Intraocular pressure (IOP) measures the fluid pressure inside the eye. A reading of 23 millimeters of mercury (mmHg) falls outside the typical healthy range of 10 to 21 mmHg. While 23 mmHg is not automatically indicative of permanent damage, it is considered medically elevated and warrants immediate investigation by an eye care professional. This sustained elevation significantly increases the risk of developing a serious condition that can harm vision over time.
Understanding Elevated Eye Pressure
IOP is governed by the aqueous humor, a clear fluid produced by the ciliary body. This fluid circulates to nourish internal structures before draining out through the trabecular meshwork. A reading of 23 mmHg is classified as elevated because it surpasses the upper limit of the normal range, established at 21 mmHg. Elevated pressure occurs when the aqueous humor is produced faster than it can be drained, or if the drainage system is obstructed.
Ocular Hypertension
The condition where IOP is consistently measured above 21 mmHg without detectable damage to the optic nerve or visual field loss is termed Ocular Hypertension. The pressure reading is obtained using a non-invasive instrument called a tonometer. This measurement reflects the current mechanical force exerted on the eye’s internal structures. The presence of Ocular Hypertension indicates the eye is under abnormal stress, generating concern regarding potential future complications.
Ocular Hypertension and Glaucoma Risk
The primary concern with sustained Ocular Hypertension is its potential progression to Glaucoma. Glaucoma is characterized by progressive, irreversible damage to the optic nerve, resulting in permanent vision loss. Ocular Hypertension is defined solely by the high pressure reading, while Glaucoma is diagnosed when that pressure has caused physical deterioration of the optic nerve fibers. A reading of 23 mmHg places an individual in a higher risk category for this progression.
Risk Factors
While not everyone with Ocular Hypertension develops Glaucoma, elevated pressure is the most significant modifiable risk factor. Professionals determine a personalized “target pressure” to prevent or slow down future optic nerve damage. For a reading of 23 mmHg, the target pressure is usually lower, often in the mid-to-high teens.
Several other factors increase the likelihood of progression from Ocular Hypertension to Glaucoma. These conditions can compromise the vascular supply to the optic nerve, making it more vulnerable to pressure damage.
- A strong family history of Glaucoma.
- African or Hispanic descent, which is associated with a higher incidence and more aggressive disease progression.
- Advanced age, as the prevalence of Glaucoma increases significantly after age 60.
- Underlying health conditions, such as diabetes, high blood pressure, or severe myopia (nearsightedness).
Next Steps in Diagnosis and Monitoring
An elevated pressure reading of 23 mmHg necessitates a comprehensive series of diagnostic tests to determine if the optic nerve has sustained damage.
Diagnostic Procedures
The first diagnostic step is pachymetry, which measures corneal thickness. A thick cornea can artificially inflate the tonometer reading, making the true IOP lower than 23 mmHg.
A visual field test maps the patient’s peripheral vision to detect vision loss. Glaucoma typically attacks peripheral vision first, creating blind spots. This test provides functional evidence of whether the elevated pressure has begun to affect sight.
A structural examination of the optic nerve head often uses advanced imaging like Optical Coherence Tomography (OCT). The OCT scan measures the thickness of the retinal nerve fiber layer (RNFL). This layer thins out when Glaucoma damage occurs, providing objective, measurable evidence of the disease’s presence.
These procedures determine whether the patient has Ocular Hypertension requiring monitoring or established Glaucoma requiring intervention. The results of these tests, not the pressure number alone, guide subsequent management decisions.
Management Strategies for Elevated IOP
Management of 23 mmHg depends entirely on the results of diagnostic testing. If tests show a healthy, undamaged optic nerve and few risk factors, the professional may recommend observation, or “watchful waiting.” This requires frequent, scheduled follow-up appointments to monitor pressure and repeat diagnostic tests periodically.
If tests reveal subtle signs of optic nerve deterioration or if the patient has numerous risk factors, medical management to lower the pressure is initiated. The standard first-line treatment involves prescription eye drops, such as prostaglandin analogs. These drops increase the outflow of aqueous humor and are highly effective at reducing IOP, aiming for the predetermined target pressure.
Supportive measures are also recommended, including regular aerobic exercise, which can temporarily reduce IOP. Maintaining a healthy weight and avoiding large, rapid fluid intakes may also support pressure regulation. The goal is to reduce pressure sufficiently to halt further progression of nerve damage and preserve vision.