Today’s computerized acuity tests: more than just eye charts

The next generation of computerized visual acuity systems is providing a modernized version of the classic eye exam, allowing for more accurate results, reduced chair time and increased comfort for the patient. Features such as randomization are standard in these acuity systems, preventing the memorization of eye charts by patients. In addition, many are equipped with video capabilities, which can be used either as a pediatric fixation point or for viewing educational materials.

M&S Smart System 20/20

The Smart System 20/20 by M&S Technologies (Skokie, Ill.) is a PC-based visual acuity and contrast testing system that produces a number of acuity tests, contrast sensitivity function testing, patient education and video media. The system includes a wireless infrared hand controller, a central processing unit, video control module, 17- or 19-inch flat screen LCD and VAFCS software.

“There is an illuminated keypad, and you can push a button and get whatever target configuration you want – letters, numbers, symbols or specialty targets such as contrast,” said David G. Kirschen, OD, PhD, a practitioner based in Brea, Calif., in an interview with Primary Care Optometry News. “You simply push the button, and the target comes up immediately. You push another button and you get another, randomized set of letters. There’s no chance of memorization.”

Dr. Kirschen said the wireless remote is particularly helpful to practitioners administering the test. “The remote is non-directional and does not have to be facing the unit,” he said, “so you don’t have to turn around and face the display.”

The system also features a large 17- or 19-inch LCD display that allows the practitioner to see what the patient is seeing. Dr. Kirschen said that, as a practitioner who sees a large number of pediatric cases, he finds the Smart System’s pediatric unit to be very convenient. “It has many pediatric targets that are immediately accessible,” he said. “It has the HOTV test, the Lea symbols and both numbers and pictures.”

For pediatric tests, the unit also offers built-in movies and fixation targets such as barking dogs, Dr. Kirschen said, which are useful in performing tests such as retinoscopy.

For the adult unit, M&S has also integrated with EyeMaginations (Towson, Md.) to provide educational software for patients. “They have a number of animations for different optometric procedures and disorders, and it runs seamlessly on the M&S system,” he said. “So if you have a patient with blepharitis, for example, and you need to go into another room, you can have the patient watch a video that explains blepharitis, controlled directly through the M&S remote.”

Dr. Kirschen added that the M&S system has a true ETDRS testing system, as well as calibrated contrast.

The Acuity Pro

The Acuity Pro (Vision Science Software, Elk City, Okla.) is a computerized acuity testing software system that will randomize any optotype on the screen. Other features of this system include ETDRS, LogMar, Snellen, number, variable contrast, 4-dot, fixation disparity, picture chart, E chart, C chart, HOTV, video, pathology photo gallery and handheld remote.

“It’s not just a matter of randomizing the chart letters,” Marcia Dettloff, OD, of Cary, N.C., said in an interview. “The program has a wide variety of targets: Worth 4-dot, starburst, fixation disparity, several-letter format, tumbling Es, Landolt Cs, pictures, numbers, etc.”

Dr. Dettloff also emphasized the diversity with which a practitioner can present the optotypes when using the Acuity Pro. “It lets you present the optotypes in just about every way you can imagine: single character, single line, multiple lines, vertical line, red/green background and in mirror image,” she said. “And you can randomize them anytime. You can get to just about any screen you want in three keystrokes or less.”

Dr. Dettloff said the Acuity Pro also allows the practitioner to program “hot keys” with his or her favorite sequences. In addition, the system features a picture gallery/slideshow with photos of common conditions and enables a doctor to import his or her own photos and cartoon videos for use during retinoscopy. She said the test is relatively easy to set up in a mirrored room.

“The computer chart will reverse the image so you only need one mirror, and the monitor is placed high on the wall behind the patient, making it easy for the doctor to see the letters (reversed),” she said. “If using a 20-foot room, you just place the monitor where you would normally place the screen.”

Dr. Dettloff said practitioners should note that the computer must be placed within 10 feet of the monitor to assure good image quality. She said the availability of a wireless keyboard/mouse or a remote allows the doctor to put the computer wherever it is needed.

