associates are highly skilled in performing this procedure.

How to Prevent Glaucoma

Although it is impossible to prevent glaucoma completely, you can take specific steps to reduce the risk of progression. Consider incorporating these suggestions into your routine:

Regular Eye Examinations

Regular comprehensive eye examinations are crucial for detecting glaucoma early—schedule annual check-ups to monitor your eye health and catch any signs of glaucoma before they progress.

Annual Glaucoma Screenings

Undergoing annual screenings specifically for glaucoma can help detect changes in your eye pressure and optic nerve health. Early detection is vital to slowing the progression of the disease.

Adhering to the Doctor’s Treatment Plan

Following your doctor’s treatment plan is essential in managing glaucoma. This plan may include medications, eye drops, or other treatments to control eye pressure and prevent further damage.

Embracing a Healthy Lifestyle

Healthy lifestyle changes, such as maintaining a balanced diet, exercising regularly, and avoiding smoking, can positively impact overall eye health. These changes can also help manage glaucoma.

Protecting Your Eyes

Protecting your eyes from injury is another important aspect of managing glaucoma. Wear protective eyewear during activities that could potentially harm your eyes.

Support for Low Vision

If you have experienced vision loss due to glaucoma, various services and programs are available to help you lead an independent life. These resources can assist you in adapting to changes in your vision and maintaining your quality of life.

Explore the support services for low vision by scheduling an appointment with our team. Stay proactive in managing glaucoma and safeguarding your eye health.

Contact us today to learn more and take the first step towards a better vision.

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Explore our wide range of specialized services at Eye Associates of South Texas

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Routine Eye Care

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Explore our wide range of specialized services at Eye Associates of South Texas

From routine exams to advanced treatments, we’re committed to safeguarding your vision.

Routine Eye Care

Get a same-day eye exam with top-notch technology from premier board-certified doctors in South Texas. Simply fill out the form below, and one of our schedulers will contact you to confirm your appointment…

Macular Degeneration

Macular degeneration, often called age-related macular degeneration (AMD), is a prevalent condition among older adults. It is the foremost cause of vision loss and blindness in individuals above 65. This condition impacts the macula, the part of the retina responsible for sharp, detailed vision necessary for activities like reading or driving…

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