Retinomax K-Plus Research Articles

Comparabilidad del autorrefractómetro portátil Retinomax K-plus 3 en modo rápido versus autorrefractómetro de sobremesa en modo estándar

IntroductionThis study analyzes the comparability of measurements taken by a Retinomax K-plus 3 handheld autorefractometer in quick mode and a Topcon KR-800 on-table autorefractometer in standard mode on the pediatric population, and establishes their correlation. MethodsIt is a retrospective comparative study. Spherical diopter power (SPH), cylindrical diopter power (CYL), angle of cylindrical axis (AX), and spherical equivalent (SE) were measured with the Retinomax in quick mode and with the Topcon in standard mode. Each patient was evaluated in cycloplegic and non-cycloplegic conditions by both autorefractometers. Student's t-test was performed between the two instruments for SPH, CYL, and SE. The Pearson correlation coefficient was calculated and the dispersion was represented using Bland-Altman graphs, also evaluating the subgroup of patients under 4 years of age. A descriptive analysis of the percentages of measures that differed was performed. ResultsIt included 98 eyes of 49 subjects (age range: 3-16 years). The data for HPS without cycloplegia are virtually identical, whereas with cycloplegia there is a hyperopic bias of +0.5 diopters measured with Retinomax. CYL results are very similar with and without cycloplegia. There is a high Pearson correlation for both instruments (>0.91) and a low degree of dispersion in the Bland-Altman plots under cycloplegia. ConclusionThe Retinomax data were consistent with those obtained by Topcon. The Retinomax is a useful instrument for detecting refractive errors in children between 3 and 16 years of age.

Comparability of the Retinomax K-plus 3 handheld autorefractometer in quick mode versus on-table autorefractometer in standard mode

IntroductionThis study analyzes the comparability of measurements taken by a Retinomax K-plus 3 handheld autorefractometer in Quick mode and a Topcon KR-800 on-table autorefractometer in standard mode on the pediatric population, and establishes their correlation. MethodsIt is a retrospective comparative study. Spherical diopter power (SPH), cylindrical diopter power (CYL), angle of cylindrical axis (AX), and spherical equivalent (SE) were measured with the Retinomax in Quick mode and with the Topcon in standard mode. Each patient was evaluated in cycloplegic and non-cycloplegic conditions by both autorefractometers. Student’s t-test was performed between the two instruments for SPH, CYL, and SE. The Pearson correlation coefficient was calculated and the dispersion was represented using Bland-Altman graphs, also evaluating the subgroup of patients under 4 years of age. A descriptive analysis of the percentages of measures that differed was performed. ResultsIt included 98 eyes of 49 subjects (age range: 3–16 years). The data for HPS without cycloplegia are virtually identical, whereas with cycloplegia there is a hyperopic bias of +0.5 diopters measured with Retinomax. CYL results are very similar with and without cycloplegia. There is a high Pearson correlation for both instruments (>0.91) and a low degree of dispersion in the Bland-Altman plots under cycloplegia. ConclusionThe Retinomax data were consistent with those obtained by Topcon. The Retinomax is a useful instrument for detecting refractive errors in children between 3 and 16 years of age.

In situ donor keratometry in deceased patients as a novel screening technique for eye banking