She said, overall, the Acuity Pro is an excellent system and is very advantageous to her practice. “Acuity Pro’s primary advantage is that it was developed by optometrists who understand our needs and are responsive to customer requests,” she said. “That has resulted in a convenient, flexible system that fits your exam routine instead of making your exam fit the program.”

Haag-Streit’s Stimuli

The Stimuli by Haag-Streit (Mason, Ohio) brings a wide variety of randomized charts to the patient in a different manner. The Stimuli supports several different types of acuity charts, optotypes, associated vision tests and fixation devices in a remote-controlled unit that can be customized for individuals.

The system offers more than 16 selectable features, including LogMar, Snellen or decimal units. It comes with an Apple iMac computer with a built-in monitor and Stimuli software.

“With a flick of a button, you can change your chart from a full chart to a single line to a single letter to multiple lines at the same acuity,” Beth Workman, OD, a practitioner based in Lorain, Ohio, told Primary Care Optometry News. “It’s very quick, and I think patients like the fact that they can’t memorize it. They have fun with it.”

Dr. Workman said she also enjoys the randomization of the Stimuli system. “I’ve been in practice for more than 30 years, and I hear the same lines being read every day. It makes it tough on the doctor,” she said. “This makes me more tuned into the exam. I found it really woke me up.”

Dr. Workman said the Stimuli system is particularly useful in dealing with low vision patients, providing more subtle gradations and levels of refractive error.

“The difference between 20/400 and 20/200 is huge, and the standard chart gives you nothing in between,” she said. “With the Stimuli, you have at least two steps in between.”

The Stimuli system also provides easy access to cartoons, which can serve as a fixation point for pediatric patients during retinoscopy, Dr. Workman said. It also includes a CD player for background music.

“It’s a great system that is very easy to use, and it provides flexibility on a lot of levels,” she said. “The few times I have had to go back to a conventional projector, I realize how much better it is.”

Accutome’s L40

Accutome’s (Malvern, Pa.) new computerized, randomized visual acuity test, the L40, includes several different refraction charts in one system. A comprehensive range of applications is available, from low vision to hyperacuity. It can operate between 6.6 feet and 19.7 feet.

“The L40 has all the charts needed for refraction, plugged into a simple system,” said Marc Pensak, OD, of Scranton, Pa., in an interview. “They can be retrieved by using its remote control.”

Dr. Pensak said the L40 features multiple tests using letters, numbers, children symbols, Landolt rings and more.

The system also features software for educational presentations.

“Because the system is a computer, it can also play videos for our practice including educational, LASIK consent, animation (for children) and up-selling for the dispensary,” he said. “The system also has contrast sensitivity testing, and we can use that with any screen.”

Dr. Pensak said the letters change randomly to prevent memorization when changing the size or contrast or by hitting the “chg” button on the remote.

The L40 is very convenient and adaptable, he said. “Everything on the unit can be adjusted on the menu screen,” he said.

The Veatch Sirius projector

The Sirius Computerized Projector (Veatch Instruments, Tempe, Ariz.) provides a complete set of visual acuity tests in one system. It offers a wide range of acuity tests that can be randomized to prevent memorization.

“It’s basically like a remote-control TV,” Ahmed Said, OD, a Dunn, N.C.- based practitioner told Primary Care Optometry News. “You flip through the charts, and you can choose numbers or letters. The letter randomization feature is very helpful in making sure the patient doesn’t memorize.”

All optotypes in the Sirius system can be displayed as single-character mode, single-line mode, multi-line mode and single-column mode (for speed acuity testing).

Acuity charts featured in the system include optotypes, Worth dot, contrast sensitivity, astigmatism, circular astigmatism, concentric circles, red-green balance and fixation points.

Optotypes include measurement in Snellen and ETDRS, HOTV, Allen or lower-case letters, tumbling E, Landolt C and numbers. The system includes a video and image gallery, which is useful as a fixation device for children or for eye care education. These galleries can also be customized, allowing the practitioner to use his or her own unique images or video presentations.

“It has user-friendly features for kids,” said Dr. Said. “You can choose numbers instead of letters, and it has a video feature as well.”

Another advantage to the Sirius system is that it can be calibrated to the size of smaller rooms with the use of mirrors,” he said. “You calibrate distance from chair to screen. I’ve heard it is very helpful in offices where space is limited. That’s another major benefit to this system,” he said.

