20 May 2015
To investigate the feasibility of estimating effective lens position (ELP) and calculating intraocular lens power using corneal height (CH), as measured using anterior segment optical coherence tomography (AS-OCT), in patients who have undergone corneal refractive surgery.
This study included 23 patients (30 eyes) who have undergone myopic corneal refractive surgery and subsequent successful cataract surgery. The CH was measured with AS-OCT, and the measured ELP (ELP m) was calculated. Intraocular lens power, which could achieve actual emmetropia (P real), was determined with medical records. Estimated ELP (ELP est) was back-calculated using P real, axial length, and keratometric value through the SRK/T formula. After searching the best-fit regression formula between ELP m and ELP est, converted ELP and intraocular lens power (ELP conv, P conv) were obtained and then compared to ELP est and P real, respectively. The proportion of eyes within a defined error was investigated.
Mean CH, ELP est, and ELP m were 3.71 ± 0.23, 7.74 ± 1.09, 5.78 ± 0.26 mm, respectively. The ELP m and ELP est were linearly correlated (ELP est = 1.841 × ELP m - 2.018, p = 0.023, R = 0.410) and ELP conv and P conv agreed well with ELP est and P real, respectively. Eyes within ±0.5, ±1.0, ±1.5, and ±2.0 diopters of the calculated P conv, were 23.3%, 66.6%, 83.3%, and 100.0%, respectively.