Variable Pupillometer Helps Optimize Vision Correction Procedures

A hand-held device helps surgeons optimize patients for laser-assisted in situ keratomileusis (LASIK) procedures and the fitting of multifocal intraocular lenses (IOLs).

The VIP-200 Pupillometer is a battery operated, hand-held device, which accurately measures pupil size with no user calibration required. It is used to screen patients for refractive surgery and can simulate scotopic, low mesopic, and high mesopic light conditions, measuring them in one run of 10 seconds. Pupil sizes are measured in a range from 1 mm to 9 mm with an accuracy of 0.1 mm. Random uncontrolled fluctuations can be compensated for, allowing average pupil aperture and standard deviation to be calculated. Moreover, because it may be hard for a clinician’s eye to estimate pupil size by a single picture, the VIP-200 records 3 seconds to overcome small continuous oscillations and presents an average size.


The VIP-200 Pupillometer can instantly measure, record, and report average pupil size and standard deviation. The data is stored on the device, and the results are displayed on the device's color liquid crystal display (LCD) screen, an optional paper printout, or as a video of the measurement. The key to reproducibility is the use of Vertex Invariant Pupillometry (VIP) technology, which compensates for differences in vertex distance among patients, which may lead to inaccurate pupil measurements and errors up to 20%. The VIP-200 Pupillometer is a product of Neuroptics (Irvine, CA, USA).

“The simplicity and versatility of this instrument is tremendous to us, in the sense that in our single clinic we can apply it to our cataract patients, our premium IOL patients, our hyperops undergoing LASIK, as well as our patients seeking monovision,” said Kerry Assil, MD, medical director of Assil Eye Institute (Los Angeles, CA, USA). “And all of that can be done because of the fact that it's so easy to use and so incredibly accurate.”

Pupil size measurement during a preoperative evaluation is crucial for refractive surgeons when screening candidates for LASIK, and is particularly helpful for optimizing the premium IOL selection for the patient, based upon the patient's stated preferences about the level of vision they value (e.g., distance, intermediate, or near), occupation, lifestyle, and frequency of nighttime driving. The most pertinent information is obtained by measuring a patient's pupils under varying light conditions, which simulate real life conditions a patient may experience in daily life such as darkness, a dimly lit room, and driving at night with streetlights.

Related Links:
Neuroptics