Innova’s Provideo

Innova Systems Inc.’s (Burr Ridge, Ill.) Provideo line of acuity systems use state-of-the-art USB-interfaced hardware, which is integrated with the company’s NCI software.

“The Innova Systems software is a comprehensive vision assessment package that goes well beyond simple Snellen acuity measurement,” said Sandra M. Brown, MD, a pediatric ophthalmologist located in Concord, N.C. “Almost any optotype-recognition test you want is available, including the standard Snellen progression, Sloan letters, ETDRS-compliant displays and ATS (Amblyopia Treatment Study)–compliant displays using HOTV letters.”

As a pediatric ophthalmologist, Dr. Brown said she finds the Innova system to be very helpful to her practice. “For pediatric evaluation, the ‘moving arrow’ is invaluable,” she said in an interview. “This is an arrow pointing up to a particular shape or letter from underneath a line of letters, which can be shifted by the examiner,” Dr. Brown said. “This helps keep the patient’s attention on the screen.”

The system also includes a movie feature, Dr. Brown said. This allows a user to select a variety of video clips that can be loaded onto the hard drive. “The kids love them as attention targets for strabismus testing, and they are great pacifiers as well, when you want the kids to quiet down so you can talk to the parents.”

The Innova software also contains a letter-recognition contrast sensitivity test, which has established normal values. Dr. Brown was among those who conducted the normal values research.

“This test is really quite valuable before and after refractive surgery, and it will clearly become increasingly important as multifocal IOLs become more widespread,” she said. “It is user- and patient-friendly and is easily interpreted.”

For more information:

• David G. Kirschen, OD, PhD, can be reached at 428 South Brea Blvd., Brea, CA 92821; (714) 529-2470; fax: (866) 801-4739; e-mail: drkirschen@sbcglobal.net.
• Marcia Dettloff, OD, can be reached at 937 N. Harrison Ave., Cary, NC 27513-3904; (919) 481-4682; e-mail: info@caryoptometric.com.
• Beth Workman, OD, can be reached at 1142 W. 37^th St., Lorain, OH 44052-5115; (440) 282-6669; fax: (440) 282-5397; e-mail: gradisekworkman@centurytel.net.
• Marc Pensak, OD, can be reached at 1879 East Steet # 3, Williamsport, PA 17701; (570) 329-0188; e-mail: docndave@aol.com.
• Ahmed Said, OD, can be reached at 801 Tilghman Dr., Ste. E, Dunn NC 28334; (910) 892-4743; fax: (910) 897-6102.
• Sandra M. Brown, MD, can be reached at 201 LePhillip Court, NE, Concord, NC 28025; (704) 782-1127; e-mail: SbrownMD@CabarrusEye.com. Drs. Kirschen, Dettloff, Workman, Pensak, Said and Brown have no direct financial interest in the products mentioned in this article, nor are they paid consultants for any companies mentioned.

• M&S Technologies can be reached at 5557 W. Howard Street, Skokie, IL 60077; (877) 225-6101, (847) 763-0500, fax: (877) 473-9806, (847) 763-9170; www.mstech-eyes.com.
• VisionScience Software can be reached at PO Box 9, Elk City, OK 73648-0009; (877) 228-4890; (580) 243-1301; e-mail: info@acuitypro.com; www.acuitypro.com.
• Haag-Streit USA can be reached at 3535 Kings Mills Rd., Mason, OH 45040; (513) 336-7255; fax: (513) 336-7260; www.haag-streit-usa.com.
• Accutome Inc. can be reached at 263 Great Valley Pkwy., Malvern, PA 19355; (800) 979-2020; fax: (610) 889-3233; e-mail: eyeopener@accutome.com; www.accutome.com.
• Veatch Ophthalmic Instruments can be reached at 136 W. Orion, Tempe, AZ 85283; (602) 438-0799; fax: (480) 838-4934; www.veatchinstruments.com.
• Innova Systems can be reached at 8330 S. Madison St., Suite 60, Burr Ridge, IL 60527-6596; (630) 920-8880; fax: (630) 920-8896; e-mail: innova.systems@sbcglobal.net; www.innovasysi.com.