Eye tension is a chronic disease in which intraocular pressure (IOP) goes out of balance and constantly puts pressure on the optic nerve, initially progressing silently but can lead to permanent blindness if not diagnosed early. When the fluid constantly produced in the eye is not sufficiently drained from the trabecular meshwork, the internal pressure slowly increases; this increase narrows the field of vision, especially starting from the outer directions. Those with a family history of glaucoma, those over the age of fifty, those with diseases that affect vascular health such as diabetes and hypertension, and those who have used cortisone for a long time are in the risk group for this insidious condition, which can be detected in the early stages even with a simple tonometer measurement.
Glaucoma is not just about “high blood pressure”; it has subtypes such as normal tension glaucoma, which can cause damage to the optic nerve even when it is within normal pressure values, and closed-angle glaucoma, which suddenly blocks the drainage angle of the iris root and requires urgent intervention. Whether it progresses silently or stormily, once the nerve fibers are damaged, the loss cannot be restored; Therefore, eye fundus examination, OCT examination and visual field test performed at least once a year are the most effective defenses in stopping the progression of the disease.
Treatment of glaucoma focuses on lowering intraocular pressure and progresses in a stepwise manner. Initially, daily drops containing prostaglandin analogs, beta blockers or carbonic anhydrase inhibitors reduce the fluid produced or increase drainage. Combination drops ease the medication burden of patients while facilitating the target pressure. In cases where pressure cannot be controlled with medication, selective laser trabeculoplasty increases the permeability of the trabecular meshwork in seconds; in cases where the iris root closes the angle, laser peripheral iridotomy eliminates the risk of sudden crisis by opening an alternative path for the fluid.
What is Glaucoma?
Glaucoma, medically known as glaucoma, describes the increase in pressure that occurs when the drainage of the aqueous humor fluid that is constantly produced and circulating in the eye slows down. Normally, intraocular pressure remains between 10–21 mmHg; microscopic channels called trabecular meshwork transfer this fluid to the bloodstream. When the channels are blocked or fluid production is excessive, the pressure increases, the eyeball stretches like a “balloon” and constantly presses on the optic nerve. This pressure reduces the blood flow to the capillaries that feed the nerve fibers; the fibers that are not fed are irreversibly damaged.
The most insidious aspect of glaucoma is that it narrows the peripheral (side) field of vision without any symptoms in the early stages. The patient usually does not notice until central acuity is affected; at this stage, most of the nerve damage is permanent. Regular intraocular pressure measurement, optic nerve head examination and visual field testing are the most reliable ways to catch this “silent thief” before vision loss begins. Pressure-reducing drops, laser or surgical treatments initiated with early diagnosis protect the remaining nerve fibers and stop the progression of the disease.
What Causes Eye Pressure (Glaucoma)?
Eye pressure occurs when the delicate balance between the production and drainage of intraocular fluid (aqueous humor) is disrupted. Normally, the fluid is produced in the ciliary body and passes into the bloodstream through microscopic channels called the trabecular meshwork, keeping the intraocular pressure between 10–21 mmHg. If these channels become blocked, narrowed, or fluid production increases, the pressure increases; the increased pressure puts pressure on the optic nerve and leads to irreversible fiber loss over time.
The most common cause of eye pressure is the loss of elasticity of the trabecular meshwork with age and the decrease in the “filter” speed of the fluid passing through it. In addition:
Genetic predisposition: In individuals with a family history of glaucoma, the drainage angle may be narrower at birth or the meshwork structure may be more impermeable.
Ocular trauma: Blows to the eye disrupt the meshwork structure, paving the way for a silent increase in pressure.
Long-term cortisone use: Chronic use of steroid drops, tablets or inhalers can cause protein accumulation and increased resistance in the canals.
Systemic diseases: Diabetes, hypertension, sleep apnea and thyroid disorders reduce intraocular blood flow, making nerve fibers more sensitive to pressure.
Structural features of the eye: In high myopia or hyperopia, anatomical differences in the eyeball can cause the drainage angle to narrow.
Sudden iris block: In closed-angle glaucoma, the iris root blocks the drainage angle like a “plug”; the fluid cannot drain and the pressure skyrockets within hours, causing severe pain, nausea and rapid vision loss.
When one or more of these factors are present, the intraocular fluid cannot drain sufficiently and eye pressure increases. Measuring the pressure with regular eye examinations, evaluating the structure of the trabecular meshwork and keeping risk factors under control is the most reliable way to stop the insidious progression of glaucoma.
Types of Glaucoma
Open-Angle Glaucoma: Progresses slowly; narrowing of the trabecular meshwork causes the pressure to silently rise.
Closed Angle Glaucoma: The iris root suddenly closes the drainage angle; severe pain, nausea and blurred vision occur, urgent treatment is required.
Normal Tension Glaucoma: Although the pressure remains within the normal range, the optic nerve is damaged due to low blood flow; blood pressure measurement alone does not provide sufficient diagnosis.
