Keratoconus (KC) is a noninflammatory, bilateral, progressive, asymmetric, and degenerative disease of the cornea characterized by stromal thinning and increased corneal curvature, with a prevalence of about 1/20,000 general population, depending on the population described [1, 2]. Although refractive correction with spectacles or contact lenses can provide acceptable improvement in visual acuity for many of these patients, the quality of vision might still be reduced in some cases due to irregular astigmatism associated with the disease .
Corneal refractive surgery, especially laser in situ keratomileusis (LASIK), in patients with such irregular corneas has long been contraindicated due to the risk of postoperative progression of the disease process. The flap created increases alterations to the biomechanical properties and weakens even more the corneal tissue, which in turn renders the cornea more prone to keratectasia . However, numerous studies report the safety of surface ablation procedures in milder forms of KC, with photorefractive keratectomy (PRK) alone or even PRK followed by corneal collagen crosslinking [1, 5, 6]. Current regimes for PRK in such cases utilize topography-guided ablation profiles intended to reduce corneal surface irregularities and therefore improve vision quality. Although corneal ectasia has been previously described after PRK in suspected keratoconus cases , other studies report encouraging results [6, 8].
A primary concern associated with refractive surgery in patients with atypical corneal topography is that the procedure might increase the speed of progression of the ectatic process . Retrospective case–control studies of patients with ectasia suggest five main risk factors for progression of the disorder after laser vision correction: (1) abnormal preoperative topography; (2) low residual bed thickness; (3) young age; (4) low preoperative corneal thickness; and (5) high myopia .
In this article, we describe the clinical outcome of a patient diagnosed with mild KC who underwent advanced surface ablation in both eyes and whose condition has been stable for 15 years.
Presentation of this case has been approved by the Ethics committee of Universidade Federal de São Paulo (UNIFESP/SP 2018; no. 2.568.770). The patient reported in the case report signed an informed consent form.