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Haidong Zou - One of the best experts on this subject based on the ideXlab platform.
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The associations of Lens Power with age, axial length and type 2 diabetes mellitus in Chinese adults aged 50 and above.
Eye and vision (London England), 2020Co-Authors: Xinji Zhang, Jianfeng Zhu, Qiuying Chen, Yao Yin, Ying Fan, Haidong ZouAbstract:BACKGROUND To investigate the associations of Lens Power with age, axial length (AL), and Type 2 diabetes mellitus (DM) in Chinese adults aged 50 and above. METHODS Random clustering sampling was used to identify adults aged 50 years and above in urban regions of Shanghai. The participants underwent a comprehensive ophthalmic examination including subjective refraction, autorefraction, and IOL-Master. The crystalline Lens Power was calculated using Bennett's formula. RESULTS A total of 4177 adults were included. A linear decrease in Lens Power was observed both with age and with AL, followed by a stop of Lens Power loss after the age of 70 or when AL ≥ 25 mm, respectively. Participants with Type 2 DM presented higher Lens Power (0.43 diopter (D), p
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The Associations of Lens Power With Age and Axial Length in Healthy Chinese Children and Adolescents Aged 6 to 18 Years.
Investigative ophthalmology & visual science, 2017Co-Authors: Shuyu Xiong, Bo Zhang, Jianfeng Zhu, Yuan Hong, Haidong ZouAbstract:Purpose To investigate the relationship between Lens Power and age as well as the relationship between Lens Power and axial length (AL) in Chinese children and adolescents. Methods The participants underwent a comprehensive ophthalmic examination that included AL, cycloplegic refraction, and Pentacam measurements. The crystalline Lens Power was calculated using Bennett's formula and then compared among the children of different age groups, refractive statuses, and AL categories. The association of Lens Power and AL was analyzed using multiple regression. Results A total of 1992 children and adolescents aged 6- to 18-years old were included. The difference in Lens Power was greater before 10-years old, followed by a relatively smaller difference in children aged 10 to 14 years and the difference in Lens Power came to a near plateau in adolescents after 14-years old. The negative association between Lens Power and AL was found to be more evident in nonmyopes than in myopes irrespective of age (younger than 10 years: nonmyopes: β = -1.499, myopes: β = -0.872; older than 10 years: nonmyopes: β = -1.288, myopes: β = -0.390, all P < 0.001). Conclusions The Lens Power in children and adolescents aged 6 to 18 years exhibited three stages. The association between Lens Power and AL differed between the nonmyopes and myopes. These findings suggested that less reduction in Lens Power might be associated with both growing age and increasing AL in myopes.
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The Relationship between Crystalline Lens Power and Refractive Error in Older Chinese Adults: The Shanghai Eye Study.
PloS one, 2017Co-Authors: Bo Zhang, Jianfeng Zhu, Huijuan Zhao, Jida Sha, Haidong ZouAbstract:Purpose To report calculated crystalline Lens Power and describe the distribution of ocular biometry and its association with refractive error in older Chinese adults. Methods Random clustering sampling was used to identify adults aged 50 years and above in Xuhui and Baoshan districts of Shanghai. Refraction was determined by subjective refraction that achieved the best corrected vision based on monocular measurement. Ocular biometry was measured by IOL Master. The crystalline Lens Power of right eyes was calculated using modified Bennett-Rabbetts formula. Results We analyzed 6099 normal phakic right eyes. The mean crystalline Lens Power was 20.34 ± 2.24D (range: 13.40–36.08). Lens Power, spherical equivalent, and anterior chamber depth changed linearly with age; however, axial length, corneal Power and AL/CR ratio did not vary with age. The overall prevalence of hyperopia, myopia, and high myopia was 48.48% (95% CI: 47.23%–49.74%), 22.82% (95% CI: 21.77%–23.88%), and 4.57% (95% CI: 4.05–5.10), respectively. The prevalence of hyperopia increased linearly with age while Lens Power decreased with age. In multivariate models, refractive error was strongly correlated with axial length, Lens Power, corneal Power, and anterior chamber depth; refractive error was slightly correlated with best corrected visual acuity, age and sex. Conclusion Lens Power, hyperopia, and spherical equivalent changed linearly with age; Moreover, the continuous loss of Lens Power produced hyperopic shifts in refraction in subjects aged more than 50 years.
