Abstract
Purpose: :
To evaluate the potential clinical value of focal electroretinogram (FERG) to sine–wave flicker in detecting retinal dysfunction associated with idiopathic macular holes (IMH)
Methods: :
FERGs to 41 Hz sine–wave stimuli presented on the macular region (18°) on a steady light–adapting background were recorded in forty patients with IMH at stage II (n =10), III (n = 13) and IV (n =17), as well as in 38 age–matched normal control subjects. The response fundamental component, isolated by Fourier analysis, was quantified in its amplitude and phase. Based on the deviation from the normal average value, an index was developed combining FERG amplitude and phase criteria, reflecting the deviation from normal expressed by the number of standard deviations away from the normal mean value
Results: :
In all patients sub–groups, the mean FERG index was significantly greater than 2 (p < 0.05 of Hotelling T2–statistics) In individual patients, sensitivity, at 95% specificity, ranged from 95% (in stage II) to 100% (in stage IV). No significant correlation for the FERG index was found with hole size or visual acuity. FERG index increased with increasing age of patients (p < 0.05)
Conclusions: :
FERG index can effectively detect early retinal dysfunction associated with IMH. and may be of help in tracking its progression or evaluating the effects of treatments
Keywords: macular holes • electroretinography: clinical • clinical laboratory testing