PurposeTo investigate the potential role of keratometry on whole globes in situ of deceased patients by assessing its repeatability and comparing it with sterile donor tomography after excision and preservation in organ culture.MethodsA sequence of 5 measurements was taken from 40 eyes in situ of deceased patients < 24 h after death using the portable Retinomax K-plus 3 (Bon, Tokyo, Japan). Keratometry of whole globes in situ, from which sclerocorneal discs were taken for organ culture, was compared to those obtained after measuring these sclerocorneal disks through their cell culture flask in medium I after 5 ± 4 days using the anterior segment optical coherence tomograph Casia 2 (Tomey Corp., Nagoya, Japan), and to 964 different donor corneas in medium II.ResultsCronbach’s alpha of the in situ keratometry was 0.891 and 0.942 for the steepest and flattest corneal power (P). The steepest (44.5D) and flattest (41.1D) P as well as the astigmatism (3.4D) of in situ corneas remained unchanged after preserving sclerocorneal discs in medium I (respectively 44.7D [p = 0.09]; 41.4D [p = 0.17]; 3.3D [p = 0.09]). The comparison of the in situ values with the 964 measured different donor corneas in medium II showed significantly (p < 0.001) higher P at the steep (45.4D) and flat (43.9D) meridian and smaller astigmatism (1.4D) for sterile donor tomography.ConclusionsMeasuring deceased patients’ eyes in situ with the portable Retinomax K-plus 3 represents a feasible and reliably repeatable screening method in the eye bank. In comparison to donor tomography in medium I, it measures a similar power and astigmatism.

Comparison of the results of four different refraction measurement devices in children with retinoscopy.

Purpose: The purpose of this study was to compare the results of 4 different autorefractometer devices with the results of retinoscopy in children. Methods: A total of 120 eyes of 60 patients aged between 6 and 18, who applied to Afyonkarahisar Health Sciences University unit of Pediatric Ophthalmology, were included in the study. Refraction with Plusoptix A09 (photoscreener) without cycloplegia was the first to be measured. Spherical and cylindrical values were recorded. Then, half an hour after the patients were instilled 2 drops of cyclopentolate with an interval of 5 minutes, dilated retinoscopy was performed, and spherical and cylindrical values were recorded. Autorefractometer measurements with cycloplegia were performed with Canon RK-F1 autorefractometer, Nidek Tonoref III and Retinomax K-Plus 3, and spherical and cylindrical values were recorded. Results: The mean age of the patients was 11.02 ± 2.1. The mean spherical equivalents were Canon RKF1 autorefractometer +0.045 ± 2.49, Nidek TonoRef III +0.023 ± 2.48, Retinomax K-Plus 3 +0.078 ± 1.42, Plusoptix A09 -0.119 ± 2.20, retinoscopy +0.124 ± 2.65. Moreover, the mean cylindrical values were Canon RK-F1 autorefractometer -0.893 ± 0.69, Nidek TonoRef III -0.927 ± 0.72, Retinomax K-Plus 3 -0.888 ± 0.73, Plusoptix A09 -0.883 ± 0.719, retinoscopy -0.923 ± 0.71. The statistical values compared with retinoscopy; Canon RKF1 spherical equivalent (p=0.376), cylindrical (p=0.515), Nidek TonoRef III spherical equivalent (p=0.485), cylindrical (p=0.198), Retinomax K-Plus 3 spherical equivalent (p=0.141), cylindrical (p=0.058), Plusoptix A09 spherical equivalent (p=0.085) and cylindrical (p=0.086) values were not different. Conclusions: In spherical and cylindrical refractive error detection, all 4 devices showed reasonable and consistent results compared to retinoscopy.

Percentile curves of refractive errors in a Spanish paediatric population

ObjectiveThe main objective of this study was to obtain percentile curves of refractive errors in a Spanish paediatric population aged between 3 and 12 years. Materials and methodA descriptive, observational and cross-sectional study was conducted, including children aged between 3 and 12 years who did not present with any known ocular and/or systemic diseases. The convenience sampling method was used to select the sample from three schools and one hospital in the Community of Madrid. The refractive error was obtained using a Retinomax K-plus 3 autorefractometer (RTX; Right Mfg. Co. Ltd., Tokyo, Japan). The 5th, 10th, 25th, 50th, 75th, 90th and 95th percentiles were calculated using the IBM SPSS Statistics v.24 statistical software (IBM Corporation, Armonk, NY, United States). ResultsA total of 688 children with a mean age of 7.68 ± 2.17 years were analysed. In the 50th percentile curve, spherical equivalent values started to become myopic at 3 years (SE < –0.50 D) and the 75th percentile curve also turned myopic at 4 years. As a result, it was observed that the spherical equivalent value became more negative with time, starting from the ages indicated above. Therefore, the 90th percentile curve was negative at 11 years. ConclusionPercentile curves of refractive errors in a Spanish paediatric population have been presented for the first time in order to help eyecare professionals detect children with refractive errors at an early age.

