Medical errors in refractive surgery can be eliminated

A medical error is defined as "the failure of a planned action to be completed as intended or the use of a wrong plan to achieve a desired plan," said Dr. Davé, citing the Institute of Medicine. She is a resident at Bascom Palmer Eye Institute, University of Miami Miller School of Medicine.

In a retrospective chart study, Dr. Davé and her colleagues reviewed 18 eyes of 15 patients from various parts of the United States. Three of the errors involved the wrong patient; four errors involved the incorrect sphere value entered into the laser; two errors involved the wrong cylinder value entered into the laser; three errors involved the wrong axis number; one error involved an incorrect axis sign; one error involved an incorrect decimal position; and one error involved an enhancement procedure using the original refraction, Dr. Davé said.

Case 1 was a 29-year-old female boat captain. The preoperative refraction was –0.75 D bilaterally and the visual acuity was 20/20. The prescription that was planned to be entered into the laser was –0.612 D and –0.625 D sphere. The values actually entered into the computer were –6.12 D and –6.25 D sphere. Three weeks after surgery, the patient had 20/400 vision, with a refraction of 4.50 D and 5.25 D sphere, respectively. Eighteen months after surgery, the vision had stabilized to 3 D (20/40) and 3.25 D (20/40).

"The reduced vision likely was related to the error programmed into the computer as well as irregular astigmatism from forme fruste keratoconus preoperatively," Dr. Davé said.

A second case was that of a 56-year-old man with a manifest refraction preoperatively of 3.50 D and 4 D. The planned prescription to be entered into the computer was 3.80 D sphere in the right eye and 4.75 D in the left eye. The data entered were for –3.80 D sphere in the right eye. The patient had 20/400 vision 3 weeks postoperatively. The refraction in the right eye was 6 D and –2.50 D in the left eye.

"In this case, the patient was treated with 6-D sphere contact lenses, which resulted in 20/25 vision in the right eye," Dr. Davé reported.

In another case a 35-year-old woman had a right eye prescription of –6 × –2.50 at 175°. This prescription was converted erroneously to –8.50 × +2.50 at 175°. After treatment, the resulting prescription was –3.50 D sphere with 3.50 D of cylinder.

"This patient was re-treated with an ablation procedure and achieved 20/25 vision," Dr. Davé said.

"The obvious question is: How is it possible to misidentify a patient that is to undergo a planned procedure? In some cases, the surgeon followed all the right procedures, but still programmed in the wrong refraction," Dr. Davé said.

The wrong patient

In one particular case before a planned refractive surgery, the surgeon explained to the patient, Mr. Smith, in the observation room what the procedure would entail and asked his permission to call him by his first name, José, which he did repeatedly throughout the surgery on the patient's right eye. As the surgery on the left eye was about to begin, the patient asked the surgeon why he continued to call him Jose when his name was Carlos.