Faculty Bibliography

OBJECTIVE:Familial Dysautonomia (FD) disease, lacks a useful biomarker for clinical monitoring. In this longitudinal study we characterized the structural changes in the macula, peripapillary and the optic nerve head (ONH) regions in subjects with FD. METHODS:Data was consecutively collected from subjects attending the FD clinic between 2012 and 2019. All subjects were imaged with spectral-domain Optical Coherence Tomography (OCT). Global and sectoral measurements of mean retinal nerve fiber layer (RNFL) and macular ganglion cell and inner plexiform layer (GCIPL) thickness, and ONH parameters of rim area, average cup-to-disc (C:D) ratio, and cup volume were used for the analysis. The best fit models (linear, quadratic and broken stick linear model) were used to describe the longitudinal change in each of the parameters. RESULTS:91 subjects (149 eyes) with FD of ages 5-56 years were included in the analysis. The rate of change for average RNFL and average GCIPL thicknesses were significant before reaching a plateau at the age of 26.2 for RNFL and 24.8 for GCIPL (- 0.861 µm/year (95% CI - 1.026, - 0.693) and - 0.553 µm/year (95% CI - 0.645, - 0.461), respectively). Significant linear rate of progression was noted for all ONH parameters, except for a subset of subjects (24%), with no cupping that did not show progression in any of the ONH parameters. CONCLUSIONS:The rapidly declining RNFL and GCIPL can explain the progressive visual impairment previously reported in these subjects. Among all structural parameters, ONH parameters might be most suitable for longitudinal follow-up, in eyes with a measurable cup.

Retinopathy of prematurity (ROP) is a biphasic disease in which the first phase is characterized by high oxygen tension leading to vaso-obliteration in the retina. Pearson syndrome is a rare multisystem mitochondrial disease with a defect in cellular respiration. The authors describe a patient with Pearson syndrome and delayed onset of ROP at a postconceptual age of 42 weeks. The proposed mechanistic theory was the increased oxygen use associated with the metabolic impairments in Pearson syndrome counterbalancing the effects of supplemental oxygen during the vaso-obliterative stage of ROP. [J Pediatr Ophthalmol Strabismus. 2019;56:e60-e64.].

PURPOSE/OBJECTIVE:To describe the rapid time course of visual and electroretinographic recovery from vitamin A deficiency in a patient with a history of multiple resected abdominal tumors, including ileal carcinoid and pancreatic adenocarcinoma. METHODS:A 61-year-old white man with a history of resected malignant ileal carcinoid and Stage III pancreatic adenocarcinoma referred with complaints of 6 weeks of difficulty with night vision. RESULTS:Initial testing showed significantly reduced scotopic rod responses in both eyes and decreased vitamin A levels and a normal cancer-associated retinopathy laboratory panel. He had complete recovery of both his symptoms and full-field electroretinography within 5 days of starting intramuscular vitamin A. CONCLUSION/CONCLUSIONS:Vitamin A deficiency-related retinopathy after abdominal surgery may be an underreported complication. This case provides a unique clinical perspective in our patient with a history of ileal carcinoid and Stage III pancreatic adenocarcinoma and confirms that rapid symptomatic and electroretinographic recovery is possible with appropriate treatment.

Varying degrees of optic neuropathy can be seen in patients with Charcot-Marie-Tooth (CMT) disease. To define and characterize the extent of optic neuropathy in patients with CMT2A and CMT1A, two patients from both sub-classifications were evaluated. All patients underwent complete neuro-ophthalmic examinations, and optical coherence (OCT) measurements of the retinal nerve fiber layer (RNFL) and ganglion cell layer complex (GCC) were obtained, along with pattern visual evoked potential (VEP) and pattern electroretinogram (ERG) recordings. RNFL thickness measurements were decreased in both patients with CMT2A, and normal in both patients with CMT1A. GCC measurements were decreased in both patients with CMT2A, mildly decreased in one patient with CMT1A and normal in the second CMT1A patient. VEP latencies were delayed in one patient with CMT2A and one patient with CMT1A. VEP latencies were immeasurable in the other CMT2A patient and not obtained in the second CMT1A patient. Pattern ERG P50-N95 amplitudes were decreased in both patients with CMT2A and normal in one patient with CMT1A. The pattern ERG was immeasurable in the second patient with CMT1A. The pattern of RNFL and GCC thinning in CMT2A with optic neuropathy, a subset of HMSN VI, closely resembles that seen in other mitochondrial optic neuropathies.

OBJECTIVE:To assess vestibular function in patients with familial dysautonomia (FD), a hereditary sensory and autonomic neuropathy - caused by a mutation in the IKBKAP gene (c.2204 + 6 T>C) - and characterized by marked gait ataxia. METHODS:Cervical and vestibular evoked myogenic potentials (cVEMPs and oVEMPs) were recorded from the sternocleidomastoid (SCM) and extraocular muscles in 14 homozygous patients, 2 heterozygous patients, and 15 healthy controls during percussion of the forehead. RESULTS:cVEMP and oVEMP amplitudes were significantly lower, and peak latencies significantly delayed, in the FD patients. There were no differences in overall EMG during attempted maximal voluntary contractions of the SCM muscle, suggesting intact efferent function. The two heterozygotes with a minor haplotype missense (R696P) mutation in exon 19 of the IKBKAP gene had cVEMP responses less affected than the homozygous. CONCLUSIONS:The founder mutation in the IKBKAP gene affects the development of vestibular afferent pathways, leading to attenuated cVEMPs. SIGNIFICANCE/CONCLUSIONS:Vestibular abnormalities may contribute to the gait ataxia in FD.