Comparison of photoscreeners and hand-held autorefractometer with cycloplegic autorefractometry in children with newly diagnosed attention deficit hyperactivity disorder

Purpose: To compare non-cycloplegic refraction measurements of two photoscreeners and the hand-held autorefractometer with cycloplegic measurements of the autorefractometer in patients with attention deficit hyperactivity disorder (ADHD).&#x0D; Meterials and methods: This cross-sectional, comparative study consisted of 53 children who were newly diagnosed with ADHD. We compared spherical, cylindrical, cylindrical axis and spherical equivalent (SE) measurements in Plusoptix A12, Spot Vision Screener, and Retinomax K-plus Screen with Tonoref II. Reliability was analyzed by using the interclass correlation coefficient (ICC) and Bland-Altman plot was used to evaluate the agreement between devices.&#x0D; Results: The mean age of children was 9.45 ± 1.68. All of the devices measured spherical power and SE significantly more myopic than the Tonoref II. While The Spot Vision Screener, PlusoptiX A12, and Tonoref II provided similar cylindrical power, Retinomax K-plus Screen measured significantly lower than the Tonoref II. The excellent reliability was detected in spherical power, cylindrical power, SE and J0 between Tonoref II and PlusoptiX A12 (ICC:0.930, 0.921, 0.927 and 0.920, respectively. All of the hand-held devices showed excellent reliability in terms of cylindrical power and J0 (ICC&gt;0.90, for all) and good reliability for J45 (ICC:0.75-0.90 for all).&#x0D; Conclusion: Despite all devices having advantages or disadvantages, Plusoptix A12 showed excellent reliability for detecting refractive errors in children with ADHD.

Comparison of Different Types of Objective Auto Refractors with Subjective Refraction

Purpose : The purpose of this study was to compare results from three different types of autorefractor including open-view, closed-view and hand-held type with subjective refraction. Methods : One hundred students (the mean age of 25.2±1.63) underwent objective refraction using three types of autorefractor including open-fied, closed type and hand-held type (Nvision-k 5001P, KR-8100P and Righton Retinomax K-plus). Subjective refraction for all was performed by an experienced optometrist without reference of autorefractors’ results. The difference of results between three autorefractors and subjective refraction was compared. Results : With the result of subjective refraction, the difference was shown minimum with open-view autorefractor followed by closed-view and hand-held autorefractor, which is significant difference among the devices (p<0.001). In addition, there was significant difference between subjective and objective refractions in spherical equivalent. The difference was minimum with open-view autorefractor followed by closed-view and hand-held autorefractor (p<0.001). Conclusion : The difference between open-view and closed-view type of autorefractor was not significant. Therefore, the results from these devices would be a good reference for subjective refraction. However, attention needs to be taken for held-held type as it may stimulate accommodation or cause measurement error.

Comparison of keratometry data using handheld and table-mounted instruments in healthy adults.

