Radial keratotomy learning curve using the American technique.

PURPOSE: To delineate the learning curve for a beginning refractive surgeon using the centrifugal (American) technique. SETTING: Naval Medical Center, San Diego, California, USA. METHODS: The first 100 radial keratotomy (RK) cases (51 patients) of one surgeon, divided into five sequential groups of 20, were retrospectively reviewed. All patients had RK using the American technique. Emmetropia was the goal in all patients. Groups were compared with respect to preoperative refractive status, age, sex, and outcome. Outcomes analysis included visual acuity, refractive error, complications, and enhancement rates. Data were reviewed preoperatively and 1 and 3 months postoperatively. RESULTS: All five groups were age and sex matched. There was no difference in preoperative refractive error among the five groups. Sequential improvement in early postoperative refractive error from a mean of -1.73 diopters (D) +/- 1.00 (SD) (first 20) to 0.45 +/- 0.55 D (last 20) (P < .001) and decreased enhancement rates from 50% (first 20) to 0% (last 20) (P = .002) were statistically significant. Visual acuity at 1 month was 20/40 or better in 47% of patients in Group 1 (first 20), whereas all patients in Group 5 (last 20) had an acuity better than 20/40 (P < .001). There was no significant difference in complication rates among the five groups. CONCLUSION: The results of RK using the American technique can improve significantly with surgeon experience. Enhancement rates decreased with experience, and there was no difference in complication rates during the learning period of one surgeon.

Propofol and alfentanil prevent the increase in intraocular pressure caused by succinylcholine and endotracheal intubation during a rapid sequence induction of anesthesia.

The increase in intraocular pressure (IOP) associated with succinylcholine (Sch) has made its use in patients with open globe injuries controversial. Studies that have examined techniques to prevent the increase in IOP due to Sch have shown a larger increase in IOP from the stimulus of laryngoscopy and endotracheal intubation. The purpose of our study was to examine whether the combination of propofol and alfentanil would prevent the increase in IOP due to Sch as well as endotracheal intubation during a rapid sequence induction of anesthesia. Sixty patients were randomized to receive either thiopental 5 mg/kg and Sch 1.5 mg/kg (Group I), propofol 2 mg/kg and Sch 1.5 mg/kg (Group II), or propofol 2 mg/kg, alfentanil 40 micrograms/kg, and Sch 1.5 mg/kg (Group III). The IOP was measured continuously from baseline awake (control) values until 15 s after successful intubation. All three groups had a significant decrease in IOP with the induction of anesthesia. Succinylcholine produced a consistent increase in IOP from the postinduction low in Groups I and II, but this increase was not significantly higher than baseline. The postintubation IOPs in Groups I and II were significantly higher than baseline (P < 0.001). During the entire study period, the IOP in Group III never increased above baseline. The IOP in Groups I and II had already begun to decline by 15 s postintubation, suggesting that laryngoscopy and intubation have the greatest effect on increasing IOP. We conclude that the combination of propofol and alfentanil prevents the increase in IOP from Sch as well as the increase associated with endotracheal intubation during a rapid sequence induction of anesthesia.