Four Cases of Keratoconus and Posterior Polymorphous Corneal Dystrophy

Classification of Posterior Polymorphous Corneal Dystrophy as a Corneal Ectatic Disorder Following Confirmation of Associated Significant Corneal Steepening

“…7–20 While the association of PPCD with keratoconus was initially reported in the English-language literature almost 40 years ago, the subsequent 9 reports of this association published between 1989 and 2010 consisted of either individual case reports (4) or small case series (3, 3, 4, 5 and 7 subjects). 7, 8, 10–15, 18, 20 Given the relative frequency of keratoconus in the general population, estimated to have an incidence of 1 in 2000, as well as its reported association with a variety of ocular and non-ocular disorders, the significance of the reported association with PPCD has been questioned. 21 However, mutations in the visual system homeobox gene 1 ( VSX1 ; MIM #605020) have been implicated as playing a pathogenic role in both PPCD and keratoconus, thus providing support to the contention that the reported association between the disorders is more than just coincidental.…”

Keratoglobus in Association With Posterior Polymorphous Dystrophy

“…[2][3][4][5][6][7] Keratoglobus has been described in association with blue sclera syndrome, Leber congenital amaurosis, thyroid ophthalmopathy, and vernal keratoconjunctivitis, but until now, not with PPMD. 8,9 Because corneal thinning disorders such as keratoconus and keratoglobus are considered different clinical manifestations of the same underlying disorder, the association of keratoglobus with PPMD probably parallels the association of PPMD and keratoconus in pathogenesis.…”

“…1 PPMD has been associated with keratoconus and Terrien marginal degeneration; however, to our knowledge, it has not yet been reported with keratoglobus. [2][3][4][5][6] Keratoglobus is a rare bilateral corneal disorder that affects visual acuity. Often, it is congenital, but it can also appear after birth.…”

Confocal microscopy identification of keratoconus associated with posterior polymorphous corneal dystrophy

“…6 An association between keratoconus and PPCD was first reported in 1974 by Gasset and Zimmerman. 7 Weissman et al 8 described 4 cases, all occurring in young men. More recently, Héon et al 9 reported a mutation of the VSX1 major gene on chromosome 20p11-q11, with significant intrafamilial phenotypic variability in patients with this association.…”