Non-invasive assessment of corneal and conjunctival deterioration in soft contact lens users using anterior segment optical coherence tomography

The aim was to evaluate the corneal and bulbar conjunctival thicknesses of soft contact lens (SCL) wearers using anterior segment optical coherence tomography (AS-OCT). The epithelial and overall thicknesses of both the central cornea and the infero-temporal bulbar conjunctiva of SCL wearers (30 subjects) were obtained by Cirrus HD-OCT and compared with those of refraction-matched controls (30 subjects) and patients with emmetropia (30 subjects). The mean corneal epithelial thicknesses in SCL wearing, spectacle-wearing and emmetropic groups were 48.97 ± 5.45, 52.18 ± 4.84 and 53.18 ± 5.05 µm, respectively. The corneal epithelium of members of the SCL group was significantly thinner than in both the spectacles and emmetropic groups (p = 0.044 and 0.006, respectively), whereas the central corneal thickness did not differ between groups (p = 0.210). The mean conjunctival epithelial thicknesses in SCL, spectacles and emmetropic groups were 41.50 ± 7.75, 54.33 ± 8.39 and 49.10 ± 7.11 µm, respectively. Conjunctival epithelium in the SCL group was significantly thinner than in both spectacle-wearing and emmetropic groups (p < 0.001 and p = 0.001, respectively). The conjunctiva was significantly thinner in the SCL group compared to the spectacles group (p = 0.001) but not the emmetropic group. Contact lens wear is related to thinning of both corneal and conjunctival layers. AS-OCT is a non-invasive and clinically applicable technique for assessing the involvement of the cornea and conjunctiva in contact lens wearers.