Anterior stromal puncture. Immunohistochemical studies in human corneas
J. K. Hsu, R. S. Rubinfeld, P. Barry and J. V. Jester
Department of Ophthalmology, Georgetown University Medical Center, Washington, DC.
OBJECTIVE: To investigate the mechanism of action of corneal anterior
stromal puncture (ASP) in humans. DESIGN: Immunocytochemical techniques
were used to localize fibronectin, type IV collagen, and laminin in human
corneas with bullous keratopathy, some of which had undergone ASP. Corneal
specimens were obtained from transplant procedures performed in a related
clinical study. SETTING: Outpatients in private practice settings.
PATIENTS: Nine patients with recurrent erosion secondary to bullous
keratopathy who were judged to be poor candidates for keratoplasty.
INTERVENTIONS: Anterior stromal puncture was performed on each patient
using a standardized needle, and corneal transplants were performed on
patients whose erosions did not resolve after ASP. PRIMARY OUTCOME
MEASURES: Subjective comfort and slit-lamp verification of resolution of
rupture of bullae and erosions in patients who underwent ASP; Nomarski
differential interference contrast photography, immunohistochemical
staining, and light microscopy were applied to the corneal specimens.
RESULTS: All three matrix glycoproteins were observed in the epithelial
basement membrane of normal corneas. In patients with bullous keratopathy
who did not undergo ASP, the epithelial basement membrane of the cornea did
not stain with antibodies against human fibronectin, type IV collagen, or
laminin. In patients with bullous keratopathy who underwent ASP, all three
major proteins were present at the puncture sites and in the reactive
subepithelial pannus adjacent to the puncture site. Epithelial basement
membrane of untreated regions showed little or no staining. CONCLUSIONS:
The results suggest that the absence of these extracellular matrix proteins
in the epithelial basement membrane of patients with bullous keratopathy
may be an important factor in the development of poor epithelial adhesion
and secondary erosions. Anterior stromal puncture may promote epithelial
reattachment, at least in bullous keratopathy, by stimulating the
production of extracellular matrix proteins that are important in the
attachment of epithelial cells to the underlying connective tissue.
Epithelial-stromal reactions and the development of subepithelial fibrosis
may also play a role in reestablishing epithelial attachment.
