A pilot study of axial length changes associated with myopia control spectacles in subjects reading under mesopic conditions.

PURPOSE: To investigate whether axial length changes in subjects wearing myopia control spectacles under mesopic conditions. METHODS: Young users of monofocal spectacles with myopic spherical equivalent ranging from -1.00 D to -5.00 D were enrolled prospectively. Subjects were tested while using a pair of special defocus spectacles with a central zone including the distance myopic correction and a peripheral zone with an addition of +3.50 D. Subjects first read an online book with black letters on white background on a desktop computer with their monofocal spectacles for 20 minutes and then read with special defocus spectacles for another 20 minutes. Reading took place in a darkened room under 20 lux illumination. Before and after these periods, axial length of the right eye was measured ten times using the Lenstar, and average measurements were recorded. RESULTS: The 11 subjects in this pilot study had a mean age of 20.9 ± 7.7 years, and 1 was female. Their mean spherical equivalent of the right eyes was -3.20 ± 2.29 D. As expected, axial length increased by 8.2 ± 9.4 µm (P < 0.01) after 20 minutes of reading with monofocal spectacles in low light. When reading with defocus spectacles under the same conditions, the axial length saw an additional, nonsignificant change of 2.2 ± 12.2 µm (P = 0.56). CONCLUSIONS: When reading in mesopic conditions, the axial length in study subjects did not return to baseline values with myopia control spectacles.

Biometric error analysis after cataract surgery performed by residents, in patients with high myopia with SRK/T formula and Wang-Koch formula adjustment / Análise de erros biométricos após cirurgia de catarata realizada por residentes em pacientes com alta miopia com a fórmula SRK/T com ajuste pela fórmula Wang-Koch

ABSTRACT Objective To evaluate intraocular lens power calculation and postoperative refractive errors in patients with high myopia undergoing cataract surgery, comparing predicted target refraction and actual postoperative refraction measured 30 days after surgery with SRK/T formula. Methods This retrospective analysis comprised 39 eyes of 31 patients undergoing cataract surgery through phacoemulsification with in-the-bag IOL implantation. Axial length was measured by partial coherence interferometry or immersion ultrasound biometry, with measurements greater than 26 mm and preoperative myopia greater than -6.0 D Manifest refraction was performed at the 1-month postoperative visit, and the spherical equivalent was analyzed. Results After analysis of 39 eyes of 31 patients undergoing cataract surgery with a mean axial length of 30.4 (standard deviation of 2.2) mm, the mean preoperative refractive spherical equivalent was -15.6 (standard deviation of 7.6) D, ranging from -24.0 to -13.4 D. At 30 days postoperatively, the mean spherical equivalent was -0.35 (standard deviation of 1.1) D, ranging from -2.4 to 2.50 D. Conclusion We encountered a correlation between the absolute refractive error and the dioptric power of the intraocular lens. Against expectations, in our study, ultrasound biometry yielded better results than the optical biometer device, probably due to the small number of patients undergoing optical biometry, suggesting that well-performed immersion biometry can still produce satisfactory results.

RESUMO Objetivo Avaliar os cálculos de potência da lente intraocular e os erros refrativos pós-operatórios em pacientes com alta miopia submetidos à cirurgia de catarata, comparando a refração-alvo prevista e a refração pós-operatória real medida 30 dias após a cirurgia com a fórmula SRK/T. Métodos Esta análise retrospectiva incluiu 39 olhos de 31 pacientes com cirurgia de catarata de facoemulsificação não complicada com implantação de lente intraocular na bolsa. Os comprimentos axiais foram medidos por biometria de coerência óptica ou ultrassônica (imersão), com medidas de axial length (AL) maiores que 26 mm em pacientes com miopia maior que -6.0 D. A refração manifesta foi realizada na consulta pós-operatória de 1 mês, e o equivalente esférico foi analisado. Resultados Após análise de 39 olhos de 31 pacientes submetidos à cirurgia de catarata com AL médio de 30,4 (desvio-padrão de 2,2) mm, o equivalente esférico refrativo médio pré-operatório foi de -15,6 (desvio-padrão de 7,6) D, variando de -24,0 a -13,4 D. Aos 30 dias de pós-operatório, o equivalente esférico médio foi de -0,35 (desvio-padrão de 1,1) D, variando de -2,4 a 2,50 D. Conclusão Encontramos uma correlação entre o erro refrativo absoluto e o poder dióptrico da lente intraocular. Contrariando as expectativas, em nosso estudo, a biometria ultrassônica apresentou melhores resultados que o biômetro óptico, provavelmente devido ao pequeno número de pacientes submetidos à biometria óptica, sugerindo que a biometria de imersão bem executada ainda pode produzir resultados satisfatórios.

Intraocular lens power estimation for future emmetropia in pediatric cataract surgery.

PURPOSE: Creating models, in pediatric cataracts, to estimate kerotometry and axial length values at future ages, based on kerotometry and axial length measured at surgery, to estimate the intraocular lens power for emmetropia in future ages. METHODS: Eyes with bilateral cataract and kerotometry and axial length measured at surgery and at least one postoperative examination with kerotometry and axial length measurements, were considered for this study. The models to estimate future kerotometry and axial length values were created considering (1) kerotometry and axial length measured at surgery, (2) the average slope of kerotometry and axial length logarithmic regression created for every single eye and (3) age at surgery. The intraocular lens for future ages can be estimated using these values in third generation formulas. The estimation errors for kerotometry, axial length and intraocular lens were also calculated. RESULTS: A total of 57 eyes from 29 patients met the inclusion criteria. The average age at the surgery and follow-up was 36.96 ± 32.04 months and 2.39 ± 1.46 years, respectively. The average slope of logarithmic regression created for every single eye were -3.286 for kerotometry and +3.189 for axial length. The average absolute estimation errors for kerotometry and axial length were respectively: 0.61 ± 0.54 D and 0.49 ± 0.55 mm, and for intraocular lens using SRK-T, Hoffer-Q and Holladay I formulas were: 2 . 04 ± 1 . 73 D , 2 . 49 ± 2 . 10 D and 2 . 26 ± 1 . 87 D , respectively. CONCLUSIONS: The presented models could be used to estimate the intraocular lens power for emmetropia at future ages to guide the choice of the intraocular lens power to be implanted in pediatric cataract.

