Purpose: The study reports the results of a histological and ultrastructural examination of the corneal button, obtained during penetrating keratoplasty from patient with clinically recognized macular corneal dystrophy.
Material and methods: 34-year-old male patient suffering from macular corneal dystrophy (MCD) has been treated on corneal epithelium defect and photophobia since his early childhood. Visual acuity was decreased on the Snellen test chart to 0.02. Slit-lamp examination, and ultrasonographical measurement of the cornea's thickness were performed. Removed during penetrating keratoplasty corneal button was divided into two pieces. One of them was prepared in standard procedure for histological examination in the light microscopy after having been stained with hematoxylin and eosin, alcian blue and paS-method. From the other part, slides for ultrastructural examination in the transmission electron microscopy were prepared with the use of standard method. The family history from the patient was also taken, and available relatives have undergone examination in search of typical MCD symptoms.
Results: Slit-lamp examination findings revealed diffuse, from limbus to limbus, stromal opacification. In measurement by pachymeter cornea's thickness was reduced. In the light microscopy, in typical stained slides, delaminations within stroma and deficit of endothelial cells were observed. After being stained with alcian blue, dark blue deposits in the places of delamination became visible. By transmission electron microscopic examination, intracellular and extracellular deposits were detected in the stroma, Descemet membrane and endothelium. Distended keratocytes with enormous vacuoles containing abnormal material were found. Pedigree was typical for autosomal recessive inherited disease.
Conclusions: Histological and ultrastructural diagnosis is a basis of recognition of macular corneal dystrophy. Analysis of the pedigree as well as ultrasonographical measurement of the cornea's thickness is very helpful to establish the right diagnosis.