Hiroyasu Iwashige

Results of Surgery for Paralytic Exotropia due to Oculomotor Palsy

In 138 cases of paralytic exotropia due to oculomotor palsy, transposition of the superior oblique muscle and resection of the medial rectus muscle were carried out. Surgery was performed with or without recession of the lateral rectus muscle. The long-term prognosis for 4 years or more was observed in 35 cases. We found that the same results could be obtained by selecting transposition of the superior oblique muscle in cases of complete palsy and resection of the medical rectus muscle in cases of incomplete palsy. There was no benefit in combining resection of the medial rectus muscle when performing the transposition of the superior oblique muscle. Regardless of which method was used, a combination with recession of the lateral rectus muscle greatly improved the effectiveness of the procedure.

Clinical Characteristics of Non-accommodative Intermittent Esotropia

We recently encountered cases of non-accommodative esotropia with intermittent esotropia observed in both far and near vision; good visual acuity and binocular visual function; variation in strabismic angle; and abnormalities on electroencephalogram (EEG). Although non-accommodative esotropia has been studied by Costenbader [1] and von Noorden [2] et al., its signs and symptoms have not been fully clarified. Therefore, we studied 17 patients with non-accommodative intermittent esotropia with common clinical symptoms (age: 3–14 years), and recognized these cases as representing new clinical entity.

DNA Repair in Cockayne Syndrome

The repair activities after ultraviolet (UV) irradiation and carcinogens treatment in ten Cockayne syndrome (CS) patients are presented. Lymphoblastoid cell lines were established after transformation with Epstein-Barr virus from peripheral lymphocytes of ten CS patients, two xerodema pigmentosum (XP) patients and two control donors. Cell survival after UV, 4-Nitroquinoline, 1 -oxide (4NQO) and N-methyl-N’-nitro-N-nitrosoguanidine (MNNG) treatment was studied. There was a severe decrease in the cell survival of all CS cell lines after UV and 4NQO. The survival rates were about equal to those of XP cells. In contrast, the sensitivities to MNNG treatment did not show any difference from the control cell lines. The rate of 3H TdR incorporation of two CS siblings cells after UV irradiation was severely decreased as equal to that of XP cell lines. However, normal rates were observed in the cells of the other eight CS patients. The results indicate the existence of two different groups of CS, the one of which is defective and the other is not defective in unscheduled DNA synthesis after UV irradiation. Post-replication repair (PRR) of ten CS cell lines after UV irradiation were compared with those normal cell lines by analysing the molecular weight distributions of newly synthesized DNA. The molecular weight of the newly synthesized DNA after the pulse or after the chase was determined by centrifugation in alkaline sucrose gradients. Results are as follows: 1. Pulse, -caffeine; A broad distribution of molecular weight was obtained. 2. Chase, -caffeine produced a peak of radioactivity near the bottom of the sucrose gradient in CS cells and normal cells. 3. Chase, +caffeine; The reduction of the molecular weight was not enhanced by caffeine in CS cells. Those results show that all of CS cell lines had not defect in PRR by our studies, and that two siblings cell lines of CS and some defect in excision repair.