To compare keratometry data between the handheld Retinomax K-plus 3 and the table-mounted IOLMaster 700. Healthy adult volunteers were prospectively recruited to the study. All participants underwent 3 consecutive keratometry measurements using the Retinomax K-plus 3 and a single biometry assessment using the IOLMaster 700. Differences between the Retinomax K-plus 3 and the IOLMaster 700 were assessed using Wilcoxon test for paired samples, Spearman correlation, Bland-Altman and mountain plots. Twenty-eight healthy subjects with a median age of 37years (interquartile range (IQR) 28-44years) were included in the study. The median mean keratometry (mean K) reading was higher using the Retinomax K-plus 3 (44.04D; IQR 42.96-45.61D) compared to the IOLMaster 700 (43.78D; IQR 43.22-44.90D, p < 0.01), with a mean difference of 0.18D (95% confidence interval (CI) 0.11-0.23D). Mean K readings were highly correlated between the 2 devices (r = 0.995, p < 0.01). Bland-Altman plots showed 95% limits of agreement between -0.14D and 0.49D. Frequency histogram of mean K reading differences between the Retinomax K-plus 3 and the IOLMaster 700 showed that 56% of cases were between ± 0.2D, 93% of cases were between ± 0.4D and all cases were between ± 0.5D. Mean corneal astigmatism measurement was higher using the Retinomax K-plus 3 (1.01 ± 0.40D) compared to the IOLMaster 700 (0.77 ± 0.36D), with a mean difference of 0.23 ± 0.37D (p < 0.01) between the devices. A good agreement exists between the Retinomax K-plus 3 and the IOLMaster 700 regarding keratometry readings. This enables cataract surgeons to safely use the Retinomax K-plus 3 device when indicated.

Comparison of Adult Refractive Disorder Measurements Using HandyRef-K, Retinomax, Plusoptix, and Table-top Autorefractometer Devices.

Objectives:This study was conducted to compare refractive error measurements recorded using the Nidek HandyRef-K handheld autorefractometer (HDY; Nidek Co. Ltd., Tokyo, Japan), Plusoptix A09 photorefractor (PO; Plusoptix GmbH, Nuremberg, Germany), Retinomax K-plus 3 (RTX; Right Mfg. Co. Ltd., Tokyo, Japan), and a table-mounted autorefractometer/keratometer (TTR; URK 800, Unicos Co. Ltd., Daejeon, Republic of Korea).Methods:Patients aged ≥18 years underwent measurement of refraction without cycloplegia using 4 devices and the spherical power (SP), cylindrical power (CP), and spherical equivalent (SE) values were analyzed and compared.Results:A total of 181 eyes of 181 patients were enrolled in the study. The mean age of the patients was 33.08±0.95 years (range: 18-79 years). There was a significantly significant difference in the SP, CP, and SE values determined by the devices (p<0.001). The SP and SE values of the RTX and the HDY were similar, while the other device results were different (Wilcoxon signed-rank test, p=0.004). The CP values of the PO and the TTR, the HDY and the TTR were also comparable.Conclusion:The HDY, RTX, and the PO are suitable for screening in clinical practice, but the findings strongly suggest that they should be used with caution.

Refraction in pseudophakic eyes after surgical treatment of congenital cataracts

To evaluate the achieved refraction and its relation to the anterior-posterior axis of pseudophakic eyes after extraction of CC in children of up to one year of age. The study included 115 children (159 eyes) examined 1 to 11 years after the extraction of bilateral or unilateral CC at the age of 2-11 months. Optical power of the implanted IOL had been calculated using SRKII formula for hypercorrection to result in emmetropic or weak myopic refraction by the time the eye growth finishes. The subjects underwent autorefractometry on Retinomax K-Plus 3 device and ultrasonic biometry on Humphrey 835 A/B-scan system. The incidence of unplanned refraction in children aged 1 to 3 years was 61.2%, aged 3 years to 5 years 11 months - 24.4%, and in children of 6-11 years - 50.0%; it was associated with pronounced unplanned eye growth in 48.6% of cases with bilateral CC and in 27.3% of cases with unilateral CC. The main cause of unplanned refraction in pseudophakic eyes in children with CC is unpredictable increase of the length of anterior-posterior axis after surgery.

HandyRef-K: Comparison of the Latest Handheld Auto Refracto-keratometer with Retinomax and Plusoptix in Patients Younger than Three Years of Age.

