Table 1.
Demographic and clinical characteristics of the study subjects and major findings of patients with MDD in eight eye movement studies.
| MDD patients | Healthy controls | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Age (years) | Male | Currently on medication | Age (years) | Male | |||||||||||
| Study | Task | N | Mean | SD | N | % | N | % | N | Mean | SD | N | % | Parameters | Major findings in MDD |
| Iacono et al. (24)a | SPEM | 25 | 37.9 | 12.9 | 5 | 20 | N/A | N/A | 46 | 35.0 | 11.9 | 8 | 22.9 | RT, RMSE | All variables: no significance |
| Abel et al. (25)b | SPEM | 16 | 48.4 | 12.4 | 16 | 100 | 4 | 25 | 21 | 37.5 | 10.9 | 21 | 100 | TWAG, CUS rates, CUS amplitude | Higher CUS rates in 5°/s SPEM |
| Malaspina et al. (26) | SPEM | 18 | 28.9 | 5.6 | N/A | N/A | 0 | 0 | 20 | 30.6 | 7 | N/A | N/A | % abn, Large saccades | All variables: no significance |
| Flechtner et al. (27) | SPEM | 34 | 46.9 | 11 | 9 | 26.5 | 30 | 88.2 | 42 | 34.3 | 10.9 | 20 | 47.6 | Pursuit gain, CUS, Anticipatory saccade, BUS, SWJ | Lower pursuit gain |
| Flechtner et al. (28)c | SPEM | 34 | 46.9 | 11 | 9 | 26.5 | 34 | 100 | 42 | 34.3 | 10.9 | 20 | 47.6 | Pursuit gain, CUS, Anticipatory saccade, BUS, SWJ | All variables: no significant difference between all time |
| Fabisch et al. (29) | SPEM | 19 | 34.4 | 8.3 | 19 | 100 | 19 | 100 | 21 | 37.8 | 5.9 | 21 | 100 | Peak gain, CUS error, CUS velocities | All variables: no significance |
| Chen et al. (30) | FVT | 19 | 28.3 | 4.7 | N/A | N/A | 0 | 0 | 19 | 27.9 | 4.6 | N/A | N/A | NF, tFD, aFD | More NF, longer tFD and aFD |
| Li et al. (31) | FST | 60 | 25.4 | 7.2 | N/A | N/A | 0 | 0 | 60 | 24.2 | 6.1 | N/A | N/A | NF, FD, Number of saccades, Saccade path | More NF and number of saccades, shorter FD, longer saccade path |
| FVT | NF, Duration of saccade, Saccade amplitude, mFD, Saccade path | Shorter duration of saccade, longer mFD | |||||||||||||
SPEM, Smooth pursuit eye movement; FVT, Free-viewing test; FST, Fixation stability test; RT, Reaction time; RMSE, Root mean square error; TWAG, Time-weight average gain; CUS, Catch-up saccade; BUS, Back-up saccade; SWJ, Square wave jerk, NF, number of fixations; tFD, total fixation duration; aFD, average fixation duration; FD, fixation duration; mFD, mean fixation duration.
a
This study analyzed remitted MDD.
b
This study analyzed affective disorders (MDD non-psychotic = 10, MDD psychotic = 1, bipolar depression non-psychotic = 4, schizoaffective disorder = 1).
c
A longitudinal study by Flechtner et al. (27).