Ocular biometry in dense cataracts: Comparison of partial-coherence interferometry, swept-source optical coherence tomography and immersion ultrasound.

PURPOSE: To assess the axial length (AL) measurement failure rate using partial-coherence interferometry (PCI) and swept-source optical coherence tomography (SS-OCT) in dense cataracts. As a secondary outcome, the SS-OCT biometry was compared to immersion ultrasound. METHODS: This is a prospective cross-sectional and comparative study. Seventy eyes from 70 patients with dense cataracts were enrolled in this study. Dense cataract was defined according to the Lens Opacities Classification System III (LOCS III) scores equal to or more than NO4, NC4, C4, and P3. The failure rate of AL measurement was evaluated using PCI and SS-OCT. Anterior chamber depth (ACD), lens thickness (LT), and AL measurements obtained by SS-OCT were compared with IUS. RESULTS: AL measurement failure rate with PCI was 68.57% and 21.43% with SS-OCT (P = 0.007). AL measurement was achieved in 69.23% of NO4, 66.6% of P3, and 15.3% of mixed cataracts using PCI, while SS-OCT was achieved in 100% of NO4, NO5, P3, and P5 and 76.9% of mixed cataracts. Cortical cataracts alone did not influence AL measurement. Biometric data of ACD, LT, and AL were statistically different comparing US and SS-OCT with a good correlation of AL. CONCLUSION: SS-OCT significantly improves the rate of successful AL measurements when compared to PCI in dense cataracts. The LOCS III clinical cut-off for the use of SS-OCT ocular biometry may well be up to P4 and NO5.

Agreement between the Swept-Source Optical Coherence Tomography and the Image-Guided System for Biometry Assessment in Cataract Surgery.

PURPOSE: To assess the agreement on biometric data obtained using the Verion image-guided surgery system and the swept-source-OCT biometer IOL Master 700. MATERIALS AND METHODS: All patients underwent biometry using the SS-OCT and the Image-Guide System. The comparison between instruments was assessed using the Intraclass correlation coefficient (ICC). Level of Agreement (LoA) employing the Bland-Altman analysis. RESULTS: The image-based system produced significantly higher keratometry values, evidencing a low LoA between the SS-OCT and the image-based system, ranging from -1.30 D to 0.65 D (1.95 D), -1.04 D to 0.72 D (1.76 D), and -1.31 D to 0.65 D (1.96 D), respectively. The LoA for the Cylinder ranged from -0.46 D to 0.74 D (1.2 D) and from 0.82 to 0.94 mm for WTW. CONCLUSIONS: In our study, the SS-OCT biometer and the Image-based System evidenced statistically significant differences in measuring the main biometric parameters except for the WTW.

Estimation of ocular axial length with optometric parameters is not accurate.

Myopia is a worldwide major public concern, aside from the visual disturbance needing optical correction, myopia may be associated with open angle glaucoma, retinal detachment and myopic maculopathy. The higher the myopia the higher the risk for retinal associated comorbidities, and the axial length is the more important measure to estimate risk of visual impairment. Recently a formula to predict axial length using spherical equivalent and keratometry was proposed, with the intention of categorizing the risk of visual impairment with Tideman et al. classification. PURPOSE: To evaluate the accuracy of an axial length prediction formula in a Colombian population 8-17 years old. METHODS: Children from MIOPUR study with optical biometer axial length measure (AL), manifest refraction and keratometry were included in the analysis. Predicted axial length (PAL) was calculated with the prediction formula. A Bland-Altman assessment was conducted, and the concordance correlation coefficient was measured. Proposed classification of AL to establish risk of visual loss was used with measured AL and with PAL. The percentage of eyes misclassified was then established. RESULTS: A total of 2129 eyes were included in the analysis. Mean difference of axial length (actual AL minus PAL) was -0.516 mm (-1.559 mm - 0.528 mm). Concordance correlation coefficient (CCC) of 0.656 (IC95 0.636-0.675) was found between the real AL and PAL. PAL differed from measured AL by 1 mm or more in 16.58 %, and by 2 mm or more, in 0.61 % of the eyes. In myopic eyes, PAL was in average 0.426 mm longer than the AL actually measured with CCC of 0.714 (IC95 0.666-0.761). PAL differed from measured AL by 1 mm or more in 21.92 %, and by 2 mm or more, in 0.45 % of the myopic eyes. The study revealed that 15.03 % of all eyes, and 29.81 % of myopic eyes, were misclassified when PAL was used. CONCLUSIONS: The proposed axial length prediction formula was not accurate, and it did not adequately classify risk of visual impairment in myopic eyes in a group of Colombian children. We consider that it is not possible to predict the axial length based only on optometric data, such as the corneal radius of curvature and the spherical equivalent. This is very possibly related to the variability of crystalline lens power within a population.

Impact of correlation of angle α with ocular biometry variables.

