Habitual excessive accommodation (HEA) in children is often accompanied by signs of autonomic imbalance, which substantiates the need for a comprehensive study of autonomic regulation in this condition.

PURPOSE

This study aimed to investigate the features of autonomic regulation in children with habitual excessive accommodation (HEA).

MATERIAL AND METHODS

A total of 104 children aged 6—17 years were examined: the main group comprised 54 patients with HEA and the control group included 50 children without this disorder. Mean manifest spherical equivalent was −1.75±0.60 D in the main group and −0.85±0.50 D in the control group (p<0.001); cycloplegic spherical equivalent was −0.72±0.52 D and −0.45±0.46 D, respectively (p<0.01). Ophthalmological examination included assessment of accommodative functions, pupil diameter, and cardiointervalography (CIG).

RESULTS

Children with HEA had lower accommodative amplitude (8.6±1.9 vs. 11.2±2.1 D), reserve (1.4±0.6 vs. 2.6±0.7 D), and facility (5.3±1.8 vs. 9.1±2.0 cycles/min; p<0.01), as well as lower (p<0.001) parasympathetic heart rate variability (HRV) indices — standard deviation of NN intervals (SDNN), root mean square of successive differences (RMSSD), percentage of NN intervals >50 ms (pNN50), and high-frequency power (HF), while sympathetic markers — low-frequency power (LF), sympathovagal index (LF/HF), and stress index (SI) — were higher (p<0.001). Pupil diameter was smaller (3.96±0.75 vs. 5.04±0.49 mm; p<0.001). The amplitude of accommodative miosis (Δ_accom) correlated positively with LF/HF (r=0.34) and negatively with SDNN and HF (r≈–0.34; p<0.05). Autonomic imbalance was most pronounced at ages 14—17 and in grade 3 HEA (LF/HF=2.67±0.3; SI=200±35).

CONCLUSION

HEA is associated with reduced parasympathetic and increased sympathetic activity. Cardiointervalography and pupillometry are informative for early detection of autonomic maladaptation.