Pattern visual evoked potentials in the early diagnosis of optic neuropathy in the course of Graves' ophthalmopathy.
OBJECTIVE
To investigate by means of pattern visual evoked potentials (PVEPs) early neuropathic changes in Graves' ophthalmopathy (GO) patients without any clinical symptoms of optic neuropathy in order to evaluate the prevalence of subclinical optic neuropathy in GO patients and to elucidate whether there is a relationship between PVEP (P100 and N75 latency), intraocular pressure (IOP) and exophthalmometry.


METHODS
Two groups of patients were examined: 15 patients with GO without clinical signs of dysthyroid optic neuropathy (DON) and 12 healthy controls. The correlations between the N75 and P100 latencies, IOP and Hertel exophthalmometry were investigated.


RESULTS
The mean PVEP N75 and P100 latencies were significantly delayed in the GO uncomplicated with DON in comparison with controls (LP100- 106.2 +/- 4.4 ms vs. 102.4 +/- 2.7 ms, p < 0.01 and LN75- 79.0 +/- 3.7 ms vs. 73.9 +/- 2.8 ms, p < 0.001). In GO patients we documented a positive correlation between the LN75 latency and exophthalmometric readings (R = 0.51; p < 0.01). The value of LP100 and LN75 was above the normal limit in 5/30 eyes (17%) and in 3/30 eyes (10%) respectively.


CONCLUSIONS
The assessment of PVEPs (especially the P100 latency) in GO patients without clinical signs of DON is a useful tool for the early diagnosis of optic nerve involvement.
Pawłowski
Przemysław
P
Department of Paediatric Ophthalmology, Medical University of Białystok.
Myśliwiec
Janusz
J
Mrugacz
Małgorzata
M
Bakunowicz-Łazarczyk
Alina
A
Górska
Maria
M
D000328:Adult; D042241:Early Diagnosis; D005074:Evoked Potentials, Visual; D005260:Female; D049970:Graves Ophthalmopathy / Q000150:complications / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D009901:Optic Nerve Diseases / Q000175:diagnosis* / Q000209:etiology; D014786:Vision Disorders / Q000175:diagnosis / Q000209:etiology; D058609:Visual Field Tests / Q000379:methods; D014794:Visual Fields