PURPOSE: To analyze the association between angle α and ocular biometry in the general population at a third-level ophthalmology hospital. SETTING: Anterior Segment Surgery Department, Asociación para Evitar la Ceguera en México I.A.P., Mexico City, Mexico. DESIGN: Prospective, cross-sectional study. METHODS: Healthy subjects who attended the hospital for a comprehensive ophthalmological evaluation were examined, and general data were collected. A complete ophthalmological assessment and biomicroscopy evaluation were performed and biometry and clinical data were obtained, including visual acuity, axial length (AL), keratometry (K), white-to-white (WTW) measurement. An OPD-Scan III analyzer was used to assess both the angle α distance and biometry parameters. RESULTS: 74 eyes from the same number of patients were included; 43 (58.10%) were women. A statistically significant inverse correlation was found between the angle α and the AL (r = -0.585; P < .0001) and between the WTW distance and the mean K (r = 0.557; P < .0001). A significant correlation was found between the mean K and the angle α (r = 0.271; P = .019). A significant inverse correlation was observed regarding the WTW distance and angle α (r = -0.359; P = .001). By contrast, a direct correlation was evidenced between the WTW and the AL (r = 0.385; P = .0007). CONCLUSIONS: There was a significant inverse correlation between the AL and the angle α magnitude. Hyperopic patients demonstrated significantly higher angle α values when compared with those of myopic patients. In addition, hyperopic eyes with steeper mean K and lesser WTW distance were associated with an increased angle α.

Índices biométricos oculares en vietnamitas de 46 a 65 años de edad / Ocular biometric indices in Vietnamese 46 to 65 years of age

Introducción: La longitud axial ocular, la profundidad de la cámara anterior y el grosor corneal central, son tres índices biométricos oculares importantes. Estas medidas son útiles para mostrar los cambios en la población vietnamita con presbicia. Objetivos: Determinar los índices biométricos oculares, longitud axial ocular, profundidad de la cámara anterior y espesor corneal central, en población vietnamita y evaluar la correlación entre ellos y con la edad y el sexo. Métodos: Se realizó un estudio transversal en población vietnamita, con edad de 46 a 65 años. Se recogieron los datos de longitud axial ocular, profundidad de la cámara anterior y grosor corneal central. Se utilizaron la prueba t de Student y ANOVA para comparar las medias de los índices, agrupados por edad y sexo. La relación entre los índices biométricos oculares fue probada mediante la correlación de Pearson, con un nivel de significación de p < 0,05. Resultados: Se analizaron 390 ojos de 195 personas. La longitud media del eje ocular fue 23,13 ± 0,66 mm, la profundidad de la cámara anterior, 3,15 ± 0,36 mm, el grosor corneal central, 529,15 ± 30,57 µm. Los tres índices biométricos disminuyeron con la edad y fueron mayores en los hombres (p < 0,05). La longitud del eje ocular tuvo relación positiva con la profundidad de la cámara anterior (r = 0,411 y p < 0,001) y el espesor corneal central (r = 0,141 y p < 0,001). No hubo relación entre la profundidad de la cámara anterior y el grosor corneal central (r = 0,039 y p = 0,44). Conclusión: Los tres índices biométricos oculares disminuyeron con la edad y fueron mayores en los hombres. La longitud del eje ocular se relacionó con la profundidad de la cámara anterior y el grosor de la córnea central(AU)

Introduction: Ocular axial length, anterior chamber depth and central corneal thickness are three important ocular biometric indices. These measurements are useful to show changes in the Vietnamese population with presbyopia. Objectives: To determine the ocular biometric indices, ocular axial length, anterior chamber depth and central corneal thickness, in Vietnamese population and evaluate the correlation between these indices. Methods: A cross-sectional study was carried out in a Vietnamese population, aged 46 to 65 years. Data on ocular axial length, anterior chamber depth and central corneal thickness were collected. The Student's t test and ANOVA were used to compare the means of the indices, grouped by age and sex. The relationship between the ocular biometric indices was tested using Pearson's correlation, with a significance level of p <0.05. Results: 390 eyes of 195 people were analyzed. The mean length of the ocular axis was 23.13 ± 0.66 mm, the depth of the anterior chamber, 3.15 ± 0.36 mm, and the central corneal thickness, 529.15 ± 30.57 µm. The three biometric indices decreased with age and were higher in men (p <0.05). The length of the ocular axis had a positive relationship with the depth of the anterior chamber (r = 0.411 and p <0.001) and the central corneal thickness (r = 0.141 and p <0.001). There was no relationship between anterior chamber depth and central corneal thickness (r = 0.039 and p = 0.44). Conclusion: Three ocular biometric indices decreased with age and were higher in men. The length of the ocular axis was related to the depth of the anterior chamber and the thickness of the central cornea(AU)

The effects of pharmacological accommodation and cycloplegia on axial length and choroidal thickness / Efeitos da acomodação farmacológica e da cicloplegia no comprimento axial e na espessura da coroide

ABSTRACT Purpose: To investigate the effects of pharmacological accommodation and cycloplegia on ocular measurements. Methods: Thirty-three healthy subjects [mean (±SD) age, 32.97 (±5.21) years] volunteered to participate in the study. Measurement of the axial length, macular and choroidal thickness, refractive error, and corneal topography, as well as anterior segment imaging, were performed. After these procedures, pharmacological accommodation was induced by applying pilocarpine eye drops (pilocarpine hydrochloride 2%), and the measurements were repeated. The measurements were repeated again after full cycloplegia was induced using cyclopentolate eye drops (cyclopentolate hydrochloride 1%). The correlations between the measurements were evaluated. Results: A significant increase in subfoveal choroidal thickness after applying 2% pilocarpine was identified (without the drops, 319.36 ± 90.08 µm; with pilocarpine instillation, 341.60 ± 99.19 µm; with cyclopentolate instillation, 318.36 ± 103.0 µm; p<0.001). A significant increase in the axial length was also detected (without the drops, 23.26 ± 0.83 mm; with pilocarpine instillation, 23.29 ± 0.84 mm; with cyclopentolate instillation, 23.27 ± 0.84 mm; p=0.003). Comparing pharmacological accommodation and cycloplegia revealed a significant difference in central macular thickness (with pilocarpine instillation, 262.27 ± 19.34 µm; with cyclopentolate instillation, 265.93 ± 17.91 µm; p=0.016). Pilocarpine-related miosis (p<0.001) and myopic shift (p<0.001) were more severe in blue eyes vs. brown eyes. Conclusion: Pharmacological accommodation may change ocular measurements, such as choroidal thickness and axial length. This condition should be considered when performing ocular measurements, such as intraocular lens power calculations.(AU)

