Elucidating the Visual Snow Spectrum: A Latent Class Analysis Study
Table 1
Summary of sample characteristics.
Complete sample
Participants without VS
Participants with VS
Participants with VSS
1,846
1,072
774
83
Mean age (SD)
38.34 (12.03)
37.79 (12.76)
36.32 (10.62)
37.64 (12.26)
Gender (male)
1,084 (58.72%)
649 (60.54%)
435 (56.20%)
45 (54.21%)
Gender (female)
746 (40.41%)
413 (38.53%)
333 (43.02%)
38 (45.79%)
Gender (nonbinary)
7 (0.38%)
4 (0.37%)
3 (0.39%)
0 (0.00%)
Gender (prefer not to say)
9 (0.49%)
6 (0.56%)
3 (0.39%)
0 (0.00%)
Relevant medical history
Probable migraine (no aura)
260 (14.08%)
99 (9.24%)
75 (9.69%)
10 (12.05%)
Probable migraine (aura)
500 (27.09%)
185 (17.25%)
401 (51.81%)
42 (50.60%)
Tinnitus
402 (21.78%)
207 (19.31%)
195 (25.20%)
33 (39.75%)
Drug history
668 (36.19%)
339 (31.62%)
329 (42.51%)
30 (36.14%)
Perceptual phenomena associated with VSS
Palinopsia
281 (15.22%)
81 (7.56%)
200 (25.84%)
33 (39.76%)
Excessive floaters
519 (28.11%)
148 (13.81%)
371 (47.93%)
60 (72.29%)
Blue field entoptic phenomenon (BFEP)
307 (16.63%)
41 (3.82%)
266 (34.37%)
44 (53.01%)
Halos
288 (15.60%)
86 (8.02%)
202 (26.10%)
25 (30.12%)
Self-light of the eyes
300 (16.25%)
92 (8.58%)
208 (26.87%)
31 (37.35%)
Photophobia
658 (35.64%)
310 (28.92%)
348 (44.96%)
50 (60.24%)
Nyctalopia
222 (12.03%)
82 (7.65%)
140 (18.10%)
19 (22.89%)
Note. The participants with visual snow here also include the participants with VSS and participants with possible HPPD. Participants who had possible HPPD, i.e., met the criteria for VSS and who had a history of drug use which was immediately prior to the onset of their perceptual phenomena, are not included in the VSS category.
