Abstract
Purpose: :
To determine the effect of general anesthesia (GA) on accommodation in children.
Methods: :
Subjects underwent cycloplegic refraction during an office visit 30-40 minutes after administration of cyclopentolate 1% twice, several minutes apart. For a planned procedure, GA was administered and pupils were dilated with phenyelphrine 2.5% twice, several minutes apart. After the non-study eye underwent the planned procedure, the study eye was refracted using the same method as in the office.
Results: :
Measurements under GA were obtained in 8 of the 9 subjects. Average age was 7.44 years (SD 4.89; range 1.83 to 18 years). Average difference in sphere was -0.44D (95% confidence interval, CI -1.24D to +0.36D). Average difference in cylinder was -0.19D (95% CI -0.97D to +0.60D). Average difference in axis was -0.13° (95% CI -3.25° to +3°). Average difference in spherical equivalent was -0.78D (95% CI -1.44D to +0.12D). The measurement under GA was within 0.25D of the office measurement in 5 of 8 subjects for sphere, 6 of 8 subjects for cylinder and 3 of 8 subjects for spherical equivalent.
Conclusions: :
Although it would be helpful to know whether GA relaxes accommodation - i.e. whether it induces cycloplegia - there is a paucity of studies evaluating the effect of GA on accommodation. Earlier studies, using GA protocols not practiced anymore, found GA to induce a significant myopic shift in some patients. Our study shows that, using current protocols, GA induces cyloplegia in most children.
Keywords: accommodation • refraction