RESUMO Objetivo: Investigar os efeitos da acomodação farmacológica e da cicloplegia nas medições oculares. Métodos: participaram do estudo 33 voluntários saudáveis (média de idade [± DP], 32,97 anos [± 5,21 anos]). Foram medidos o comprimento axial, a espessura macular e coroidal e o erro refrativo, bem como realizados exames de imagem da topografia corneana e do segmento anterior. Em seguida, foi induzida a acomodação farmacológica aplicando-se colírio de pilocarpina (cloridrato de pilocarpina a 2%) e as medições foram repetidas nos participantes. As mesmas medições foram repetidas depois de induzir a cicloplegia completa com colírio de ciclopentolato (cloridrato de ciclopentolato a 1%) e foram avaliadas as correlações entre as medidas. Resultados: Identificou-se aumento significativo da espessura coroidal subfoveal com o uso da pilocarpina a 2% (sem colírio, 319,36 ± 90,08 µm; com a instilação de pilocarpina, 341,60 ± 99,19 µm; com a instilação de ciclopentolato, 318,36 ± 103,0 µm; p<0,001). Detectou-se também aumento significativo do comprimento axial (sem colírio, 23,26 ± 0,83 mm; com a instilação de pilocarpina, 23,29 ± 0,84 mm; com a instilação de ciclopentolato, 23,27 ± 0,84 mm; p=0,003). Ao se comparar a acomodação farmacológica e a cicloplegia, houve diferença significativa na espessura macular central (com a instilação de pilocarpina, 262,27 ± 19,34 µm; com a instilação de ciclopentolato, 265,93 ± 17,91 µm; p=0,016). Observou-se que a miose associada à pilocarpina (p<0,001) e o desvio miópico (p<0,001) foram mais severos nos olhos azuis que nos castanhos. Conclusão: A acomodação farmacológica pode alterar medidas oculares como a espessura da coroide e o comprimento axial. Essa possibilidade deve ser levada em consideração ao se efetuarem medições oculares, tais como cálculos de potência de lentes intraoculares.(AU)

Comparison of prediction accuracy of five different biometric formulas / Comparação da acurácia preditiva de cinco fórmulas biométricas diferentes

ABSTRACT Objective To compare the performance of Sanders-Retzlaff-Kraft/Theoretical, Hoffer Q, Barrett Universal II, Kane, and Hill-radial basis function formulas to calculate intraocular lens power in eyes with normal axial length, in terms of predicting target refraction by using partial coherence interferometry technology. Methods Phacoemulsification and intraocular lens implantation were performed in 135 eyes of 135 patients with an axial length between 22 and 24.5 mm. Axial length, keratometry, and anterior chamber depth were measured by intraocular lens Master 500. Sanders-Retzlaff-Kraft/Theoretical, Hoffer Q, Barrett Universal II, Kane, and Hill-radial basis function formulas were used for intraocular lens power calculations. The difference between the expected postoperative refraction and the mean absolute prediction error was calculated for each eye. Statistical significance was evaluated at the level of p<0.05. Results The study included 135 subjects. The mean axial length, anterior chamber depth, keratometry, and intraocular lens power were 23.2±1.2 (22 to 24.5) mm, 3.2±0.4 (2.4 to 4.4) mm, 43.5±1.5 (40.8 to 46.2) diopter, 21.5±1.8 (18.5 to 25.5) diopter, respectively. The mean absolute prediction error for Sanders-Retzlaff-Kraft/Theoretical, Hoffer Q, Barrett Universal II, Kane, and Hill-radial basis function was 0.306±0.291, 0.312±0.257, 0.314±0.268, 0.299±0.206 and 0.308±0.280, respectively (p>0.05). Conclusion The study showed the third-generation (Sanders-Retzlaff-Kraft/Theoretical and Hoffer Q), fourth-generation (Barrett Universal II) and new-generation (Kane and Hill-radial basis function) intraocular lens power calculation formulas had similar performances regarding calculation of intraocular lens power to predict target refraction after phacoemulsification in eyes with normal axial length.

RESUMO Objetivo Comparar o desempenho das fórmulas Sanders-Retzlaff-Kraft/Teórica, Hoffer Q, Barrett Universal II, Kane, e Hill-radial basis function (RBF) para cálculo de poder dióptrico das lentes intraoculares, em olhos com comprimento axial normal, em termos de predição da refração alvo, utilizando a tecnologia de interferometria de coerência parcial. Métodos Facoemulsificação e implante de lentes intraoculares foram realizados em 135 olhos de 135 pacientes com comprimento axial entre 22 e 24.5 mm. Comprimento axial, ceratometria, e profundidade da câmara anterior foram medidos por lente intraocular Master 500. As fórmulas Sanders-Retzlaff-Kraft/Teórica, Hoffer Q, Barrett Universal II, Kane, e Hill-radial basis function foram empregadas para cálculo de poder dióptrico das lentes intraoculares. A diferença entre a refração esperada no pós-operatório e a média dos erros absolutos preditivos foi calculada para cada olho. Os valores de p<0,05 foram considerados estatisticamente significativos. Resultados O estudo incluiu 135 sujeitos. As médias de comprimento axial, profundidade da câmara anterior, ceratometria, e poder dióptrico das lentes intraoculares foram 23,2±1,2 (22 a 24,5) mm, 3,2±0,4 (2,4 a 4,4) mm, 43,5±1,5 (40,8 a 46,2) dioptria, 21,5±1,8 (18,5 a 25,5) dioptria, respectivamente. A média de erro absoluto preditivo para as fórmulas Sanders-Retzlaff-Kraft/Teórica, Hoffer Q, Barrett Universal II, Kane, e Hill-radial basis function foi 0,306±0,291, 0,312±0,257, 0,314±0,268, 0,299±0,206 e 0,308±0,280, respectivamente (p>0,05). Conclusão O estudo mostrou que as fórmulas de terceira geração (Sanders-Retzlaff-Kraft/Teórica e Hoffer Q), de quarta geração (Barrett Universal II) e as da nova geração (Kane e Hill-radial basis function) para cálculo de poder dióptrico das lentes intraoculares, têm desempenhos semelhantes para cálculo do poder dióptrico das lentes intraoculares, para predizer a refração alvo após facoemulsificação em olhos com comprimento axial normal.

