Videokeratographic changes after laser in situ keratomileusis to correct high myopia.

PURPOSE: To evaluate the videokeratographic changes and patterns after laser in situ keratomileusis (LASIK) in high myopia using computerized videokeratography. SETTING: San Salvatore Hospital, Chair of Ophthalmology, University of L'Aquila, L'Aquila, Italy. METHODS: Forty-one eyes of 26 patients treated with no-suture nasal-hinged flap LASIK for an attempted mean spherical equivalent correction of -13.9 diopters (D) +/- 4.1 (SD) (range -8.0 to -22.0 D) were evaluated. Mean patient age was 35.2 +/- 9.8 years. Mean follow-up was 15.1 +/- 6.7 months (range 6 to 26 months). RESULTS: Thirty-five eyes (85.4%) were within +/- 2.0 D of the planned correction, with a refractive error greater than 3.0 D in the 7.3% of eyes. Mean central corneal power decreased from 43.2 +/- 1.8 D (range 38.70 to 47.40 D) to 35.8 +/- 3.8 D (range 30.3 to 42.6 D). Mean preoperative corneal astigmatism decreased from 1.2 +/- 0.9 D (range 0.2 to 4.2 D) to 0.9 +/- 0.9 D (range 0.2 to 3.3 D). Videokeratographic qualitative analysis showed corneal shape changes within 15 days after surgery. Corneal patterns then stabilized, and 37 eyes (90.3%) had no significant modifications in corneal refractive power after 1 month. CONCLUSION: After LASIK in highly myopic eyes, videokeratographic maps showed corneal power stabilized within 1 month in most eyes and there was no irregular astigmatism if the treatment was well centered.

[Percutaneous angioplasty of arterio-venous fistulae with Zijlstra catheters]. / Angioplastica percutanea delle fistole artero-venose con catetere di Zijlstra.

Brescia-Cimino arteriovenous fistulas are the most common vascular accesses in hemodialysis patients. Arterial blood pressure inside the vein and repeated punctures cause progressive sclerosis of the vessel wall and stenosis or occlusion are the final outcome. Percutaneous dilatation is an effective method to preserve arteriovenous fistulas function. From January 1991 through December 1992, eleven dilatations were performed in 10 patients (7 women and 3 men, mean age: 55 years) using a Zijlstra dedicated catheter provided with multiple infusion holes, which allows long dilatation times and therefore progressive wall distention. A high-pressure balloon yields better results in case of stiff and diffuse stenosis. The immediate results of the maneuver were good in all patients. One acute thrombosis of the fistula was observed a few hours after the procedure, and a second dilatation was performed in a patient 8 months after the first one. Mean arteriovenous fistula patency time was 6 months. Finally, a critical review of the international literature on the subject is made and the value of dilatation in the treatment of fistula stenosis is reported; the necessity to use new dedicated catheters in also stressed.