97th DOG Annual Meeting 1999



M. König1,2, L. P. Werner1, L. P. Werner1, J. M. Legeais1, G. Renard1

Introduction: Using the confocal microscope principle, the cornea can be scanned layer by layer and the obtained images are similar to histologic sections. The examination is done in vivo without damage to corneal tissue and without direct contact with the eye.

Materials/Methods: The confocal microscope Tomey ConfoScan was used in our study to assess the size and shape of the deposits in cases of corneal dystrophy. After topical anesthesia (oxybuprocain 0.4%) an immersion technique using a tear replacement liquid (Lacrigel®) was performed. Because of this, the corneal epithelium was not touched during the investigation. Two Achroplan (40/0.75, field 330 x 240 µm, depth of visible field 15 µm, lateral resolution 1mm and 63/0.9, field 210 x 150 µm, depth of visible field 10µm, lateral resolution 0.5 µm) water-immersion objectives can be used for examination of the cornea. The aim of our study was to find out the images obtainable with both objectives.

Results: Granular dystrophy: The epithelium showed irregular, highly reflective deposits of 50 µm in diameter, located between the basal cell layer and the intermediate cell layer. These deposits had a breadcrumb-like appearance and the outlines of the basal cells were normal. Deposits in the stroma varied from round to irregular and were 50 to 500 µm in diameter. The lesions were generally highly reflective, dense, gray-white and separated from the normal stroma. Lattice dystrophy type 1: Characteristic reflective, branching filaments, 80-100 µm in diameter, in the anterior and middle stroma. Their edges were easily visible and they were randomly oriented. Cogan dystrophy: The epithelium showed an abnormal intraepithelial basement membrane in the subepithelial space which appeared separated from the basal epithelial cells. Reis-Bückler's dystrophy: The anterior stroma contained fine, diffuse deposits of dystrophic material interspersed between keratocyte nuclei, rendering observation of their appearance difficult. The underlying stroma with the keratocyte nuclei was normal, as were the Descemet's membrane and endothelium. Fuchs' Dystrophy: Cystic lesions in the stroma and the endothelium showed an abnormal pattern, which had lost its normal architecture.

Summary: Confocal microscopy is a useful adjunct in the diagnosis and management of corneal dystrophies.

1Department of Ophthalmology Hôtel-Dieu Paris, 1, Place du Parvis de Notre Dame, 75181 Paris, France (Dir.: Prof. Dr. G. Renard)