Refractive Error Assessment: Influence of Different Optical Elements and Current Limits of Biometric Techniques

Ribeiro, Filomena; Castanheira–Dinis, A.; Dias, J. M.

doi:10.3928/1081597x-20130129-07

Cited by 14 publications

(22 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The mean difference found is relevant, since a 1 mm error in AL results in a residual postoperative refractive error of 2.35 D in a 23.5 mm eye, 1.75 D in a 30.0 mm eye and 3.75 D in a 20 mm eye or about 2.0–4.0 D in the power of the implanted IOL. [ 21 ]…”

Section: Discussionmentioning

confidence: 99%

“…[ 15 ] Although the keratometry evaluation methods are different, there is a close relationship between the values reported in Caucasian populations, which are generally lower than in the Far Eastern populations. The difference observed with respect to Far Eastern populations is significant, representing a potential difference in the refractive error greater than 0.50 D. [ 21 ]…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Ocular biometric measurements in cataract surgery candidates in Portugal

et al. 2017

Self Cite

View full text Add to dashboard Cite

ObjectiveDescribe the ocular biometric parameters and their associations in a population of cataract surgery candidates.MethodsA cross-sectional study of 13,012 eyes of 6,506 patients was performed. Biometric parameters of the eyes were measured by optical low-coherence reflectometry. The axial length (AL), mean keratometry (K) and astigmatism, anterior chamber depth (ACD) (epithelium to lens), lens thickness (LT), and Corneal Diameter (CD) were evaluated.ResultsThe mean age was 69 ± 10 years (44–99 years). Mean AL, Km, and ACD were 23.87 ± 1.55 mm (19.8–31.92 mm), 43.91 ± 1.71 D (40.61–51.14 D), and 3.25 ± 0.44 mm (2.04–5.28 mm), respectively. The mean LT was 4.32 ± 0.49 mm (2.73–5.77 mm) and the mean CD was 12.02 ± 0.46 mm (10.50–14.15 mm). The mean corneal astigmatism was 1.08 ± 0.84 D (0.00–7.58 D) and 43.5% of eyes had astigmatism ≥ 1.00 D. Male patients had longer AL and ACDs (p < .001) and flatter corneas (p < .001). In regression models considering age, gender, Km, ACD, LT, and CD, a longer AL was associated with being male and having higher ACD, LT and CD.ConclusionsThese data represent normative biometric values for the Portuguese population. The greatest predictor of ocular biometrics was gender. There was no significant correlation between age and AL, ACD, or Km. These results may be relevant in the evaluation of refractive error and in the calculation of intraocular lens power.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Ocular biometric measurements in cataract surgery candidates in Portugal

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…In the study by Ribeiro et al (12) they evaluated the changes of each optical parameter on the refractive state of the eye and found that a 0.25 mm change in ACD measurement corresponds to an error of 0.10 D in an eye with an NA of 30.0 mm and 0.50 D in an eye with an AL of 20.0 mm. Following these results, studies were carried out assessing various ranges of ACD values to evaluate which formula was more effective.…”

Section: Discussionmentioning

confidence: 99%

“…In an older population, as is often the case in the cataract population, the lens is thickened and therefore the depth of the ACD is shallower. Ribeiro et al (12) found that for every 1% increase in lens thickness, the refractive error changes by 0.097, a 0.104 mm change in LT means a 0.25 D change in refractive error. Studies have already been published relating the different ocular parameters, including LT and the prediction error of the different formulas (16, 17).…”

Section: Discussionmentioning

confidence: 99%

Macular Thickness, a New Variable to Take Into Account in Intraocular Lens Calculation?

Sánchez-Liñán¹,

Pérez-Rueda

Alaskar³

et al. 2022

Preprint

View full text Add to dashboard Cite

Purpose Evaluate the influence of a posterior pole variable, macular thickness, in the calculation of the intraocular lens to be implanted in cataract patients since optical biometry has been used. Therefore, the aim of this work is to determine the importance of different biometric, topographic and retinal variables in the calculation of the intraocular lens to be implanted and to propose a new biometric formula that includes these new variables. Methods A retrospective cross-sectional observational study was carried out using a database of 230 patients who underwent cataract surgery at the Oftalvist centre in Almeria between January 2021-December 2021. Correlations between implanted IOL power and biometric, topography and retina variables were explored. A linear model was proposed with IOL power as dependent variable. The method was forward-backward steps. Results The model achieves an adjusted R-squared of 0.96 indicating that the power of the implanted lens is 96% dependent on the value of the axial length, the mean of the preoperative Ks (the mean has been performed because of the excessive collinearity between the two Ks) and the preoperative macular thickness. The introduction of the preoperative macular thickness improves the R-squared of the model and is significant in the calculation of the coefficients. Conclusions Macular thickness is a variable to take into account as it improves our prediction model of the IOL to be implanted. Keywords: Biometry, macular thickness, cataract surgery, intraocular lens power, calculation formula, precision, refractive accuracy.

show abstract

“…Los modelos personalizados obtenidos con una finalidad óptica están basados fundamentalmente en técnicas de tratamiento de imágenes obtenidas de un OCT, pudiendo así cuantificar la influencia del espesor corneal en el índice de refracción (Lai y Tang, 2014), o la influencia de la inclinación y del descentrado de una lente intraocular en la potencia corneal (Einighammer et al, 2009;Ribeiro et al, 2012;Wang et al, 2013). Otros equipos, como los biómetros, se pueden utilizar para medir la potencia corneal a partir de las imágenes generadas por éstos (Ribeiro et al, 2013). Figura 1.8 Modelos personalizados.…”

Section: Caracterización a Partir De Técnicas De Tratamiento De Imágenesunclassified

Modelado geométrico personalizado de la córnea humana y su aplicación a la detección de ectasias corneales

Cavas-Martínez¹

View full text Add to dashboard Cite

Refractive Error Assessment: Influence of Different Optical Elements and Current Limits of Biometric Techniques

Abstract: The most relevant optical elements either do not have available measurement instruments or the existing instruments still need to improve their accuracy. Ray tracing can be used as an optical assessment technique, and may be the correct path for future personalized refractive assessment.

Cited by 14 publications

References 22 publications

Ocular biometric measurements in cataract surgery candidates in Portugal

Ocular biometric measurements in cataract surgery candidates in Portugal

Macular Thickness, a New Variable to Take Into Account in Intraocular Lens Calculation?

Modelado geométrico personalizado de la córnea humana y su aplicación a la detección de ectasias corneales

Contact Info

Product

Resources

About