Case Report: Recurrence of Keratoconus After Penetrating Keratoplasty

Introduction Keratoconus (KC) is a progressive eye disease characterized by thinning and bulging of the cornea, which takes on a conical shape, resulting in visual distortion. In the early stages of KC, non-surgical measures such as glasses and contact lenses help to improve vision, while corneal cross-linking can halt the progression of the disease. In advanced cases, however, a corneal transplantation may be necessary.(1) Even though keratoplasties offer good outcomes in long-term KC treatment, primary corneal disease may reoccur. Case Presentation We present the case of a 44-year-old man who was diagnosed with KC in both eyes at the age of 14. At the age of 18, he underwent penetrating keratoplasty (PK) with a small graft diameter (7 mm) on the right eye (RE). At the age of 24, a PK was performed on his left eye (LE). The patient consulted three years ago because his vision and sensitivity to light in the LE had deteriorated. His uncorrected visual acuity (decimal) was 0.06 in the RE and 0.07 in the LE, with a best corrected visual acuity of 0.2 in the RE and 0.1 in the LE. Slit lamp examination showed bulging of the host cornea in both eyes and central stromal opacities of the graft in LE. In addition, corneal topography of LE revealed an inferior steepening with a maximum corneal curvature of 48.05 diopters and a thinnest point of 553 µm. The measurements in RE were consistent. As the patient was diagnosed with a recurrence of KC in both eyes and opaque cornea in LE, he underwent LE PK with a larger graft diameter at the age of 41. Almost three years after surgery, his visual acuity improved to 0.8 in LE. Even though patient‘s vision in RE remained relatively stable over the years, rigid gas permeable contact lens was recommended in order to improve visual acuity and avoid repeated KP. Discussion Studies show that 6-11% of patients who undergo PK experience a recurrence of ectasia.(2) This recurrence is often associated with smaller diameter PK, which gradually leads to lateral reappeared KC expansion around the graft. On the other hand, smaller diameter PK is often preferred in young KC patients to preserve corneal tissue in case retransplantation is required later.(3) Conclusions In this case, a repeat keratoplasty was necessary due to central graft opacities and the recurrence of KC in the host cornea.