Abstract
Abstract: :
Purpose: Posterior amorphous corneal dystrophy (PACD) is a rare condition characterized by bilateral symmetric, irregular, sheet–like opacifications of the deep posterior stroma and Descemet’s membrane. There has been disagreement as to whether PACD is a dystrophy or a dysgenesis and whether it is recessive or dominant. We are reporting an additional case and its clinical manifestations. Methods: We utilized biomicroscopy, refraction, keratometry, pachymetry, and corneal topography. Additional family members were examined. Results: In our case, the cornea showed a bilateral diffuse, sheet–like haze at the level of the posterior stroma and Descemet’s membrane. These findings were present both centrally and peripherally with no intervening clear areas of stroma. Our patient was a high hyperope with a refraction of +6.50–2.50 x 180 and +7.75–1.75 x 180 in the right and left eyes respectively. The corrected vision was 20/60 in the right eye and 20/40 in the left eye with Allen pictures. Her keratometry readings were 38/40 x 90 in both eyes and her ultrasonic pachymetry measured 465 microns in the right eye and 450 microns in the left eye. Corneal plana and sclerocornea were also present. Both parents were not affected. Conclusions: The initial reports classified PACD as a dystrophy; however subsequent studies have suggested that the condition should be classified as a developmental dysgenesis based on both clinical and histopathological studies. Our case with its associated findings of corneal plana and sclerocornea lends support towards classification as a dysgenesis. Furthermore, all but one of the previous studies documented an autosomal dominant inheritance pattern. One previous study indicated a possible autosomal recessive inheritance; it suggested that the recessive variant would have more severe symptoms. In our case the parents were not affected and the patient had corneal plana and sclerocornea. This case therefore presents additional evidence that PACD can be a dysgenesis with a recessive inheritance pattern.
Keywords: cornea: clinical science • degenerations/dystrophies • cornea: stroma and keratocytes