Analysis of protein composition and protein expression in the tear fluid of patients with congenital aniridia.

Aniridia is a rare congenital genetic disorder caused by haploinsuffiency of the PAX6 gene, the master gene for development of the eye. The expression of tear proteins in aniridia is unknown. To screen for proteins involved in the aniridia pathophysiology, the tear fluid of patients with diagnosed congenital aniridia was examined using two-dimensional electrophoresis (2-DE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Two-dimensional map of tear proteins in aniridia has been established and 7 proteins were differentially expressed with P<0.01 between aniridia patients and control subjects. Five of them were more abundant in healthy subjects, particularly α-enolase, peroxiredoxin 6, cystatin S, gelsolin, apolipoprotein A-1 and two other proteins, zinc-α2-glycoprotein and lactoferrin were more expressed in the tears of aniridia patients. Moreover, immunoblot analysis revealed elevated levels of vascular endothelial growth factor (VEGF) in aniridia tears which is in concordance with clinical finding of pathological blood and lymph vessels in the central and peripheral cornea of aniridia patients. The proteins with different expression in patients' tears may be new candidate molecules involved in the pathophysiology of aniridia and thus may be helpful for development of novel treatment strategies for the symptomatic therapy of this vision threatening condition. BIOLOGICAL SIGNIFICANCE: This study is first to demonstrate protein composition and protein expression in aniridic tears and identifies proteins with different abundance in tear fluid from patients with congenital aniridia vs. healthy tears.

In vivo morphology of the limbal palisades of vogt correlates with progressive stem cell deficiency in aniridia-related keratopathy.

PURPOSE: To investigate morphologic alterations in the limbal palisades of Vogt in a progressive form of limbal stem cell deficiency. METHODS: Twenty Norwegian subjects (40 eyes) with congenital aniridia and 9 healthy family members (18 eyes) without aniridia were examined. Clinical grade of aniridia-related keratopathy (ARK) was assessed by slit-lamp biomicroscopy, and tear production and quality, corneal thickness, and sensitivity were additionally measured. The superior and inferior limbal palisades of Vogt and central cornea were examined by laser scanning in vivo confocal microscopy (IVCM). RESULTS: In an aniridia patient with grade 0 ARK, a transparent cornea and normal limbal palisade morphology were found. In grade 1 ARK, 5 of 12 eyes had degraded palisade structures. In the remaining grade 1 eyes and in all 20 eyes with stage 2, 3, and 4 ARK, palisade structures were absent by IVCM. Increasing ARK grade significantly correlated with reduced visual acuity and corneal sensitivity, increased corneal thickness, degree of degradation of superior and inferior palisade structures, reduced peripheral nerves, increased inflammatory cell invasion, and reduced density of basal epithelial cells and central subbasal nerves. Moreover, limbal basal epithelial cell density and central corneal subbasal nerve density were both significantly reduced in aniridia compared to healthy corneas (P = 0.002 and 0.003, respectively). CONCLUSIONS: Progression of limbal stem cell deficiency in aniridia correlates with degradation of palisade structures, gradual transformation of epithelial phenotype, onset of inflammation, and a corneal nerve deficit. IVCM can be useful in monitoring early- to late-stage degenerative changes in stem cell-deficient patients.

Dystrophia Helsinglandica--corneal morphology, topography and sensitivity in a hereditary corneal disease with recurrent erosive episodes.

PURPOSE: The aim of this study was to describe the morphology, corneal topography and sensitivity in individuals with Dystrophia Helsinglandica. This autosomal dominant corneal disease is characterized by recurrent corneal erosive episodes and progressive subepithelial fibrosis not significantly affecting visual acuity. METHODS: The corneas of nine affected and nine unaffected individuals were examined using slit-lamp biomicroscopy, in vivo confocal microscopy (IVCM) and videokeratography. Corneal mechanical sensitivity was also measured using a non-contact esthesiometer. RESULTS: Slit-lamp biomicroscopy revealed that the affected individuals represented different stages of corneal changes, from a nearly normal cornea to subepithelial fibrosis of the central cornea. Corneal changes in affected individuals did not significantly decrease the best spectacle-corrected visual acuity. In vivo confocal microscopy detected morphological changes in the epithelium and stroma. Subepithelial opacity formation including altered keratocytes could be found in the anterior stroma in all affected eyes. With the exception of two eyes (one affected and one unaffected), all videokeratographies showed irregular astigmatism. Corneal sensitivity was significantly lower in affected individuals (p = 0.01). Age and corneal sensitivity showed no correlation. CONCLUSION: The main morphological findings in affected individuals were discrete and progressive subepithelial fibrosis, in the in vivo confocal microscope corresponding to optically dense extracellular matrix and activated keratocytes. Subbasal nerve morphology was changed in the affected family members who also showed a decreased corneal sensitivity. The findings are per se not specific to the disease. The changes probably reflect a healing response to erosive events on the corneal surface influenced by the genotype.

Dystrophia Smolandiensis: a novel morphological picture of recurrent corneal erosions.