Objectives:The purpose of the study was to compare the refractive error measurements of pediatric patients performed with a Plusoptix A09 photorefractor (PO; Plusoptix AG, Nuremberg, Germany), a Retinomax K-plus 3 (RTX; Right Group, Tokyo, Japan), and the new handheld auto refracto-keratometer, the Nidek HandyRef-K (HDY; Nidek SA, Créteil, France), and to evaluate the intermethods agreement.Methods:A total of 194 eyes of 194 children were included in the study. All of the children underwent refraction measurement with the PO before cycloplegia and 2 autorefractors were used after cycloplegia: the RTX and the HDY.Results:The mean age of the patients was 16.65±10.04 months (range: 3-34 months). There were no statistically significant differences between the spherical values (SV) or cylindrical axis values (CAV) measured with the PO (SV: 1.61±1.79 diopters [D]; CAV: 94.25±72.47 D), the RTX (SV: 1.91±2.06 D; CAV: 94.3±73.44 D), and the HDY (SV: 1.89±2.04 D; CAV: 93.55±73.71 D) (p>0.05).There was a statistically significant difference in the cylindrical values (CV) assessed with the RTX (CV: -0.97±0.75 D) and the HDY (CV: -1.11±0.76 D) (p=0.003) and the HDY and the PO (CV: -0.92±0.68 D)(p=0.002), while there was no statistically significant difference between the values determined with the RTX and the PO (p>0.05). Statistically significant differences were demonstrated for spherical equivalent values (SEV) obtained with the RTX (SEV: 1.43±1.97 D) and the PO (SEV: 1.15±1.74 D) (p=0.02), and the HDY (SEV: 1.34±1.95 D) and the PO (p=0.03), but no significant difference was found between the RTX and the HDY values (p>0.05).Conclusion:No significant difference was found between the SEV measured by the RTX and the HDY, but the PO was significantly less hyperopic than the RTX and the HDY. The CV measured by HDY was higher than that of other devices. These devices can be used for screening in crowded pediatric ophthalmology clinics and may be an easier way of measuring refractive errors in children younger than 3 years of age, but high SEV and CV results should serve as an alert to physicians. It should also be kept in mind that cycloplegic retinoscopy is still the gold standard and these alternative methods can only be used for screening. The prescription of eyeglasses should not be made without cycloplegic retinoscopy.

Preoperative biometry data of eyes with unilateral congenital cataract

To investigate the differences in biometry data of eyes with unilateral congenital cataract and the contralateral normal eyes in pediatric patients. Pediatric Ophthalmology Division, Ophthalmology Department, Semmelweis University in Budapest, Hungary. Retrospective case series. Data of visually significant unilateral congenital cataract patients who had cataract surgery in the ophthalmology department at Semmelweis University between 2013 and 2016 were collected. At the time of the examinations, the mean age of the patients was 36.4weeks±25.3 (SD). Central corneal thickness (CCT), corneal refractive power (keratometry [K]), horizontal corneal diameter, and axial length (AL) measurement data were obtained from both eyes of each patient. The measurements were taken under general anesthesia using a handheld kerato-refractometer (Retinomax K-plus 3) and an ultrasound instrument (Ocuscan RxP) with contact applanation method and Castroviejo straight-tip calipers at the beginning of the cataract surgery. For statistical evaluation, Originlab 7.0 software was used; paired t tests were performed for the difference analysis between the 2 sides. Forty-two infants (50% girls) were included. In the cases of eyes with unilateral congenital cataract, a greater CCT (P=.01330), higher average K (P=.00243), and smaller corneal diameter (P=.00010) were found, although there was no significant difference in AL when compared with the unaffected contralateral eyes. The data showed that biometric characteristics of the eyes with unilateral congenital cataract differ from the opposite normal eye before the cataract surgery. It is essential to use this biometric data in intraocular lens power calculation and to take them into account in long-term care when screening for secondary glaucoma.

Prevalence of Refractive Errors in the INK Area, Durban, South Africa.

