Transmission electron microscopy of the rabbit posterior capsule irrigated with thapsigargin and 5-fluorouracil in a sealed-capsule irrigation device.

PURPOSE: To investigate, by transmission electron microscopy (TEM), the effect on the posterior capsule of a young rabbit eye of 5-fluorouracil (5-FU) or thapsigargin in a sealed-capsule irrigation device. SETTING: St Erik's Eye Hospital, Stockholm, Sweden. METHODS: Clear lens extraction was performed unilaterally in eight 4-week-old rabbits. A sealed-capsule irrigation device was irrigated for 2 min with 20 ml of one of the following: balanced salt solution (BSS; n=2), thapsigargin 300 muM (n=2), 5-FU 50 mg/ml (n=2), or 5-FU 25 mg/ml (n=2). The substances were washed out for 10 s with BSS. The eyes were left aphakic. Six weeks postoperatively, the animals were killed, and the posterior capsule was extracted and fixed for TEM. As a control, we also evaluated the capsules from the two fellow eyes in the BSS group that did not undergo surgery. RESULTS: The ultrastructure of the posterior capsule in eyes irrigated with 5-FU or thapsigargin did not differ from that in the eyes irrigated with BSS or in the eyes that did not have surgery. The membranes had the same ultrastructure with thin collagen fibres on the anterior and posterior face of the posterior capsule and an amorphic matrix. CONCLUSION: Thapsigargin or 5-FU used in a sealed-capsule irrigation device does not seem to harm the posterior capsule, which appeared similar to when the capsule is irrigated with BSS.

Irrigation with thapsigargin and various concentrations of 5-fluorouracil in a sealed-capsule irrigation device in young rabbit eyes to prevent after-cataract.

AIM: To investigate the effect on after-cataract and synechiae formation after clear lens extraction and irrigation with different substances in a sealed-capsule irrigation device. SETTING: St Erik's Eye Hospital, Stockholm, Sweden. METHODS: Clear lens extraction was performed in one eye of 42 4-week-old rabbits. The sealed-capsule irrigation device was applied and the sealed system was irrigated for 2 min with 20 ml of one of four substances: balanced salt solution (BSS), thapsigargin, 5-fluorouracil (5-FU) 50 mg/ml, or 5-FU 25 mg/ml. The substance then was washed out for 10 s with BSS. The eyes were left aphakic. Formation of after-cataract and synechiae was evaluated during two clinical examinations 3.5 and 5.5 weeks postoperatively, by photographs 5 weeks postoperatively, and by histologic evaluation of haematoxylin-eosin-stained slides after the 6-week end point postoperatively. After-cataract and synechiae were graded on a scale from 0 to 4. Kruskal-Wallis analysis of variance with multiple comparisons was used for statistical analyses. RESULTS: 5-FU 50 mg/ml prevented after-cataract and synechiae formation best when compared with all other substances at all evaluations. 5-FU 25 mg/ml was not as effective, and thapsigargin was ineffective in this animal model. CONCLUSION: 5-FU 50 mg/ml used in the sealed-capsule irrigation device satisfactorily prevents after-cataract and synechiae. Thapsigargin was ineffective in this animal model.