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Lens Power, Axial Length-to-Corneal Radius Ratio, and Association with Diabetic Retinopathy in the Adult Population with Type 2 Diabetes
Ophthalmology, 2017Co-Authors: Jiangnan He, Xiangui He, Bijun Zhu, Xuelin Bai, Xian Xu, Lina Lu, Xun Xu, Jianfeng Zhu, Bo Zhang, Haidong ZouAbstract:Purpose To calculate crystalline Lens Power and to determine the relationship between ocular biometry and diabetic retinopathy (DR) in an adult population with type 2 diabetes mellitus (T2DM). Design Cross-sectional, population-based study. Participants Patients with T2DM from the Beixinjing community, Changning district, Shanghai. Methods Random clustering sampling was used to identify adults with T2DM in the Beixinjing community. Spherical equivalent (SE) was determined by subjective refraction that achieved the best corrected vision. Axial length (AL), corneal Power (CP), and anterior chamber depth (ACD) were measured using the IOLMaster. Diabetic retinopathy and diabetic macular edema (DME) were assessed according to the international DR classification. Main Outcome Measures The crystalline Lens Power was calculated using the Bennett–Rabbetts formula. The AL–to–corneal radius ratio (AL/CR ratio) was defined as the axial length divided by the mean corneal radius of curvature. Results A total of 4011 eyes of 2057 subjects with T2DM were included in the analysis. In multivariate logistic models adjusting for age, sex, duration of diabetes, glycosylated hemoglobin A1c, serum creatinine, body mass index, systolic blood pressure, and cataract, after categorizing values into quartiles, there were trend associations between Lens Power and any DR (P = 0.01), between AL/CR ratio and any DR (P = 0.02), and between AL and any DR (P = 0.03), between Lens Power and moderate DR (P = 0.02), and between AL and moderate DR (P = 0.02); eyes with higher AL/CR ratio were less likely to have any DR (odds ratio [OR], 0.43; 95% confidence interval [CI], 0.24–0.78; P = 0.01 per 1 increase) and moderate DR (OR, 0.44; 95% CI, 0.21–0.93; P = 0.03 per 1 increase), eyes with longer AL were less likely to have any DR (OR, 0.88; 95% CI, 0.81–0.95; P = 0.002 per millimeter increase) or moderate DR (OR, 0.89; 95% CI, 0.80–0.98; P = 0.02 per millimeter increase), and eyes with higher SE were more likely to have any DR (OR, 1.08; 95% CI, 1.03–1.13; P = 0.003 per diopter increase). Conclusions In persons with T2DM, Lens Power, AL/CR ratio, and AL were associated with the presence of any DR and moderate DR. These findings suggested that globe elongation plays a major role in protective effects against DR, with contributions from Lens Power and other refractive components.
Michael Lawless - One of the best experts on this subject based on the ideXlab platform.
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comparison of hill radial basis function barrett universal and current third generation formulas for the calculation of intraocular Lens Power during cataract surgery
Clinical and Experimental Ophthalmology, 2018Co-Authors: Timothy V. Roberts, Chris Hodge, Gerard Sutton, Michael LawlessAbstract:Importance This study represents a novel comparison of recently introduced intraocular Lens Power calculation formulas. Background To compare current new generation formulas for calculating the intraocular Lens Power for a standard cohort of patients undergoing cataract and Lens replacement surgery in a private group practice in Australia. Design Retrospective case series comparison. Participants Postoperative results from 400 consecutive patients undergoing implantation of an SN60WF intraocular Lens post cataract removal by 12 surgeons were used. Methods Refractive outcomes were compared with expected targets to determine the predicted refractive outcomes using the Hill-radial basis function, Barrett Universal II and readily available third or fourth generation intraocular Lens Power calculation formulas. Main Outcome Measure Mean absolute predicted error. Results The mean absolute predicted difference ranged from 0.30 to 0.34 D. There was no overall significant difference in the predicted difference or variance between formulas. All formulas achieved greater than 78.3% of eyes within ±0.5 D of intended refraction. The Hill-radial basis function and Barrett formulas provided the lowest mean numerical error compared with existing formulas in short and long eyes, respectively. The Barrett Universal II formula had the lowest percentage of refractive surprises (>1 D from predicted error) across all axial lengths. Conclusions and Relevance Acceptable outcomes can be achieved with optical biometry, consistent surgical technique and use of current intraocular Lens Power calculation formulas. The Barrett Universal II formula may provide the lowest risk of refractive surprise compared with other intraocular Lens Power calculation formulas.