To determine the prevalence and types of refractive errors in persons aged 35 years and older in the Inanda, Ntuzuma, and KwaMashu (INK) area of Durban, KwaZulu-Natal Province, South Africa. Refractive error data were obtained by autorefraction (Retinomax K-Plus; Nikon, Tokyo, Japan), retinoscopy, and subjective refraction. Refractive error was defined using spherical equivalents as myopia (<-0.5D) and hyperopia (>+0.5D). Astigmatism was defined as cylinder equal to or greater than -0.5D in either eye. Participants' ages ranged from 35 to 90 years, with a mean of 53.05 ± 11.4 years. Women comprised 75% of the subjects. The prevalence of refractive error was 57.3%, with myopia 11.4%, hyperopia 37.7%, and astigmatism 25.7%. Myopia and astigmatism were significantly more prevalent in men (p < 0.01), whereas hyperopia was more prevalent in women (p < 0.01). Hyperopia was significantly associated with education (p < 0.01), whereas myopia and astigmatism were not (p = 0.09 and p = 0.15, respectively). Approximately 57.3% of the population 35 years and older in the INK area of Durban were affected by refractive errors, with myopia, hyperopia, and astigmatism being significantly associated with sex. This study suggests that there is a need for interventions to alleviate refractive error in the INK area as well as in other communities affected by the lack of access to affordable services.

Comparison of the refractive measurements with hand-held autorefractometer, table-mounted autorefractometer and cycloplegic retinoscopy in children.

PurposeTo evaluate the performance of the hand-held and table-top autorefractokeratometer in measuring refractive errors by comparing them with cycloplegic retinoscopy.MethodsIncluded 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.ResultsThe 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 0° and 45°; keratometer values respectively.ConclusionsThe refractive error components were highly correlated between the two instruments and cycloplegic retinoscopy.

Zur Messung der objektiven Refraktion in Zykloplegie im Kindesalter mit Skiaskopie und automatischer Refraktometrie mit dem Pediatric Autorefractor und dem Retinomax

In children, measuring refraction is of interest particularly with regard to the risk of amblyopia. Cycloplegic retinoscopy is the gold standard method for this age group. In a prospective study we compared readings from two hand-held photorefractors, the Pediatric Autorefractor and the Retinomax, to those from retinoscopy. 74 patients were recruited consecutively at the outpatient department of Heidelberg University Eye Hospital's Section for Strabismology and Neuroophthalmology. All patients underwent standardised cycloplegia measurements first by the Pediatric Autorefractor plusoptiX A 08 in 1 metre working distance, then adding an infrared filter to reduce interferences, followed by the Retinomax K-plus 3 in 5 cm working distance and retinoscopy as reference on the right eye. Spherical equivalents measured by the Pediatric Autorefractor plusoptiX A 08 coincided in 51.2% with retinoscopy (± 0.5 D). Adding an infrared filter increased this to 60.0%. However, the success rate of measurement decreased to 47% on adding an infrared filter as compared to 55.4% in cycloplegia alone. Children showed no cooperation in 11% and 16% with the infrared filter, respectively. The remaining children were not measurable by means of the device. With regard to spherical equivalents, the measurements done with Retinomax K-plus 3 coincide in 57% with those done in retinoscopy. The success rate of measurements with the Retinomax was 91%. The remaining children showed no cooperation. Retinoscopy in cycloplegia is still the method of choice when determining refraction in children. Autorefractors quickly provide results for comparison which coincide with retinoscopy in 50-60% in spherical equivalent and in 80-90% in cylindrical values. The Pediatric Autorefractor is not suited for everyday clinical routine due to a low success rate of 50% and tight measuring range of + 5.0 to -7.0 D in spherical equivalents.