Analise dos dados biométricos gerados por interferometria comparada com Scheimpflug / Analysis of biometric data generated by interferometry compared with Scheimpflug

Resumo Objetivo: Observar o grau de concordância das variáveis analisadas entre os dispositivos IOL Master 500 e Pentacam AXL e descrever as medias Métodos: Foram analisados 35 prontuários, totalizando 61 olhos. Todos os pacientes se submeteram à avaliação biométrica nos dois dispositivos, no período de agosto de 2018 a agosto de 2019. Os dados coletados foram: idade, sexo, profundidade da câmara anterior, comprimento axial, K1, K2, poder dióptrico da LIO e alvo refracional. Resultados: As médias das variáveis analisadas entre os dispositivos de biométricos óptica em questão tiveram diferença estatisticamente significante (p<0,05). A regressão linear não apontou influência de nenhuma das variáveis da câmara anterior na diferença de valores do poder dióptrico da LIO e do alvo refracional entre os dispositivos. Conclusão: Não houve concordância estatística entre os dispositivos para as variáveis analisadas. Portanto, deve se evitar intercambiar o uso do Pentacam AXL com o IOL Master 500.

Abstract Objective: Observe the agreement between IOL Master 500 and Pentacam AXL and describe the averages. Methods: We analyzed 35 medical records, totaling 61 eyes. All patients underwent biometric evaluation on both devices from August 2018 to August 2019. The data collected were: age, gender, anterior chamber depth, axial length, K1, K2, biometrics and IOL target. Results: The averages of the variables analyzed between the optical biometric devices in question had a statistically significant difference (p <0.05). Linear regression showed no influence of any anterior chamber variables on the difference in biometrics and target values between the devices. Conclusion: There was no statistical agreement between the devices for the analyzed variables. Therefore, the interchange of Pentacam AXL with IOL Master 500 should be avoided.

Effects of pupillary dilation on ocular optical biometry outcomes in pediatric patients.

PURPOSE: Pharmacological pupillary dilation is performed in comprehensive ophthalmological examinations and before biometric measurements. So far, there is no consensus regarding its impact on biometric measurements. This study's aim was to investigate the effects of pharmacological pupillary dilation on ocular biometric measurements in healthy children. METHODS: This was a prospective, observational, non-randomized study of children (4-18 years of age) who were admitted for routine ophthalmological examination. Biometric measurements were performed, using a non-contact optical biometry device, both before and after pharmacological pupillary dilation with cyclopentolate hydrochloride. Intraocular lens power calculations were performed using Hill-RBF, Barrett, Olsen, Sanders-Retzlaff-Kraff/Theoretical, Holladay, and Hoffer Q formulas. Descriptive statistical analyses were also performed. The Wilcoxon signed-rank test was used to compare measurements before and after pharmacological pupillary dilation. Relationships between variables were analyzed using the Spearman-Brown rank correlation coefficient. RESULTS: The study included 116 eyes of 58 children (mean age, 8.4 ± 0.32 years; 34 girls). Significant changes were observed after pupillary dilation, compared with before pupillary dilation, in terms of anterior chamber depth, aqueous depth, and central corneal and lens thicknesses. No significant change was observed in axial length. Intraocular lens power calculations revealed no significant changes after pupillary dilation in most formulas except for the Olsen formula. The intraocular lens power was significantly inversely correlated with axial length and anterior chamber depth. CONCLUSIONS: Pharmacological pupillary dilation in children appeared to have no impact on axial length and intraocular lens power, but caused a significant increase in anterior chamber depth. The difference in anterior chamber depth measurements before and after pupillary dilation could be related to the optical biometry device model used. These outcomes should be considered in intraocular lens power calculations performed using anterior chamber depth parameters.

Effects of pupillary dilation on ocular optical biometry outcomes in pediatric patients / Efeitos da dilatação pupilar nos resultados da biometria óptica ocular em pacientes pediátricos

ABSTRACT Purpose: Pharmacological pupillary dilation is performed in comprehensive ophthalmological examinations and before biometric measurements. So far, there is no consensus regarding its impact on biometric measurements. This study's aim was to investigate the effects of pharmacological pupillary dilation on ocular biometric measurements in healthy children. Methods: This was a prospective, observational, non-randomized study of children (4-18 years of age) who were admitted for routine ophthalmological examination. Biometric measurements were performed, using a non-contact optical biometry device, both before and after pharmacological pupillary dilation with cyclopentolate hydrochloride. Intraocular lens power calculations were performed using Hill-RBF, Barrett, Olsen, Sanders-Retzlaff-Kraff/Theoretical, Holladay, and Hoffer Q formulas. Descriptive statistical analyses were also performed. The Wilcoxon signed-rank test was used to compare measurements before and after pharmacological pupillary dilation. Relationships between variables were analyzed using the Spearman-Brown rank correlation coefficient. Results: The study included 116 eyes of 58 children (mean age, 8.4 ± 0.32 years; 34 girls). Significant changes were observed after pupillary dilation, compared with before pupillary dilation, in terms of anterior chamber depth, aqueous depth, and central corneal and lens thicknesses. No significant change was observed in axial length. Intraocular lens power calculations revealed no significant changes after pupillary dilation in most formulas except for the Olsen formula. The intraocular lens power was significantly inversely correlated with axial length and anterior chamber depth. Conclusions: Pharmacological pupillary dilation in children appeared to have no impact on axial length and intraocular lens power, but caused a significant increase in anterior chamber depth. The difference in anterior chamber depth measurements before and after pupillary dilation could be related to the optical biometry device model used. These outcomes should be considered in intraocular lens power calculations performed using anterior chamber depth parameters.

