HISTOPATHOLOGY OF RECURRENT GELATINOUS DROP-LIKE CORNEAL-DYSTROPHY

Purpose. To elucidate more fully the histopathology of gelatinous drop -like corneal dystrophy in a case that recurred and was operated on 7 years after the original surgery. Methods. Transmission electron micro scopy, including the use of cuprolinic blue to image sulfated proteogl ycans, and horseradish peroxidase as a marker for in vitro epithelial permeability. Results, Our patient's epithelium was often abnormally t hick, and many intercellular spaces were present at all levels, althou gh cell-cell contact via desmosomes was also evident. Horseradish pero xidase, when used as an in vitro tracer, was able to penetrate the mos t superficial tight junctions of the corneal epithelium. Basal epithel ial cells were not columnar, and numerous spike-like projections protr uded into the underlying amyloid/collagenous tissue from the basal epi thelium. Beneath this, duplication of a discontinuous epithelial basem ent membrane was noted. In this region, collagen often coexisted with amyloid, the deposition of which was extensive. As in some other corne al pathologies, long-spacing collagen was detected. The association of small proteoglycans with collagen was unremarkable, although some abn ormally large, sulfated proteoglycan filaments were interspersed with the amyloid and underlying stroma. Conclusion. Recurrent gelatinous dr op-like corneal dystrophy shares several histopathologic features with its primary counterpart, although some features, such as the presence of abnormally large, sulfated proteoglycans and long-spacing collagen , the permeability of the epithelial tight junctions, and the duplicat ion of the epithelial basement membrane, have not been reported previo usly.