Quantitative analysis of lipid deposits from Schnyder's corneal dystrophy

Abstract

Aim: To report the quantitation of the lipid composition of a corneal button from a Japanese woman in her 60s with clinically and histopathologically proved Schnyder's corneal dystrophy.

Methods: Total lipids extracted from the corneal button of the patient were analysed by the method of thin layer chromatography flame ionisation detection. Two different solvent systems were used for neutral lipid analysis and phospholipid analysis. Results were compared with three age matched corneal buttons obtained from cadaveric eyes.

Results: The lipids that accumulated in the cornea in Schnyder's dystrophy consisted mainly of unesterified cholesterol and phospholipids. The analysis of phospholipids showed sphingomyelin to be the predominant phospholipid in the patient's cornea.

Conclusion: Findings suggest that this disorder involves a disturbance of the metabolism of cholesterol and/or sphingomyelin metabolism that is limited to the cornea.

Figure 1

On slit lamp examination, right eye shows arcus lipoides and diffuse, central corneal opacity with subepithelial crystals.

Figure 2

Photomicrograph of right corneal button. Loosened spaces representing dissolved lipids were present in the stroma (haematoxylin and eosin; original magnification, × 40).

Figure 3

Photomicrograph of frozen section of the same corneal button stained with oil red O shows panstromal reactivity (oil red O; original magnification, × 40).

Figure 4

Chromatograms of neutral lipid analysis. (P) patient; (C1) control 1. 1 = esterified cholesterol; 2 = free fatty acids; 3 = unesterified cholesterol; 4 = monoglycerides + diglycerides; and 5 = phospholipids.

Figure 5

Chromatograms of phospholipids analysis. (P) patient; (C1) control 1. 1 = neutral lipids; 2 = phosphatidylethanolamine; 3 = phosphatidylserine + phosphatidylinositol; 4 = phosphatidylcholine; 5 = sphingomyelin; and 6 = origin.