Polarimetric nerve fiber analysis in patients with peripapillary myelinated retinal nerve fibers

Purpose: The aim of this study was to compare the RNFL thickness in eyes wi th myelinated retinal nerve fibers (MRNF) and age, sex-matched controls usi ng scanning laser polarimetry. Methods: Seventeen patients with MRNF underwent a comprehensive ophthalmolo gical examination including automated visual field testing, and scanning la ser polarimetry with Nerve Fiber Analyser (NFA II). Twenty eyes with MRNF f rom 17 patients were available for the study. Sixteen healthy, age and sex- matched subjects were taken as controls. Retinal nerve fiber thickness meas urements of the four sectors (superior, inferior, nasal, temporal) and alon g the whole circumference of the optic disc were obtained for affected and control eyes, and compared. Results: Inferior average and inferior integral parameters of the NFA revea led significantly thinner RNFL thickness measurements in eyes with inferior ly located MRNF compared to controls. Conclusion: Retinal myelination alters the birefringent property of the RNF L, and results in diminished thickness measurements. Hence, NFA measurement s in patients with MRNF may not be reliable.