Abstract
Purpose::
The clinical routine of patients who attend OTG Research & Consultancy clinic includes an examination of anterior segment of the eye and collection of tear samples. The determination of individual basal tear protein composition is important to monitor subtle changes taking place with contact lens wear and/ or dry eye conditions. The objective of this investigation was to identify the effect of contact lens wear and symptomatology on the tear film protein composition.
Methods::
The test population was made up of 67 subjects attending OTG clinic for routine examination and was divided into three groups: asymptomatic soft contact lens wearers (n=31) (Group A), symptomatic contact lens wearers (n=17) (Group B) (Positive control) and asymptomatic non contact lens wearers (n=19) (Group C) (Negative control). The clinical routine included the examination of anterior segment of the eye, the collection of tear samples and the assessment of dry eye symptomatology using the McMonnies questionnaires. Basal tear proteins (~ 1 µl) were collected with glass capillaries and separated by one-dimensional SDS-PAGE on 4-15% Minigel followed by silver stain detection using the Pharmacia PhastSystem and TotalLab analysis software. The tear protein profiles were compared i. between normal soft contact lens wearers and normal non wearers to evaluate the effect of contact lens wear and ii. between asymptomatic and symptomatic contact lens wearers to assess any changes related to dry eye symptomatology.
Results::
The results obtained showed that: i). For normal contact lens wearers and non contact lens wearers, the tear protein profiles were similar. The only trend noted was towards a higher level of IgA in the tear film of normal contact lens wearers compared to non wearers (p=0.055) , ii). When comparing the asymptomatic and dry eye symptomatic contact lens wearers, the main difference was a significantly higher level of albumin (p=0.015) in symptomatic compared to asymptomatic contact lens wearers. Further the ratio of albumin vs lactoferrin was significantly higher in the symptomatic contact lens wearers.
Conclusions::
Very little differences were found in the tear film of well adapted asymptomatic contact lens wearers compared to normal non contact lens wearers. The level of albumin was the main discriminating factor between symptomatic and asymptomatic contact lens wearers. The clinical implications of these findings will be discussed.
Keywords: contact lens • cornea: tears/tear film/dry eye