What goes wrong
Fluid produced behind the iris flows through the pupil and drains through the trabecular meshwork at the angle. In open-angle glaucoma the angle is anatomically open but the meshwork resists outflow, from age-related change and, in some patients, genetic factors. Pressure rises gradually, often only slightly above normal, and over years compresses and starves the optic nerve fibers at the back of the eye. In normal-tension glaucoma the same damage occurs at pressures in the normal range, which is why the nerve, not the pressure, defines the disease.
Why there are no symptoms
Nerve fibers are lost from the periphery inward, and the brain fills in the missing areas, so a patient can lose a large fraction of the visual field while reading and driving normally. By the time vision seems affected, damage is advanced. This is the argument for routine glaucoma checks after 40 and for taking a family history seriously.
Diagnosis
The glaucoma evaluation: pressure, corneal thickness, gonioscopy confirming an open angle, OCT of the nerve fiber layer, visual field testing and examination of the optic nerve. Diagnosis usually rests on structural loss on OCT with a matching field defect. Borderline findings are followed as a glaucoma suspect with repeat testing until the picture is clear.
Treatment
- Eye drops that reduce fluid production or increase outflow, used once or twice daily for life; prostaglandin analogs are the usual first choice
- Selective laser trabeculoplasty, an office laser to the meshwork that improves drainage, now accepted as an equal first-line treatment and repeatable
- Minimally invasive glaucoma surgery (small stents or procedures often performed during cataract surgery) for mild to moderate disease
- Filtration surgery or drainage tubes for advanced or uncontrolled disease, arranged with a glaucoma subspecialist
A target pressure is set from the stage of damage, and treatment is escalated until the nerve and field are stable at that pressure.
Living with open-angle glaucoma
Treatment works only if it is used: missed drops are the most common reason glaucoma progresses, which is why laser is often preferred for patients who struggle with them. Monitoring every four to twelve months with OCT and fields continues for life. Relatives should be checked. With consistent treatment, most patients keep good vision indefinitely.
Is this right for your eyes?
Nothing on this page is a diagnosis. Whether this is what is affecting your vision is decided by a full examination at one of our 4 offices: Pasadena, Huntington Beach, Woodland Hills and Beverly Hills.
About this content: This page was written with the assistance of AI tools and reviewed for medical accuracy by Dr. Bavand Youssefzadeh, DO. It is general information, not medical advice, and does not replace an eye examination. Individual results vary. Read our medical disclaimer.
