Abstract
Purpose:
Controversy exists regarding changes in conjunctival goblet cell densities (CGCD) after contact lens wear (CLW). To investigate changes in CGCD and symptoms of dry eye in CLW, we conducted a six-month longitudinal, observational, dispensing study using laser scanning confocal microscopy (LSCM) and conjunctival impression cytology (CIC) to measure CGCD of the nasal bulbar conjunctiva.
Methods:
A total of eighty-three (83) non-contact lens wearers were enrolled in the study. Sixty (60) participants were fitted with disposable hydrogel lenses with follow-up at one week and one and six months of daily wear. Twenty-three (23) age-balanced non-contact lens-wearing participants, assessed at the same time intervals, acted as the control group. Participants with history of CLW for at least 6 months, pregnancy and breastfeeding, ocular trauma or surgery, ocular surface dysfunction, classification as symptomatic for dry eye (DE) based on answers to DEQ-5 and a sign of DE evaluation, current or long-term use of topical ocular medication, and ocular or systemic disease that may affect the conjunctiva were excluded. After one week all participants were assigned into two further categories related to dry eye; symptomatic (n=25) and asymptomatic (n=35) based on answers to the contact lens dry eye questionnaire-8 (CLDEQ-8). At each visit participant measurements included DEQ-5 for controls and CLDEQ-8 for CL wearers, non-invasive tear film break-up time, ocular surface assessment and phenol red thread (PRT) test. Nasal bulbar conjunctiva was imaged using LSCM (HRTIII with Corneal Rostock Module). CIC was obtained a few minutes later from the same area evaluated with LSCM. The CGCD was calculated as the number of cells per mm² of tissue.
Results:
CGCD in the CLW group decreased significantly over six months as assessed with both LSCM and CIC (p<0.001) CGCD decreased by 23% and 27% from baseline in the symptomatic group as assessed using CIC and LSCM, respectively, and by 19% in the asymptomatic group using both techniques. The control group did not change significantly from baseline at 1 and 6 months (P=0.054).
Conclusions:
CGCD is reduced after short-term contact lens wear in both symptomatic and asymptomatic wearers.