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Comparison of Hill‐radial basis function, Barrett Universal and current third generation formulas for the calculation of intraocular Lens Power during cataract surgery
Clinical & experimental ophthalmology, 2017Co-Authors: Timothy V. Roberts, Chris Hodge, Gerard Sutton, Michael LawlessAbstract:Importance This study represents a novel comparison of recently introduced intraocular Lens Power calculation formulas. Background To compare current new generation formulas for calculating the intraocular Lens Power for a standard cohort of patients undergoing cataract and Lens replacement surgery in a private group practice in Australia. Design Retrospective case series comparison. Participants Postoperative results from 400 consecutive patients undergoing implantation of an SN60WF intraocular Lens post cataract removal by 12 surgeons were used. Methods Refractive outcomes were compared with expected targets to determine the predicted refractive outcomes using the Hill-radial basis function, Barrett Universal II and readily available third or fourth generation intraocular Lens Power calculation formulas. Main Outcome Measure Mean absolute predicted error. Results The mean absolute predicted difference ranged from 0.30 to 0.34 D. There was no overall significant difference in the predicted difference or variance between formulas. All formulas achieved greater than 78.3% of eyes within ±0.5 D of intended refraction. The Hill-radial basis function and Barrett formulas provided the lowest mean numerical error compared with existing formulas in short and long eyes, respectively. The Barrett Universal II formula had the lowest percentage of refractive surprises (>1 D from predicted error) across all axial lengths. Conclusions and Relevance Acceptable outcomes can be achieved with optical biometry, consistent surgical technique and use of current intraocular Lens Power calculation formulas. The Barrett Universal II formula may provide the lowest risk of refractive surprise compared with other intraocular Lens Power calculation formulas.
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Intraocular Lens Power calculation following laser refractive surgery.
Eye and vision (London England), 2015Co-Authors: Chris Hodge, Colm Mcalinden, Michael Lawless, Colin Chan, Gerard Sutton, Aifric Isabel MartinAbstract:Refractive outcomes following cataract surgery in patients that have previously undergone laser refractive surgery have traditionally been underwhelming. This is related to several key issues including the preoperative assessment (keratometry) and intraocular Lens Power calculations. Peer-reviewed literature is overwhelmed by the influx of methodology to manipulate the corneal or intraocular Lens (IOL) Powers following refractive surgery. This would suggest that the optimal derivative formula has yet been introduced. This review discusses the problems facing surgeons approaching IOL calculations in these post-refractive laser patients, the existing formulae and programs to address these concerns. Prior published outcomes will be reviewed.
Rafael Iribarren - One of the best experts on this subject based on the ideXlab platform.
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Axial Growth and Lens Power Loss at Myopia Onset in Singaporean Children.
Investigative ophthalmology & visual science, 2019Co-Authors: Jos J. Rozema, Rafael Iribarren, Sebastian Dankert, Carla Lanca, Seang-mei SawAbstract:Purpose We studied biometry changes before and after myopia onset in a cohort of Singaporean children. Methods All data were taken from the Singapore Cohort Study of the Risk Factors for Myopia (SCORM). Participants underwent refraction and biometry measurements with a follow-up of 3 to 6 years. The longitudinal ocular biometry (spherical equivalent refraction, axial length, and Lens Power) changes were compared between children who suffered myopia during the study (N = 303), emmetropic children (N = 490), and children myopic at baseline (N = 509). Results At myopia onset, the myopic shift increased to 0.50 diopters (D)/y or more in new myopes compared to the minor changes in emmetropes of the same age. New myopes had higher axial growth rates than emmetropes, even years before myopia onset (0.37 and 0.14 mm/y, respectively; ANOVA with Bonferroni post hoc test, P < 0.001). After onset, the change in both parameters slowed down gradually, but significantly (P < 0.05). In new myopes, Lens Power loss (-0.71 D/y) was significantly higher up to 1 year before myopia onset compared to emmetropes (-0.46 D/y), after which Lens Power loss slows down rapidly. At age 7 years, (future) new myopes had Lens Power values close to those of emmetropes (25.12 and 25.23 D, respectively), while later these values approached those of children who were myopic at baseline (23.06 and 22.79 D, respectively, compared to 23.71 D for emmetropes; P < 0.001). Conclusions New myopes have higher axial growth rates and Lens Power loss before myopia onset than persistent emmetropes.
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Hyperopia and Lens Power in an Adult Population: The Shahroud Eye Study.
