Abstract
Purpose::
Pterygium is a frequent ocular surface disorder of unknown origin characterized by chronic conjunctival inflammation with a clear central cornea at the slit lamp examination in most patients. The purpose of the present study was to test the hypothesis that anatomical and immunological changes are present in the cornea.
Methods::
The central cornea of twenty eyes of 18 patients (14 males, average age 45 ± 17 yrs.) with primary pterygium was examined by in vivo confocal microscopy using a 40x lens and an axial resolution of 5 µm. The size of pterygia was measured by analyzing photographic images. Data from 20 age-matched normal subjects were used as control for analysis.
Results::
The images obtained showed a significant lower number of epithelial cells in patients with pterygium (1043 ± 214 cc/mm2) compared to controls (1575 ± 238 cc/mm2), superficial epithelial cell area considerably higher than normal, reduced nucleus/cytoplasm ratio, halos around the nuclei, and sharp borders. Numerous highly reflective dendritic-like cells were present in the epithelial cell basal layer, and their density correlated with the size of pterygium. The stroma showed a loss of keratocytes and the presence of lacunae. In particular, the anterior stroma showed a higher reflectivity of the extracellular matrix, and in the middle stroma some fiber-like structures were found. Tortuosity and number of vesicles of subbasal nerves were significantly higher than controls. The endothelial cell count showed a normal density of cells of this layer.
Conclusions::
In vivo confocal microscopy may be helpful in evaluating the immunological and structural changes of the cornea in patients with pterygium, and in understanding its pathophysiology and the possible role of an anti-inflammatory therapy.
Keywords: Pterygium • conjunctiva