Prevalence of Refractive Error among Preschool Children in an Urban Population: The Baltimore Pediatric Eye Disease Study

To determine the age-specific prevalence of refractive errors in white and African-American preschool children. The Baltimore Pediatric Eye Disease Study is a population-based evaluation of the prevalence of ocular disorders in children aged 6 to 71 months in Baltimore, Maryland. Among 4132 children identified, 3990 eligible children (97%) were enrolled and 2546 children (62%) were examined. Cycloplegic autorefraction was attempted in all children with the use of a Nikon Retinomax K-Plus 2 (Nikon Corporation, Tokyo, Japan). If a reliable autorefraction could not be obtained after 3 attempts, cycloplegic streak retinoscopy was performed. Mean spherical equivalent (SE) refractive error, astigmatism, and prevalence of higher refractive errors among African-American and white children. The mean SE of right eyes was +1.49 diopters (D) (standard deviation [SD] = 1.23) in white children and +0.71 D (SD = 1.35) in African-American children (mean difference of 0.78 D; 95% confidence interval [CI], 0.67-0.89). Mean SE refractive error did not decline with age in either group. The prevalence of myopia of 1.00 D or more in the eye with the lesser refractive error was 0.7% in white children and 5.5% in African-American children (relative risk [RR], 8.01; 95% CI, 3.70-17.35). The prevalence of hyperopia of +3 D or more in the eye with the lesser refractive error was 8.9% in white children and 4.4% in African-American children (RR, 0.49; 95% CI, 0.35-0.68). The prevalence of emmetropia (<-1.00 D to <+1.00 D) was 35.6% in white children and 58.0% in African-American children (RR, 1.64; 95% CI, 1.49-1.80). On the basis of published prescribing guidelines, 5.1% of the children would have benefited from spectacle correction. However, only 1.3% had been prescribed correction. Significant refractive errors are uncommon in this population of urban preschool children. There was no evidence for a myopic shift over this age range in this cross-sectional study. A small proportion of preschool children would likely benefit from refractive correction, but few have had this prescribed.

096: The comparison of the keratometric measurements of optical biometer, handheld autokeratometer, classic autokeratometer, and corneal topography device

Introduction: This study was designed to assess the correlation of keratometric readings between Optical biometry (Zeiss IOLMaster), hand-held autokeratometry (Righton Retinomax K-plus 2), classic autokeratometry (Topcon KR8800 and Canon RF-F1), and corneal topography (Allegretto Wave Topolyzer).

Induced Astigmatism With 2.2- and 3.0-mm Coaxial Phacoemulsification Incisions

To evaluate the difference between 2.2-mm incision micro-coaxial phacoemulsification and traditional 3.0-mm coaxial phacoemulsification with respect to surgically induced astigmatism after temporally oriented clear corneal incision cataract surgery. This prospective, randomized, intra-patient controlled study comprised 22 patients who underwent clear corneal cataract surgery in both eyes. One eye received 2.2-mm incision micro-coaxial phacoemulsification with intraocular lens (IOL) implantation and the fellow eye received traditional 3.0-mm coaxial incision phacoemulsification with IOL implantation. The 2.2-mm incisions were created with a diamond keratome after a 200-microm groove was constructed in clear cornea at the temporal limbus. The 3.0-mm incisions were created without a pre-cut groove, using a metal keratome. All cases were uncomplicated. Pre- and postoperative keratometric astigmatism at 6 weeks was measured using a hand held Nikon Retinomax K-plus 2 Autorefractor. Three methods were used to analyze the surgically induced astigmatism (SIA) data: 1) algebraic analysis of the magnitude of keratometric astigmatism induced by the surgery, 2) magnitude of SIA by vector analysis, and 3) aggregate analysis of astigmatism using vector analysis. The mean change in the magnitude of keratometric astigmatism was 0.10+/-0.08 diopters (D) with the 2.2-mm micro-coaxial incisions and 0.32+/-0.20 D with the 3.0-mm traditional incisions (P=.0002). Usingvector analysis, the mean magnitude of SIA was 0.35+/-0.21 D with the 2.2-mm incisions and 0.67+/-0.48 D (P=.006) with the 3.0-mm incisions. Surgically induced astigmatism with 2.2-mm micro-coaxial incisions and traditional 3.0-mm clear corneal incisions with intra-patient control resulted in statistically and clinically significant reduction in surgically induced astigmatism with the smaller incision size.