Journal of ophthalmic & vision research, 2015Co-Authors: Rafael Iribarren, Ian G. Morgan, Hassan Hashemi, Mehdi Khabazkhoob, Mohammad Hassan Emamian, Mohammad Shariati, Akbar FotouhiAbstract:Purpose: To explore the relationship between Lens Power and refractive error in older adults following age-related hyperopic shifts. Methods: From the Shahroud Eye Cohort Study, subjects aged 55-64 years without clinically significant cataracts (with nuclear opacity of grade 0 to 1) were included to maximize the proportion of subjects with age-related hyperopic shifts that normally occur between 40 to 60 years of age, before interference from the myopic shift due to nuclear cataracts. Mean axial length (AL) values, corneal Power, anterior chamber depth, Lens thickness, and Lens Power were analyzed and compared among three refractive groups (myopes, emmetropes, and hyperopes). Results: A total of 1,006 subjects including 496 (49.63%) male subjects were studied. Corneal Power was similar in all refractive groups. Hyperopes had + 1.69 diopters higher mean spherical equivalent refractive error and − 0.50 mm shorter AL than emmetropes. Myopes had 0.67 mm longer AL than emmetropes. Hyperopes had significantly increased Lens thickness as compared to emmetropes (4.42 vs. 4.39 mm respectively). In this adult sample, the hyperopic group had lower Lens Power (+22.29 diopters vs. +22.54 diopters in emmetropes, P = 0.132). Myopes had similar Lens Power as emmetropes. Conclusion: Axial length is the principal determinant of refractive errors. Lens Power may have importance in determining hyperopia in adults free of cataract.
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Lens Power in a population-based cross-sectional sample of adults aged 40 to 64 years in the Shahroud eye study
Investigative ophthalmology & visual science, 2014Co-Authors: Rafael Iribarren, Ian G. Morgan, Hassan Hashemi, Mehdi Khabazkhoob, Mohammad Hassan Emamian, Mohammad Shariati, Akbar FotouhiAbstract:PURPOSE To report on calculated Lens Power in adults in relation to other ocular components of refraction, analyzed in relation to secular change in height and education. METHODS The first phase of the Shahroud Eye Cohort Study is a cross-sectional population-based study in Iranian subjects 40 to 64 years old. Data on cycloplegic spherical equivalent refraction and the ocular components of the right eyes were used for the calculation of crystalline Lens Power with Bennett's formula. Interactions between sex and age as independent variables were analyzed by two-way analysis of variances. RESULTS Cycloplegic refraction data and biometry were obtained from 4592 subjects, of whom 2666 (58%) were women. The mean Lens Power showed a biphasic trend. Up to the age of 50, younger subjects had lower Lens Power than older subjects, but after the age of 50, older subjects had lower Lens Power. A secular trend in height was found, with younger subjects significantly taller than older ones. Taller men or women had longer eyes, with flatter corneas and less Powerful Lenses, independent of refractive error. In multiple regression models, corneal Power (P < 0.001), axial length (P < 0.001), and Lens Power (P < 0.001) were all associated with height, independent of age and sex. CONCLUSIONS There was an unexpected biphasic pattern of the distribution of Lens Power with age in this cross-sectional study. Younger subjects were taller, and despite having longer axial lengths, their bigger eyes were still predominantly emmetropic. The greater axial lengths were counterbalanced by both lower corneal and lower Lens Powers.
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Calculation of crystalline Lens Power in chickens with a customized version of Bennett’s equation
Vision research, 2014Co-Authors: Rafael Iribarren, Jos J. Rozema, Frank Schaeffel, Ian G. MorganAbstract:This paper customizes Bennett's equation for calculating Lens Power in chicken eyes from refraction, keratometry and biometry. Previously published data on refraction, corneal Power, anterior chamber depth, Lens thickness, Lens radii of curvature, axial length and eye Power in chickens aged 10-90 days were used to estimate Gullstrand's Lens Power and Bennett's Lens Power for chicken eyes, and to calculate the Lens equivalent refractive index. Bennett's A and B constants for the front and back surface Powers of the Lens were calculated for data measured from day 10 to 90 at 10 day intervals, and mean customized constants were calculated. The mean customized constants for Bennett's equation for chicks were A=0.574±0.023 and B=0.379±0.021. As found previously, Lens Power decreases with age in chicks, while corneal Power decreases and axial length increases. The Lens equivalent refractive index decreases with age from 10 to 90 days after hatching. Bennett's equation can be used to calculate Lens Power in chicken eyes for studies on animal myopia, using standard biometry.
