Natural Course and Risk Factors of Glaucoma Development in the Untreated Fellow Eye in Unilateral Normal-Tension...

Area of Science:

• Ophthalmology
• Glaucoma Research
• Intraocular Pressure Studies

Background:

• Normal-tension glaucoma (NTG) affects individuals without elevated intraocular pressure (IOP).
• Unilateral NTG presents a unique challenge in predicting disease progression in the contralateral eye.
• Understanding factors influencing fellow eye development is crucial for early intervention.

Purpose of the Study:

• To determine if intraocular pressure (IOP) levels in the untreated fellow eye impact glaucoma development in patients with unilateral normal-tension glaucoma (NTG).
• To identify the association between longitudinal IOP profiles and the incidence of NTG in the fellow eye.

Main Methods:

• A long-term observational study followed 194 patients newly diagnosed with unilateral NTG for over 8 years.
• More than five intraocular pressure (IOP) measurements were recorded per patient during follow-up.
• Kaplan-Meier survival and multivariate Cox regression analyses were employed to assess risk factors.

Main Results:

• Glaucoma developed in the untreated fellow eye of 24.7% of patients within a mean of 5.2 years.
• Patients who developed fellow eye NTG had significantly higher baseline and follow-up IOPs in both eyes.
• An average follow-up IOP of ≥14 mm Hg in the fellow eye was associated with a 3.6-fold increased risk of glaucoma development (P=0.004).

Conclusions:

• A significant proportion of patients with unilateral NTG develop glaucoma in the untreated fellow eye.
• Elevated untreated intraocular pressure in the fellow eye is a significant risk factor for NTG development.
• An average follow-up IOP of 14 mm Hg or higher in the fellow eye indicates a substantially increased risk of developing normal-tension glaucoma.