Analysis between two optical biometric devices in patients with cataract / Análise entre dois dispositivos de biometria óptica em pacientes com catarata

ABSTRACT Objective: To evaluate the correlation of optical biometry and target with variable ages, anterior chamber depth, axial length, R1/K1 and R2/K2 established by two optical biometry devices in patients with cataract. Methods: The study included the analysis of 348 medical records, from which 503 cataract eyes were selected, which underwent evaluation by the optical biometric devices IOL Master 700 and Lenstar LS 900 in the period of April to July 2017. Data collected were: age, anterior chamber depth, axial length, R1/K1 and R2/K2. Results: The average of the biometrics obtained using Lenstar was 21.02, varying 3.46, more or less, with an average target of -0.02, varying 0.45. In relation to the IOL Master it was 21.19, with a variation of 3.40 and average target of -0.01, a variation of 0.11. It can be observed that despite close values in relation to the mean, there was significance (p<0.001). Axial length (p<0.001) and R1/K1 (p<0.001) had an influence on the difference of the biometric values between the devices. Conclusion: A high degree of clinical and statistical correspondence was observed between the results obtained by the biometry devices in patients with cataract.

RESUMO Objetivos: Avaliar a correlação da biometria óptica e target com as variáveis idade, profundidade da câmara anterior, comprimento axial, R1/K1 e R2/K2 estabelecidos por dois dispositivos de biometria óptica em pacientes com catarata. Métodos: O trabalho abrangeu a análise de 348 prontuários dos quais foram selecionados 503 olhos com catarata ,que passaram pela avaliação nos dispositivos de biometria óptica IOL Master 700 e Lenstar LS 900 no período de abril a julho de 2017. Os dados colhidos foram: idade, profundidade da câmara anterior, comprimento axial, R1/K1 e R2/K2 . Resultados: A média da biometria obtida utilizando o Lenstar foi de 21,02, variando 3,46 para mais ou para menos, com target médio de -0,02, variando 0,45. Já em relação ao IOL Master foi de 21,19, com variação de 3,40 e target médio de -0,01, variação de 0,11. Pode-se observar que apesar de valores próximos em relação à média, houve significância (p < 0,001). Houve a concordância da biometria em relação ao comprimento axial (p < 0,001) e R1/K1(p < 0,001). Conclusão: Observou-se alto grau de correspondência clínica e estatística entre os resultados obtidos pelos dispositivos de biometria em pacientes com catarata.

Comparison of ultrasound and optic biometry with respect to eye refractive errors after phacoemulsification

Phacoemulsification is one of the best surgical treatments for the cataract. Secondary to the technical advances in estimating the intraocular lens [IOL] power, the refractive errors, one of the most important surgical complications after surgery, is now reduced. Currently, two methods of biometry are used to calculate the IOL power, ultrasound biometry and optical biometry. Both methods have their own advantages and it is controversial to use which of them before surgery. We would like to know if there is any difference between these two biometry methods to reduce refractive errors after cataract surgery. Present research was a cohort study on the patients undergone phacoemulsification due to cataract in Feiz and Farabi academic hospitals and Aban ophthalmology clinic. We compared eye refractions after cataract surgery in two groups of patients. Ultrasound biometry was done for the first group and the optical biometry for the second one. Mean absolute refractive error [MAE] was compared in the two groups by t test. Eye refractions of 132 patients were studied; 76 patients in group one and 56 patients in group two. The MAE measured 0.67 +/- 0.70 diopters for the first group and 0.79 +/- 0.76 diopters for the second one and the difference was not significant [P = 0.342]. According to our results the refractive errors after phacoemulsification was the same for both ultrasound and optical biometry methods. The claim of optical biometry, however, to gain a higher precision and thus a significantly better prediction of individual postoperative refraction after cataract surgery is not yet fulfilled. To determine which method is definitely better, more studies are required