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Changes in Lens Power in Singapore Chinese children during refractive development.
Investigative ophthalmology & visual science, 2012Co-Authors: Rafael Iribarren, Ian G. Morgan, Yiong Huak Chan, Xiao-yu Lin, Seang-mei SawAbstract:PURPOSE To examine changes in Lens Power during refractive development in Singapore Chinese children. METHODS Children aged six to nine years from three Singapore schools were invited to participate in the Singapore Cohort study Of the Risk factors for Myopia (SCORM) study. Cycloplegic refractions and biometry were measured annually in the schools over a five year period from 1999. Children were classified into five refractive error groups: persistent hyperopia, emmetropizing hyperopia, persistent emmetropia, newly developed myopia, or persistent myopia. Crystalline Lens Power was calculated using Bennett's formula. The rate of change per year across the refractive groups was adjusted for age and sex using General Linear Models. RESULTS There were 1747 children with at least three sets of measurements for Lens Power calculations. The mean age at baseline was 7.94 ± 0.84 years and the mean spherical equivalent refraction was -0.41 ± 1.71 diopters (D). Lower Lens Power and lower Lens thickness were associated with persistent myopia. As expected, the newly developed myopes and the persistent myopes showed the largest changes in axial length (AL). Changes in Lens Power and thickness at follow-up were similar in all refractive groups, except for the newly developed myopes, who showed significantly greater decreases in Lens Power (0.36 vs. 0.29 D/year; P < 0.001) and Lens thickness (0.015 vs. 0.0003 mm/year; P < 0.001) than the persistently emmetropic group. CONCLUSIONS Newly developed myopes showed a significantly greater decrease in Lens Power than other refractive groups, which may be linked to rapid changes in AL and refraction that occur around the onset of myopia.
Timothy V. Roberts - One of the best experts on this subject based on the ideXlab platform.
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comparison of hill radial basis function barrett universal and current third generation formulas for the calculation of intraocular Lens Power during cataract surgery
Clinical and Experimental Ophthalmology, 2018Co-Authors: Timothy V. Roberts, Chris Hodge, Gerard Sutton, Michael LawlessAbstract:Importance This study represents a novel comparison of recently introduced intraocular Lens Power calculation formulas. Background To compare current new generation formulas for calculating the intraocular Lens Power for a standard cohort of patients undergoing cataract and Lens replacement surgery in a private group practice in Australia. Design Retrospective case series comparison. Participants Postoperative results from 400 consecutive patients undergoing implantation of an SN60WF intraocular Lens post cataract removal by 12 surgeons were used. Methods Refractive outcomes were compared with expected targets to determine the predicted refractive outcomes using the Hill-radial basis function, Barrett Universal II and readily available third or fourth generation intraocular Lens Power calculation formulas. Main Outcome Measure Mean absolute predicted error. Results The mean absolute predicted difference ranged from 0.30 to 0.34 D. There was no overall significant difference in the predicted difference or variance between formulas. All formulas achieved greater than 78.3% of eyes within ±0.5 D of intended refraction. The Hill-radial basis function and Barrett formulas provided the lowest mean numerical error compared with existing formulas in short and long eyes, respectively. The Barrett Universal II formula had the lowest percentage of refractive surprises (>1 D from predicted error) across all axial lengths. Conclusions and Relevance Acceptable outcomes can be achieved with optical biometry, consistent surgical technique and use of current intraocular Lens Power calculation formulas. The Barrett Universal II formula may provide the lowest risk of refractive surprise compared with other intraocular Lens Power calculation formulas.
