Contact lens use induces a variety of ocular complications, such as allergic conjunctivitis, infections and dry eye. One of the most important complications of prolonged contact lens wear is dry eye 11-12
. The prevalence of dry eye and related findings were reported up to 50% in the literature 4
. MG plays an important role in structuring the lipid layer of the tear film 13
. MGD consequently causes dry eye, mainly of evaporative type. There are several ways to evaluate MG function; slit lamp biomicroscopy for MG appearance, T-BUT measurement, analyzing meibum expressed from the glands 4
Meibography is a relatively objective and new technique for evaluating the MG, which images the MG and also advances with the developments in medical imaging. It can be performed in various ways by using contact or noncontact infrared cameras, confocal microscopy, ultrasound and OCT devices 14.
Currently, it is not clear which device is the most suitable one for this purpose. Besides, grading MGS is still a controversial issue. Most of the researchers defined their own grading systems and scoring the drop out of the gland percentage is the most common system 5,6,15-20. However, some of the researchers also evaluate the morphology of the glands 6,21-26.
There are only a few studies that investigate the relation of these two parameters, contact lens wear and MG. In most of the published literature, MG evaluation with conventional methods in gas permeable or hydrogel contact lens users was performed 13,25-26. In 2009, Arita et al 13, reported a significant MG loss in rigid gas permeable and hydrogel contact lens wearers with one-year history of lens use. They also reported that meiboscore difference that is demonstrated with their own developed infrared Meibography camera was prominent between upper and lower eyelids of contact lens wearer group. Herein, silicone hydrogel contact lens wearers at least for 5 years - were included and MG imaging was performed with the infrared acquisition feature of the OCT device, which is widely present in most of the ophthalmology clinics. Contact lens wear is a probable reason of alterations in MG, which may result with MGD 13,27. We found a slight meiboscore difference between upper and lower eyelids in silicone hydrogel contact lens wearer group was detected, however the statistical difference did not reach the significance point.
In the present study, an increased Oxford scoring and decreased T-BUT in contact lens wearer group compared to the control group were found. The differences were statistically significant which is consistent with the literature confirming the negative effects of contact lens wear on the ocular surface 8,13.