Research Article Impaired Corneal Biomechanical Properties and the Prevalence of Keratoconus in Mitral Valve Prolapse Emine Kalkan Akcay, 1 Murat Akcay, 2 Betul Seher Uysal, 1 Pinar Kosekahya, 1 Abdullah Nabi Aslan, 2 Mehtap Caglayan, 1 Cemal Koseoglu, 2 Fatma Yulek, 1 and Nurullah Cagil 1 1 Department of Ophthalmology, Ankara Ataturk Training and Research Hospital, Yildirim Beyazit University, 06810 Ankara, Turkey 2 Department of Cardiology, Ankara Ataturk Training and Research Hospital, Yildirim Beyazit University, 06810 Ankara, Turkey Correspondence should be addressed to Emine Kalkan Akcay; dremineakcay@yahoo.com Received 16 February 2014; Revised 26 March 2014; Accepted 31 March 2014; Published 17 April 2014 Academic Editor: Antonio Queiros Copyright © 2014 Emine Kalkan Akcay et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Objective. To investigate the biomechanical characteristics of the cornea in patients with mitral valve prolapse (MVP) and the prevalence of keratoconus (KC) in MVP. Materials and Methods. Fity-two patients with MVP, 39 patients with KC, and 45 control individuals were recruited in this study. All the participants underwent ophthalmologic examination, corneal analysis with the Sirius system (CSO), and the corneal biomechanical evaluation with Reichert ocular response analyzer (ORA). Results. KC was found in six eyes of four patients (5.7%) and suspect KC in eight eyes of ive patients (7.7%) in the MVP group. KC was found in one eye of one patient (1.1%) in the control group ( = 0.035). A signiicant diference occurred in the mean CH and CRF between the MVP and control groups ( = 0.006 and  = 0.009, resp.). All corneal biomechanical and topographical parameters except IOPcc were signiicantly diferent between the KC-MVP groups ( < 0.05). Conclusions. KC prevalence is higher than control individuals in MVP patients and the biomechanical properties of the cornea are altered in patients with MVP. hese indings should be considered when the MVP patients are evaluated before refractive surgery. 1. Introduction Mitral valve prolapse (MVP) is a primary connective tissue abnormality of lealets, the chordae tendineae, and the annu- lus of the mitral valves [1]. he prevalence of MVP in the general population ranges from 0.6% to10% and can change according to the diagnostic methods used, the diagnostic cri- teria, and the population assessed [2]. MVP can be associated with ophthalmological diseases such as keratoconus (KC), chronic progressive external ophthalmoplegia, and retinal artery embolism [3, 4]. KC is a progressive, noninlammatory, idiopathic corneal ectasia characterized by changes in corneal collagen structure and organization [5, 6]. he prevalence of KC in the general population is 50–230 per 100,000 (approximately 1/2000) [7]. It is most commonly an isolated condition, despite the multiple singular reports of coexistence with other disorders [8]. Commonly recognized associations include MVP, Down syndrome, Leber’s congenital amaurosis, and various connec- tive tissue disorders [8]. he corneal stroma is the main structure that provides corneal refraction, mechanical properties, and corneal trans- parency. he anterior stromal part plays especially important role in corneal stability and shape [9]. Aging, corneal patholo- gies, corneal surgery (e.g., LASIK), and systemic diseases may afect corneal biomechanical characteristics by afecting this stromal structure rich in collagen connective tissue [10–14]. Given the cornea’s rich collagen connective tissue, corneal biomechanics may be afected by collagen connective tissue diseases. Both KC and MVP are noninlammatory conditions, the etiology of which has not yet been clearly identiied. In most cases of KC, thinning and ectasia of the central cornea with subsequent progressive reduction of vision occurs [15]. Hindawi Publishing Corporation Journal of Ophthalmology Volume 2014, Article ID 402193, 6 pages http://dx.doi.org/10.1155/2014/402193