RESUMO Objetivo: A dilatação pupilar farmacológica é realizada em exames oftalmológicos abrangentes e antes das medições biométricas. Até o momento, não há consenso sobre seu impacto nas medições biométricas. O objetivo deste estudo foi investigar os efeitos da dilatação pupilar nas medidas biométricas oculares em crianças saudáveis. Métodos: Estudo prospectivo, observacional e não randomizado de crianças (4-18 anos) que foram admitidas para exame oftalmológico de rotina. As medidas biométricas foram realizadas usando um dispositivo de biometria óptica sem contato, antes e após a dilatação pupilar farmacológica com cloridrato de ciclopentolato. Os cálculos de potência das lentes intraoculares foram realizados utilizando as fórmulas de Hill-RBF, Barrett, Olsen, Sanders-Retzlaff-Kraff/ Teórica, Holladay e Hoffer Q. Análises estatísticas descritivas também foram realizadas. O teste dos postos sinalizados de Wilcoxon foi usado para comparar as medidas antes e após a dilatação pupilar farmacológica. As relações entre as variáveis foram analisadas pelo coeficiente de correlação de Spearman-Brown. Resultados: O estudo incluiu 116 olhos de 58 crianças (idade média de 8,4 ± 0,32 anos; 34 meninas). Alterações significativas foram observadas após a dilatação pupilar, em termos de profundidade da câmara anterior, profundidade do humor aquoso e espessura central da córnea e do cristalino. Nenhuma mudança significativa ocorreu no comprimento axial. Os cálculos de potência da lente intraocular não revelaram alterações significativas após a dilatação pupilar na maioria das fórmulas, com exceção da fórmula Olsen. O poder da lente intraocular foi significativamente inversa correlacionada com o comprimento axial e a profundidade da câmara anterior. Conclusões: A dilatação pupilar farmacológica em crianças parece não ter impacto no comprimento axial e no poder da lente intraocular, mas causou um aumento significativo na profundidade da câmara anterior. A diferença nas medidas da profundidade da câmara anterior antes e após a dilatação pupilar pode estar relacionada ao modelo do dispositivo de biometria óptica utilizado. Tais resultados devem ser considerados nos cálculos de potência da lente intraocular realizados usando parâmetros de profundidade da câmara anterior.

Anterior chamber depth and axial length affect clinical performance of Spot Vision Screener / A profundidade da câmara anterior e o comprimento axial afetam o desempenho clínico do Spot Vision Screener

ABSTRACT Purpose: The aim of this study was to evaluate the effect of anterior chamber depth and axial length on clinical performance of the Spot Vision Screener in detecting amblyopia risk factors in children aged 3-10 years. Methods: A total of 300 eyes from 150 patients aged 3-10 years were prospectively tested with Spot Vision Screener (firmware version 3.0.02.32, software version 3.0.04.06) and a standard autorefractometer (Nidek ARK-1). The anterior chamber depth and axial length were measured with an optical biometer (Nidek AL-Scan). The sensitivity and specificity values for detecting significant refractive errors using the referral criteria of the American Association for Pediatric Ophthalmology and Strabismus were determined. Pearson's correlation analysis was employed to evaluate the relationship between the Spot Vision results and the anterior chamber depth and axial length. Results: Compared with the standard autorefractometer results, the Spot Vision Screener's sensitivity and specificity was 59% and 94%, respectively. The differences between the cycloplegic autorefractometer and the Spot Vision Screener spherical equivalents were negatively correlated with anterior chamber depth (r=-0.48; p<0.001) and axial length (r=-0.45; p<0.001). Conclusion: The Spot Vision Screener has moderate sensitivity and high specificity, using the criteria of the American Association for Pediatric Ophthalmology and Strabismus. The anterior chamber depth and axial length affect the Spot Vision results.

RESUMO Objetivo: O objetivo deste estudo foi avaliar o efeito da profundidade da câmara anterior e do comprimento axial sobre o desempenho clínico do Spot Vision Screener, na deteção de fatores de risco para a ambliopia em crianças de 3 a 10 anos de idade. Métodos: Um total de 300 olhos de 150 pacientes de 3-10 anos de idade foram prospectivamente testados com o Spot Vision Screener (firmware: 3.0.02.32, software: 3.0.04.06) e com autorefratómetro padrão (Nidek ARK-1). Todas as medições de profundidade e comprimento axial da câmara anterior dos pacientes foram realizadas através de Nidek AL Scan. A sensibilidade e especificidade para a deteção de erros refrativos significativos foram determinadas de acordo com os critérios de referência da Associação Americana de Oftalmologia e Estrabismo Pediátricos. A análise da Correlação de Pearson foi utilizada para avaliar a correlação entre os resultados do Spot Vision e a profundidade ou comprimento axial da câmara anterior dos pacientes. Resultados: Em comparação com os resultados do autorefratómetro padrão, a sensibilidade do Spot foi de 59% e a especificidade de 94%. As diferenças entre os equivalentes esféricos do autorefratómetro cicloplégico e o Spot Vision Screener foram correlacionados negativamente com a profundidade (r=-0,48; p<0,001) e o comprimento axial (r=-0,45; p<0,001) da câmara anterior dos casos. Conclusão: O Spot Vision Screener possui uma sensibilidade moderada e uma especificidade elevada utilizando os critérios da Associação Americana de Oftalmologia Pediátrica e Estrabismo; a profundidade da câmara anterior e o comprimento axial dos pacientes afetam os resultados do Spot Vision.

Correlation between lens thickness and lens density in patients with mild to moderate cataracts.

