Characteristics and risk factors of recurrent keratoconus over the long term after penetrating keratoplasty

Abstract

KC progresses even after PK over the long term, requiring re-grafting in some cases. Risk factors for recurrent KC after PK are increasing Ks over time and a large CYL.

Risk factors and evaluation of keratoconus progression after penetrating keratoplasty with anterior segment optical coherence tomography

“…The finding that both IHT/CCT and IGT/CCT were smaller in the KC group than in the Others group supports the notion that the progression occurs in both the graft and host. This notion is also supported by our previous reports on histopathologic specimens of corneas with recurrent KC 7 , 8 . In the regression analysis that we performed to find out the factors contributing to the keratometric changes, IHT/CCT, a parameter reflecting host thinning, was selected in the analyses.…”

“…We recently reported that KC recurs in up to 36% of PK patients who had maintained clear grafts for over 10 years 8 . Also, in a report of acute hydrops cases in recurrent KC 7 , Descemet’s membrane breaks are seen around the graft-host junction, not around the center as usually seen in keratoplasty-naïve KC.…”

Corneal topography in keratoconus evaluated more than 30 years after penetrating keratoplasty: a Fourier harmonic analysis

“…Moreover, differences in components using Fourier harmonic analysis were detected for the analysis of the 6-mm diameter, but not for the analysis of the 3-mm diameter. Given that topographic changes after PK in patients with KC possibly occur at the pericenter or inferior side of the cornea rather than at the center 8 , our research also suggested that AS-OCT analysis with a wider area can more sensitively detect changes in the cornea and be a useful evaluation tool. In addition, this approach using AS-OCT with Fourier harmonic analysis could be applicable for the long-term evaluation of other procedures involving corneal transplantation for KC such as deep anterior lamellar keratoplasty (DALK).…”

“…The corneal shape can gradually change after PK for KC, and several studies have investigated the parameters that could be useful for its assessment. Yoshida et al 8 previously reported that a large corneal cylinder power was a risk factor for recurrent KC after PK. We analyzed corneal topography in more detail and demonstrated that regular astigmatism in the anterior cornea was significantly larger in the KC group than in the Others group; this result suggested the progression of recurrent keratoconic changes in the KC group.…”

“…The clinical outcome after PK for KC is better than that for other diseases such as bullous keratopathy or regrafts 1 , 7 , and the corneal graft usually survives for a long time. However, KC sometimes recurs and progresses postoperatively, thereby resulting in acute hydrops, reduced visual acuity, and graft failure 8 , 9 . To understand and detect the recurrence of KC, detailed observation after PK is required.…”