Random Implantation of Asymmetric Intracorneal Rings

Intracorneal ring employment for treating ectasia is widespread. Although the mechanism of action of intracorneal rings in the regularization of the corneal surface after its implantation is well known in most cases, there are still many doubts. We present a case of implanted intracorneal rings, where, despite the peculiar position of the rings, the patient gains lines of visual acuity and keratoconus remains stable. 1. Introduction Keratoconus is the most common corneal ectasia in which central or paracentral thinning occurs without presenting signs of inflammation; it induces irregular corneal astigmatism and myopic shift [1]. The use of spectacles and contact lenses is sufficient to correct the refractive error in the initial stages. However, in more advanced cases, the therapeutic options may be different, ranging from intrastromal ring implantation, the use of cross-linking techniques, and lamellar keratoplasty to finally, in advanced cases, penetrating keratoplasty [2]. 2. Clinical Case Report A 48-year-old woman, with no relevant personal systemic history, was diagnosed with keratoconus in both eyes. Her ophthalmologic history presented penetrating keratoplasty of her right eye (RE) performed ten years previously due to advanced keratoconus and myopia magna of 12 D. The patient’s visual acuity (VA) was 0.2 with (？14.5, ) in her RE and 0.5 with (？10.75, ) in her left eye (LE). Ocular pressure was 16？mm？Hg in her RE and 17？mm？Hg in her LE. Slit lamp examination showed that the corneal button of her RE was clear, with no signs of rejection or vascularization at the edges (Figure 1). Her LE clearly presented an advanced keratoconus with signs of Vogt’s striae, an iron line forming a Fleischer ring, and the presence of prominent intrastromal corneal nerves. Figure 1: Right eye image of the patient by slit lamp, which shows penetrating keratoplasty and two upper iridectomies. The funduscopic examination revealed the existence of advanced myopic retinochoroid it is with paripapillary and retinal atrophy areas in both eyes. Even though the stage of the keratoconus was so advanced in her LE, two intrastromal rings were implanted by IntraLase femtosecond laser. We used the femtosecond laser to make the channel and the corneal incision where the intracorneal rings were inserted. To introduce the corneal rings into the unique corneal channel, specific forceps and Sinskey hook were employed. Two symmetrical rings were placed, one upper and one lower, with a triangular-shaped cross-section like the Keraring model, 300 microns thick, 160° arch length, axis at