Spotlight ON TECHNOLOGY & TECHNIQUE

The Octopus 900: Tracking Trouble Spots

By Leslie Goldberg, Associate Editor

Historically, the problem with perimetry tests has been that results are highly variable from session to session. A change in a patient's level of attentiveness or a techs level of experience can affect the test's outcome. Haag Streits Octopus 900 perimeter and its Eyesuite software minimizes errors caused by such variables.

The device covers the full range of glaucoma detection and follow-up with standard white/white perimetry short-wavelength automated perimetry and flicker for early detection plus real Goldmann kinetic perimetry.

Physician Feedback

“The Eyesuite software is extremely helpful in identifying global and local trends for change,” says Jonathan Myers, MD, associate attending surgeon for the glaucoma service at Philadelphia's Wills Eye Hospital. “The software helps me to more quickly identify areas of concern and assess their significance. I find this quicker and easier than paper printout evaluation. It provides analysis by looking for a trend, applying linear regression analysis to clusters and highlighting significant changes and their severity. Every field you add is then added to the analysis.”

Eyesuite also includes eye-tracking software.“When the system detects the patient not looking centrally, it stops presenting stimuli,” says Dr. Myers. “The machine restarts when the patient looks back at the screen. It also monitors the position of the eye so that if it is not quite centered, the machine's chin-rest will move and re-center the eye.”

Lastly, Dr. Myers notes that the software takes into account a patient's fluctuation historically in assessing whether change is statistically significant and helps to identify trends that may indicate worsening glaucoma.

“I think, technologically, this is a big advance,” says Randy Kardon, MD, PhD, director of the neuro-ophthalmology service at the University of Iowa Hospitals and director of the Center of Excellence for the Prevention and Treatment of Vision Loss at the Iowa City VA hospital. “Kinetic perimetry is very important because static perimetry is often overly sensitive and highly variable, especially in patients with moderate to severe visual field damage.”

Dr. Kardon considers Octopus a step in the right direction toward standardizing kinetic perimetry. He emphasizes the importance of thorough training for techs using kinetic perimetry, as the test is interactive. “A perimetrist may need to retest at certain locations that look abnormal. There is decision-making that needs to be made on the part of the technician. With the Octopus, you can pause the machine and add more testing in that area,” says Dr. Kardon.

He says that the system's reaction-time feature is a good example of how to improve standardization of perimetry results. The device monitors reaction time — from the moment a patient sees a light to when the button is pushed — and adjusts the isopter borders for that time difference. “The system will help differentiate a visual field constriction due to disease from that due to a slow reaction time, which is important because many patients take longer to respond to a light stimulus, which can confound visual field test results.”

When a patient who had been previously tested by kinetic perimetry is retested, the instrument can select the same examinations, strategies and other parameters used reviously This saves time with the set-up and ensures matching data for more accurate progression analysis.

Additional Features

Dr. Myers says that the open virtualization format (OVF) is truly networked, which is something essential in an EMR setting. “All data from every test is immediately stored on a central server for easy access by any OVF or PC. This means patients can be tested on any OVF machine for subsequent exams and all data is secure and backed up,” says Dr. Myers.

He says its Tendency Oriented Perimetry program is another nice feature. “This program is very fast, about two and a half minutes per eye, through a strategy of reduced testing at each point and interpolation between points. This algorithm is greatly appreciated by patients for its brevity and may be appropriate to monitor many patients.” OM

For more information on the Octopus 900, visit www.haag-streit-usa.com or call (800) 787-5426.