Ocular surface microvascular response and its relation to contact lens fitting and ocular comfort: an update of recent research.

This review examines vascular responses in the ocular surface to contact lens wear and its relation to lens fitting characteristics and contact lens-related discomfort. A search of PubMed was performed to find original research in English, within the past 10 years, that studied the ocular surface, including lid-wiper vascular responses to the lens. The interaction between the lens and ocular surface triggers vascular responses, impacting the lens fitting and contact lens-related discomfort. Contact lens-related discomfort is a multifactorial event, which is affected by lens characteristics. Overall, contact lenses with low modulus and a relatively tight fit produce significant ocular comfort. If an appropriate lens fit is achieved, lens fitting characteristics may not play a critical role in contact lens-related discomfort. On the other hand, the pathogenic and vascular changes of lid-wiper vascular responses appear to play an essential role in developing contact lens-related discomfort, in concert with reactions of the cornea (compression and staining) and conjunctiva (indentation and staining). Robust evaluation of lid-wiper changes at the cellular and microvascular level may hold the key to better understanding the mechanism of contact lens-related discomfort and reveal strategies for eliminating lid wiper epitheliopathy and improving ocular comfort in contact lens wearers.