Abstract
Purpose: Previous studies of the composition of lipid deposits in aging human eyes were performed using retinal pigment epithelium (RPE) and Bruch's membrane extracts, without any correlation to their original location. We employed hot stage polarizing light microscopy to study the pattern of abnormal lipid deposition m-situ within histologie sections Methods: Human autopsy eyes were fixed in calcium-buffered formalin. Full-thickness buttons of the central macula and the periphery were cryo-sectioned and alternate sections were stained with Oil-red-O, Sudan black, or analyzed by hot stage polarizing microscopy. The changes in lipid birefringence when the sections were heated, cooled and re-heated, were analyzed and photographed. Results: The lipids within diffuse Bruch's membrane deposits and discrete drusen in aging human eyes (n=12) or in eyes with a clinical history of ARMD (n=1) had melting points (30°-35°C) and birefringence patterns characteristic of cholesterol esters ("maltese cross"). Lipids within some drusen also showed a higher melting point (>50 °C) and a "myelin figure" pattern of birefringence suggesting phospholipid deposition. No triglycérides or free cholesterol crystals were detected. Conclusions: This is the first study to identify individual lipid subtypes within drusen and Bruch's membrane in-situ. Lipid deposits within aging Bruch's membrane and drusen contain cholesterol esters probably rich in unsaturated fatty acids. Some drusen also contain phospholipids. Further studies will investigate lipid metabolism at the RPE-Bruch's membrane interface and the factors leading to lipid deposition. Fight for Sight GA95-096, Macula Foundation; Research to Prevent Blindness; Mass Lions Eye Research Fund. none.
| Original language | English |
|---|---|
| Pages (from-to) | S93 |
| Journal | Investigative Ophthalmology and Visual Science |
| Volume | 38 |
| Issue number | 4 |
| State | Published - 1997 |
| Externally published | Yes |