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Comparison of Hill‐radial basis function, Barrett Universal and current third generation formulas for the calculation of intraocular Lens Power during cataract surgery
Clinical & experimental ophthalmology, 2017Co-Authors: Timothy V. Roberts, Chris Hodge, Gerard Sutton, Michael LawlessAbstract:Importance This study represents a novel comparison of recently introduced intraocular Lens Power calculation formulas. Background To compare current new generation formulas for calculating the intraocular Lens Power for a standard cohort of patients undergoing cataract and Lens replacement surgery in a private group practice in Australia. Design Retrospective case series comparison. Participants Postoperative results from 400 consecutive patients undergoing implantation of an SN60WF intraocular Lens post cataract removal by 12 surgeons were used. Methods Refractive outcomes were compared with expected targets to determine the predicted refractive outcomes using the Hill-radial basis function, Barrett Universal II and readily available third or fourth generation intraocular Lens Power calculation formulas. Main Outcome Measure Mean absolute predicted error. Results The mean absolute predicted difference ranged from 0.30 to 0.34 D. There was no overall significant difference in the predicted difference or variance between formulas. All formulas achieved greater than 78.3% of eyes within ±0.5 D of intended refraction. The Hill-radial basis function and Barrett formulas provided the lowest mean numerical error compared with existing formulas in short and long eyes, respectively. The Barrett Universal II formula had the lowest percentage of refractive surprises (>1 D from predicted error) across all axial lengths. Conclusions and Relevance Acceptable outcomes can be achieved with optical biometry, consistent surgical technique and use of current intraocular Lens Power calculation formulas. The Barrett Universal II formula may provide the lowest risk of refractive surprise compared with other intraocular Lens Power calculation formulas.
Akbar Fotouhi - One of the best experts on this subject based on the ideXlab platform.
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Hyperopia and Lens Power in an Adult Population: The Shahroud Eye Study.
Journal of ophthalmic & vision research, 2015Co-Authors: Rafael Iribarren, Ian G. Morgan, Hassan Hashemi, Mehdi Khabazkhoob, Mohammad Hassan Emamian, Mohammad Shariati, Akbar FotouhiAbstract:Purpose: To explore the relationship between Lens Power and refractive error in older adults following age-related hyperopic shifts. Methods: From the Shahroud Eye Cohort Study, subjects aged 55-64 years without clinically significant cataracts (with nuclear opacity of grade 0 to 1) were included to maximize the proportion of subjects with age-related hyperopic shifts that normally occur between 40 to 60 years of age, before interference from the myopic shift due to nuclear cataracts. Mean axial length (AL) values, corneal Power, anterior chamber depth, Lens thickness, and Lens Power were analyzed and compared among three refractive groups (myopes, emmetropes, and hyperopes). Results: A total of 1,006 subjects including 496 (49.63%) male subjects were studied. Corneal Power was similar in all refractive groups. Hyperopes had + 1.69 diopters higher mean spherical equivalent refractive error and − 0.50 mm shorter AL than emmetropes. Myopes had 0.67 mm longer AL than emmetropes. Hyperopes had significantly increased Lens thickness as compared to emmetropes (4.42 vs. 4.39 mm respectively). In this adult sample, the hyperopic group had lower Lens Power (+22.29 diopters vs. +22.54 diopters in emmetropes, P = 0.132). Myopes had similar Lens Power as emmetropes. Conclusion: Axial length is the principal determinant of refractive errors. Lens Power may have importance in determining hyperopia in adults free of cataract.
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Lens Power in a population-based cross-sectional sample of adults aged 40 to 64 years in the Shahroud eye study
Investigative ophthalmology & visual science, 2014Co-Authors: Rafael Iribarren, Ian G. Morgan, Hassan Hashemi, Mehdi Khabazkhoob, Mohammad Hassan Emamian, Mohammad Shariati, Akbar FotouhiAbstract:PURPOSE To report on calculated Lens Power in adults in relation to other ocular components of refraction, analyzed in relation to secular change in height and education. METHODS The first phase of the Shahroud Eye Cohort Study is a cross-sectional population-based study in Iranian subjects 40 to 64 years old. Data on cycloplegic spherical equivalent refraction and the ocular components of the right eyes were used for the calculation of crystalline Lens Power with Bennett's formula. Interactions between sex and age as independent variables were analyzed by two-way analysis of variances. RESULTS Cycloplegic refraction data and biometry were obtained from 4592 subjects, of whom 2666 (58%) were women. The mean Lens Power showed a biphasic trend. Up to the age of 50, younger subjects had lower Lens Power than older subjects, but after the age of 50, older subjects had lower Lens Power. A secular trend in height was found, with younger subjects significantly taller than older ones. Taller men or women had longer eyes, with flatter corneas and less Powerful Lenses, independent of refractive error. In multiple regression models, corneal Power (P < 0.001), axial length (P < 0.001), and Lens Power (P < 0.001) were all associated with height, independent of age and sex. CONCLUSIONS There was an unexpected biphasic pattern of the distribution of Lens Power with age in this cross-sectional study. Younger subjects were taller, and despite having longer axial lengths, their bigger eyes were still predominantly emmetropic. The greater axial lengths were counterbalanced by both lower corneal and lower Lens Powers.