170 likes | 427 Views
Intraday Variability of Control in Intermittent Exotropia. Sarah R. Hatt, Brian G. Mohney, David A. Leske, Jonathan M. Holmes Mayo Clinic, Rochester, MN, USA. Commercial relationships: None. Poor control: > 50% of waking hours Deterioration – consecutive visits: indicator for surgery
E N D
Intraday Variability of Control in Intermittent Exotropia Sarah R. Hatt, Brian G. Mohney, David A. Leske, Jonathan M. Holmes Mayo Clinic, Rochester, MN, USA Commercial relationships: None
Poor control: > 50% of waking hours Deterioration – consecutive visits: indicator for surgery Type and degree of variability of control within 1 day is not known Implications for: defining severity interpreting change in control over time Intermittent Exotropia - Control
Purpose To assess the variability of control over one day in children with intermittent exotropia using control scale to quantify control
Methods – Control Assessment Mohney BG, Holmes JM. An office-based scale for assessing control in intermittent exotropia. Strabismus 2006;14:147-50.
5 4 3 Investigator 2 2 1 0 0 1 2 3 4 5 Investigator 1 Control scale reliability near control k=0.95 distance control k=0.94 5 4 3 Investigator 2 2 1 0 0 1 2 3 4 5 Investigator 1 Scores differed by no more than one level on the control scale: Real change in control defined as change of 2 or more levels on scale.
Methods – Intraday variability • 13 children with intermittent exotropia (median age 8 years; range 1 to 13) • No convergence insufficiency type exotropia • No co-existing ocular pathology • No amblyopia
Methods – Intraday variability • Examined 3 or 4 times over one day (minimum 2 hours apart) • Control assessed using control scale Variable = change in control 2 or more levels on control scale over day (distance or near) Stable = no change in control over day 8:00 -10:30 10:31-13:00 13:01-15:30 15:31-18:00
Results – Intraday variability of control N=13 Variable control 6/13 (46%) Stable control 7/13 (54%) Mean age 7.3 years 7.2 years Median control - distance 2.75 1* Median control - near 1 1 Median angle - distance 26^ 30^ Median angle - near 25^ 20^ * p=0.04
Patient 1 Patient 10 5 Patient 13 Tropic 4 3 2 Phoric 1 0 8:00 -10:30 10:31-13:00 13:01-15:30 15:31-18:00 Results – Variable distance control Control scale rating Assessment time
Patient 3 5 Patient 5 Patient 11 4 Patient 13 3 2 1 0 8:00 -10:30 10:31-13:00 13:01-15:30 15:31-18:00 Results – Variable near control Tropic Control scale rating Phoric Assessment time
Results – Summary • Control varies over one day in some patients with intermittent exotropia. • Change occurs between spontaneous tropia and well controlled phoria. • Worst control not always at the end of the clinical day.
10:30 12:45 14:49 Change in distance control 5 Tropic 4 3 Control scale rating 2 Phoric 1 0 January April August Assessment time
Conclusions • An isolated measure of control may be insufficient to represent: • baseline severity • change over time. • If control has a role in evaluating severity, multiple measures will be needed. • Change in isolated measures of control should not be used for surgical decision making.
EY015799 (JMH) Thank You Supported by: Research to Prevent Blindness, Inc.