Case Report of Myopia Correction by ReLEx SMILE in a Patient with Superficial Corneal Opacity

Abstract
Introduction.Reduced corneal transparency leads to dissipation of energy of the femtosecond laser (FSL), which may complicate the formation of the intrastromal incision and limits the use of FSL in eyes with corneal opacities and scars. The purpose of this work is to demonstrate the possibility of successful ReLEx SMILE in a patient with superficial corneal opacity located in the paracentral zone.Case report.Patient R., 29 years old, complained of decreased vision in both eyes since childhood. Visual acuity OD = 0.1 sph –2.75D = 1.0; OS = 0.1 sph –3.50 D cyl –0.75D ax 165° = 1.0. Biomicroscopy of the right eye visualized a superficial semi-transparent corneal opacity of 5 x 3 mm located at 5.30–6 hours at a distance of 1.3 mm from the optical center. According to the anterior segment optical coherence tomography (AS-OCT) the depth of the opacity was 73–78 microns and was limited by the Bowman’s membrane. ReLEx SMILE for myopia correction was performed on both eyes with 6.7 mm lenticule diameter at a depth of 120 µm, which covered the opacity area by 1.1 mm. The surgery was standard and uncomplicated. Seven days postoperatively the patient did not complain. Uncorrected visual acuity (UCVA) was 1.0 for both eyes (and binocularly it was 1.2). According to the AS-OCT data, a hyperreflective line of the interface zone was visualized on the right eye at the depth of 141–147 µm; the opacified superficial corneal layers were detected in the lower paracental zone over the interface line. In one month after the surgery the visual acuity did not change: UCVA = 1.0 in both eyes (binocularly 1.2).Conclusion.ReLEx SMILE technology can be considered as one of the options for myopia correction in patients with superficial corneal opacity located in the paracental zone. More observations are required to evaluate the effectiveness of this technology on corneas with paracentral opacities different in sizes and located at different depths.