A prospective clinical evaluation of augmented Anderson procedure for idiopathic infantile nystagmus.

PURPOSE

To evaluate the efficacy of the augmented Anderson procedure in idiopathic infantile nystagmus (IIN).

METHODS

Twelve consecutive patients older than 5 years having IIN with eccentric null position and anomalous head position were enrolled in an institution-based study. Best-corrected visual acuity (uniocular and binocular and in both null position and primary position), slit-lamp examination, fundus examination, ocular motility examination, and stereopsis using TNO were recorded. In all cases the augmented Anderson procedure, that is, recession of the yoke muscles (9-mm medial rectus and 12-mm lateral rectus), was performed. Eye movements were recorded before and 3 months after surgery in the primary position, right gaze 15 and 30 degrees, and left gaze 15 and 30 degrees.

RESULTS

All patients had improvement in their anomalous head posture after surgery (p = 0.0001). The nystagmus intensity in the primary position decreased from 22.0 +/- 15.9 degrees cycles/s preoperatively to 10.6 +/- 10.2 degrees cycles/s at 3 months postoperatively. The change was statistically significant (p = 0.006). After surgery, binocular visual acuity using the Early Treatment Diabetic Retinopathy Study chart improved in primary position (p = 0.007). No patient developed more than mild limitation of horizontal movements after surgery.

CONCLUSION

The augmented Anderson procedure is successful in correcting face turn in patients having IIN with eccentric null position, resulting in an increase in visual acuity and a decrease in nystagmus intensity in primary position. Further studies with a longer follow-up are required to assess the long-term efficacy of this procedure.