Contact Lens & Anterior Eye 34 (2011) 274–281 Contents lists available at ScienceDirect Contact Lens & Anterior Eye journal homepage: www.elsevier.com/locate/clae Case report Fitting an MSD (Mini Scleral Design) rigid contact lens in advanced keratoconus with INTACS Kristine Dalton a,∗ , Luigina Sorbara b,1 a School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, United Kingdom b School of Optometry, University of Waterloo, Waterloo, Ontario, Canada, N2L 3G1 article info Keywords: Keratoconus Rigid contact lenses Scleral contact lenses INTACS abstract Keratoconus is a bilateral degenerative disease characterized by a non-inflammatory, progressive central corneal ectasia (typically asymmetric) and decreased vision. In its early stages it may be managed with spectacles and soft contact lenses but more commonly it is managed with rigid contact lenses. In advanced stages, when contact lenses can no longer be fit, have become intolerable, or corneal damage is severe, a penetrating keratoplasty is commonly performed. Alternative surgical techniques, such as the use of intra-stromal corneal ring segments (INTACS) have been developed to try and improve the fit of rigid contact lenses in keratoconic patients and avoid penetrating keratoplasties. This case report follows through the fitting of rigid contact lenses in an advanced keratoconic cornea after an INTACS procedure and discusses clinical findings, treatment options, and the use of mini-scleral and scleral lens designs as they relate to the challenges encountered in managing such a patient. Mini-scleral and scleral lenses are relatively easy to fit, and can be of benefit to many patients, including advanced keratoconic patients, post-INTAC patients and post-penetrating keratoplasty patients. © 2011 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved. 1. Introduction Keratoconus is a bilateral, albeit asymmetrical, degenerative, non-inflammatory, progressive central corneal ectasia leading to decreased vision [1–4]. Clinically, keratoconus is characterized by both progressive central epithelial and stromal corneal thinning – although the stromal thinning is predominate – corneal steepen- ing and increased irregular astigmatism [5,6]. It has the potential to cause significant corneal scarring and/or acute corneal hydrops [6,7]. Vogt’s striae and Fleischer’s rings are commonly associated biomicroscopic findings in keratoconic corneas, especially in more advanced cases of the disease [2]. The vast majority of keratoconus cases are managed with con- tact lenses – studies have demonstrated that 80–90% of keratoconic patients wear contact lenses [8–10], and of those patients wearing contact lenses, approximately 70% wear rigid contact lenses [8]. Only 12–26% of keratoconic patients have been found to need sur- gical intervention [8,10,11]; with penetrating keratoplasty being the most commonly performed procedure [8,12–14]. The presence of corneal scarring and steep keratometry values have been found to be risk factors associated with the need of penetrating kerato- ∗ Corresponding author. Tel.: +44 0121 204 3000. E-mail addresses: kristinedalton.od@gmail.com (K. Dalton), gsorbara@sciborg.uwaterloo.ca (L. Sorbara). 1 Tel.: +1 519 888 4567. plasty in keratoconic patients [14], although clinically, the decision to opt for surgical interventions often depends on a patient’s moti- vation, satisfaction with, and ability to tolerate their contact lenses. Advances in technology have led to development of surgical inter- ventions, such as collagen cross linking and INTACS, which although invasive do not require corneal transplantation. Both collagen cross linking and INTACS are now being made available to patients who are in a less severe stage of their keratoconus, as an alternative too, or to be used in conjunction with contact lens wear. INTACS (Addition Technology, Inc., Des Plaines, IL), are 150 ◦ polymethylmethacrylate semi-circular ring segments which are inserted, traditionally in pairs, into the corneal stroma. They were originally designed as a refractive surgery procedure for the cor- rection of low to moderate myopia as they induce central corneal flattening [15], although they are now being used as a treatment for keratoconus as well [16–20]. One or two intra-stromal ring seg- ments have been used in keratoconic corneas in attempts to flatten the central corneal curvature, which has been thought to improve patients’ comfort and vision in contact lenses by improving the actual fit of the contact lenses [16–20]. Research has shown that intra-stromal rings do induce some central corneal flattening in keratoconic eyes, however, the greatest effect of the flattening has been found to occur in the mid-peripheral region of the cornea, directly over the INTAC. In turn, this creates an abnormal, artificial steepening of the peripheral corneal, relative to the mid-periphery which can make contact lens fitting after INTACS difficult [21–23]. The case presented here is one such case, whereby the contact lens 1367-0484/$ – see front matter © 2011 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.clae.2011.05.001