Time Course of Changes in Goblet Cell Density in Symptomatic and Asymptomatic Contact Lens Wearers

PURPOSE. To investigate longitudinal changes in goblet cell density (GCD) in contact lens (CL) wearers who do and do not develop symptoms of dry eye (DE). METHODS. Sixty healthy individuals fitted with daily disposable hydrogel CLs and 23 age-balanced non-CL-wearing controls underwent assessment using the 5-item dry eye questionnaire, noninvasive tear film break-up time measurement, ocular surface assessment, and phenol red thread test evaluation. Laser scanning confocal microscopy (LSCM) and conjunctival impression cytology (CIC) were used to assess GCD at baseline and follow-up visits at 1 week and 1 and 6 months. After 1 week, all CL wearers were categorized as those who were and were not symptomatic based on responses to the CL dry eye questionnaire-8 (CLDEQ-8). A linear mixed-model was used to examine changes in GCD over time. RESULTS. The global mean GCD of the 83 participants at baseline (before CL wear) was 476 +/- 41 and 467 +/- 52 cells/mm(2) using LSCM and CIC, respectively. After 6 months of CL wear, GCD was reduced by approximately 13% and 29% in asymptomatic (N = 29) and symptomatic (N = 17) CL wearers (all P < 0.001), respectively, observed with both LSCM and CIC. CONCLUSIONS. Contact lens wear induces a reduction of GCD over 6 months, which is exacerbated in those with DE symptoms. Either LSCM or CIC can be used to assess GCD in the conjunctiva.