The assessment of the effects of long-term silicone hydrogel contact lens wear on ocular surface and the correlation with meibography

The aim of this study is to evaluate the effects of long-term contact lens (CL) wear on the ocular surface and its association with dry eye disease. Furthermore the effects of CL wear on Meibomian gland dysfunction (MGD) is assessed clinically and with Meibography, which is an objective method, and is associated with patient-dependent factors. 50 patients wearing silicone hydrogel contact lens (SIHCL) for at least 6 months who admitted to our clinic and a sex and age matched control group of 50 patients who had no history of any ocular disease except refractive errors were enrolled. Visual display terminal (VDT) work and CL wear duration were examined, ocular surface and tear functions were evaluated with; OSDI questionnaire, corneal sensitivity measurement with Cochet-Bonnet, MGD staging with slit lamp examination, tear breakup time (TBUT) assessment, corneal Fluorescein staining, Schirmer test, meibography and in vivo confocal microscopy (IVCM) measurements. MGD was found in 34% of CL group and 20% of control group, but there was no statistical difference between groups (p>0,05). In CL group, TBUTs were shorter (p=0,001), corneal Fluorescein staining was increased (p=0,036), and OSDI score (p<0,0001) and Meiboscore (p<0,0001) were higher. The difference in IVCM measurements was observed only in endothelial cell density (p=0,01) and polymegethism (p<0,0001). The differences of subbasal nerve plexus (p=0,247), and corneal sensitivity (p=0,173) were not significant between groups. None of the parameters associated with CL wear duration were significantly different between groups. The longer VDT work duration was associated with increased Fluorescein staining in CL group (p=0,048). In conclusion; our study established that CL wear causes changes on the ocular surface and tear film. Although the association between CL wear and MGD was not determined precisely, examination with meibography revealed changes of Meibomian gland structure in CL group. Keywords: Contact lens, dry eye, in vivo confocal microscopy, meibography, meibomian gland, meibomian gland dysfunction, silicone hydrogel contact lens