Purchase this article with an account.
Z. Wang, L.F. Dell'Osso, J.B. Jacobs, R.A. Burnstine, R.L. Tomsak; Effects of Tenotomy on Patients With Infantile Nystagmus Syndrome: Acuity Improvement Over a Broadened Visual Field . Invest. Ophthalmol. Vis. Sci. 2006;47(13):2511.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To investigate the effects of four–muscle tenotomy on visual function and gaze angle in patients with infantile nystagmus syndrome (INS).
Eye movements of 9 patients with INS were recorded using infrared reflection or high–speed digital video techniques. Experimental protocols were designed to record the patients' eye–movement waveforms, pre– and post–tenotomy, at different gaze angles. We used the eXpanded Nystagmus Acuity Function (NAFX) to measure tenotomy–induced changes in the IN at primary position and various gaze angles. The longest foveation domains (LFD) were measured from fitted curves. Peak–to–peak nystagmus amplitudes and foveation–period durations were also measured.
All seven patients with narrow, high–NAFX, gaze–angle regions showed broadening of these regions of higher visual function. Three patients showed moderate NAFX improvement (13.9–32.6%) at primary position, 5 showed large improvement (39.9–162.4%), and 1 showed no NAFX change (due to his high pre–tenotomy NAFX). All patients had reductions in nystagmus amplitudes ranging from 14.6–37%. Foveation–period duration increases for all 9 patients ranged from 11.2–200%. The percentage increases in both the NAFX and LFD decreased as their pre–tenotomy values increased respectively.
In addition to elevating primary–position NAFX, tenotomy also broadened the high–NAFX regions. This broadening effect was more prominent in patients who had sharp pre–tenotomy NAFX peaks. Not surprisingly, four–muscle tenotomy produced higher primary–position NAFX increases in INS patients whose pre–tenotomy values were relatively low, with the improvement decreasing at higher pre–tenotomy values. The tenotomy procedure results in improvements in visual function beyond primary–position acuity. This extends the utility of surgical therapy to several different classes of patients with INS for whom other procedures are contraindicated. The pre–tenotomy NAFX can now be used to predict both primary–position acuity improvements and broadening of a patient's high–acuity range of gaze angles.
This PDF is available to Subscribers Only