Clinical results of excimer laser photorefractive keratectomy: a multicenter study of 265 eyes.

Efficacy, predictability, and safety of excimer laser photorefractive keratectomy were evaluated at centers in Paris and Brest, France. Photoablation was performed with the VISX laser on 265 eyes (151 at the Paris center and 114 at the Brest center). The eyes were clinically and statistically evaluated over a six month follow-up. Initial myopia ranged from -0.7 to -19.4 diopters (D) (mean spherical equivalent [SE] -5.9 D) in the Paris center and from -0.9 to -14.5 D (SE -4.5 D) in the Brest center. At both centers, the mean uncorrected visual acuity was worse than 20/200; over 90% of cases in each center had a best uncorrected visual acuity of 20/100 or worse. Results are reported globally and for subgroups of myopia: Group A, SE better than or equal to -3.0 D; Group B, SE worse than -3.0 D and better than or equal to -7.0 D; Group C, SE worse than -7.0 D. Uncorrected visual acuity was significantly improved in the patients followed for six months; 64% of Paris cases and 62% of Brest cases obtained an uncorrected visual acuity of 20/40 or better. Predictability of the treatment was good; 67% of Paris eyes and 74% of Brest eyes were less than 1.0 D from the intended correction after six months. The data suggest that the initial myopia affected the efficacy and predictability of the treatment; results in the mild to moderate myopia eyes were significantly better than results in the severe myopia eyes. One case of visual acuity regression (less than one line) was observed in the two groups. This was associated with corneal haze of moderate intensity.

Effect of preoperative YAG laser anterior capsulotomy on the incidence of posterior capsule opacification: ten year follow-up.

One hundred twenty-two patients, who were followed for ten years, had bilateral extracapsular cataract surgery with implantation of J-looped posterior chamber lenses between 1980 and 1981. On the first eye an anterior capsulotomy was performed with a pico-second YAG laser 12 to 20 hours before surgery; on the second eye a capsulotomy was performed manually at the time of surgery. Four of the eyes (3.27%) with laser capsulotomies had opacified posterior capsules after ten years; 61 of the eyes (50.00%) with manual capsulotomies had opacified capsules that had to be opened with a YAG laser.

One-movement insertion of the superior loop into the bag.

An efficient, simple technique for one-movement insertion of the superior intraocular lens loop into the capsular bag is described. This bimanual technique avoids undue stress on the capsular bag and zonules, may be used with all extracapsular techniques, and is suitable for almost all flexible loop intraocular lenses designed for in-the-bag implantation.

Corneal wound healing after excimer laser keratotomy in a human eye.

A pulsed excimer argon-fluorine laser was used to produce corneal incisions in vivo in a human cornea. Fourteen days after the laser surgery, the incisions were examined by light and transmission electron microscopy. There was good initial healing, with no inflammatory or immune reactions in the incisions.

Excimer laser surgery of the cornea: qualitative and quantitative aspects of photoablation according to the energy density.

Using an excimer laser working in the far ultraviolet and cutting fresh corneas of human cadaver eyes, we were able to demonstrate that there is an ideal fluence (joule/cm2/pulse) that allows a maximum tissue ablation depth per shot. Above the threshold of 1 J/cm2/pulse the depth of tissue ablated does not increase and both thermal and mechanical damage appears at the cut edges.

Influence of picosecond and nanosecond YAG laser capsulotomy on intraocular pressure.

To evaluate laser-induced intraocular pressure rise with three YAG lasers, I performed posterior capsulotomies on three groups of patients. Each group contained 100 nonglaucomatous patients who had extracapsular cataract extraction with and without lens implantation. In each group 50 patients were treated with prophylactic medications. The three YAG lasers were (1) a picosecond TEMoo, mode locked, ten-degree cone angle; (2) a nanosecond TEMoo, Q-switched, 16-degree cone angle, delivering the energy in five nanoseconds per pulse; and (3) a Q-switched, 15-degree cone angle, closer to multimode than TEMoo, delivering energy in 14 nanoseconds seconds per pulse. The energy delivered per pulse, the thickness of the lens material, the shape (mode) of the pulse, the optical delivery system, and the width of the shock wave appear to act on intraocular pressure and to be factors influencing the possibility of marking the lens.

Use of a pulsed picosecond Nd: YAG laser in 6,664 cases.

We used a modulated picosecond Nd:YAG laser to perform preoperative anterior capsulotomies and posterior capsulotomies in eyes with and without an intraocular lens, and to cut a variety of cyclitic membranes, iridocapsular adhesions, and vitreous traction bands in more than 6,500 cases. The complications were transient bleeding when vascularized tissues were cut because the laser does not coagulate, temporary anterior chamber inflammation, and transient increased intraocular pressure. The last two were caused by released lens material and shock wave side effects.