Objective: To determine visual prognostic value of electrophysiologic tests in unilateral-eye-disease patients who underwent corneal transplantation.
Material and Method: Retrospective charts of the patients who underwent unilateral optical penetrating keratoplasty at Siriraj Hospital from September 2003-June 2009 were reviewed. The amplitude of a-wave and b-wave in dark-adapted bright flash ERG and the amplitude of major positivity (P2) in flash VEP were recorded and compared with the good fellow eye. Area under receiver operating characteristic curve (AUC) was used to determine the best predictor of good visual prognosis. Positive predictive value (PPV) and negative predictive value (NPV) were used to determine the accuracy of the tests.
Results: Thirty-nine patients were included. The present study showed that a-wave amplitude was a good predictor (AUC = 0.83). For a-wave amplitude that was equal to or more than 80% and P2 amplitude that was equal to or more than 67%, PPV was 95.65%.
Conclusion: The a-wave amplitude and P2 amplitude predict good visual outcome most accurately when changing less than 20% and 33%, respectively, compared to the normal fellow eye.

Keywords: Electrophysiologic test, Corneal transplantation