PURPOSE: To determine the relationships between lens thickness (LT), lens density and anterior segment parameters in patients with mild to moderate cataracts. SETTING: Oftalmosalud Instituto de Ojos, Lima, Perú. DESIGN: Prospective, single-centre, cross-sectional study. METHODS: 169 eyes with age-related mild to moderate cataracts had lens density assessed using the Lens Opacification Classification System III, the built-in Pentacam HR Nucleus Staging software and ImageJ software. LT and axial length (AL) were measured with the IOLMaster 700, and angle parameters were measured using anterior segment optical coherence tomography. Pearson correlation coefficients and Kruskal-Wallis tests were used for statistical analyses. RESULTS: Nuclear colour score was the only clinical parameter with a weak significant correlation with LT (r=0.24, p=0.003) after accounting for age, AL, gender and anterior chamber depth (ACD). The maximum value of average lens density and the mean nuclear density were significantly correlated with LT (r=0.24, p=0.003 and -0.17, p=0.03, respectively) after controlling for the same factors. Central LT greater than 4.48 mm was present in 54.5% of the eyes with a nuclear opalescence grade 1. CONCLUSIONS: LT is independent of lens density in mild to moderate cataracts after accounting for age, AL, ACD and gender contrary to previous studies.

Anterior chamber depth and axial length affect clinical performance of Spot Vision Screener.

PURPOSE: The aim of this study was to evaluate the effect of anterior chamber depth and axial length on clinical performance of the Spot Vision Screener in detecting amblyopia risk factors in children aged 3-10 years. METHODS: A total of 300 eyes from 150 patients aged 3-10 years were prospectively tested with Spot Vision Screener (firmware version 3.0.02.32, software version 3.0.04.06) and a standard autorefractometer (Nidek ARK-1). The anterior chamber depth and axial length were measured with an optical biometer (Nidek AL-Scan). The sensitivity and specificity values for detecting significant refractive errors using the referral criteria of the American Association for Pediatric Ophthalmology and Strabismus were determined. Pearson's correlation analysis was employed to evaluate the relationship between the Spot Vision results and the anterior chamber depth and axial length. RESULTS: Compared with the standard autorefractometer results, the Spot Vision Screener's sensitivity and specificity was 59% and 94%, respectively. The differences between the cycloplegic autorefractometer and the Spot Vision Screener spherical equivalents were negatively correlated with anterior chamber depth (r=-0.48; p<0.001) and axial length (r=-0.45; p<0.001). CONCLUSION: The Spot Vision Screener has moderate sensitivity and high specificity, using the criteria of the American Association for Pediatric Ophthalmology and Strabismus. The anterior chamber depth and axial length affect the Spot Vision results.

T2 formula in a highly myopic population, comparison with other methods and description of an improved approach for estimating corneal height.

BACKGROUND: To determine the accuracy of the T2 formula as applied to highly myopic eyes, to compare the T2 formula to the SRK/T and Holladay 1 formulas, and to describe possible ways to improve the estimation of corneal height and prediction error in two settings, the Hadassah Hospital, Ophthalmology Department, Jerusalem, Israel and Clínica Barraquer, Bogotá, Colombia. METHODS: In this retrospective case series, optical biometer measurements were taken for 63 highly myopic patients (> 25 mm) undergoing uneventful crystalline lens phacoemulsification and insertion of an acrylic intraocular lens. Prediction errors were obtained, with estimations of ±0.50 D, ± 1.00 D, and greater than ±2.00 D. A method to improve the corneal height calculation is described. RESULTS: The SRK/T formula (mean absolute error [MAE] = 0.418; median absolute error [MedAE] = 0.352) was the most accurate, followed by the T2 (MAE = 0.435; MedAE = 0.381) and Holladay 1 (MAE = 0.455; MedAE = 0.389) formulas. Both the SRK/T and T2 formulas overestimated corneal height, but values were higher with the T2 formula. Corneal height was more precisely estimated using an alternative method that, when combined with axial length optimization, resulted in lower MAE (0.425) and MedAE (0.365) values than when applying the T2 formula alone. CONCLUSIONS: The T2 formula seems to be less accurate than the SRK/T formula in highly myopic eyes. An improved corneal height estimation method is described for the the T2 formula.

The effect of pseudoexfoliation syndrome on choroidal thickness in open-angle glaucoma / O efeito do glaucoma pseudoesfoliativo sobre a espessura da coroide em comparação com o glaucoma de ângulo abertos

ABSTRACT Purpose: To investigate the effect of pseudoex foliation syndrome on choroidal thickness as compared with healthy individuals and subjects with primary open-angle glaucoma. Methods: This prospective, randomized study included 30 primary open angle glaucoma patients and 30 pseudoexfoliation glaucoma patients with similar demographic characteristics and 30 eyes of 30 healthy individuals comprised the control group. Regular optic nerve and macular images were obtained using a Cirrus HD spectral domain optical coherence tomography instrument, along with macular choroidal thickness measurements with enhanced depth imaging mode. Results: Age, sex, and axial length values were similar among the three groups (p>0.05). The primary open angle glaucoma and pseudoexfoliation glaucoma groups had comparable levels of glaucomatous damage. The mean subfoveal choroidal thickness values in the primary open angle glaucoma, pseudoexfoliation glaucoma, and control groups were 271.80 ± 19.96 μm, 241.43 ± 32.47 μm, and 268.03 ± 24.50 μm, respectively. The pseudoexfoliation glaucoma group had the lowest choroidal thickness values of the three groups (p values: pseudoexfoliation-control: 0.001; pseudoexfoliation-primary open angle glaucoma: <0.001, primary open angle glaucoma-control: 0.516, independent samples t-test). Conclusion: The macular choroid was thinner in patients with pseudoexfoliation glaucoma, as compared with both healthy individuals and open-angle glaucoma patients with similar degrees of glaucomatous damage.

