Chiasmal decussation in tilted disc syndrome PVER in tilted disc

The tilted disc syndrome is a benign congenital abnormality of the optic ne rve head. Since it can be confused with papilledema and chiasmal lesions, d ifferential diagnosis is important. The tilting anomaly may be associated w ith other abnormalities along the optic nerve. Visual field defects may be similar to those in chiasmal lesions. In order to determine whether the nor mal crossover of nerve fibers at the chiasm is altered, the crossed and the uncrossed fibers were investigated using the pattern visual evoked respons es (PVER) test. Thirty-four eyes of 17 patients diagnosed with tilted disc syndrome were evaluated for refraction, keratometry, color vision with Ishi hara, visual field, and PVER. The presence of abnormal nerve fiber decussat ion was determined by recording PVER from the electrodes mounted on the sca lp of both hemispheres. The amplitude and latency differences between the ' crossed' and 'uncrossed' fibers were not statistically significant (p>0.05) . As a result, the tilting abnormality of papilla was found to be without c hiasmal abnormal decussation.