Comparison of the Refractive Measurements with Hand-held Autorefractometer, Table-mounted Autorefractometer and Cycloplegic Retinoscopy in Children

PURPOSE: To evaluate the performance of the hand-held and table-top autorefractokeratometer in measuring refractive errors by comparing them with cycloplegic retinoscopy. METHODS: Included in the study were 112 eyes of 112 pediatric patients whose mean age was 6.78 +/- 2.61 years (range, 2 to 12 years). The refractive errors of all the eyes were measured with and without cycloplegia using a hand held autorefractokeratometer (Retinomax K-plus 3), table top autorefractokeratometer (Canon RK-F1) and performing cycloplegic retinoscopy. The spherical equivalent, cylindrical axis and keratometer values were statistically compared. RESULTS: The mean spherical equivalent obtained from the Retinomax K-plus 3 was significantly less hyperopic than that of Canon RK-F1 (p = 0.004) before cycloplegia. When the Bland Altman analysis was performed in comparisons of spherical equivalent values measured with the Retinomax K-plus 3, Canon RK-F1 and cycloplegic retinoscopy, it was seen that almost all of the differences between the measurements remained within the range of +/-2 standard deviation. Good agreement was found between Retinomax K-plus 3 and Canon RK-F1 for the Jackson cross-cylinder values at axis 0degrees and 45degrees; keratometer values respectively. CONCLUSIONS: The refractive error components were highly correlated between the two instruments and cycloplegic retinoscopy.

Comparison of the Refractive Measurements with Hand-held Autorefractometer, Table-mounted Autorefractometer and Cycloplegic Retinoscopy in Children

PURPOSE: To evaluate the performance of the hand-held and table-top autorefractokeratometer in measuring refractive errors by comparing them with cycloplegic retinoscopy. METHODS: Included in the study were 112 eyes of 112 pediatric patients whose mean age was 6.78 +/- 2.61 years (range, 2 to 12 years). The refractive errors of all the eyes were measured with and without cycloplegia using a hand held autorefractokeratometer (Retinomax K-plus 3), table top autorefractokeratometer (Canon RK-F1) and performing cycloplegic retinoscopy. The spherical equivalent, cylindrical axis and keratometer values were statistically compared. RESULTS: The mean spherical equivalent obtained from the Retinomax K-plus 3 was significantly less hyperopic than that of Canon RK-F1 (p = 0.004) before cycloplegia. When the Bland Altman analysis was performed in comparisons of spherical equivalent values measured with the Retinomax K-plus 3, Canon RK-F1 and cycloplegic retinoscopy, it was seen that almost all of the differences between the measurements remained within the range of +/-2 standard deviation. Good agreement was found between Retinomax K-plus 3 and Canon RK-F1 for the Jackson cross-cylinder values at axis 0degrees and 45degrees; keratometer values respectively. CONCLUSIONS: The refractive error components were highly correlated between the two instruments and cycloplegic retinoscopy.

Measurement of Central Keratometric Value with Orbscan II(R) Topography after LASIK

PURPOSE: To compare central keratometric values (K-values) measured at the pupillary center by Orbscan II (R) topography (Orbtek, Bausch & Lomb, USA) with preexisting methods for K-values in patients who have been treated with laser in situ keratomileusis (LASIK). METHODS: A total of 36 consecutive eyes of 25 patients who were treated with LASIK for myopia have been followed up for more than 1 year. Central K-values measured by Orbscan II(R) topography, K-values measured with autorefractokeratometer, and refraction-derived K-values were compared . RESULTS: The mean central keratometric K-value measured by Orbscan II (R) topography was 39.65+/-1.94 (35.82 to 43.45) diopter (D), and was not statistically significantly different from the mean refraction derived K-value which was 39.63+/-1.95 D (35.95 to 43.41) (p>0.05), but was statistically lower than the mean K-value measured with autorefractokeratometer which was 40.23+/-1.76 D (36.56 to 43.69) (P<0.05). CONCLUSIONS: In patients who have been treated with LASIK for myopia, central keratometric K-value measured with Orbscan II R topography is not statistically significantly different from refraction derived K-value, but is lower than K-value measured with autorefractokeratometer.