Ophthalmic surgical instrument with cold light UV laser - has laser pulse homogeniser by two cylindrical lenses with optical axes intersecting at 90 deg.

摘要

A continuous alteration of energy distribution of the laser beam (16) results radially from the centre point axis (17) to the external flank of the beam, and the emanating laser beam is reflected with the desired radial absorption profile on the cornea, by a liq. tray (5), transparent to UV radiation, with a cylindrical lens type optical part (4), which contains a liq. partly absorbing the laser radiation, and its rotational axis coincides with the centre point axis of the laser radiation. Two cylindrical lenses with their optical axes crossing at 90 deg. are used for homogenising the laser pulses so that in a vertical quadratic cross section of 20 x 20 mm. An expansion optic (3) is provided, in which the 20 x 20 mm quadratic laser pulses are expanded to a larger cross section, reducing the pulse energy density to a smaller level of 100 ins./sq.cm. USE/ADVANTAGE - For treating myopia, hyperopia, astigmatism etc., with simple mfr., improved reliability and easy handling.