Objective: To study the effect of acute intraocular pressure (IOP) elevation on the optic nerve and retina in laser in situ keratomileusis (LASIK).
Methods: Acute IOP was increased to 65 mm Hg for different period of time (30 s, 1 min and 3 min) by using scleral suction on rabbit eyes. The tissues of retina and optic nerve of immediately extirpated group (instant group), of 2 weeks later extirpated group (recovery group) both after the negative pressure suction and of normal rabbit eyes were examined with electron and light microscope.
Results: After the negative pressure suction for 30 s, 1 min, and 3 min respectively, the optic nerve and retinal cells changed lightly; some part of optic nerve and retinal cells changed; optic nerve fibers and retinal cells changed sharply.
Conclusion: Ultrastructural changes of retina and optic nerve may be induced by acute IOP elevation in LASIK. The longer the time, the more apparent the changes.