RESUMO Objetivo: Investigar o efeito do glaucoma pseudoexfoliativo sobre a espessura da coroide em comparação com indivíduos saudáveis e com glaucoma primário de ângulo aberto. Métodos: Este estudo prospectivo e randomizado incluiu 30 pacientes com glaucoma primário de ângulo aberto e 30 com glaucoma pseudoexfoliativo, com características demográficas semelhantes e 30 olhos de 30 indivíduos saudáveis compuseram o grupo controle. Imagens da área macular e do nervo óptico foram obtidas usando um tomógrafo por coerência óptica no domínio espectral do modelo Cirrus HD, juntamente com medições da espessura da coroide na área macular através do modo de imagem de profundidade realçada. Resultados: Os valores de idade, sexo e comprimento axial foram semelhantes nos três grupos (p>0,05). Os grupos de glaucoma primário de ângulo aberto e de glaucoma pseudoexfoliativo tinham níveis comparáveis de lesões glaucomatosas. Os valores médios da espessura subfoveal da coroide nos grupos do glaucoma primário de ângulo aberto, glaucoma pseudoexfoliativo e de controle foram 271,80 ± 19,96 μm, 241,43 ± 32,47 μm e 268,03 ± 24,50 μm, respectivamente. O grupo glaucoma pseudoexfoliativo apresentou os menores valores de espessura de coroide dos três grupos (valores de p: pseudoexfoliativo-controle: 0,001; pseudoexfoliativo-glaucoma primário de ângulo aberto: <0,001, controle de glaucoma primário de ângulo aberto: 0,516; teste de t de amostras independentes). Conclusão: A coroide na área macular era mais fina em pacientes com glaucoma pseudoexfoliativo, quando comparada com indivíduos saudáveis e pacientes com glaucoma de ângulo aberto com graus similares de lesão glaucomatosa.

The effect of pseudoexfoliation syndrome on choroidal thickness in open-angle glaucoma.

PURPOSE: To investigate the effect of pseudoex foliation syndrome on choroidal thickness as compared with healthy individuals and subjects with primary open-angle glaucoma. METHODS: This prospective, randomized study included 30 primary open angle glaucoma patients and 30 pseudoexfoliation glaucoma patients with similar demographic characteristics and 30 eyes of 30 healthy individuals comprised the control group. Regular optic nerve and macular images were obtained using a Cirrus HD spectral domain optical coherence tomography instrument, along with macular choroidal thickness measurements with enhanced depth imaging mode. RESULTS: Age, sex, and axial length values were similar among the three groups (p>0.05). The primary open angle glaucoma and pseudoexfoliation glaucoma groups had comparable levels of glaucomatous damage. The mean subfoveal choroidal thickness values in the primary open angle glaucoma, pseudoexfoliation glaucoma, and control groups were 271.80 ± 19.96 µm, 241.43 ± 32.47 µm, and 268.03 ± 24.50 µm, respectively. The pseudoexfoliation glaucoma group had the lowest choroidal thickness values of the three groups (p values: pseudoexfoliation-control: 0.001; pseudoexfoliation-primary open angle glaucoma: <0.001, primary open angle glaucoma-control: 0.516, independent samples t-test). CONCLUSION: The macular choroid was thinner in patients with pseudoexfoliation glaucoma, as compared with both healthy individuals and open-angle glaucoma patients with similar degrees of glaucomatous damage.

Optical biometry-based axial length alterations after intravitreal dexamethasone implant / Alterações do comprimento axial com base na biometria óptica após o implante de dexametasona intravítrea

ABSTRACT Purpose: To investigate changes in axial length after intravitreal dexamethasone implantation in patients with macular edema. Methods: We performed a prospective comparative study of 46 patients with unilateral macular edema, due to diabetic retinopathy, retinal vein occlusion, and non-infectious uveitis, who underwent dexamethasone implantation. The fellow eyes of the patients were considered the control group. The central macular thickness was measured by spectral-domain optical coherence tomography, and axial length was measured by IOLMaster 700 optical coherence biometry. We compared axial length and central macular thickness values within the groups. Results: In the study group, the baseline central macular thickness was 460.19 ± 128.64 mm, significantly decreasing to 324.00 ± 79.84 mm after dexamethasone implantation (p=0.000). No significant change in central macular thickness measurements was seen in the control group (p=0.244). In the study group, the baseline axial length was 23.16 ± 0.68 mm, significantly increasing to 23.22 ± 0.65 mm after dexamethasone implantation (p=0.039). However, the control group exhibited no significant change in axial length (p=0.123). Conclusions: In addition to significantly reducing central macular thickness measurements, intravitreal dexamethasone implantation also significantly changes optical biometry-based axial length measurements.

RESUMO Objetivo: Investigar alterações no comprimento axial após implante de dexametasona intravítrea em pacientes com edema macular. Métodos: Foi realizado um estudo prospectivo e comparativo de 46 pacientes com edema macular unilateral, devido à retinopatia diabética, oclusão da veia retiniana e uveíte não infecciosa, que foram submetidos ao implante de dexametasona. Os olhos contralateral de cada paciente foram considerados o grupo controle. A espessura macular central foi medida por tomografia de coerência óptica de domínio espectral, e o comprimento axial foi medido por meio de biometria de coerência óptica de domínio espectral e o comprimento axial foi medido pela biometria de coerência óptica com IOLMaster 700. Comparamos o comprimento axial e os valores da espessura macular central dentro dos grupos. Resultados: No grupo de estudo, a espessura macular basal foi de 460,19 ± 128,64 mm, diminuindo significativamente para 324,00 ± 79,84 mm após o implante de dexametasona (p=0,000). Nenhuma mudança significativa nas medidas da espessura macular central foi observada no grupo controle (p=0,244). No grupo de estudo, o comprimento axial basal foi de 23,16 ± 0,68 mm, aumentando significativamente para 23,22 ± 0,65 mm após o implante de dexametasona (p=0,039). No entanto, o grupo controle não apresentou alteração significativa no comprimento axial (p=0,123). Conclusões: Além de reduzir significativamente as medidas da espessura macular central, o implante de dexametasona intravítrea também altera significativamente as medidas de comprimento axial baseadas na biometria óptica.