Effect of Acupuncture on Waveform Characteristics and Visual Acuity in Idiopathic Infantile Nystagmus: A Prospective Interventional Study

Abstract

Introduction: Idiopathic Infantile Nystagmus or Infantile Nystagmus Syndrome (INS) is one of the known causes for congenital nystagmus. Though the exact aetiology is unknown, there have been studies related to its treatment using prisms and contact lens. However, there have been not many clinical studies using the alternative therapy like acupuncture is done to analyse the effect on nystagmus. Therefore, the rationale of the study was to know the effect of acupuncture in INS and identify the same by Videonystagmography (VNG). Aim: To evaluate the effect of acupuncture on waveform characteristics and visual acuity in INS. Materials and Methods: This prospective interventional study was performed at Dr. Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS, New Delhi, India, during the period of March 2004 to March 2006. Institutional Review Board/Ethical Clearance was obtained and patients with INS of more than 18 years, who were co-operative, underwent acupuncture needle stimulation of sternocleidomastoid. The needles in sternocleidomastoid were stimulated every five minutes for 15 minutes for 10 sittings (5 days). Nystagmus parameters like slow phase velocity, amplitude, frequency were recorded by VNG for 20 minutes. Changes in waveform and visual acuity (Snellen visual acuity charts) were examined on every visit on all five days and patients were followed-up for three months. Visual acuity, nystagmus intensity, amplitude, frequency and slow phase velocity were the parameters analysed. A repeated measure- Analysis of Variance (ANOVA) test and Freidman test was performed using Statistical Package for the Social Sciences (SPSS) (version 16.1) to analyse the data. A p-value <0.05 was considered significant. Results: Ten patients with INS underwent the procedure. Significant improvement in distant visual acuity was noted at three months (right eye p=0.039, left eye p=0.050). Significant decrease in frequency during treatment (p=0.046, p=0.014 at 10 minutes and 15 minutes, respectively) was noted. Dampening of nystagmus amplitude was seen during acupuncture therapy, which got enhanced by twirling of the needles. No permanent changes in waveform characteristics were seen after therapy in the follow-up for over three months. Conclusion: The afferent stimulation from neck muscles by acupuncture in infantile nystagmus does affect waveforms during therapy and visual acuity after the therapy on short-term.

Keywords

• acupuncture therapy
• foveation duration
• infantile nystagmus syndrome
• nystagmography
• videonystagmography
• waveform changes