OM t of c.iii - Vision Research Coordinating Center - Washington ...

1/1/2005 Chapter 8 Corneal Curvature and Topography page 8-22
8.6.2 Visioptic EH-270 Protocol
(1) From the MAIN MENU, select the PATIENT command, and press ENTER.
Press F1 to enter the patient’s last and first name in the appropriate fields. Press F10 to
permanently file this information.
(2) With the CURRENT PATIENT correctly identified, position the patient with
his or her chin resting comfortably on the chin rest and forehead resting against the
forehead rest. Adjust the chin rest up or down so that the patient’s eyes align with the
LED markers on the side of the instrument.
(3) From the CURRENT PATIENT INFORMATION screen, highlight the word
LEFT on the bottom.
(4) Ask the patient to try and keep still and to fixate the central ring. Ask the
patient to blink a few times to lubricate the eye and make it more reflective, and then to
open both eyes as wide as possible.
(5) Position the patient’s eye near the center of the screen, and adjust the focus by
use of the keyboard controls. The LEFT and RIGHT arrow keys move the optical head
horizontally, while the PgUp and PgDn keys move the optical head vertically. The UP
and DOWN arrow keys move the optical head in and out to adjust focus.
(6) When the ring images are focused—automatically, if possible, otherwise
manually—and the crosshair is close to the center, ask the patient to completely blink.
Then ask the patient to open both eyes as widely as possible while fixating the fixation
light, and press the ENTER key to capture an image.
(7) Verify image quality before proceeding to take a second image of the left eye.
A good image has complete ring data, eyelids are open, and good corneal wettability as
evidenced by smooth rings.
(8) Repeat steps 3 through 7 for the left eye.
(9) After all images have been obtained, select UTILITIES from the MAIN
MENU. Select COPY IMAGE TO DISKETTE to transfer the images one at a time to a
floopy diskette labelled with the patient’s CLEK ID number, eye (OD or OS), and date.
(10) Diskettes are stored on site.
8.7 Humphrey Mastervue