Abstract
Abstract: :
Purpose: To present previously unreported ophthalmic features associated with distal arthrogryposis (DA) type IIB. Methods: Distal arthrogryposes are a group of inherited contractural syndromes with tightly clenched fists, medially overlapping fingers and positional foot deformities. They have been subclassified according to their additional features. We describe four members spanning three generations of a Caucasian family with DA type IIB transmitted as an autosomal dominant inheritance with variable expressivity. These included three females and one male. All patients underwent full ophthalmological and rheumatological examination. Light and electron microscopy was performed on the corneal specimen obtained from the index patient during penetrating keratoplasty. Results: All four patients had different degrees of ophthalmoplegia, blepharophimosis, astigmatism and strabismus. The three females had increased central corneal thickness of 680 micrometer on orbscan. Two of them also had choroidal folds at the macula which did not affect their vision. The index patient, a fifty three year old male, underwent penetrating keratoplasty for progressive visual loss due to keratoconus. Electron microscopy of the corneal tissue showed loss of normal regular collagen arrangement with apparent haphazard collagen fibril deposition in a herring bone pattern. Conclusion: A variety of ocular findings have been reported in distal arthrogryposis. Increased corneal thickness, choroidal folds and electron microscopy of the affected cornea have not been documented previously. Mutations in extracellular matrix proteins have been implicated as a cause of the distal limb contractures seen in this condition. The abnormal corneal collagen arrangement may be a result of similar mutations in the corneal extracellular matrix.
Keywords: 420 genetics • 450 keratoconus • 472 microscopy: electron microscopy