[Treatment and prognosis of diplopia].

The case notes of 341 patients who had consulted the Ocular Motility Clinic of Hyogo College of Medicine between 1986 to 1992 with a chief complaint of diplopia were studied. The recovery rates of diplopia from major causes were as follows: 72% of patients recovered from diplopia in oculomotor nerve palsy, 70% in trochlear nerve palsy and 71% in abducens nerve palsy. Various treatments were effective to eliminate the diplopia in 69% of patients with myasthenia gravis, 60% in Graves' ophthalmopathy, 78% in blowout fractures and orbital tumors. Pharmaceutical therapy was applied in 236 cases. In ocular motor nerve palsy oral prednisone gave a higher recovery rate than other medicines. The recovery rate of diplopia in medicinal therapy was 60% and it increased to 69% when combined with surgical treatment. We concluded that it is better to select the surgical treatment if the patient complains of diplopia after more than 6 months of conservative therapy.

Single fiber electromyography in cat extraocular muscles.

Single fiber electromyography (SFEMG) was carried out in the extraocular muscles (EOMs) of 40 adult cats, and the recordings were analyzed. The small fluctuations of the interpotential interval (IPI), so-called "jitter phenomenon", were represented quantitatively as a mean consecutive difference (MCD). The MCD and the IPI recorded from the orbital layer of the rectus muscles were similar among the 4 rectus muscles: the MCD and the mean IPI measured in 58 motor units from the 4 rectus muscles averaged 25.82 microseconds and 0.94 ms, respectively. These values were similar to those recorded from the oblique muscles. The MCD and IPI were 34.12 microseconds and 1.70 ms, respectively, in the retractor bulbi muscles and 45.54 microseconds and 1.23 ms, respectively, in the triceps muscles. The MCDs of the rectus and inferior oblique muscles were considerably smaller than those in the retractor bulbi and the skeletal muscles.