Shinji Kurimoto

Objective evaluation of eye strain using measurements of accommodative oscillation

Accommodative oscillations occurring during eye strain induced by two different types of experimental visual search task—visual display terminal (VDT) work and conventional hard-copy (paper) work— were objectively measured using infrared optometry. The low-frequency component (0 to 1-5 Hz) of the accommodative oscillation was found to be significantly increased after the VDT work, but not after the paper work. At other frequencies there were no significant differences between the two work types and no significant effect of the task itself. In a questionnaire survey the subjects using the VDT complained more than the subjects given paper work of ocular symptoms such as eye strain and blurred vision. These results suggest that measurement of changes in accommodative oscillation, particularly the low-frequency component (0 to 15 Hz), may provide an objective parameter of eye strain.

The change in colour critical flicker fusion (CFF) values and accommodation times during experimental repetitive tasks with CRT display screens

Two groups of normal subjects were loaded an experimental visual task, or a calculating and discriminating task, on a CRT display screen under different work speeds and amounts. The colour (red, green and yellow) CFF values of the subjects were measured every 15 min during the task and their accommodative function, represented by the accommodation time, was measured before and after the task. The two groups of subjects showed no significant differences in the pattern of change in the colour CFF values. The green and yellow CFF deteriorated significantly at 30 min after the start of the task. The red CFF values decreased significantly at 15 min after the start of the task and this conditions continued to the end of the task. Both groups showed a lengthening accommodation relaxation time but no change in the accommodation relaxation time after the task. This increase in the relaxation time was larger in the group of subjects who were loaded a larger amount of work at a higher speed. The results suggest that the decrease in the CFF value of the subject, particularly when the subject sees light directly using a CRT display screen, does not signify the decline in the activity or consciousness level of the brain centre alone.

Vogt-Koyanagi-Harada disease in monozygotic twins.

We encountered two cases of Haradas disease in monozygotic twins, and this is the first such report as far as could be determined. Case 1 was a 32-year-old woman who presented a typical clinical picture of Haradas disease. Seven years later, case 2 (the younger sister), also presented with the disease at 39 years of age. Case 2 had a transitional diffuse type of Haradas disease, which was possibly due to differences in her treatment. Both patients had papilledema. Since these twins both developed Haradas disease, it is suggested that hereditary factors including HLA type are very important in its development. The HLA type of both these patients was A2, A26, B51, B7, CW7, DR1, and DR4.

Eye-strain and changes in accommodation of the eye and in visual evoked potential following quantified visual load

The measurements were made of the muscular contractions and relaxations of accommodation (infrared optometer) and of visual evoked potential (VEP) (photic stimulation) before and after one hours visual load, checking calculations (1800 questions/hour and 900 questions/hour). The results showed that the relaxation time in accommodation lengthened and the latency of the positive wave appearing at about 100 ms in VEP increased with the increase in visual load. In addition, the complaint rate for eye-strain was higher in the group given heavier visual work. In this group, there was no significant difference in amplitude of VEP before and after the visual task. The difference in the relaxation time before and after the visual task tended to be negatively correlated to the difference in amplitude of VEP and positively related to that in the latency. In the group given lighter visual work there were significant differences in the latency and the amplitude of VEP before and after the visual task, neither were co...

Effect of lymphokine-activated killer cells on human retinoblastoma cells (Y-79) in vitro: Enhancement of the activity by a polysaccharide preparation, krestin

Peripheral blood mononuclear cells (PBMC) cultured in a medium containing interleukin 2 (IL 2) develop the ability to kill fresh tumor cells. This function has been termed lymphokine activated killing (LAK). Recently, cord LAK cell activity was demonstrated to be equally as cytotoxic against similar in vitro targets as adult (peripheral) LAK cells. We investigated the future therapeutic use of LAK adoptive immunotherapy by examining LAK in vitro cytotoxicity from both cord and peripheral blood mononuclear cells against pediatric malignant tumor cell lines Y-79 (retinoblastoma). Cord LAK cells show higher levels of cytotoxicity toward Y-79 targets than do adult LAK cells. Attempts to enhance the rIL 2-induced LAK activity by addition of rIFN-gamma or PSK (krestin) were successful. Furthermore, we found that PSK has a function to enhance rIL 2-induced IFN-gamma and TNF-alpha production. These findings suggest that combined administration of cord LAK cells and PSK may account for the improvement of advanced retinoblastoma in the neonatal period.

