Abstract
Purpose: :
To assess the validity of the tenotomy procedure in patients with infantile nystagmus in terms of visual acuity and nystagmus intensity.
Methods: :
Eye movements (500Hz) and LogMAR visual acuities were recorded from 6 patients with infantile nystagmus before and after a tenotomy procedure was performed. Eye movements and visual acuity (VA) were recorded at distance (1.2m) and near (0.4m) for 4 patients with albinism and nystagmus (1 of which had combined tenotomy/strabismus surgery) and 2 patients with idiopathic periodic alternating nystagmus (PAN). Nystagmus intensity was measured at positions from -30° to 30° eccentricity (for both 1.2m and 0.4m) at 3° intervals along the horizontal plane and the data was compared before and after (1wk, 4wks, 8wks, 12wks) surgery. Changes in intensity were viewed at null point and across all positions and compared to changes in VA. The patients’ own subjective estimates of change in VA and nystagmus were also recorded.
Results: :
In terms of LogMAR VA the albinism patients improved by 13.8%, 17.8% and -3.5% for distance and 15.3%, 14.8% and 12.6% for near. The combination tenotomy/strabismus patient improved by 3.4% for distance and 18.8% for near. The amount of improvement appeared to be dependent upon gaze position. Both PAN patients showed no change in VA. Variable changes were found on eye movement recordings, particularly reduction of nystagmus intensity on lateral gaze. All patients felt subjectively that their nystagmus had improved and all but one patient felt they had an improvement in VA.
Conclusions: :
Early reports suggest that tentomy may improve infantile nystagmus. However, it is necessary to evaluate more patients to substantiate these findings and find which patients respond best to the procedure.
Keywords: nystagmus • eye movements