Congenital Glaucoma: The drainage channels are not developed at birth; the baby is not able to look at light, has watery eyes and a large cornea.
Secondary Glaucoma: Develops after diseases such as uveitis, eye trauma, long-term steroid use or diabetes.
Risk Factors
• Having a family history of glaucoma
• Being 50 years of age or older
• High myopia or hyperopia
• Diabetes, hypertension, sleep apnea syndrome
• Long-term cortisone treatment
• Having an eye trauma
Everyone in the risk group should have their eyes measured at least once a year.
Eye Pressure Symptoms
• Noticing a gradual narrowing of the outer edges of the visual field
• Seeing colored rings of light in the dark or when looking at bright headlights
• Feeling dull pressure and mild headache around the eyes when waking up in the morning
• Skipping lines while reading or noticing objects coming from the sides late
• Severe eye and forehead pain, nausea, blurred vision in sudden closed angle attacks
• Weakening of the perception of stairs or steps in dim light
• Extreme dazzling of oncoming headlights while driving at night
• In the advanced stage, even if clarity in central vision continues, side vision remains in the form of a “tunnel”
Eye Pressure Diagnosis
The diagnosis of eye pressure is not just a simple pressure measurement with a tonometer; damage to the optic nerve may begin even if the pressure value remains within normal limits. Therefore, the diagnosis consists of five basic stages that complement each other.
In the first step, intraocular pressure is measured with a flat or “applanation” tonometer. If the value is above 21 mmHg, glaucoma is suspected; However, since nerve damage can also be seen in patients below this limit, the measurement alone is not sufficient. Gonioscopy, which evaluates the eye angle, is performed immediately afterwards; the doctor determines whether the iris is open or closed by viewing the drainage channel with a special prismatic lens. If the angle is open but the pressure is high, the diagnosis of “open-angle glaucoma” is strengthened, and if the angle is closed, the diagnosis of “closed-angle glaucoma” is strengthened.
In the third stage, the optic nerve head is examined under a biomicroscope. An increased cup/cup ratio is an early warning that the nerve fibers are thinning. Optical coherence tomography (OCT) is taken to perform the examination with submillimeter sensitivity; this imaging measures the thickness of the retinal nerve fiber layer and forms a reference before treatment.
In the fourth stage, a visual field test is performed. Even the smallest losses in peripheral vision are reflected on the screen and a map is created. This test is an indispensable part of the diagnosis, as it can show the decrease in nerve function even in patients who initially appear completely normal.
Finally, pachymetry, which measures the thickness of the cornea, is performed. The thin cornea underestimates the pressure; This value is taken into account for the correct interpretation of the real intraocular pressure, as the thick cornea may show it as high. When all this data is brought together, a diagnosis of “glaucoma risk”, “early glaucoma” or “advanced glaucoma” is made and a personalized treatment schedule is created.
Eye Pressure Treatment
Eye pressure treatment basically aims to protect the optic nerve by reducing intraocular pressure to the target range, and in most patients, the first step is eye drop treatment. While prostaglandin analogs dilate the drainage channels, beta blockers and carbonic anhydrase inhibitors reduce fluid production; thus, eye pressure treatment begins with daily, regular drop use. Applying the medication at the same time every day prevents pressure fluctuations, thus slowing down optic nerve loss.
When eye pressure treatment cannot provide sufficient reduction with medications, modern laser methods are used. Selective laser trabeculoplasty can keep the pressure under control for a long time by increasing the permeability of the trabecular meshwork in seconds. In eyes with a high risk of closure, peripheral iridotomy minimizes the possibility of sudden crisis thanks to the micro window opened in the iris. At this stage, eye pressure treatment can reduce the number of drops with the relief provided by the laser, but it requires regular check-ups of the patient.
Surgical options may be needed for treatment if the pressure is still high or the field of vision narrows rapidly. Small gates or micro stent implants created on the surface of the eye with trabeculectomy protect the nerve fibers by allowing the fluid to drain out permanently. Protective drops and a frequent examination program are put into effect after glaucoma treatment to ensure the continuity of surgical success; otherwise, scar tissue formation can narrow the drainage path again.
Treatment is not limited to medical interventions alone; regular exercise, smoking and caffeine restriction, salt reduction and a diet rich in omega-3 also support nerve nutrition. Avoiding yoga poses where the head is held below the level of the heart for long periods, keeping the head upright during screen breaks and not skipping doctor appointments are also integral parts of treatment. If such a multifaceted approach is adopted, glaucoma treatment can stop the progression of the disease and significantly reduce the risk of permanent blindness.
Lifestyle and Preventive Recommendations
• Walking at a moderate pace five days a week increases circulation.
• Avoiding smoking and excessive caffeine protects vascular health.
• Keeping the head slightly above the level of the heart during screen breaks limits pressure fluctuations.
• Restricting salt intake improves nerve nutrition by balancing systemic blood pressure.
• Using polarized glasses that reduce light reflections increases visual comfort.
These simple steps, along with medication, support nerve fibers.