Phenotypic variation in combined granular-lattice (Avellino) corneal dystrophy
G. O. Rosenwasser, B. M. Sucheski, N. Rosa, B. Pastena, A. Sebastiani, J. W. Sassani and H. D. Perry
Department of Ophthalmology, Pennsylvania State University, Hershey.
OBJECTIVE: To describe the phenotypic variation exhibited by members of
families with combined granular-lattice (Avellino) corneal dystrophy.
SETTING: We examined 40 patients (age range, 12 to 85 years) from six
unrelated families with Avellino corneal dystrophy. This included the first
individuals to ever be examined near the presumed site of origin in Italy.
In addition, one family was the first to trace its origins to Germany
rather than to Italy. We studied the phenotypic expression of the disease
in the cornea, visual acuities, subjective complaints, complications,
treatment, and histologic condition of these individuals. RESULTS: The
granular stromal lesions reach their mature quantity and size early in
life, and appear as either gray and crumb-shaped deposits or superficial
with an annular and planar distribution. The lattice component appears
gradually, beginning and maturing later in life. The phenotypic variation
within families was found to be substantial. Widely variable proportions of
lattice and granular changes were found within single sibships. Visual
acuities ranged from 20/20 to 20/400. Recurrent corneal erosions were
present but infrequent. Subjective complaints included glare and decreased
night vision. Penetrating keratoplasty was required in one individual to
restore vision. Histopathologic examination revealed typical amyloid and
granular deposits. Granular deposits were found replacing Bowman's membrane
and extending to the corneal surface. These deposits probably represent the
cause of recurrent erosions. CONCLUSIONS: Combined granular and lattice
corneal dystrophy may present with substantial phenotypic variation. The
disease can be found in individuals who trace their ancestry to both Italy
and Germany, a wider geographic distribution than previously proposed.
