The relationship between BDFM and the sensory tests is shown in
Table 1 . None of the patients passed Test 2 regardless of the time of onset of
the ocular deviation (i.e., none had stereopsis). Fifteen (36.5%)
patients in the infantile group and 16 (57.1%) in the late-onset group
(total = 31, 44.9%) passed Tests 1 and 3 but not 2 and were
classified as having positive BDFM without stereopsis. Of the other 38
patients, 26 in the infantile group and 12 in the late-onset group did
not pass any test. There was no statistical difference between
early-onset esotropia and late-onset esotropia in the incidence of
positive BDFM.
The distribution of the angle of deviation at near for the infantile
esotropia and the late-onset esotropia groups is shown in
Figures 3 A and 3B, respectively. The patients with positive BDFM (black squares)
had significantly smaller angles of deviation (infantile onset, 4.33
SD, 5.68 prism diopters [pd]; late-onset, 8.00 SD, 6.65 pd) than the
patients lacking BDFM (infantile-onset, 12.2 SD, 2.46 pd; late-onset,
18.4 SD, 9.00 pd;
P = 0.0016; Mann–Whitney test).
There was no statistical difference between the age at the time of
examination and the presence of BDFM in both groups (infantile-onset,
P = 0.205; late-onset,
P = 0.0885
Mann–Whitney test). Of the 41 infantile esotropia patients, 36 had
undergone strabismus surgery at a mean age of 49.8 months with a
(range, 25–120 months). Of the 28 late-onset esotropia patients, 10
patients had undergone strabismus surgery at a mean age of 166 months
(range, 24–356 months). There was no statistical difference between
the presence of BDFM and whether the patient had undergone surgery. In
addition, there was no statistical difference between a positive BDFM
and the age at the time of surgery in both groups (infantile-onset,
P = 0.796; late-onset,
P = 0.317
Mann–Whitney test).
There was a high correlation between a positive Titmus Fly test and a
positive BDFM (P = 0.0009, chi-square test). None of
the patients passed Plate I of the TNO stereo test. Fusion of the Worth
four-dot test at 0.3 m and positive BDFM were highly correlated
(P < 0.0001, chi-square test). There was a
significantly higher number of patients with BDFM who were able to fuse
the Worth four-dot test at 0.3 m. None of the patients fused the
Worth four-dot test at 5 meters. There was no correlation between
suppression under Bagolini striated lenses test and BDFM and also no
correlation between the visual acuity and the presence of BDFM.