Comparison and analysis of mydriasis optometry and prescription for refractive error in juveniles / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To compare the results of computer optometry and manifest refraction after mydriasis and prescription for refractive error in juveniles and explore the emphasis and notes of juvenile optometry. <p>METHODS: Totally 334 ametropic eyes of juveniles(including 212 myopic eyes and 122 hypermetropic eyes)were examined with computer optometry and manifest refraction after mydriasis. The manifest refraction was done again after the pupil recovered to obtain the prescription for refractive error. The results of computer optometry and manifest refraction after mydriasis and prescriptions for refractive error were compared and analyzed retrospectively. <p>RESULTS: When comparing computer optometry and manifest refraction after mydriasis, the differences of spherical power and cylindrical axis in general group, the differences of spherical power, cylindrical power and axis in myopia group and cylindrical axis in hyperopia group were all statistically significant(<i>P</i><0.05). The differences of spherical power and cylindrical axis between computer optometry and manifest refraction after mydriasis and prescriptions in general and hyperopia group were statistically significant(<i>P</i><0.05). The spherical power of computer optometry and manifest refraction after mydriasis in hyperopia group was greater than that of prescription and there was statistically significant difference in cylindrical power between manifest refraction after mydriasis and prescription(<i>P</i><0.05). In myopia group the differences in spherical power, cylindrical power and axis between computer optometry after mydriasis and prescription were statistically significant(<i>P</i><0.05)and the differences in cylindrical power and axis between manifest refraction after mydriasis and prescription were statistically significant(<i>P</i><0.05). The Bland-Altman analysis in three groups showed the good consistency of spherical and cylindrical power between computer optometry and manifest refraction after mydriasis and that the differences between them were acceptable clinically. It also showed the poor consistency of cylindrical axis between them. The Bland-Altman analysis in general and hyperopia groups showed the poor consistency of spherical power and cylindrical axis and the good consistency of cylindrical power between computer optometry and manifest refraction after mydriasis and prescription. In myopia group the spherical and cylindrical power between computer optometry and manifest refraction after mydriasis and prescription revealed good consistency and the cylindrical axis presented poor consistency.<p>CONCLUSION: The results of computer optometry and manifest refraction after mydriasis cannot be used as prescription. There was statistically significant difference between computer optometry and manifest refraction after mydriasis, but the spherical and cylindrical power between them revealed good consistency clinically. The cylindrical axis between computer optometry and manifest refraction after mydriasis presented poor consistency and so did the cylindrical axis between them and prescription. In conclusion, the cylindrical axis should be paid much attention to in optometry and glasses taking.

Comparison of Manifest Refraction and Cycloplegic Refraction Using Retinoscopy or an Autorefractor in Children

PURPOSE: To compare the measurements between manifest refraction and cycloplegic refraction using retinoscopy or an autorefractor in children and to investigate factors affecting the difference. METHODS: A total of 388 children with a mean age of 7.4 ± 3.6 years were examined using retinoscopy and a Grand Seiko GR-3500KA autorefractor before and after cycloplegia. We compared the difference in spherical and cylindrical components between refractions and analyzed the results according to gender, age, type of refractive error, amblyopia, strabismus, and neuro-developmental disorder. A difference in refractions of ±0.50 D or more was considered as a significant discrepancy. RESULTS: Before cycloplegia, the spherical portion of the refractive error via autorefractor measurement was more myopic than for the retinoscopic measurement in 47.2% of patients, and the cylindrical portion was greater in 37.1%. The spherical discrepancies were more common in children aged < 7 years, with hyperopia, or amblyopia (respectively, p = 0.002, p < 0.001, and p = 0.033). After cycloplegia, the spherical component of the refractive error by auto-refraction differed from retinoscopic measurement in 29.4% of patients, and the cylindrical portion differed in 30.7%. However, the difference was not significant and there was no difference according to clinical features. More than half of the children with discrepancies in the spherical component between retinoscopic refractions before and after cycloplegia had a discrepancy between auto-refraction and retinoscopic refraction before cycloplegia, and the two discrepancies had a significant correlation. CONCLUSIONS: Auto-refraction after cycloplegia can estimate retinoscopic values partially. Nevertheless, 30% of the children still showed a discrepancy. The discrepancy of manifest refraction or auto-refraction compared to retinoscopic refraction with cycloplegia should be considered in younger children, cases with hyperopia or amblyopia, and cases with a difference in auto-refraction and retinoscopic refraction before cycloplegia.

Predictive Factors of Successful Weaning From Glasses in Accommodative Esotropia Patients

PURPOSE: To investigate the predictive factors of successfully weaning children from glasses with accommodative esotropia who were monitored with manifest refraction on follow-up visits. METHODS: A retrospective review of 48 patients with accommodative esotropia was performed. Weaning was accomplished by monitoring patients with manifest refraction on follow-up visits. The patients were divided into 2 groups: patients who were weaned successfully from glasses and patients who still needed glasses at their final visit. A comparative analysis of the multiple clinical features between the 2 groups was performed. RESULTS: Among the 48 patients, 15 patients were weaned successfully from glasses. The age of onset was significantly different between the 2 groups, 39.6 +/- 14.9 months in patients who were weaned successfully from glasses and 30.7 +/- 16.9 months in patients who still needed glasses. In particular, the patients with onset of accommodative esotropia after 3 years of age were more likely to be weaned from glasses at their final visit. CONCLUSIONS: Monitoring with manifest refraction could be another method of weaning children from glasses with accommodative esotropia and the age of onset appears to be the useful predictor of successful weaning in children who can finally be weaned from glasses.

