MAUDE Adverse Event Report: ALCON RESEARCH, LTD. - IRVINE TECHNOLOGY CENTER OCUSCAN RXP OPHTHALMIC ULTRASOUND SYSTEM; SYSTEM, IMAGING, PULSED ECHO, ULTRASONIC

Catalog Number 8065741076

Device Problem Calibration Problem (2890)

Patient Problem No Known Impact Or Consequence To Patient (2692)

Event Type  malfunction  

Manufacturer Narrative

Investigation including root cause analysis is in progress.A supplemental mdr will be filed as necessary in accordance with 21 cfr 803.56 when addition reportable information becomes available.(b)(4).

Event Description

A customer reported patients were experiencing unexpected refractions after cataract surgery.The customer indicated they suspect the equipment is out of calibration.This is the second of three files.Additional information has been requested.

Manufacturer Narrative

The customer reported that patients were having unexpected refraction after cataract surgery.Some patients were presenting with refractions which were not possible to prescribe glasses due to the big difference between the right and left eyes.Other patients did not want to wear contact lenses for resolution.The customer suspects that the machine is out of calibration.The machine did not display any error message.The customer states the directions for use (dfu) was followed.The measurement of axial length measurement has the greatest potential for error in calculating iol power.Traditionally, contact a-scan ultrasonography is used.This measures the time taken for sound to traverse the eye and converts it to a linear value using a velocity formula.Part of the ultrasound beam reflects back from each surface in the eye ¿ cornea, anterior lens, posterior lens, and retina.The reflected beam is translated into an image showing lines (spikes) for each surface.The distance between the corneal and retinal spikes gives the axial length of the eye.The alignment of the a-scan is vitally important.If the alignment is incorrect, the length of the eye will be underestimated.Most systems rely on the patient fixing on a target ¿ usually a light in the probe.Patients with poor vision, whether from cataract or from some other pathology, are less likely to fixate accurately, and are more prone to biometry errors.Tips for accurate measurement of axial length (using applanation): ensure the machine is calibrated and set for the correct velocity setting (e.G.Cataract, aphakia, pseudophakia); the echoes from cornea, anterior lens, posterior lens, and retina should be present and of good amplitude; misalignment along the optic nerve is recognized by an absent scleral spike; the gain should be set at the lowest level at which a good reading is obtained; take care with axial alignment, especially with a hand-held probe and a moving patient (as described above); don't push too hard ¿ corneal compression commonly causes errors; errors may arise from an insufficient or greasy corneal meniscus due to ointment or methylcellulose used previously.Extremely dense cataracts create difficulties, as they absorb sound as it passes through the lens.A higher gain setting may be necessary to achieve adequate spikes.Posterior staphylomata in myopic eyes not only cause an elongated globe, but often tilt the macula as well so that the ultrasound beam is deflected.There are known reasons for biometry errors include: people in a hurry, lack of training or accessible guidelines, reliance on others, technical failure (rarely), and human error (often).Some common mistakes that may result in unexpected refractive outcome include: wrong a-constant selected, wrong formula used, wrong k-readings entered by hand (90 degrees out), biometry print-out stuck in wrong patient's notes, wrong patient in theatre, reversed iol optic, or wrong iol implanted.The operators manual includes the warning: ensure that the correct technique (contact or immersion) is selected for the technique being performed.Incorrect technique selection will impact the accuracy of the results.Contact - in the contact technique, readings are obtained by placing the biometry probe directly on the patient¿s cornea.Immersion - in the immersion technique, an immersion shell containing the probe is placed on the patient's eye and filled with solution between the probe and the cornea.Since the probe is not touching the cornea, there is an offset on the display between the peak from the probe tip and the peak from the cornea.The company representative examined the system and was unable to replicate the reported event.The system was then tested and met all product specifications.The system was manufactured on september 28, 2009.Based on qa assessment, the product met specifications at the time of release.The system was found to meet specifications; therefore, the root cause of the reported event cannot be determined conclusively.(b)(4).

• Brand Name: OCUSCAN RXP OPHTHALMIC ULTRASOUND SYSTEM
• Type of Device: SYSTEM, IMAGING, PULSED ECHO, ULTRASONIC
• Manufacturer (Section D): ALCON RESEARCH, LTD. - IRVINE TECHNOLOGY CENTER; 15800 alton parkway; irvine CA 92618
• Manufacturer (Section G): ALCON RESEARCH, LTD. - IRVINE TECHNOLOGY CENTER; 15800 alton parkway; irvine CA 92618
• Manufacturer Contact: eddie darton, md, jd ; 6201 south freeway; mail stop ab2-6; fort worth, TX 76134 ; 8175686660
• MDR Report Key: 5043912
• MDR Text Key: 25287437
• Report Number: 2028159-2015-08021
• Device Sequence Number: 1
• Product Code: IYO
• Combination Product (y/n): N
• Reporter Country Code: BR
• PMA/PMN Number: K844686
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: company representative,foreig
• Reporter Occupation: Other
• Remedial Action: Other
• Report Date: 09/16/2015

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 08/31/2015
• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Catalogue Number: 8065741076
• Other Device ID Number: 1.15
• Was Device Available for Evaluation?: Yes
• Is the Reporter a Health Professional?: No
• Date Manufacturer Received: 09/11/2015
• Was Device Evaluated by Manufacturer?: Device Not Returned to Manufacturer
• Date Device Manufactured: 09/28/2009
• Is the Device Single Use?: No
• Is This a Reprocessed and Reused Single-Use Device?: No
• Type of Device Usage: Reuse
• Patient Sequence Number: 1
• Patient Outcome(s): Other