Use your ears (not your eyes) to identify CL-related dryness

Dryness and discomfort with contact lenses are extremely common, affecting nearly half of all soft lens wearers. The large number of sufferers, estimated at nearly one million in the UK alone, should be strong motivation for eye care practitioners to re-examine and retune their approach to diagnosing and treating the problems of their symptomatic contact lens patients (Figure 1).

Contact lens patients who are experiencing a less than optimum lens wearing experience not only have a negative experience, but are at higher risk of limiting their wearing time and abandoning lens wear altogether. It has been reported that most patients who discontinue contact lens wear were in their mid-20s when they began lens wear and stopped within the first two years of wear.1 The investment of chair time with a patient who soon discontinues lens wear is lost if their comfort problems are ignored or glossed over. Through the past decade the authors have been researching the measurement of ocular surface symptoms and developing methods to specifically elicit them in dry eye patients and contact lens wearers alike. A number of our research experiences have reshaped our thinking on how practitioners should approach mild to moderate dry eye and CL-related dryness with a new level of forethought. This article will outline some findings that support reasons to better diagnose contact lens related dryness and point to effective strategies for treatment.

In 1998 the authors, along with a collaborative research team, studied over 1,000 unselected clinical patients presenting in six clinical centres in North America.2 We distributed the newly developed Dry Eye Questionnaire and Contact Lens Dry Eye Questionnaires (DEQ and CLDEQ) to these patients presenting for all types of eye care in order to establish population norms for ocular surface symptoms. Surveying patients who were not selected for their dry eye diagnosis is the best method to determine the breadth and seriousness of the problem of ocular dryness in the population overall, as well as establishing normal symptoms reported by patients who do not suffer from dry eyes. These symptom norms can then be compared to symptoms among groups of patients with various types of dry eye to see if their symptoms alone can distinguish them from patients without dry eye diagnoses. Although they are not a group with a dry eye diagnosis, per se, we studied the contact lens wearers as a distinct group to compare with non-lens wearers.

The DEQ and CLDEQ questionnaires thoroughly query a number of habitual ocular surface symptoms, contact lens wearing history and habits, along with other lifestyle factors that were suspected to influence dryness symptoms. Figure 2 shows a sample symptom question. The frequency of each symptom is first established and, if that symptom is reported at all, the intensity at the beginning and end of the day is gathered. At the end of the survey we asked patients whether they had a practitioner or self-diagnosis of dry eye as a global indicator of their condition. The power of practitioner and self-assessment of dry eye have been analysed to show that practitioners often under-estimate the patients' perception of the dry eye condition in both contact lens wearers and non-wearers alike.3 Nearly 40 per cent more contact lens wearers self-described themselves as having dry eye (17.7 per cent) compared to the number who had been told they had dry eye by their practitioner.2 Patients who self-diagnose but aren't given a practitioner diagnosis represent patients whose needs are not being met by their eye care providers.

Among the 1,054 subjects surveyed were 367 current contact lens wearers and 181 former contact lens wearers (26 per cent of those who were not currently wearing lenses). When asked their reasons for discontinuation of lens wear, the former contact lens wearers cited dryness and discomfort late in the day as their top two reasons. As shown in Table 1, four of the top five reasons related to ocular surface sensations rather than inconvenience, cost or other reasons unrelated to lens comfort. These results are in agreement with researchers from the University of Waterloo, Ontario, Canada, who found that 50 per cent of the patients cited discomfort or dryness as the reason for discontinuation. They also reported that patients who discontinued lens wear had a reduced wearing time compared to successful wearers.4 A more recent study conducted in the UK concurred, finding that 51 per cent of the subjects cited discomfort as the principal reason for giving up lens wear.5