Electron microscopic study on the development of precapsular layer in eyeswith exfoliation syndrome

Purpose: To search for a pathogenic mechanism for the formation of the prec apsular layer on the anterior lens surface in pre-exfoliative eyes. Methods: We examined anterior lens capsules obtained during surgery from 38 patients (control, 16; exfoliation suspect, 10; exfoliation, 12) by transm ission electron microscopy. Results: A precapsular layer was found in 5 of 16 controls and 7 of 10 exfo liation suspects. It was composed mainly of microfibrils 5-8 nm in diameter . Degenerated zonular fragments were occasionally found interspersed in, an d sometimes merged with microfibrils of the precapsular layer. Conclusion: Zonular fibers might contribute to the formation of the precaps ular layer in pre-exfoliation stages. (C) 2000 Japanese Ophthalmological So ciety.