PURPOSE: The aim of this study was to describe morphological changes in Dystrophia Smolandiensis, a corneal disease that is characterized by recurrent corneal erosive episodes and the formation of central corneal keloid-like opacities in approximately half of those affected. METHODS: The corneas of seven affected individuals were examined using in-vivo confocal microscopy. Specimens of one primary corneal graft, one regraft and one biopsied keloid-like region--all obtained from members of a large family with the disease--were re-examined with a light microscope. Sections were stained with Congo red and analysed immunohistochemically for fibronectin and S100A4. RESULTS: Light microscopic examination revealed epithelial hyperplasia, absence of Bowman's layer and subepithelial fibrosis. Fibronectin was expressed in the area of subepithelial fibrosis, and the keratocytes in this area generally expressed S100A4. The biopsy specimen stained positive for Congo red, suggesting an amyloid deposit. In-vivo confocal microscopy confirmed epithelial abnormalities, loss of Bowman's layer and significant alterations of the subbasal nerve plexus in affected individuals. CONCLUSION: The morphological picture in Dystrophia Smolandiensis is novel for a condition dominated by recurrent corneal erosions at the clinical level. Although no single morphological feature unique to the disease could be found, the general morphological pattern of pathology (true keloid formation, absence of Bowman's layer, subepithelial fibrosis and abnormal subbasal nerves) probably reflects a novel phenotypic expression of the healing response to recurrent erosion of the corneal epithelium. However, the pathogenesis of Dystrophia Smolandiensis remains to be elucidated fully.

Dystrophia Helsinglandica: a new type of hereditary corneal recurrent erosions with late subepithelial fibrosis.

PURPOSE: To describe the phenotype of an autosomal-dominant corneal dystrophy with an early onset of recurrent corneal erosions and development of subepithelial fibrosis in the cornea, and also to exclude genetic linkage to known corneal dystrophies with autosomal-dominant inheritance and clinical resemblance. METHODS: We describe the medical history and clinical findings in individuals from a seven-generation family with recurrent corneal erosions. A total of 43 individuals were evaluated by ophthalmological examination. Genomic DNA was prepared from peripheral blood and polymorphic microsatellite markers were analysed to study haplotypes surrounding genes causing corneal dystrophies with similar phenotypes. RESULTS: Erosive symptoms usually lasted for between 1 and 10 days. By the age of 7 almost all of the affected individuals suffered from recurrent corneal erosions. The attacks generally declined in frequency and intensity from the late 20s, but all examined individuals had developed subepithelial fibrosis by the age of 37. The fibrosis generally started in the mid periphery and was followed in some family members by central fibrosis and the development of gelatinous superficial elevations. Only a marginal reduction of visual acuity was seen in a few individuals. The affected individuals did not share haplotypes for genetic microsatellite markers surrounding genes that are known to cause autosomal-dominant corneal dystrophies. CONCLUSION: We describe a new type of autosomal-dominant corneal disorder with recurrent corneal erosions and subepithelial fibrosis not significantly affecting visual acuity.

A new corneal disease with recurrent erosive episodes and autosomal-dominant inheritance.

PURPOSE: The aim of this study was to characterize the phenotype in a large family with autosomal-dominant recurrent corneal erosions, and also to exclude genetic linkage to known autosomal-dominant inherited corneal dystrophies with clinical resemblance. METHODS: We describe the medical history and clinical findings in patients from a six-generation family with recurrent corneal erosions. A total of 28 individuals were evaluated by ophthalmological examination. Genomic DNA was prepared from peripheral blood and analysed with polymorphic microsatellite markers close to known genes causing autosomal-dominant corneal dystrophies. RESULTS: The patients had erosive symptoms that usually lasted from 1 to 7 days. The symptoms were described as early as at 8 months of age, and by the age of 5 the majority of the affected individuals suffered from recurrent corneal erosions. The attacks generally declined in frequency and intensity with age, and 52% of the patients developed central keloid-like corneal opacities. Nine patients received corneal grafts, and recurrences were seen in all grafts. The affected patients did not share haplotypes for genetic microsatellite markers surrounding known genes causing autosomal-dominant corneal dystrophies. CONCLUSION: We describe a new hereditary disease with recurrent corneal erosions. Attacks of symptoms similar to recurrent erosions dominate the phenotype, but half of those affected also developed corneal, keloid-like, central opacities. This disorder was not genetically linked to any clinically resembling corneal dystrophies with autosomal-dominant inheritance.

Inherited corneal opacifications with an unusual distribution.

PURPOSE: To describe corneal opacities of a new type and distribution in a small family. METHODS: Family members were interviewed and examined to establish a pedigree and to detect any corneal abnormalities. RESULTS: Two family members presented with corneal opacities. Both had, in the very peripheral cornea, flat, greyish, rounded opacities, 20-200 microm in diameter, on the Descemet's membrane. In addition, the mother had the same type of opacities over the central cornea just inside the Bowman's layer. The remaining parts of the corneas were clear. Vision was unaffected and the opacities caused no discomfort. There was no other corneal pathology. The subjects' general health was good. CONCLUSIONS: To our knowledge, these types and distribution of corneal opacities have not been described previously. Although the mode of inheritance at this point is uncertain, we believe the changes are of a dystrophic nature.