• Page 1 of 6 • Uzunel. Int J Ophthalmol Clin Res 2018, 5:084 gested mechanism of IOP reduction involves aqueous humor outflow enhancement through the uveoscleral pathway accompanied by collagen degradation in the ciliary body. This collagen degradation is believed to be mediated by Matrix Metalloproteinases (MMPs) induced by prostaglandin F2-alpha [2,3]. Furthermore, because the cornea is mainly composed of collagen fiber [4], corneal thinning may be anticipated after pros-Elevated IOP is a risk factor for glaucoma and it's believed that to decrease the IOP values is the first choice of treatment in glaucoma [5]. Goldmann Applanation Tonometry (GAT) is known to be a standart method for IOP measurements however it's also well known that changes in Central Corneal Thickness (CCT) measurements may influence the GAT results accurate results of GAT are produced with a CCT of 520 mm, but CCT values higher or lower than 520 mm produces unreliable IOP measurements by over or under estimating of IOP values [6]. Besides its importance in IOP measurements it's also been suggested that CCT is an independent risk factor of progression in open angle glaucoma [7].The purpose of this study was to evaluate 5-year changes in the CCT in glaucoma patients treated with PG analogues monotherapy and to investigate the association between the CCT and the IOP in these patients. Material and MethodsMedical charts of 3696 glaucoma patients who have been followed up at Izmir Bozyaka Training and Research Hospital were reviewed retrospectively. Seventy-three eyes of 73 glaucoma patients constituted the glaucoma group and 75 eyes of 75 glaucoma-suspect patients constituted the control group. The inclusion