Role of ultrasound biomicroscopy in diagnosis and treatment of Terrien disease.

PURPOSE: Terrien disease is a rare form of peripheral corneal degeneration characterized by vascularization, opacification, lipid deposition, and corneal thinning. In this study, a high-frequency ultrasound biomicroscope (UBM) was used to detect the morphologic changes before and after surgery and to determine the stages of this disease. METHODS: Two patients with Terrien disease were examined by UBM, corneal topography, and a keratometer before and after surgery (full-thickness keratectomy). RESULTS: The absence of the Bowman layer and thinning of the Descemet layer in the ectatic part of the peripheral cornea were detected by using the UBM before surgery. Earlier, these signs could be detected only with optical and electron microscopy from histologic samples; now we can detect the signs of Terrien disease with noninvasive devices such as the UBM. CONCLUSIONS: The UBM is an effective device for following the progression of Terrien disease and determining the timing of these patients' surgeries.

Excimer laser exacerbation of Avellino corneal dystrophy.

We review the clinical, histopathological, and ultrastructural findings and DNA phenotyping of a patient with Avellino corneal dystrophy exacerbated by laser in situ keratomileusis. The findings are reported and interpreted in the context of a literature review. The case highlights the possible difficulty of recognizing subtle dystrophic findings, as well as the importance of avoiding refractive surgical intervention in patients with Avellino corneal dystrophy to avoid exacerbation of dystrophic deposits in the cornea and subsequent reduction in vision.

[Corneal macular dystrophy: clinical, histopathologic and ultrastructural features]. / Distrofia macular corneal: características clínicas, histopatológicas y ultraestructurales.

OBJECTIVE: To assess the main clinical, genetic, histopathological and ultrastructural features of Mexican patients with macular corneal dystrophy, and to compare the results with those previously reported. METHOD: We analyzed six cases where a histopathologic diagnosis of macular corneal dystrophy had been made between 1957 and 2004. RESULTS: Clinically, all corneas showed focal grayish-white stromal opacities with diffuse edges. Histopathologically, intrastromal granules stained strongly positive with Alcian blue and colloidal iron. Transmission electron microscopy showed enlargement of smooth endoplasmic reticulum and the presence of intracytoplasmic vacuoles that corresponded to glycosaminoglycans. Genetic analysis showed novel mutations in the CHST6 gene in 2 of the patients. CONCLUSIONS: Females were more affected than males and the mean age at the time of diagnosis was older than that reported previously, however the clinical, histopathological and ultrastructural features were similar to those of previous reports. As described in other cases in the literature, in some instances a disorder is found in CHST6 gene as a basis for this condition.

Identification of oxytalan fibers in Salzmann's nodular degeneration.

PURPOSE: Diagnosis of Salzmann's nodular degeneration is based on clinical findings, as histopathologic findings in nodules are nonspecific on routine examination. This study demonstrates that presence of oxytalan fibers (ie, elastic system fibers) in lesions of Salzmann's nodular degeneration under light and electron microscopy allows definitive diagnosis. METHODS: A 55-year-old woman noticed white nodular lesions on both corneas. Excised lesion tissues were examined under light microscopy with special staining and transmission electron microscopy. RESULTS: Nodular lesions comprised hyalinized connective tissue showing nonspecific findings on routine histologic examination. However, oxidized aldehyde fuchsin staining yielded positive results in lesions, indicating the presence of oxytalan fibers. Transmission electron microscopy identified bundles of microfibrils in lesions, confirming the presence of oxytalan fibers. CONCLUSIONS: Light microscopic examination by oxidized aldehyde fuchsin staining should be performed when diagnosing Salzmann's nodular degeneration.

Avellino corneal dystrophy exacerbated after LASIK: scanning electron microscopic findings.

PURPOSE: To evaluate the ultrastructure of the cornea of Avellino corneal dystrophy (ACD) exacerbated by LASIK. METHODS: Three ACD patients with exacerbation of granular corneal deposits after LASIK underwent surgical removal of the corneal flap. The corneal flap was processed for scanning electron microscopy (SEM). RESULTS: SEM of all patients showed abnormal granular clusters in the fibrils of the corneal flap. CONCLUSION: Laser in situ keratomileusis induces corneal collagen abnormalities and adhesions of granular material in ACD patients.

[Macular corneal dystrophy including histologic and ultrastructural changes]. / Dystrofia plamkowata rogówki z uwzglednieniem zmian histopatologicznych i ultrastrukturalnych.

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.