Clinical Report: Importance of Diurnal IOP Fluctuations in Glaucoma Management

Overview

Single office intraocular pressure (IOP) measurements may underestimate true pressure fluctuations, potentially leading to overtreatment in glaucoma patients. Considering diurnal IOP variability alongside mean IOP can improve risk assessment and guide more balanced therapeutic decisions.

Background

Glaucoma management traditionally relies on single IOP readings obtained during office visits to guide treatment intensity. However, IOP naturally fluctuates throughout the day, and these variations may not be captured by isolated measurements. Overly aggressive IOP lowering, especially targeting single-digit pressures, can increase the risk of complications without clear benefit, particularly in patients with stable or slowly progressing disease. Understanding the role of IOP variability and patient adherence is critical to optimizing long-term outcomes.

Data Highlights

Key Findings

• Single office IOP readings often underestimate true 24-hour IOP, with diurnal fluctuations averaging 3 mmHg higher in some patients.
• Relying solely on office measurements may prompt unnecessarily aggressive treatment aiming for IOPs below 10 mmHg.
• Lowering IOP to single-digit levels can increase surgical risks and complications, especially in patients with limited life expectancy or slow disease progression.
• Reducing IOP variability may be as important as lowering mean IOP in preventing glaucoma progression.
• Postoperative patients may maintain similar mean IOP but benefit from reduced variability, potentially lowering progression risk.
• Clinicians should evaluate whether apparent progression at low office-measured IOPs reflects true pressure control or undetected spikes.

Clinical Implications

Clinicians should incorporate diurnal IOP fluctuations into glaucoma risk assessments rather than relying on single office measurements. Treatment goals should balance the benefits of IOP lowering against the risks of overtreatment, particularly avoiding overly aggressive targets in stable patients. Monitoring and reducing IOP variability may offer an additional strategy to slow disease progression.

Conclusion

Accounting for diurnal IOP fluctuations and patient-specific factors can improve glaucoma management by preventing overtreatment and minimizing complications. A more comprehensive approach to IOP monitoring may enhance long-term patient outcomes.

References

1. Sheybani A, 2025 AAO Meeting -- Role of IOP Fluctuation and Ocular Pulse Amplitude in Glaucoma Progression