Abstract
Purpose::
To elucidate the morphological alterations in eyes with atopic keratoconjunctivitis (AKC) using the new-generation Heidelberg Retina Tomograph II (HRT II)/ Rostock Cornea Module confocal microscope.
Methods::
10 eyes of 5 AKC patients with atopic dermatitis (5 males, average age: 27 years) as well as 8 eyes of 4 healthy normal subjects (4males, average age 21 years) were studied. Those with a history of ocular or systemic disease other than AKC or a history of ocular surgery, contact lens or ocular surface altering drug were excluded. All subjects underwent tear function and ocular surface examinations including corneal sensitivity measurements, Schirmer testing, tear film break-up time (BUT), fluorescein and Rose Bengal staining of the ocular surface and confocal laser scanning microscopy for the central cornea. The morphology characteristics of AKC in different layers of the cornea was observed and compared to those of normal eyes. The ratio of superior and basal epithelial cells was counted. The density of the nerve plexus at the plane of Bowman’s membrane was also calculated. This research followed the tenets of the Declaration of Helsinki. Informed consent from all subjects was obtained.
Results::
In eyes with AKC, the corneal sensitivity(46.9mm) was lower compared to healthy control eyes (60mm) , (p<0.05). The tear functions including BUT(2.2 seconds) and vital staining scores (fluorescein 6.8 points, Rose-Bengal 6.6 points) were also considerably worse. With confocal laser scanning microscopy, eyes with AKC showed a lower ratio of superior epithelial cells to basal epithelial cells (1:6 ). This was due to the decrease in the average basal epithelial density (4658cells/mm2) of AKC patients compared to the density of normal eyes (8550 cells/mm2). The density of nerve fibers at the layer of Bowman’s membrane in eyes with AKC was significantly lower than that of normal eyes , and some nerve fiber morphological abnormalities were observed.
Conclusions::
Abnormal corneal nerve morphology and nerve fiber density was observed in eyes with AKC, which appears to be closely related to change in tear function and corneal sensitivity . Confocal scanning laser microscopy is a useful method to study the pathological changes of corneal morphology in vivo in AKC.
Keywords: cornea: clinical science • conjunctivitis • cornea: stroma and keratocytes