Corneal stromal dystrophies: a clinical pathologic study

Abstract

Introduction: Corneal dystrophy is defined as bilateral and symmetric prima ry corneal disease, without previous associated ocular inflammation. Corneal dystro phies are classified according to the involved corneal layer in superficial, stromal, and posterior dystrophy. Incidence of each dystrophy varies according to the geographic region studied. Purpose: To evaluate the prevalence of stromal corneal dystrophies among cor neal buttons specimens obtained by penetrating keratoplasty (PK) in an ocular pathology laboratory and to correlate the diagnosis with patient age and gender. Methods: Corneal button cases of penetrating keratoplasty from January1996 to May2009 were retrieved from the archives of The Henry C. Witelson Ophthalmic Pathology Laboratory and Registry, Montreal, Canada. The cases with histopatho logical diagnosis of stromal corneal dystrophies were stained with special stains (Peroxid acid Schiff, Masson trichrome, Congo red analyzed under polarized light, and alcian blue) for classification and correlated with epidemiological informa tion (age at time of PK and gender) from patients' file. Results: 1,300 corneal buttons cases with clinical diagnose of corneal dystrophy were retrieved. Stromal corneal dystrophy was found in 40 (3.1%) cases. Lattice corneal dystrophy was the most prevalent with 26 cases (65%). Nineteen were female (73.07%) and the PK was performed at average age of 59.3 years old. Combined corneal dystrophy was found in 8 (20%) cases, 5 (62.5%) of them were female and the average age of the penetrating keratoplasty was 54.8 years old. Granular corneal dystrophy was represented by 5 (12.5%) cases, and 2 (40%) of them were female. Penetrating ke ratoplasty was performed at average age of 39.5 years old in granular corneal dystrophy cases. Macular corneal dystrophy was present in only 1 (2.5%) case, in a 36 years old female. Conclusion: Systematic histopathological approach and evaluation, including special stains in all stromal corneal dystrophies is critical to establish the correct diagnosis.

Histomorphological study of corneal dystrophies

“…1 There are many exceptions to the said features; some of the entities are not hereditary, while others are unilateral. Incidence of each subtype varies in different geographic regions studied [4][5][6][7][8] . The worldwide prevalence of Corneal Dystrophies in corneal button specimens ranges from 1.3% to 4%.…”

“…Most of the dystrophies have Autosomal Dominant pattern of inheritance, start in the first decade of life, with stable or slowly progressive course. 5 The clinical presentations vary from photophobia, pain, blurring to progressive loss of vision. The most commonly used classification system is based on the anatomical level of cornea that is predominantly involved: Superficial, stromal and Posterior.…”

Collagen Fibrils and Proteoglycans of Macular Dystrophy Cornea: Ultrastructure and 3D Transmission Electron Tomography

“…Macular corneal dystrophy (MCD) is the least common of all classical stromal dystrophies. The disorder is observed in 75% of MCD cases in Iceland (Jonasson et al, 1996), 30% in Europe and the United States (Lang & Naumann, 1987), 20% in Japan (Santo et al, 1995), 29.3% in South India (Pandrowala et al, 2004), and 2.5% Brazil (Abrew et al, 2012). Faran & Tabarra (1991) studied various corneal dystrophies in Saudi Arabia and reported that macular dystrophy is the most common dystrophy (52%) in Saudi Arabia.…”