Messgenauigkeit des Autorefraktometers Power-Refractor in der klinischen Praxis - eine vergleichende Studie*

The aim of this prospective study was to investigate accuracy and efficiency of the autorefractometer PowerRefractor compared to established autorefractometers and retinoscopy as standard method. 150 patients (300 eyes) were examined. Patients were initially (pupil not influenced) analyzed with the Power Refractor (PR (neutral)). After that a examination followed under standardized Cyclopentolat cycloplegia with the Power Refractor (PR (cyclo)), the hand-held Retinomax K-plus (Nikon), the table-top mounted RK-5 (Canon) and retinoscopy. Deviation from retinoscopy (percentage of values with more than 1 dpt difference/maximal deviation): Sphere: PR (neutral): 66.3 %/8.5 dpt; PR (cyclo): 48 %/5 dpt; RK-5: 26.7 %/4.75 dpt; Retinomax K-plus: 6.7 %/1.25 dpt; Cylinder: PR (neutral): 12 %/6.25 dpt; PR (cyclo): 21 %/4.75 dpt; RK-5: 1.3 %/2.75 dpt; Retinomax K-plus: 2.3 %/2.5 dpt; spherical equivalent: PR (neutral): 44.7 %/7.1 dpt; PR (cyclo): 35.3 %/5.4 dpt; RK-5: 9 %/4.5 dpt; Retinomax K-plus: 1.3 %/1.,4 dpt; error of entire refraction: PR (neutral): 62.7 %/7.8 dpt; PR (cyclo): 61.3 %/7.3 dpt; RK-5: 24 %/4,5 dpt; Retinomax K-plus: 14.7 %/3.6 dpt The best accuracy compared to retinoscopy had Retinomax K-plus followed by RK-5. PowerRefractor had the biggest deviations of the tested devices. PowerRefractor may be a usefull device for screening small children and handicapped people because of the one meter observing distance. For a precise refraction especially in children a retinoscopy under cycloplegic conditions is still necessary.

Corneal and lenticular components of total astigmatism in a preschool sample.

To examine the contribution of corneal and lenticular components to total astigmatism in preschool low and high astigmats to determine whether there was any compensation for high astigmatism by the lenticular component. Cycloplegic refractive and keratometric measures using the Retinomax K-Plus (Nikon Inc., Melville, NY) were conducted on 129 children (mean age, 51.1 +/- 8.4 mo) in Oxford County, Canada. We divided the sample into high astigmats (total cylinder > or =1 D; mean, 1.38 +/- 0.43 D; n = 29) and normal astigmats (total cylinder < or =0.75 D; mean, 0.22 +/- 0.20 D; n = 100). Measures of total and corneal cylinder were transposed into J0 and J45 components, where positive and negative J0 values quantified with-the-rule (WTR) and against-the-rule astigmatisms, respectively, and J45 quantified oblique astigmatism. WTR astigmatism was dominant in both the high and normal astigmatic group. J0 and J45 components of corneal astigmatism were highly correlated with total astigmatism in high astigmats, whereas only J0 was significantly correlated with total astigmatism in normal astigmats. Although the magnitude of total and corneal cylinder was significantly greater in high astigmats, overall lenticular cylinder was similar in both groups. However, the Fourier transforms showed high astigmats to have significantly lower lenticular J0 and higher lenticular J45 than the normal astigmats. Astigmatism in 3- to 5-year-old children is primarily corneal. In preschool children, the lens does not vary in response to high amounts of corneal WTR astigmatism, and in fact, it increases the oblique astigmatism component when the corneal component is high. In high astigmats, lenticular astigmatism contributes to both J0 and J45 components, whereas the corneal contribution is primarily J0.