A comparison of drop instillation and spray application of 1% cyclopentolate hydrochloride

We compared the objective cycloplegic refractive error of 37 hyperopic children (ages 18 months to 6 years). Cycloplegia was by spray application to the closed eye, or by a one-drop instillation to the open eye. Patients were initially screened for hyperopia using a masked noncycloplegic retinoscopy with loose trial lenses. Spray and drop cycloplegias (1% cyclopentolate hydrochloride; 1% Spectro Pentolate) were administered to each patient in random order within a 2-week period. A masked cycloplegic retinoscopy was performed 20 min after drug administration for patients with "light" iris coloration and after 40 min for those with "dark" irides. One examiner conducted all cyclopentolate administrations; a separate examiner (masked to application method) conducted all refractive testing. For right eyes, the mean spherical equivalent refractive error after spray application was 1.76 D (SD = 1.63 D) and after drop instillation 1.78 D (SD = 1.85 D). Results were similar for the left eyes. These small differences were not statistically significant (ANOVA, F = 0.05, p = 0.82). The absolute difference in spherical equivalent was 0.50 D or less in 93% of all subject eyes. A scaling system was used to rate the ease of administration and the patient's response to each method. Using an exact test of marginal homogeneity, the response rating for the spray method was significantly better (p = 0.038). The spray application of cyclopentolate hydrochloride is easier to administer and is an effective alternative to traditional drop instillation.