[Critical thoughts on current laser surgery of the cornea].

OBJECTIVE

To analyze critically refractive surgery of the cornea by excimer laser and to compare laser surgery with other methods of treatment of refractive errors of the eye.

MATERIAL AND METHODS

This analysis has to be restricted to a comparison of the treatment of myopia by keratotomy and photoablation with the ArF excimer laser. Correction of hypermetropia and of astigmatismus has to be left out, along with all the other methods to correct myopia, such as glasses, contact lenses, keratomileusis, epikeratoplasty, alloplastic implants, implantation of intraocular lenses with negative power, and replacement of the clear lens by an posterior chamber lens. The essential literature is screened. For intrastromal ablation with the picosecond Nd:YLF laser we relay on own experiences, also with the use of the ArF excimer laser we are not without own experiences. RESULTS AND STATEMENTS: For comparison of refractive surgery of the cornea not only the PERK study and the recommendations of the American Academy of Ophthalmology have to be considered, but also the newest developments in radial keratotomy such as two-step incision and reoperation with reopening of the keratotomy wounds. With these techniques the same precision can be reached as with the excimerlaser, and also higher myopias can be corrected. The dangers of the procedure, such as infection, perforation at surgery or laceration by contusion remain much larger. Intrastromal photoablation did not reach clinical maturity. Superficial photoablation is an almost safe procedure. A reduction of 3 D of myopia can be reached with satisfying precision, although higher myopias are still a problem. Pain following the ablation is considerable. Haze and disturbed vision at night can be present; infectious keratitis is rare, but possible.

CONCLUSIONS

The critical fact of both procedures, keratotomy and photoablation with excimer laser, remains that healthy eyes are treated; therefore, even rare complications weigh much heavier than if sick eyes are treated. Because this is cosmetic surgery, the individuum asking for this type of procedure has to pay for on his own. Olson demands: "In determining when new technology is acceptable, we must consider the financial cost and the expected benefit to society. Is it an equitable tradeoff?" If we look at refractive surgery, especially laser photoablation, in the context of the needs for ophthalmic care of the whole world, then this type of surgery is out of proportion. The balance could be restored if, with every laser application, funds were given for third-world projects. Excimer-laser surgery may be justified insofar as the research with these lasers leads to useful therapeutic methods.