Behaviour of hTERT in the tears of neophyte contact lens wearers during the sleep/wake cycle

Purpose: To investigate the behaviour of telomerase reverse transcriptase (hTERT) in the tears of healthy neophyte contact lenses-wearing individuals during the sleep/wake cycle. A subsequent aim was to investigate whether hTERT behaviour was associated with inflammatory mediators interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha) in tears.Methods: Flush tears were collected from 19 healthy, non-contact lens-wearing participants (11 males, 8 females, mean age 31.9 +/- 5.7 years), before and during contact lens wear. Tears were collected at noon, before sleep and upon awakening and levels of hTERT, IL-6 and TNF-alpha, were determined using enzyme-linked immunosorbent assays (ELISA).Results: hTERT levels (median [interquartile range]) during contact lens wear were significantly higher before sleep (436.5 (263.9 - 697.7) ng/ml compared to the same time point without contact lenses (256.1 (0.0 - 590.9) ng/ml (p = 0.01). There was no difference between contact lens wear (851.3 [353.2 - 2109.9]) ng/ml, and no wear (1091.0 [492.3 - 3045.4]) ng/ml, upon awakening (p = 0.94). A significant increase was found upon awakening compared to before sleep, irrespective of the presence of a contact lens (p = 0.02). IL-6 and TNF-alpha levels in tears were below the limit of detection. Conclusions: The study showed that hTERT increases after a contact lens is placed on the eye, but this change is small, compared to the impact of overnight eye closure. Taken together with the lack of responses of the inflammatory markers monitored at the same time points, this may suggest that hTERT can respond both to lowlevel stress stimuli acting on the ocular surface, and to situations where inflammation is a likely factor.