Screening for refractive errors with the Topcon PR2000 Pediatric Refractometer

PURPOSE. The PR2000 (Topcon, Tokyo, Japan) is a photorefractor that has bee n used in a population study comparing different methods of screening presc hool children. The present study was conducted to determine the accuracy of the device in a largely clinical population. METHODS. Two hundred twenty-two children less than 8 years of age were incl uded. All children were examined by an orthoptist using the PR2000 without inducing cycloplegia. All children then underwent retinoscopy with cyclople gia by an examiner who was unaware of the results from the PR2000 examinati on. RESULTS. The PR2000 gave a numerical reading for 90% of the children's righ t eyes and the message "Out of range" for a further 5%. The readings undere stimated the amount of hypermetropic or astigmatic refractive error found o n retinoscopy by an amount proportional to the magnitude of the refractive error. Agreement with retinoscopy for the axis of astigmatism more than 0.7 5 D was moderately good (intraclass correlation coefficient [ICC] = 0.63). The PR2000 was more useful as a screener, especially for anisometropia for which it was 91% sensitive and 92% specific. The repeatability was good for sphere (ICC = 0.74), less so for astigmatism (ICC = 0.59), and better than the optometrist for anisometropia (ICC = 0.38). The presence of nonrefract ive diagnoses and the age of the children examined made Little difference i n the screening results. CONCLUSIONS. The PR2000 underestimated hypermetropic refractive errors when used without cycloplegia. However, it was at least as good a screening dev ice as other similar instruments, especially when judged by its ability to detect anisometropia and the repeatability of the results.