Work

Combined structural and functional assessment of the ophthalmic trigeminal pathway in healthy adults: a feasibility study with preliminary reference data

Year: 2026

Type: article

Abstract: Background Structural and functional evaluation of the ophthalmic division (V1) of the trigeminal nerve lacks standardised approaches integrating high-resolution anatomical imaging with complementary neurophysiological testing.Objectives To evaluate the feasibility of a multimodal assessment of the ophthalmic trigeminal pathway using high-resolution non-contrast MRI, blink reflex testing (BRT) and Quantitative Cutaneous Sensory Testing (QEST) and to report preliminary descriptive anatomical, neurophysiological and cutaneous sensory measurements in healthy adults.Methods In this prospective observational study, 20 healthy volunteers (11 males and 9 females; mean age 32 years) underwent 3-T MRI, BRT and QEST. MRI included three-dimensional isotropic T1-weighted sequences for morphometric assessment of the left frontal and supraorbital nerves. Blink reflex latencies and QEST thresholds were assessed bilaterally.Results Frontal and supraorbital nerves were visualised in all subjects. Mean frontal nerve calibre was 0.160 cm×0.160 cm; proximal and distal supraorbital segments measured 0.148 cm×0.135 cm and 0.140 cm×0.114 cm, respectively. All blink reflex responses were present. R2 latencies were strongly correlated between sides, and the mean absolute inter-side differences were 0.63 ms for R1, 2.03 ms for ipsilateral R2 and 1.17 ms for contralateral R2. QEST thresholds demonstrated no significant lateral differences.Conclusions This study supports the feasibility of a combined MRI–blink reflex–QEST protocol and provides preliminary descriptive measurements of complementary structural, reflex and cutaneous sensory domains of the ophthalmic trigeminal pathway. Larger, age-diverse cohorts and prospective clinical validation are required before these measurements can be used as normative intervals or for clinical decision-making.

Source: BMJ Open Ophthalmology

DOI: 10.1136/bmjophth-2026-002871