Table 2.
Binocular vision parameters among normal and NSBVA group.
| Parameter | Normal BV (n = 20) Median values with inter-quartile range in brackets |
NSBVA (n = 46) Median values with inter-quartile range in brackets |
p-Value (Mann–Whitney U test) |
|---|---|---|---|
| Distance NFV break (in PD) | 8 (6–10) | 8 (6–10) | >0.05 |
| Distance NFV recovery (in PD) | 6 (4–8) | 6 (4–8) | |
| Near NFV break (in PD) | 17 (16–20) | 16 (14–20) | |
| Near NFV recovery (in PD) | 14 (14–16) | 14 (11.50–16.0) | |
| Distance PFV break (in PD) | 16 (12–19.50) | 14 (10.0–18.50) | |
| Distance PFV recovery (in PD) | 10 (8–17) | 10 (8.0–15.25) | |
| Near point of accommodation – OD (in D) | 14.30 (12.5–16.7) | 12.5 (11.1–14.3) | |
| Near point of accommodation – OS (in D) | 14.30 (12.5–16.7) | 14.30 (11.1–15.72) | |
| NPC break (cm) | 7 (5–8) | 9 (7.0–10.25) | 0.005 |
| NPC recovery (cm) | 8 (6–9) | 10 (8.0–11.25) | 0.006 |
| Near PFV break (in PD) | 30 (25–35) | 25 (14–30) | 0.024 |
| Near PFV recovery (in PD) | 20 (16–35) | 19 (11.5–21.25) | 0.048 |
| AF OD (cpm) | 11 (10–12) | 4 (2–6) | <0.0001 |
| AF OS (cpm) | 11 (10–12) | 4 (1–6) | |
| AF OU (cpm) | 11 (10.63–12) | 6 (3.50–9.25) |
Unit: cm, centimetre; PD, prism dioptre; D, dioptre; cpm, cycle per minute.
NPC, near point of convergence; NFV, negative fusional vergence; PFV, positive fusional vergence; NPA, near point of accommodation; OD/OS/OU, oculus dexter/oculus sinister/oculus uterque; AF, accommodative facility.