Longitudinal Assessment of Large Optic Discs in Children and Adults Using Spectral Domain Optical Coherence Tomography

Objectives: Children with large optic discs are frequently referred to as glaucoma suspects. The aim of this study was to longitudinally analyze and compare the peripapillary retinal nerve fiber layer (pRNFL) thickness and minimum rim width (BMO-MRW) of large optic discs in children (LOD-C), normal sized optic discs in children (NOD-C) and large optic discs in adults (LOD-A) in order to evaluate longitudinal structural stability and intergroup differences in optic nerve head morphology. Methods: Briefly, 85 LOD-C, 72 NOD-C and 78 LOD-A were included. Large optic discs were identified based on a Bruch’s membrane opening (BMO) area threshold of ≥2.5 mm2. pRNFL thickness and minimal rim width (BMO-MRW) of optical coherence tomography (OCT) were compared between baseline and follow-up examination at a median of 1.4 [1.0; 2.5] years. Results: Mean global pRNFL thickness and BMO-MRW did not significantly change during the follow-up period. LOD-C showed a significant increase in pRNFL thickness in the superonasal segments, NOD-C in the nasal segments. pRNFL and BMO-MRW of LOD-A decreased during the follow-up period. However, there was a higher variance of pRNFL thickness change in LOD-C as compared with NOD-C in the superotemporal and inferonasal segments. Four optic discs in the LOD-A group showed a glaucomatous conversion, whereas none of the discs of LOD-C or NOD-C progressed to glaucoma. Conclusions: Children with large optic discs presented with stable pRNFL and BMO-MRW and without clinical progression to glaucoma at follow-up. A careful interpretation of the OCT measurement results is necessary when assessing pediatric large optic discs, as growth and remodelling may impair the accuracy of segmentation and automated classification algorithms.