Management of a Patient with Intraocular Pressure of 17.3 mmHg
For a patient with an intraocular pressure of 17.3 mmHg without other risk factors, observation rather than treatment is recommended as this IOP falls within normal range. 1
Understanding Normal IOP Values
An intraocular pressure of 17.3 mmHg is considered within the normal range:
- Normal IOP in healthy young adults is approximately 12 ± 2 mmHg, increasing by about 1 mmHg per decade after age 40 2
- Values between 7 and 21 mmHg are generally considered normal 2
- The specific value of 17.3 mmHg falls well within this normal range
Assessment Algorithm for Glaucoma Suspect Management
Step 1: Determine if the patient is a glaucoma suspect
A patient with IOP of 17.3 mmHg may be considered a glaucoma suspect if they have:
- Optic nerve abnormalities suggestive of glaucoma
- Visual field defects consistent with glaucoma
- Strong risk factors for developing glaucoma
Step 2: Evaluate for additional risk factors
If any of the following risk factors are present, closer monitoring or potential treatment may be warranted:
- Older age
- Family history of glaucoma
- African-derived race or Latino/Hispanic ethnicity
- Thin central cornea (< 555 μm)
- Large cup-to-disc ratio
- Disc hemorrhage
- Low ocular perfusion pressure
- Diabetes mellitus
- Myopia 3
Step 3: Management decision based on risk assessment
For patients with IOP of 17.3 mmHg WITHOUT significant risk factors:
- Regular monitoring without treatment is appropriate
- Schedule follow-up examinations to monitor:
- IOP measurements
- Optic disc and retinal nerve fiber layer (RNFL) evaluation
- Visual field testing 3
For patients with IOP of 17.3 mmHg WITH significant risk factors:
- Consider more frequent monitoring
- Treatment generally not indicated unless there are multiple significant risk factors or evidence of progression 3, 1
Evidence Supporting Observation vs. Treatment
The decision to observe rather than treat is supported by strong evidence:
- The Ocular Hypertension Treatment Study (OHTS) showed that 90-95% of patients with ocular hypertension did not progress to glaucoma over 5 years 3
- Treatment is typically considered for patients with higher IOP (≥ 26 mmHg) combined with risk factors like thin central cornea (≤ 555 μm) 3
- Patients with IOP < 24 mmHg and CCT > 588 μm had only a 2% risk of developing optic nerve damage during long-term follow-up 3
Monitoring Recommendations
For a patient with IOP of 17.3 mmHg:
- Schedule regular follow-up examinations (typically every 6-12 months)
- Monitor for:
- Changes in IOP
- Changes in optic disc appearance and RNFL
- Development of visual field defects 3
- Consider baseline imaging of the optic nerve and RNFL for future comparison
When to Consider Treatment
Treatment should be initiated if:
- Evidence of optic nerve deterioration develops
- Visual field defects consistent with glaucoma appear
- IOP increases significantly over time
- Multiple high-risk factors are present 3, 1
Treatment Options (if needed in the future)
If treatment becomes necessary, options include:
Medical therapy:
Laser therapy:
- Selective laser trabeculoplasty (SLT) can be considered as primary therapy 1
Important Considerations
- IOP fluctuates throughout the day and can be influenced by body position, exercise, breath-holding, and dietary habits 5, 6
- A single IOP measurement may not provide sufficient information for effective management 5, 6
- Goldmann applanation tonometry remains the gold standard for IOP measurement, though it can be influenced by corneal parameters 7
- The relationship between IOP and glaucoma risk continues to evolve with improved understanding and monitoring technologies 6, 8
Remember that while IOP is an important risk factor for glaucoma, glaucoma can develop and progress even within the normal IOP range, highlighting the importance of comprehensive evaluation beyond just IOP measurement 5.