Postcataract against-the-rule astigmatism after phacoemulsification procedure

To further determine whether postoperative astigmatism is related to the amount of preoperative astigmatism, we analyzed two types of against-the-rule (AR) astigmatism induced by phacoemulsification and aspiration (PEA) procedures. The operations all utilized 10+0 polyester (Mersilene) in double running fashion for the closure of the corneoscleral incisions. The induction and spontaneous regression of several types of astigmatism were analyzed over 6 months. Surgery was all done by one surgeon, with the same surgical procedure and the same number of sutures. In postoperative AR astigmatism < 0.7 D at 6 months, although the amount of the astigmatism 1 week postoperatively was remarkably increased (2.66 ± 0.17 D), post-operative astigmatism was decreased 6 months following surgery. On the other hand, in postoperative AR astigmatism > 1.5 D at 6 months, the power of the astigmatism 1 week postoperatively (2.12 ± 0.13 D) was not much higher than the preoperative level (1.38 ± 0.08 D), but tended to continue increasing even 6 months after surgery. There was no difference in the power of astigmatism between 1 and 3 months postoperatively. The eyes with preoperative astigmatism (e.g. 1.38 ± 0.08 D) and especially preoperative AR astigmatism (e.g. 1.60 ± 0.11 D), showed an increase of their astigmatism after the PEA procedure. We discussed some risk factors which may induce greater postoperative AR astigmatism.

Outcome of Preoperative Against-the-Rule Astigmatism after Phacoemulsification: Characteristic Changes over Time

To determine the outcome of preoperative against-the rule (AR) astigmatism among 1,648 phacoemulsification and aspiration (PEA) procedures, we analyzed the post-cataract time course of astigmatism over 6 months in 618 eyes divided into three groups. In preoperative AR astigmatism less than 0.75 dptr (n = 208), the astigmatism increase 1 week postoperatively was rapid. In preoperative AR astigmatism greater than or equal to 1.5 dptr (n = 185), no difference in the power of astigmatism was apparent between 1 and 3 months postoperatively. The third group (0.75 less than or equal to preoperative AR astigmatism less than 1.5 dptr, n = 143) showed intermediate characteristics. The eyes with preoperative low AR astigmatism showed exacerbation of astigmatism after the PEA procedure, whereas the degree of astigmatism, corneal curvatures and the rate of AR astigmatism became lower in the eyes with higher preoperative AR astigmatism.

Intraocular Muscle Function in Pseudoexfoliation Syndrome

Pseudoexfoliation (PE) material has been studied pathologically. However, there are no reports about intraocular muscle function in pseudoexfoliation syndrome (PXS). We studied intraocular muscle function in 12 patients (70.3 +/- 10.1 years of age) with ipsilateral PE material by measuring the time course of pupillary diameter change and accommodogram. Initial intraocular pressure (16.3 +/- 4.2 mmHg) was significantly higher in eyes with PXS than in normal fellow eyes (13.1 +/- 3.5 mmHg). The pupillary diameter of an affected eye was smaller than that of a fellow eye after bilateral topical application of tropicamide. Continuous near-point testing revealed no significant difference; accommodative contractile time, relaxation time, and/or accommodopattern showed different patterns from the fellow eye. The results suggest that intraocular muscle function is disturbed in PXS.

Similarities and Differences between the Kelman Phacoemulsification and Extracapsular Cataract Extraction Procedures in the Spontaneous Regression of Corneal Astigmatism from Against-the-Rule Astigmatism

We perspectively examined the induction and spontaneous regression of corneal astigmatism from preoperative against-the-rule astigmatism [Kelman phacoemulsification (KPE), n = 618; extracapsular cataract extraction (ECCE), n = 192] among cataract extraction surgeries (KPE, n = 1,648; ECCE, n = 443). All data were set on a double-angle coordinate graph, from which the mean +/- SE of the axis and the amount of astigmatism were obtained simultaneously. In the KPE group, the surgically induced astigmatism was independent of preoperative state or age. In the ECCE group, surgically induced astigmatism shifted toward with-the-rule astigmatism, and postoperative recovery was delayed longer in patients over 80 years of age than in those under 70. Postoperative against-the-rule astigmatism was more frequent after KPE. Our first trial to calculate astigmatism from a double-angle coordinate graph was useful in showing astigmatism changes.

Effects of ultraviolet radiation and visible light on hamster pupil

Light does not cause a miotic response in mammals after a topical application of atropine. However, such common sense is based on the pupillary response to visible light. We found ultraviolet (UV) caused slight but evident miosis, even when the patient did not perceive visible light. In order to understand this mechanism further, we conducted in vitro experiments using hamsters. The in vitro hamster iris contracted even when the retina was withdrawn in an incubation solution. The contraction of the hamster pupil caused by visible light was inhibited by procaine, quinacrine, and by the withdrawal of divalent cations, but not by indomethacin, AA861, FPL55712 or autonomic blocking agents. UV-induced miosis was very delayed, continuing after cessation of UV stimuli. Nordihydroguaiaretic acid did not inhibit the miosis induced by UV and/or visible light. The UV-induced miosis was not significantly affected by allopurinol or verapamil, suggesting mechanisms other than neuronal mediation and oxidative stress. This study shows that the isolated hamster iris can react to UV and visible rays. UV-induced miosis is different from the miosis caused by light reflex. To our knowledge, UV-induced miosis has not yet been reported.