Abstract
Purpose :
To investigate the presence and development of aniridia-associated keratopathy and limbal stem cell insufficiency in its earliest phases in young subjects.
Methods :
A cohort of 46 persons with aniridia (92 eyes) were examined in Germany by slit lamp photography, anterior segment OCT, and in vivo confocal microscopy of the cornea. Half of the examined subjects were children under the age of 18 and as young as nine months. Special attention was paid to the condition of the ocular surface in terms of keratopathy grade, inflammation and ocular surface cellular morphology.
Results :
Central thickness of clear corneas in children increased with peripheral AAK grade and acuity declined with increasing AAK grade (P = 0.02) despite a clear central cornea. 67% of children (24% of adults) had a central corneal epithelial phenotype, the remainder with partial or total conjunctivalization centrally. Corneal subbasal nerve density declined with age at an annual rate of 1.6%, five times the normal rate. Mature dendritic cells in the central cornea were elevated 10 to 20 times the healthy level (P < 0.001), already starting in childhood. Limbal palisdade breakdown was observed with a specific pattern of changes occurring in limbal epithelial cells, blood vessels and dendritic cells.
Conclusions :
In the earliest stages of aniridia-associated keratopathy prior to pannus formation, corneal thickness is elevated, visual acuity declines, nerves degenerate at an increased rate, and antigen-presenting dendritic cells invade the central cornea. These results indicate AAK starts early in life with profound ocular surface changes appearing prior to observable limbal insufficiency.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.