Pupillometry(동공크기검사기) in Refractive Surgery & Ophthalmology

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Pupillometry in Refractive Surgery & Ophthalmology

Accurate pupillometry is now an essential part of the eval‎uation, screening, and refractive surgery planning process.

The NeurOptics Pupillometer is a portable device used to measure pupils and screen candidates for refractive procedures and other ophthalmic applications such as the fitting of multifocal intraocular lenses (IOLs) and orthokeratology.

The Pupillometer:

• Accurately measures pupils in total darkness;
• Instantly and accurately measures, records, and reports average pupil size and standard deviation;

• Has one-button activation

• Requires no calibration by the user (just point and shoot)
• Provides printed verification

Watch a VIDEO about the Pupillometer (Windows Media File)

Is pre-operative measurement of the pupils important?

Doctors must define the area of the cornea they will reshape (the optical zone). As the optical zone gets larger, complications from higher order aberrations become more likely. These aberrations are often responsible for post-surgical problems related to night driving such as glare or halos.

The latest article on this topic, "Pupil size and night vision disturbances after LASIK," published in August of 2004, recommended preoperative eval‎uation of pupil size in all patients prior to refractive surgery because of the correlation the researchers found between large scotopic pupil sizes and the impression of worsened night vision.

Pre-operative pupil measurement has become part of the guidelines for refractive surgery www.eyesurgeryeducation.com/LASIK_Patient_Screening_Guidelines.html published by the ASCRS.

Visit our Stark Pupil Library for a complete list of papers related to refractive surgery and the pupil.

Why the NeurOptics Pupillometer?

The NeurOptics Pupillometer is consistent from unit to unit and operator to operator. The key to the reproducibility in measurement is the use of NeurOptics’ exclusive VIP (Vertex Invariant Pupillometry) technology.

Measurement of the pupil is more difficult than it might seem because of the phenomenon of pupillary hippus or noise. The pupil is never entirely at rest but rather has normal, small continuous oscillations (±0.5mm). Therefore, when trying to measure the pupil, a single “snapshot” estimate is not a reliable predictor of the true mean size (because the clinician might catch the pupil at the maximum or minimum.) The NeurOptics Pupillometer records 3 seconds of data to ensure the effects of hippus are minimized. The average size (i.e., ensemble average) as well as the standard deviation of the pupil are reported by the instrument.

Another consideration is the importance of adjusting for differences in the distance from the lens of the Pupillometer to the front of the eye (the vertex distance). Vertex distance can vary up to 12mm in the normal population. This distance affects a pupillometer’s calculation of pupil size. If the Pupillometer is not calibrated correctly to adjust for this distance it can create an error up to 20%. A pupillometer should calculate the distance variation to maintain accuracy.

The NeurOptics Pupillometer is the only hand-held Pupillometer on the market designed to compensate for vertex distance variance as well as accounting for pupillary noise and reporting an average measurement.

A recent study showed that the NeurOptics Pupillometer has high repeatability and agreement in scotopic pupil diameter for repeated measurements.

What other refractive surgeons have to say about the Neuroptics Pupillometer

“It was really easy to train my staff to use this. It took about five minutes per staff member which is faster than learning the autorefractor and certainly much faster than learning the topographer so I found it very easy to implement in the office.”
Dr. Robert Maloney

“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 phakic IOL patients, our hyperops [farsighted patients]undergoing LASIK, as well as our patients that are seeking monovision. And all of that can be done because of the fact that it’s so easy to use and so incredibly accurate.”
Dr. Kerry Assil

“From a medical-legal perspective, it’s not only important to show that you put thought into it and have numbers that you can refer back to but also defend that those numbers are accurate and reproducible.”
Dr. Kerry Assil

“When we compared the accuracy of this with other competing systems, it was unbelievable how accurate it was, how simple it was to use, and how reasonably priced it was.”
Dr. James Salz

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