ABSTRACT
PURPOSE: To evaluate the prediction of refraction using the SRK/T formula for intraocular lens (IOL) calculation in eyes with medium axial length after phacoemulsification. METHODS: This prospective study enrolled 33 eyes with nuclear cataract that underwent phacoemulsification. All procedures were performed by one surgeon with the intraocular lens placed within the capsular bag. The same technician who was unaware of the purpose of the study made all the measurements. The achieved refractive error one month after surgery was compared to the predicted postoperative refractive error by the SRK/T formula. RESULTS: The ocular axial length varied between 22.2 mm and 24.5 mm. The mean predicted refraction was -0.431 +/- 0.181 D and the mean achieved postoperative spherical equivalent was -0.220 +/- 0.732 D. Eighteen eyes (55%) had a refractive error between +/- 0.50 D and thirty eyes (91%) between +/- 1.00 D of the predicted refraction. There was a tendency toward hyperopic shift (mean +/- SD: 0.211 +/- 0.708 D, p=0.009). CONCLUSION: The SRK/T formula demonstrated a satisfactory accuracy to calculate the error of refraction in eyes with medium axial length.
Subject(s)
Lens Implantation, Intraocular , Phacoemulsification/methods , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Prospective Studies , Refractometry , Reproducibility of Results , Treatment Outcome , Visual AcuityABSTRACT
Purpose: To evaluate the prediction of refraction using the SRK/T formula for intraocular lens (IOL) calculation in eyes with medium axial length after phacoemulsification. Methods: This prospective study enrolled 33 eyes with nuclear cataract that underwent phacoemulsification. All procedures were performed by one surgeon with theintraocular lens placed within the capsular bag. The same technician whowas unaware of the purpose of the study made all the measurements. Theachieved refractive error one month after surgery was compared to the predicted postoperative refractive error by the SRK/T formula. Results: The ocular axial length varied between 22.2 mm and 24.5 mm. The mean predicted refraction was -0.431 ± 0.181 D and the mean achieved postoperative spherical equivalent was -0.220 ± 0.732 D. Eighteen eyes (55%) had a refractive error between ± 0.50 D and thirty eyes (91%) between ± 1.00 D of the predicted refraction. There was a tendency toward hyperopic shift (mean ± SD: 0.211 ± 0.708 D, p=0.009). Conclusion: The SRK/T formula demonstrated a satisfactory accuracy to calculate the error of refraction in eyes with medium axial length.
Objetivo: Avaliar resultados refracionais utilizando a fórmula SRK/T no cálculo de lentes intraoculares (LIO) em olhos comcomprimento axial médio após facoemulsificação. Métodos: Este estudo prospectivo envolveu 33 olhos com catarata nuclear que foram submetidos a facoemulsificação. Todas as cirurgias foram realizadas pelo mesmo cirurgião com lentes intraoculares no saco capsular. O mesmo tecnólogo, o qualnão sabia o objetivo do estudo, realizou todas as medidas biométricas. O erro refracional atingido um mês após a cirurgia foi comparado ao erro refracional pós-operatório previsto pelafórmula SRK/T. Resultados: O comprimento axial variou entre 22,2 mm e 24,5 mm. A refração média prevista foi -0,431 ± 0,181 dioptrias (D) e o equivalente esférico pós-operatório alcançado foi -0,220 ± 0,732 D. Dezoito olhos (55%) obtiveram errorefracional de ± 0,50 D e 30 olhos (91%) entre ± 1,00 D da refração prevista. Houve tendência a um erro hipermetrópico (média±SD: 0,211 ± 0,708 D, p=0,009). Conclusão: A fórmula SRK/T demonstrou acurácia satisfatória no cálculo do erro refracional em olhos de comprimento axial médio.
