Keratoconus Associated with Corneal Macular Dystrophy: In vivo Confocal Microscopic Evaluation

Abstract

In this case, using in vivo confocal microscopy, morphologic changes were detected in many corneal layers and compared with the histopathologic findings. The morphologic alterations were found mainly in the area of the cornea apex.

Macular corneal dystrophy and associated corneal thinning

“…14 Given our current lack of knowledge of the cause of keratoconus, it is important to determine whether there is any potential involvement of the CHST6 gene or associated pathways. Interestingly, concurrent keratoconus and MCD has been previously described in five cases, [15][16][17][18] and one of the linked loci for keratoconus (16q22.3-q23.1) contains the CHST6 gene. 19 When we used the Pentacam Scheimpflug system to evaluate anterior corneal surface parameters in cases with MCD, there was a pattern suggestive of keratoconus in all six eyes that were examined.…”

Concurrent macular corneal dystrophy and keratoconus

“…The association between macular dystrophy and keratoconus has been described previously in 2 case reports 412. The causes of this association remains unknown but may include a poorly understood molecular mechanism, or genetic linkage.…”

“…They12 suggested this observation was a focal rupture of Bowman's membrane that is visible in both keratoconus and macular dystrophy. In fact, the main histopathologic alteration of macular dystrophy is represented by focal ruptures of Bowman's membrane that may be irregular, thinned or absent in some areas 12.…”

“…They12 suggested this observation was a focal rupture of Bowman's membrane that is visible in both keratoconus and macular dystrophy. In fact, the main histopathologic alteration of macular dystrophy is represented by focal ruptures of Bowman's membrane that may be irregular, thinned or absent in some areas 12. Macular dystrophy is a stromal dystrophy that is histopathologically characterized by an accumulation of glycosaminoglycans between the stromal lamellae, hence, the deposits may be a large extracellular accumulation of abnormal material 12…”

“…Using confocal microscopy, Balestrazzi et al .,12 found highly reflective scar tissue that extended from the basal membrane to the underlying stroma. They12 suggested this observation was a focal rupture of Bowman's membrane that is visible in both keratoconus and macular dystrophy.…”