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Ophthalmology

Normal Tension Glaucoma

Normal-tension glaucoma is a characteristic glaucomatous optic neuropathy with intraocular pressures in the normal range. It is a common condition and can lead to bilateral blindness. Monitoring and treatment can reduce the risk of visual morbidity in most patients. This activity reviews the evaluation and management of normal-tension glaucoma and highlights the role of the interprofessional team in evaluating and treating patients with this condition. Objectives: Identify the risk factors for d

v1 · Reviewed Nov 7, 2026 by Automated Clinical Reviewer (Strict Verbatim v1)
  • Red flags include young age without a family history, rapid progression, unilateral disease, proptosis, associated neurological symptoms or signs, atypical disc findings, such as disc pallor without cupping, or field defects that respect the vertical midline.
  • NTG can progress to bilateral blindness in the worst cases, sometimes despite treatment.
  • The impact of NTG can range from non-progressive, asymptomatic disease to bilateral blindness.
  • Patients who present with advanced disease or rapidly progressing visual field loss are most likely to be blinded by the condition, and these so-called ‘rapid progressors’ should be identified and treated more aggressively.
  • Automated perimetry, particularly the Humphrey 24-2 visual field, is the most common algorithm for monitoring glaucoma, including NTG.
  • Alternatively, 10-2 fields (especially in advanced disease) and wide-field exams (30-2 and Estermann) can be employed.
  • SITA fast and faster algorithms shorten test duration, achieving similar accuracies.
  • Stereoscopic fundus photos of the optic nerve head at presentation provide a baseline comparison for future fundus examinations.
  • OCT technology has revolutionized the monitoring of glaucoma.
  • OCT helps determine a healthy optic nerve structure or document structural progression on serial scans.
  • Corneal pachymetry is used to measure the central corneal thickness (CCT).
  • Reduced CCT is associated with progression risk.
  • Thinner corneas are associated with the underestimation of intraocular pressure using applanation tonometry.
  • IOP phasing is repeated IOP measurements, measured throughout the day during office hours or at home over 24 hours with a home rebound tonometry device.
  • An alternative method to simulate labile IOP in the office is the water-drinking test.
  • Slit-lamp examination and gonioscopy are essential to determine an open iridocorneal angle status and exclude secondary glaucoma causes.
  • In particular, evidence of angle closure, uveitis, pigment dispersion, and pseudoexfoliation syndrome should be sought, as these are common causes of glaucoma presenting with an IOP in the normal range.
  • A dilated fundus examination revealed changes in the glaucomatous optic disc.
  • Measurement of the optic disc size can help identify hypoplasia, physiological disc cupping, and disc asymmetry.
  • Optic disc hemorrhages are more common in NTG than in POAG.
  • So-called Drance hemorrhages are typically small flame hemorrhages at the disc margin in superior or inferior quadrants.
  • Glaucomatous disc abnormalities typically precede visual field defects in early (preperimetric) disease.
  • A relative afferent pupillary defect is typical, though it may not be present in the early or symmetrical disease.
  • Color vision is usually preserved, except in advanced disease.
  • In the presence of these red flags, contrast-enhanced MRI of the anterior visual pathway is indicated to exclude compressive lesions.
  • Monitoring a patient without treatment is a suitable initial management strategy in many cases but requires discussion with the patient.
  • IOP lowering treatment should be instituted if there are confirmed progressive changes of the optic disc or visual field, and such progression is likely to lead to visual morbidity in their lifetime.
  • Treatment at diagnosis may also be recommended in eyes with moderate or advanced disease, paracentral visual field defects that threaten fixation, and those with multiple risk factors for blindness.
  • Prostaglandin analogs are a common first-line therapy.
Prostaglandin analogs
Not specified in source
Adult
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Renal
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Duration
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brimonidine
topical
Adult
Not specified in source
Renal
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Duration
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timolol
topical
Adult
Not specified in source
Renal
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Duration
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  • Adverse effects and costs of medical and surgical treatments should be weighed against the risk of visual loss.
  • NTG can masquerade as other optic neuropathies, and care should be taken to investigate other causes when indicated adequately.
  • The presumed benefit of escalating treatment should always be weighed against each patient's risks and side effects.
  • In eyes with continued progression or very low pressure (less than 12mmHg) requiring treatment, surgical management with augmented trabeculectomy is likely required to achieve optimal IOP lowering.
  • No IOP-independent treatments have been proven to alter disease progression; however, non-IOP risk factors are being investigated to understand better their role in the pathogenesis of NTG and their feasibility as interventions.
  • In patients with these risk factors or progressive disease despite IOP treatment, treatment could be considered.
  • A 24-hour blood pressure analysis and avoiding nighttime dosing of systemic anti-hypertensives can be considered.
  • Nicotinamide (vitamin B3) and ginkgo biloba are under investigation.
  • Screening questions for this disease can be asked to identify patients at risk.
  • Meditation – A randomized-controlled trial showed mindfulness meditation could lower IOP, reduce IOP fluctuation, and positively affect neuroprotective markers.
  • Cannabinoids – These have been shown to reduce IOP, but not in a clinically meaningful way.
  • Smoking – Smoking may be associated with both raised IOP and glaucoma.
  • Topical beta-blockers are relatively contraindicated in patients with asthma and COPD.
  • Carbonic anhydrase inhibitors should be used with caution in those with a history of sulfonamide allergy.
  • Alpha-agonists are contraindicated in young children.
  • Monitoring and treatment can reduce the risk of visual morbidity in most patients.
  • The presumed benefit of escalating treatment should always be weighed against each patient's risks and side effects.
  • Conjunctival hyperemia and ocular surface symptoms are the most common side effects seen with all classes of topical IOP-lowering medications.
  • Side effects of prostaglandin analogs include hypertrichosis and changes in iris pigmentation.
  • Prostaglandin-associated periorbitopathy is an important complication of long-term prostaglandin analog use.
  • This includes orbital fat atrophy, ptosis, chronic inflammation of the eyelids, and skin discoloration.
  • It is seen most commonly with bimatoprost.
  • In addition, filtration surgery may have lower success rates in these patients.
  • Additional systemic side effects include cardiovascular effects, vivid dreams, erectile dysfunction, and mood changes.
  • Complications from SLT are rare but may include intraocular inflammation or an IOP spike after treatment.
  • Glaucoma surgery complications include failure, hypotony, cataracts, phlebitis, tube erosion, endophthalmitis, and corneal decompensation.
  • Morbidity from vision loss in NTG can be significant and lead to difficulty with activities of daily living (ADL).
  • Tasks that involve visual searching are commonly affected, and fall risk increases.
  • Paracentral defects are more common in NTG, so there is a higher risk of developing a central defect on binocular visual field testing.
  • In many countries, licensing rules would exclude them from driving.
  • review
    Normal Tension Glaucoma. StatPearls [Internet] — Daniel Gosling, Jay J. Meyer — StatPearls Publishing, 2022

Decision support only. Verify against local protocols and current labeling. Source: www.ncbi.nlm.nih.gov