In the present study, we used the questionnaire to verify the personality types, daily anxieties, and the means of relaxation. The questionnaire was developed by modifying Munakata’s questionnaire 11 to evaluate the personality types of outpatients in Japanese clinics. The questionnaire had been evaluated for usability and validity [18
]. The questionnaire had selected the three personalities regarding with stress in Japan. These personalities may affect the retune rate of the questioners.
In the current study, we showed that the scores for items pertaining to the three personalities evaluated were related to the frequencies of ocular symptoms. There have been few reports on the relation between ocular symptoms and behavioral characteristics. Individuals who often complained of dry eye had high scores associated with the type A personality. The subjects may be exposed to the same degree of stress and the personalities of the subjects may affect their symptoms of dry eye, because no significant difference was detected in the daily anxiety scores.
Most employees who participated in this study used a VDT. Long periods of time spent in front of a VDT could cause ocular stress, because the VDT reduces the rate of blinking and changes the tear dynamics [15
]. In addition, the employees worked in an air-conditioned room that also can cause tear evaporation [21
]. Furthermore, individuals with a type A personality often work at a VDT for extended periods compared with individuals who do not have a type A personality [22
]. Therefore, the work environment may be causing the symptoms. In the current study, stress resulting from the work environment containing the VDT could not be evaluated. These factors can affect the frequency of autonomic imbalance. The subjects in the current study spent more time in front of a VDT, as a result of their occupation. Therefore, we analyzed the samples after stratifying for age and gender because of matching.
In addition to the work environment, the wearing of contact lenses (CLs) can be a source of stress that affects symptoms of dry eye syndrome. CLs have become increasingly popular in Japan, with 11.1% of the population wearing lenses in 2002. The percentage of CL use in young women was the greatest of all age groups, with 45.6% of females wearing CLs in the group of subjects who were between the ages of 15 and 24 years. In our study, 71% of the individuals who responded that they often had dry eye were women younger than 30 years of age. This percentage was much higher than the percentages of young females who reported other symptoms such as lightheadedness/fainting (55%) and muffled hearing/tinnitus (43%). Use of CLs often reduces the corneal oxygen supply, often absorbs essential water from the ocular surface, possibly accelerates the evaporation over the CLs, and results in dry eye [23
]. In the current study, we did not evaluate the use of VDTs or CLs. This may be the reason why the results did not detect a relationship between the anxiety scores and the frequency of ocular symptoms. The questionnaire is now being revised to evaluate the relation between stress triggers and ocular symptoms.
We also investigated the personalities of subjects who reported otolaryngologic symptoms. The scores associated with personality types that tended to experience stress were higher in the group in which individuals often complained of giddiness/fainting compared with the other groups. In the current study, giddiness/fainting were considered to have been induced by orthostatic hypotension, according to a report about the incidence of giddiness in Japan. Exposure to excessive stress attenuates the autonomic function of individuals with stress-related personalities [24
]; subsequently, autonomic dysfunction often causes orthostatic hypotension and giddiness [26
]. Therefore, our results agree with those of previous reports. Meanwhile, we did not detect a correlation between the frequency of tinnitus and personality types. Stressful events are risk factors in patients with Meniere’s disease, which can cause giddiness, hearing loss, and tinnitus [28
]. In addition, we reported that patients with Meniere’s disease had the self-resistant type personality and the escape type personality more frequently than the normal controls [20
]. The tinnitus that the study subjects complained of is likely not a symptom of Meniere’s disease or an autonomic disorder.
We also studied the relation between personality and other symptoms of autonomic dysfunction, such as gastrointestinal distress/diarrhea and palpitations/perspiration. The symptoms of digestive organ dysfunction often arise from autonomic dysfunction [32
], and thus these symptoms are closely related to the personalities associated with stress [33
]. Palpitations and excessive perspiration were also common autonomic symptoms. The personality types played an important role as risk factors for heart diseases. Previously, we investigated the relationship between these symptoms and personality types, and the outcome was as we reported [19
]. The results of the current study were consistent with numerous reports published previously, and thus the questionnaire used in our studies seems useful for evaluating personalities associated with stress.
Daily anxiety and relaxation were not strongly related to the frequencies of ophthalmic and otolaryngologic symptoms and autonomic dysfunction. The responses to daily stressful events are regulated by coping mechanisms associated with the different personality types [34
Sociomedical aspects from an ophthalmic standpoint:
Questionnaires tend to consider the causes of ocular fatigue or dryness mostly as related to workers’ posture, the position and the glare of the display terminal (distance from the eye and angle from the ocular axis), and gastrointestinal and vasculo-circulatory symptoms including headache and musculoskeletal features, especially the very popular Katakori in Japanese, which differs in nature from shoulder stiffness.
Finally, the current results neither mention the degree of refractive error nor appropriate or inappropriate correction. Nonetheless, the current study shows that ocular dryness including ocular discomfort is clearly related to the type A personality. Although the type A personality seem to be considered less important in medical science except for cases of individual hostility, this study shows the impact of personality type on ocular dryness, and cautions workers and ophthalmologists about CL use. The current study, therefore, is noteworthy for CL wearers’ unexpressed or neglected claims of ocular discomfort including dry eye.
We should, of course, be concerned that dry eye symptoms can be related to other factors such as employment type (full-time or part-time worker), the level of responsibility of a job, or life-style factors such as smoking, alcohol, and exercise.
Our results suggest that the differences in the personality types were attributable mainly to the frequencies of many of the symptoms. Recently, the number of patients with autonomic imbalances including dry eye has increased. If factors such as personality type affect the onset of dry eye syndrome, managing stress by evaluating personality type may be one method to treat patients.