Ivermectin for onchocercal eye disease (river blindness) (Review)

Whitworth 1991 reported explicitly data for the incidence of
blindness and visual impairment. The definition used for blindness
and visual impairment was consistent with the WHO guidelines.
In this trial, six out of 255 people who were not visually impaired
at baseline (2.4%) and who received four six-monthly doses
of ivermectin developed visual impairment compared to 5/230
(2.3%) in the placebo group after four six-monthly doses of ivermectin
or placebo (risk ratio (RR) 1.08, 95% confidence interval
(CI) 0.33 to 3.50).
2. Visual fields
Abiose 1993 reported the effect of ivermectin on visual field deterioration.
Of the participants who were treated with at least one
dose of ivermectin and completed a Friedmann field analysis at one
or more of the follow-up exams, 34/314 (10.8%) in the ivermectin
group developed visual field deterioration compared to 58/322
(18%) in the placebo group (RR 0.60, 95% CI 0.41 to 0.89).
We assessed the effects of missing data for this outcome (Table 4).
There was little evidence that this effect could be attributed to the
effects of missing data.
Table 4. Effect of missing data
Outcome: visual field loss
Assumption regarding missing data Risk ratio 95% confidence interval
Missing at random (available case analysis) 0.60 0.41 to 0.89
Odds outcome in non-observed twice that
in observed in ivermectin and control
groups
Odds outcome in non-observed half that in
observed in ivermectin and control groups
Odds outcome in non-observed twice that
in observed in ivermectin and half in control
groups
Odds outcome in non-observed twice that
in observed in ivermectin and half in control
groups
0.61 0.42 to 0.90
0.60 0.40 to 0.89
0.75 0.51 to 1.11
0.49 0.33 to 0.72
Ivermectin for onchocercal eye disease (river blindness) (Review)
Copyright © 2009 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
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