ABSTRACT
AIM: To explore the clinical effect of small incision lenticule extraction(SMILE)on the treatment of myopic anisometropia.METHODS: Clinical data of 76 patients(146 eyes)with myopic anisometropia who received SMILE or femtosecond assisted laser in situ keratomileusis(FS-LASIK)in our hospital from January 2021 to December 2022 were retrospectively analyzed. The patients were divided into SMILE group(39 cases, 77 eyes)and FS-LASIK group(37 cases, 69 eyes)according to surgical methods. Uncorrected visual acuity(UCVA), diopter, anisometropia, corneal aberration and occurrence of postoperative complications were compared between the two groups at 1 wk, 1 and 3 mo after surgery.RESULTS: The UCVA of the two groups was improved after surgery compared with that before surgery, and the coma, trefoil, spherical aberration and total higher-order aberration were significantly increased compared to those before surgery(P<0.05), and the coma, trefoil, spherical aberration and total higher-order aberration in the FS-LASIK group were significantly higher than those in the SMILE group(P<0.05). After follow-up to 3 mo after surgery, the incidence of postoperative complications was significantly lower in the SMILE group than that in the FS-LASIK group(5.2% vs 15.9%, P<0.05).CONCLUSION: Both SMILE and FS-LASIK can effectively enhance the UCVA and improve the visual quality in patients with myopic anisometropia, but SMILE has lower corneal higher order aberrations, lower incidence of postoperative complications and better overall effect.
ABSTRACT
This paper introduces a novel focusing method Refraction Topography (RT) for wide-angle refraction measurement. The agreement of the test results obtained using RT is evaluated against simulation results and expected refraction. RT develops a refraction algorithm on fundus images at various focusing statuses. Unlike conventional techniques for peripheral refraction measurement, RT requires the subject to stare at a stationary fixation target. The refraction algorithm calculates the focus measure for multiple images at the Point of Interest and formulates them into a focus profile. The maximum focus measure correlates with the optimal focus position. Refraction Characterization Function (RCF) is proposed to translate the focus position into refraction determination, thus forming the refraction topography. The refraction characterization of RT optical system is performed using Isabel schematic eye. Three test eyes of - 15 D, 0 D, and + 15 D are defined, and expected refraction is obtained through simulation on an independent test schematic eye. Both simulation results and experimental results are obtained by combining the test eyes and RT system. Test results are compared with simulation results and expected refraction. The study demonstrates agreement among the test results, simulation results, and expected refraction on three test eyes.
ABSTRACT
Branch retinal artery occlusion (BRAO) is an ocular emergency, which could lead to blindness. Quantitative analysis of the BRAO region in the retina is necessary for the assessment of the severity of retinal ischemia. In this paper, a fully automatic framework was proposed to segment BRAO regions based on 3D spectral-domain optical coherence tomography (SD-OCT) images. To the best of our knowledge, this is the first automatic 3D BRAO segmentation framework. First, the input 3D image is automatically classified into BRAO of acute phase and BRAO of chronic phase or normal retina using an AdaBoost classifier based on combining local structural, intensity, textural features with our new feature distribution analyzing strategy. Then, BRAO regions of acute phase and chronic phase are segmented separately. A thickness model is built to segment BRAO in the chronic phase. While for segmenting BRAO in the acute phase, a two-step segmentation strategy is performed: rough initialization and refine segmentation. The proposed method was tested on SD-OCT images of 35 patients (12 BRAO acute phase, 11 BRAO chronic phase, and 12 normal eyes) using the leave-one-out strategy. The classification accuracy for BRAO acute phase, BRAO chronic phase, and normal retina were 100%, 90.9%, and 91.7%, respectively. The overall true positive volume fraction (TPVF) and false positive volume fraction (FPVF) for the acute phase were 91.1% and 5.5% and for the chronic phase were 92.7% and 8.4%, respectively.
