Primary congenital glaucoma: An iridotrabeculodysgenesis?

Area of Science:

• Ophthalmology
• Genetics
• Biomarkers

Background:

• Primary congenital glaucoma (PCG) is a severe developmental disorder affecting the anterior segment of the eye.
• Understanding the structural anomalies in PCG is crucial for predicting disease progression and treatment outcomes.

Purpose of the Study:

• To analyze anterior chamber and angle anomalies in PCG patients using anterior segment optical coherence tomography (ASOCT).
• To identify potential biomarkers for assessing PCG severity and prognosis.

Main Methods:

• A cross-sectional observational study involving PCG patients (age > 4) and age-matched controls.
• Anterior segment anomalies were analyzed using ASOCT (CASIA-2).
• Anterior iridotrabecular adhesions and iris insertion were quantified using the iridotrabecular contact (ITC) index.

Main Results:

• PCG eyes exhibited significantly increased anterior iridotrabecular adhesion, altered corneal and anterior chamber volumes, and reduced trabecular meshwork compared to controls.
• Anterior iridotrabecular adhesion positively correlated with central corneal thickness and iris thickness.
• Iris hypoplasia, characterized by fewer folds and absent collarette/pupillary ruff, was significantly different in PCG eyes.

Conclusions:

• ASOCT reveals variable anterior iridotrabecular adhesions, anomalous angle tissues, and iris hypoplasia in PCG eyes.
• These features correlate with pre-operative cup-disc ratio and can serve as clinical biomarkers for PCG severity and prognosis.
• PCG appears to be part of a broader anterior segment dysgenesis spectrum, not just isolated trabeculodysgenesis.