Head Mounted Eye Tracking Aide for Loss of Central Vision (HETALCEV)

Participants with bilateral central scotomas will be selected for this study during their routine clinical visits at the University of Minnesota Eye Clinic. Written consent will be obtained from all participants.

Each participant will have their scotomas mapped using a Nidek MP-1 microperimeter housed in the psychology department to give exact size and shape information. This allows for the extent of each eye's scotoma to be put into the remapping software, and their intersection used in remapping calculation. Comparisons will be made between participants with small scotoma, less than 5 degrees, and participants with large scotoma, larger than 5 degrees. Experiments to be performed with the device are also divided into two categories. Category 1 involves reading of naturalistic text, and everyday task performance. Category 2 involves studying the effects of practice with the device on performance in category 1 experiments.

Participants will schedule an initial one-hour session for testing. During testing, participants will be told about the device and its functionality. Main instructions include what patients can expect to experience and see when wearing the HMD. Following this, the participants will be instructed on how to wear the HMD. If they have any glasses/ corrective lenses, they can be kept on. Once the patients don the HMD, testing will begin.

Initially, a calibration-free mode will be tested. This will entail asking the subject to focus on a particular point on the screen and checking if the gaze point determined by the eye tracker corresponds to this point. If good calibration is obtained, the investigators proceed with testing. Otherwise, a 3-point calibration sequence will be initiated following instructions on the software program. For the 3-point calibration sequence, the participant will be instructed to fixate at 3-5 different points on the screen one at a time. Following this calibration sequence, testing will resume and visual performance such as reading speed in words/minute will be measured as the primary outcome measure, with and without remapping.

Inclusion criteria

• 18 years or older
• Central vision loss from bilateral central scotomas
• No cognitive impairment as indicated by a Mini-Mental State Examination (MMSE)

Exclusion criteria

• Failed MMSE