Abstract
Purpose:
There are controversial reports that lattice corneal dystrophy, type 1 (LCD1) is of epithelial or stromal origin. The aim of this study is to evaluate this question.
Methods:
We observed ten eyes of five LCD1 patients after penetrating keratoplasty (PKP) on both eyes with a follow-up of 8-14 years post-op. A slit-lamp photo-documentation of all patients in direct and indirect illumination was performed with dilated pupil.
Results:
All ten corneal transplants of the LCD1-patients showed subepithelial diffuse opacities of different severity, beginning after 3-4 years postoperatively, that were often combined with corneal erosions and consecutive pain. In none of our patients, we were able to disclose any signs of lattice formation in form of gray lines which run obliquely from the surface to the midstroma in direct illumination. In retroillumination, no lattice opacity units in form of translucent and refractile lines were visible.
Conclusions:
The transforming growth factor beta-induced (TGFBI) gene, that is also responsible for LCD1, is expressed above all by the corneal epithelial cells but also by the keratocytes. We interpret the superficial, diffuse LCD1 opacities on the graft as the product of the epithelial cells, whereas the non-occurrence of lattice lines as long as 14 years postoperatively as an indirect sign that the lattice lines are the product of the keratocytes. We know, that stromal corneal dystrophies such as macular corneal dystrophy may not recur before decades on the graft due to the very slow transformation of transplant keratocytes into pathological host keratocytes. Thus, LCD1 seems to represent an epithelial-stromal entity, because both, the epithelial cells and keratocytes are pathophysiologically involved.
Keywords: 494 degenerations/dystrophies •
482 cornea: epithelium •
484 cornea: stroma and keratocytes