Comparison of WaveScan Aberrometer Refraction to Subjective Manifest Refraction and Autorefractor

PURPOSE:To compare the accuracy of myopic refraction using an aberrometer (WaveScan, Visx, Santa Clara, CA, USA) with manifest refraction using retinoscopy and an autorefractor. METHODS: The medical records of 200 eyes in 100 patients who visited our clinic from February 2005 to February 2007 for refractive surgery were reviewed retrospectively. We compared the refractive errors obtained using an aberrometer, retinoscopy, and an autorefractor (KR-7100, Topcon, Tokyo, Japan). All of the measured refractive errors were converted to power vectors for statistical analysis. The power vectors consisted of the M vector (M), J0 vector (J0), and J45 vector (J45). RESULTS: The mean sphere was -4.75 diopters (D) and the mean cylinder was -0.66D with retinoscopy. Power vectors of the aberrometer (PVw) were highly correlated with power vectors of retinoscopy (PVr) and the autrorefractor (PVa). The correlation coefficients (R2) between PVw and PVr were 0.960 (M), 0.852 (J0), and 0.679 (J45) and the correlation coefficients between PVw and PVr were 0.963 (M), 0.685 (J0), and 0.516 (J45). Mean differences were -0.247+/-0.412D (M), 0.034+/-0.120D (J0), and -0.017+/-1.07D (J45) between PVw and PVr, and were -0.068+/-0.403D (M), -0.055+/-0.194D (J0), and -0.052+/-0.165D (J45) between PVw and PVa. CONCLUSIONS: The measurement of refractive errors using a WaveScan aberrometer seems to be reliable and accurate, although some myopic shift was observed.

The Accuracy of the Orbscan-derived Total Refractive Power after Laser in Situ Keratomileusis

PURPOSE: This study was performed to evaluate the correlation between the change of the manifest refraction and change of the Orbscan-derived total refractive and axial power after laser in situ keratomileusis (LASIK). METHODS: A total of 34 consecutive eyes of 19 patients who were followed up for at least6 months after LASIK were included in study. The manifest refraction and Orbscan topography analysis of the 2, 3, 4, and 5 mm diameter zones of total refractive power and axial power maps were measured preoperatively and at least 6 month postoperatively. RESULTS: There were statistically significant correlations between all Orbscan-derived corneal power changes and changes of manifest refraction. Especially the total refractive power map in the central 4.0 mm zone gave the best statistically significant correlation with manifest refractive change (r2=0.790, p<0.01). CONCLUSIONS: These results indicate that the change of the manifest refraction in LASIK is best correlated with the change of the total refractive power map in the central 4.0 mm zone.

Comparison of Refractive Errors Measured by Several Different Methods

PURPOSE: Preoperative measurement of refractive error before LASIK or PRK is very important for good postoperative result because the measured refractive error is the basis of correction amount of operation. We analyzed the difference in spherical equivalent values of manifest refraction by operator (OMR), manifest and cycloplegic refraction by resident (RMR and RCR), noncycloplegic automated refraction (AMR). METHODS: The randomized charts of 50 patients (100 eyes) who had undergone LASIK or PRK for myopia at the Department of Ophthalmology at Samsung Medical Center between May 2000 and November 2000 were reviewed retrospectively and spherical equivalent values of preoperative OMR, RMR, RCR, and AMR by Nikon NRK-8000 autorefractor were analyzed by paired T-test. RESULTS: The mean spherical equivalent values of OMR, RMR, RCR, AMR were -5.40+/-2.10 D, -5.47+/-2.23 D, -5.36+/-2.18 D, -6.25+/-2.24 D, respectively. The spherical equivalent value of AMR was more myopic than the values of others and the bias was statistically significant. The absolute difference of spherical equivalent diopter between OMR and RMR was 0.27+/-0.27 D and that between OMR and RCR was 0.30+/-0.33 D. These two absolute difference did not show statistical significance. CONCLUSIONS: This study revealed that there was statistically significant difference in spherical equivalent diopter measured by AMR compared to those measured by OMR, RMR, or RCR. So we recommend the method of manifest and cycloplegic refraction by two ophthalmologists before LASIK or PRK for accurate measurement of refractive error.

A Study about the Accuracy of Automated Refraction

We analysed the differences between the values of noncycloplegicautomated refraction and manifest refraction by ophthalmologist 150 patients(274 eyes)were studied. We divided these patients into five groups according to the age; Group 1 included patients under 10 yea(n=50 eyes), Group 2 from 10 yrs to 19 yrs(n=74 eyes), Group 3 from 20 yrs to 39 yrs(n=66 eyes), Group 4 from 40 yrs to 49yrs(n=39 eyes), Group 5 over 50 yrs(n=46 eyes); We used Canon Auto Ref R-10 autorefractor and ophthalmologist's refractions were the results of both subjective refraction by retinoscope and objective refraction used by cross cylinder. Between the two examinations, the percentages of eyes of disagreement beyond +/-0.5D were 22%(group 1), 39.2%(group 2), 14.1%(group 3), 15.8%(group 4), 17.4%(group 5) in spherical power; 18%, 23%, 27.3%, 29%, 15.2% in cylindrical power respectively; 20%, 31.9%, 18.2%, 15.8%, 19.6% in spherical equivalent respectively and the percentages of eyes of disagreement beyond +/-10 degrees in cylindrical axis were 25%, 42.6%, 39.2%, 40%, 52.9% respectively. There was no statistic significance between the age groups when we compared the absolute differences of values between two examinations. Conclusively, this study revealed that there were large differences between the values of noncycloplegic automated refraction and manifest refraction by ophthalmologist in the large amout of patients and then our results indicated that automated refraction was dangerous to patient's eyes and subjective refinement was needed by ophthalmologist if patients wanted the spectacle or contact lens.