Research Article Prevalence of Keratoconus in a Refractive Surgery Population Abdulrahman Mohammed Al-Amri College of Medicine, King Khalid University, Abha, Saudi Arabia Correspondence should be addressed to Abdulrahman Mohammed Al-Amri; amaamri@gmail.com Received 7 May 2018; Accepted 7 August 2018; Published 6 September 2018 Academic Editor: Antonio Queiros Copyright © 2018 Abdulrahman Mohammed Al-Amri. is 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. is study examined the prevalence of keratoconus among patients who were interested in undergoing refractive surgery. Corneal tomography measurements were used to help detect keratoconus. Methods. Adult subjects who presented to the private hospital Cataract and Refractive Surgery Unit (Abha, Saudi Arabia) for refractive surgery evaluation were considered for inclusion in this cross-sectional, retrospective study. All subjects were from the Aseer province, a southern, high-altitude region in Saudi Arabia, and presented between January and December 2017. e incidence of keratoconus and other refractive surgery contraindications were examined. Results. A total of 2931 patients were considered for inclusion in analyses. Of these, 2280 patients (77.8%) were not candidates for refractive surgery. ese 2280 patients had a mean age of 24.1 ± 6.6 years and 1231 patients (54.0%) were male. Of the subjects who did not undergo refractive surgery, 548 (24%) had keratoconus, 400 (17.5%) were keratoconus suspects, 344 (15.1%) had thin corneas, 321 (14.1%) had high myopia, and 52 (2.3%) had a high astigmatism. An additional 479 subjects (21%) were candidates for refractive surgery, but chose not to undergo a procedure. Conclusion. e incidence of keratoconus in Saudi Arabian refractive surgery prospects was 18.7%. Keratoconus was the most common reason for not performing refractive surgery and accounted for 24.0% of cases in which surgery was not performed. 1. Introduction Keratoconus is a cone-shaped protrusion of the cornea that was named using the Greek terms “kerato” and “konos,” which mean “cornea” and “cone,” respectively. Keratoconus begins as a corneal thinning and results in a corneal bulge. As a result, light is irregularly refracted through the cornea (astigmatism), which is apparent during retinoscopy. As the cornea progressively steepens, astigmatism becomes more severe and visual acuity subsequently decreases [1, 2]. Ker- atoconus can be treated in several ways, depending upon disease stage. Contact lenses can be used to correct vision in early disease stages, but this solution often becomes in- adequate and some patients cannot wear contact lenses. erefore, some treating physicians choose to implant intrastromal corneal ring segments to flatten and stabilize the cornea, to improve vision, and, in some cases, enable the use of contact lenses [3]. However, in advanced cases, corneal transplantation (full or partial thickness) is often needed. In recent years, collagen cross-linking procedures have been used to successfully stabilize and reshape the cornea, resulting in long-term vision improvements [4–7]. Additionally, suc- cessfully treated patients may avoid corneal transplantation. Keratoconus is of particular significance in refractive surgery candidates because operating on an eye with un- detected keratoconus is a major cause of postoperative corneal ectasia [8–11]. e underlying cause of this progressive, bi- lateral, ectatic condition remains unknown. However, ge- netics are believed to play a role because up to 20% of patients with keratoconus have a positive family history for condition [12, 13] and a family history of keratoconus is a risk factor for developing the condition [14–18]. Allergy-induced mecha- nisms may also play a role because the risks of developing keratoconus are higher [19–21] and age of onset is lower [22] in patients with allergic or atopic disease. Many studies have been performed around the globe to assess the incidence of keratoconus. e overall incidence of keratoconus is estimated at 50 cases per 100,000 people (0.05%) [23]. However, this widely varies by geographical region, as summarized in Table 1. For example, a study on Hindawi Journal of Ophthalmology Volume 2018, Article ID 5983530, 5 pages https://doi.org/10.1155/2018/5983530