Iris Insertion and Trabecular Meshwork Composition in Primary Congenital Glaucoma and Normal Eyes using Anterior Segment OCT.

Purpose

To quantify iridocorneal angle morphology in pediatric eyes with primary congenital glaucoma (PCG) compared to normal controls using overhead-mounted anterior segment optical coherence tomography (AS-OCT), including iris insertion and trabecular meshwork (TM) intensity.

Design

Prospective, cross-sectional, masked observational study.

Participants

Eyes of children <5 years old with PCG and normal controls undergoing examination under anesthesia (EUA).

Methods

Nasal and temporal angles were imaged using AS-OCT.A masked ophthalmologist analyzed images using Matlab and ImageJ. Clinical data were collected. MAIN OUTCOME MEASURES Iris insertion (distance from scleral spur to iris plane), normalized TM intensity, and TM homogeneity.

Results

49 patients (86 eyes: 33 PCG; 53 normal) from one center were imaged (01/2023-02/2026). Mean age was younger (9.2±9.1 vs. 15.9±11.0 months, p=0.003), and mean intraocular pressure (IOP) higher (29.8±8.1 vs. 12.9±4.9 mmHg, p<0.001), in PCG vs. controls, respectively. Iris insertion was more anterior in PCG eyes vs. controls (80.6±85.0 vs. 143.7±68.8 μm, p<0.001). Iris insertion did not correlate with IOP in PCG (p=0.30) or controls (p=0.33). Iris insertion also showed no significant association with age. Normalized TM intensity did not differ significantly between PCG and controls (0.59±0.17 vs. 0.58±0.19, p=0.70), but decreased with age.

Conclusions

In our cohort, AS-OCT imaging demonstrated a more anterior iris insertion in PCG eyes compared to controls, independent of IOP and age, confirming structural alteration of the anterior chamber angle. These findings may help guide further studies on the relationship between angle morphology and glaucoma phenotype.