Purpose:
To report the onset and progression of retinal nerve fiber layer myelination (RNFM) in two young children with an associated finding of optic nerve head drusen.
Methods:
A 7 year-old male (Case 1) and a 9 year-old female (Case 2) presented for routine ophthalmic care in two different practices and were followed 7 years and 4 years later, respectively. The 7 year-old had a family history of optic disc drusen.
Results:
Case 1: Visual acuities were 20/20 in each eye at both visits. At the initial examination, the 7-year old was found to have peripapillary RNFM of the left eye only. When he was re-examined 7 years later, the myelination of the left eye had increased and there was new peripapillary myelination in the right eye. B-scan ultrasound was performed to rule out optic disc edema but instead revealed bilateral optic disc drusen. Automated perimetry revealed a full visual field in the right eye and an enlarged blind spot in the left eye with a mild, inferior arcuate scotoma in the left eye. Case 2: Visual acuities were 20/20 in each eye at both visits. At the initial examination, no abnormalities were noted in either eye. At the follow-up examination 4 years later, the optic nerve heads in both eyes were remarkable for blurred nasal borders. There was an onset of superior peripapillary RNFM off the optic nerve head of both eyes, greater in the right eye (Image). An SD-OCT of the optic nerve heads was commensurate with optic disc drusen. Visual fields were full in both eyes. Fluorescein angiography did not reveal any leakage from either disc. An MRI of the brain and orbits was normal.
Conclusions:
Acquired and progressive peripapillary RNFM can be associated with optic nerve head drusen. It is hypothesized that in some cases, an increase in disc drusen may disrupt the lamina cribrosa and thereby break the chemical barrier which would normally inhibit oligodendrocytes, resulting in myelination moving forward.
Keywords: drusen • optic disc • nerve fiber layer