Data from this study suggest that approximately 29% of the sample experiences reported dry eye disease, and women are more likely than men to report these problems. Of these patients, 3.5% reported severe dryness and light sensitivity at the end of the day. These results seem to be in relatively good agreement with other reports. For example, Lin et al.
10 reported that 33.7% of a sample of Taiwanese patients reported a dry eye symptom often or all the time, and again, women were more likely than men to be affected. Shimmura et al.
1 reported that 33% of a Japanese sample believed they had dry eye disease. Schein et al.
17 showed 14.6% of an elderly sample were symptomatic of dry eye, although there was no association with either age or gender. McCarty et al.
8 reported that 5.5% of a sample in Australia reported “severe” dry eye symptoms, and that women were significantly more likely than men to report problems with dry eyes. Moss et al.
7 showed the prevalence of dry eye by self-report to be 14.4% in the Beaver Dam Eye Study; women were again significantly more likely to report problems with dry eye than men (16.7% vs. 11.4%, respectively). Chia et al.
6 showed that 16.6% of the sample from the Blue Mountains Eye Study reported at least moderate dry eye symptoms. Finally, Schaumberg et al.
5 reported in a cohort from the Women’s Health Study that the age-adjusted prevalence of dry eye among women was 7.8%. Again, we found that approximately 33% of women in this sample reported dry eye, which is much higher than the estimate of Schaumberg et al., probably because of the significant number of contact-lens–wearing females in the present study.
Of interest in this study is that even after controlling for age and mode of refractive correction, women were approximately twice as likely as men to report dry eye than were men. Others have also found that women are between 1.5 and 2 times more likely to report dry eye disease than are men.
6 7 8 10 That being said, no clinical testing (i.e., Schirmer’s test, tear breakup time, ocular surface staining) for dry eye was concurrently performed, making it difficult to rule out a gender-related response bias, wherein previous studies have shown that women are more likely to report symptoms in general than men.
18 19 20 21 This tendency has been shown to be true after adjustment for disease status differences through objective measures of disease.
22 Thus, although this and other studies have shown that women are more affected by dry eye than men, the finding may be a somewhat biased estimate.
Very little detail has been published on comparisons of the frequency of dry eye disease across modes of refractive correction, or more specifically, when comparing emmetropes to those requiring refractive correction through spectacle and contact lens wear. Overall, these data show that approximately 53% of contact lens wearers, 17% of spectacle wearers, and 7% of emmetropes report dry eye disease. Several studies have indicated that approximately 50% of contact lens wearers report dry eye, and indeed, our findings agree with that estimate.
3 12 23 24 After we controlled for age and gender, we found that contact lens wearers were approximately 12 times more likely than emmetropes and about five times more likely than spectacle wearers to report dry eye. However, after we adjusted for age and gender, we found that spectacle lens wearers were still twice as likely as emmetropes to report dry eye disease. Although this finding is not necessarily novel for contact lens wearers, it is noteworthy for spectacle wearers and difficult to explain. However, there were several potential explanations that can be put forward. First, it is likely that many of the spectacle wearers had tried and failed to adjust to contact lenses because of the problems with dryness and discomfort described in this study. Second, it is possible that spectacle wearers had sought more frequent vision care for refractive error (unlike the emmetropes), and this may play a role in explaining the relation between spectacle wear and dry eye. Spectacle lens wearers may have more of an awareness of their ocular health and status than an individual not requiring refractive correction. In addition, those wearing spectacles may have had a previous diagnosis of dry eye disease from their eye care providers, which may have influenced their self-reported dry eye status. Finally, one cannot rule out the potential relation between refractive error and dry eye. Although this was a cross-sectional survey study, it would have been interesting to examine the actual relation between measured refractive error and self-reported dry eye. To our knowledge, this relation has not been addressed in the literature before, and indeed this is an idea that needs further study.
When the responses to the questions regarding the frequency and intensity of individual symptoms were compared, 68% of the contact lens wearers, 32% of spectacle wearers, and 18% of emmetropes reported experiencing dryness, at least occasionally. However, light sensitivity was experienced by approximately 45% of spectacle wearers at least occasionally and by approximately 33.6% and 27.3% of emmetropes and contact lens wearers, respectively. The high percentage of light-sensitive spectacle wearers may be explained by potential glare or reflections associated with spectacle wear, and this increased scatter of light may be perceived by the patient as light sensitivity, although the temporal relation between symptoms and choice of correction cannot truly be determined from this study. For both symptoms, contact lens wearers were much more likely to report an increase in the intensity of the symptom toward the end of the day, which has also been reported by Begley et al.
12
In summary, these data show that a significant number of individuals are affected by dry eye symptoms. Contact lens wearers report very frequent dry eye problems, as do spectacle wearers, which is a novel finding. Progress needs to be continued in developing an understanding of the factors that explain the etiology of this problem.