98th Annual Meeting DOG 2000

P 6

Ocular findings in myotonic dystrophy (MIM # 160900)

S. J. Fröhlich, G. Rudolph, M. W. Ulbig

Introduction: The myotonic dystrophy Curschmann Steinert is an autosomal dominant hereditary disorder with great variability of the phenotype. The genetic basis is a trinucleotide repeat expansion in the 3´-untranslated region of a protein kinase-encoding gene, which is on the long arm of chromosome 19. Besides its multi-organic involvement, progressive muscle wasting of the facial muscles, sternomastoids, shoulder girdles and the distal limb muscles occurs. The eye reveals ptosis and a characteristic "christmas tree" cataract. As a retinal involvement unspecific pigmentary lesions are known which are usually innocuous. This case report describes further ocular findings of this neuromuscular disorder.

Methods: In November 1999, a 42 years old male patient was seen and the diagnosis of myotonic dystrophy was confirmed by molecular and genetic tests. He was refered from a general practitioner to exclude diabetic retinopathy. A complete ophthalmologic examination was performed. Ocular manifestations found by slitlamp biomicroscopy were documented photographically.

Results: Our patient presented the characteristic mournful expression caused by facial weakness ("facies myopathica") with bilateral ptosis. Furthermore, pigmentary deposits at the anterior lens capsule as well as irregular pigmentation of the pupillary border were seen. The cristalline lens showed mild opacity. A bilateral premacular gliosis with surface-wrinkling was present. Visual acuity was 20/25 on both eyes, intraocular pressure was 10 and 13 mm Hg. There was no diabetic retinopathy.

Discussion: This case describes for the first time the presence of pigment dispersion and premacular gliosis in a patient with myotonic dystrophy. Thus there can be seen further ocular abnormalities besides the most frequent such as ptosis and cataract. Our observation confirms the considerable variation in the severity of phenotypic expression in the eye due to a generalized membrane defect. None.

Department of Ophthalmology, Ludwig-Maximilians-Universität, Munich, Germany