ABSTRACT
We wanted to assess the extent and pattern of ophthalmoplegia, by a quantitative and reproducible method. We also wanted to identify whether any correlation existed between the amount of ophthalmoplegia and the percentage of mitochondrial DNA deletion. The prospective study involved 24 patients with confirmed CPEO from muscle biopsy of the vastus lateralis muscle. Uniocular fields of fixation, using the Goldmann perimeter measured the excursion of extra-ocular muscle movement. Six cardinal axes, corresponding to the main field of action of each extra-ocular muscle, were recorded in degrees. These results from patients with CPEO were then compared to normal values. In conclusion, our research proves down-gaze is relatively spared and that a clear correlation exists between the percentage of cytochrome oxidase negative fibres and the extent of ophthalmoplegia.
