Diagnostic Considerations
Lattice corneal dystrophy is differentiated among the three major stromal corneal dystrophies (granular, macular, and lattice) based on history and examination.
Family history may distinguish macular dystrophy (autosomal-recessive inheritance) from granular and lattice (autosomal-dominant inheritance). Clinically, all three may present in the first decade of life; however, lattice and granular corneal dystrophy typically do not result in reduced visual acuity until later in life.
On examination, each has a distinct appearance. In granular dystrophy, the corneal opacities are discrete globular opacities with clear intervening stroma sparing the limbus. In macular dystrophy, opacities have indistinct margins, the intervening stroma is hazy, and lesions may extend to the limbus. In lattice dystrophy, lesions are linear and refractile, and, while there may be diffuse central haze, the limbal zone is clear except in extreme cases. The table below, adapted from Cornea (1996), presents characteristics of the three major corneal dystrophies. [13]
Table 1. Characteristics of the Three Major Stromal Corneal Dystrophies (Open Table in a new window)
Feature |
Granular Dystrophy |
Macular Dystrophy |
Lattice Dystrophy |
|---|---|---|---|
Age of onset |
First decade of life |
First decade of life |
First decade of life |
Heredity |
Autosomal dominant |
Autosomal recessive |
Autosomal dominant |
Reduced vision |
Fourth or fifth decade of life |
First or second decade of life |
Second or third decade of life |
Erosions |
Uncommon |
Common |
Frequent |
Opacities |
Discrete, intervening stroma Clear, not to limbus |
Indistinct margins, intervening Stroma hazy, extends to limbus |
Refractile lines and dots Usually not to limbus |
Material |
Hyaline |
Glycosaminoglycans |
Amyloid |
Recurrent erosions in lattice dystrophy may follow the branching pattern of the underlying lattice network and can therefore appear similar to the dendritic lesions characteristic of epithelial herpetic keratitis. Epithelial lesions associated with lattice dystrophy, however, lack terminal bulbs and elevated borders. Owing to the implications in treatment planning, distinguishing recurrent erosions in lattice corneal dystrophy from herpetic keratitis is essential to the diagnostic process. [15]
Differential Diagnoses
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Dendritic Herpetic Kerititis
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Lattice corneal dystrophy. Image courtesy of James J. Reidy, MD, FACS, Associate Professor of Ophthalmology, State University of New York, School of Medicine & Biomedical Sciences, Buffalo, New York.
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Slit lamp image of lattice corneal dystrophy. Image courtesy of James J. Reidy, MD, FACS, Associate Professor of Ophthalmology, State University of New York, School of Medicine & Biomedical Sciences, Buffalo, New York.
Tables
Feature |
Granular Dystrophy |
Macular Dystrophy |
Lattice Dystrophy |
|---|---|---|---|
Age of onset |
First decade of life |
First decade of life |
First decade of life |
Heredity |
Autosomal dominant |
Autosomal recessive |
Autosomal dominant |
Reduced vision |
Fourth or fifth decade of life |
First or second decade of life |
Second or third decade of life |
Erosions |
Uncommon |
Common |
Frequent |
Opacities |
Discrete, intervening stroma Clear, not to limbus |
Indistinct margins, intervening Stroma hazy, extends to limbus |
Refractile lines and dots Usually not to limbus |
Material |
Hyaline |
Glycosaminoglycans |
Amyloid |
