Abstract
Purpose:
To investigate morphologic alterations in the limbal palisades of Vogt in a cohort of Norwegian patients with congenital aniridia.
Methods:
All subjects were examined bilaterally by slit lamp biomicroscopy, and the limbal palisades of Vogt were examined microscopically by laser-scanning confocal microscopy (IVCM). Slit lamp biomicroscopy was used to grade the stage of aniridia-related keratopathy (ARK) based on degree of conjunctivalization of the peripheral and central cornea. By IVCM, specific limbal morphology of epithelial cells, palisade ridges and projections was assessed.
Results:
Two eyes were found without clinical signs of ARK, and in these eyes, the limbal palisades had a normal-appearing morphology. In the earliest stages of ARK where conjunctiva extended over the limbal barrier, recognizable microscopic remnants of palisade structures were apparent, but no normal-appearing palisade structures were visible by IVCM. Limbal epithelial cells lost a regular mosaic and conjunctival-type epithelium invaded the limbal space. In all eyes with later stages of ARK, conjunctivalization of the periphery or entire cornea was observed clinically, while no palisade structures were present by IVCM. In a control group, normal limbal palisades of Vogt structures were observed in the superior limbus in all eyes, but in five eyes in the inferior limbus normal palisades structures were replaced by abnormal features.
Conclusions:
There appears to be a strong relationship of the microscopic appearance of the limbal palisades of Vogt in aniridia and the corresponding clinical degree of conjunctivalization of the cornea, which lends support to the theory that the palisades of Vogt represents a stem cell niche. IVCM could be a useful tool to assess early morphologic changes that accompany stem cell deficiency.
Keywords: 482 cornea: epithelium