New Threshold for Large Optic Discs in Children Using Bruch's Membrane Opening Area

Area of Science:

• Ophthalmology
• Pediatric Ophthalmology
• Glaucoma Research

Background:

• Optic disc size can influence measurements of the peripapillary retinal nerve fiber layer (pRNFL) and Bruch's membrane opening minimal rim width (BMO-MRW).
• Understanding these influences is crucial for accurate glaucoma diagnosis, especially in pediatric populations.

Purpose of the Study:

• To compare pRNFL thickness in children with large optic discs (LOD-C) against children with normal-sized optic discs (NOD-C) and adults with large optic discs (LOD-A).

Main Methods:

• Included 127 eyes per group (n=381).
• Defined large optic discs by Bruch's membrane opening (BMO) area ≥2.5 mm².
• Compared pRNFL thickness and BMO-MRW between pediatric and adult large optic disc groups.

Main Results:

• Mean global pRNFL thickness was significantly thicker in LOD-C (100.2 ± 12.1 µm) than NOD-C (95.9 ± 11.7 µm).
• Mean global BMO-MRW was significantly thinner in LOD-C (280.0 ± 41.1 µm) compared to NOD-C (320.7 ± 10.5 µm) and LOD-A (252.9 ± 45.8 µm).
• Found positive correlation between pRNFL and BMO area, and negative correlation between BMO-MRW and BMO area, with stronger associations at specific BMO area thresholds.

Conclusions:

• RNFL and BMO-MRW in pediatric optic discs with BMO area <1.9 mm² and >2.8 mm² require cautious interpretation due to strong influence of optic disc size.
• Novel thresholds for pediatric large optic discs can aid in accounting for disc size effects on RNFL and MRW, improving glaucoma diagnosis in children.