离轴视网膜检影对成人临床客观屈光测量的影响——前瞻

Abstract

Purpose The objective of this study was to examine the effect of the off axis retinoscopy on objective central refractive measurement in adult clinical practice.Methods In all, 40 subjects underwent undilated retinoscopy in a randomly selected

eye both on and off the visual axis by a single masked examiner. Off axis retinoscopy was defined as retinoscopy performed with the testing eye of the examiner aligned with thecontralateral (non-test) eye of the subject resulting in an off axis deviation in the nasal horizontal visual field. Retinoscopy was performed in negative cylinder only and

spherocylindrical measurements were converted to power vectors for analysis. Paired t-test was used to assess differences in M, J0 and J45 power vectors including differences between mean aided and unaided LogMar acuities. Results In all, 14 subjects were myopic (SEr0.5 D), 13 subjects were emmetropic (SE between 0.49 and 1.0 D) and 13 subjects were

hyperopic (SE 41.0 D). Mean angle of deviation was 5.581 in the nasal horizontal visual field. J0 showed a significant negative shift in those with myopia (Po0.001) and emmetropia (P ¼ 0.049) following off axis retinoscopy. No significant differences in M,J0 and J45 were found in the hyperopes. Mean aided LogMar acuities after on and off axis retinoscopy were both significantly better than mean unaided LogMar VA (Po0.001 in both cases).Conclusion Small degrees of off axis

retinoscopy encountered in everyday clinical practice can induce errors in objective central refractive measurement.