Abstract
Purpose:
To investigate the changes of conjunctival epithelium at the pterygium and donor graft sites after pterygium excision and limbal-conjunctival autograft.
Methods:
This is a prospective study that included 16 eyes of 15 patients. Impression cytology specimens were obtained preoperatively and at 1, 3 and 6 months postoperatively, at the site of the pterygium and donor graft site, respectively. In each specimen, changes of conjunctival epithelium were evaluated using the nucleus-to-cytoplasm(N/C) ratio and goblet cell density (GCD). Morphologic changes of cell and nucleus were also evaluated.
Results:
Preoperatively, Both N/C ratio and GCD were significantly higher in specimens from pterygium site than those from graft harvest site. At both sites, GCD decreased rapidly at 1 month after surgery, but showed gradual recovery. No significant difference in GCD was found between the two sites at postoperative 1, 3 and 6 months. Although there was no significant difference in the N/C ratio at 1 and 3 month, pterygium site showed significantly higher N/C ratio than donor graft site at 6 months. At postoperative 6 months, changes suggesting squamous metaplasia elongation of the cells and pyknotic changes in the nuclei-was noticed in 5 samples from the pterygium site, although these changes were never found at donor graft site.
Conclusions:
Conjunctival epithelial metaplasia may persist even after pterygium removal and limbal reconstruction. Restoration of limbal barrier function may prevent the corneal involvement of the metaplastic conjunctival epithelial cells.