Unilateral Corneal Ectasia After Bilateral Transepithelial Photorefractive Keratectomy.

We present the case of a 23-year-old male who experienced vision loss in his left eye 15 months after undergoing bilateral transepithelial photorefractive keratectomy (T-PRK). Despite the absence of any significant preoperative topographical risk factors in either eye, corneal ectasia was later confirmed in the left eye, while the right eye remained normal. Subtle asymmetry in topometric indices and a borderline high Index of vertical asymmetry (IVA) reading suggested the possibility of early subclinical keratoconus, potentially increasing the risk of post-refractive ectasia. The patient received corneal cross-linking (CXL) treatment in the affected eye to halt further progression, while the right eye remained under observation. This report reviews the rare instances of post-refractive ectasia. It highlights the potential role of subtle corneal irregularities in predisposing to ectasia, even without traditional risk factors.