Purpose The aim of this study was to investigate the wavefront aberration changes in human eyes caused by a gradient of increasing accommodation stimuli. Design This is a prospective, single-site study. Methods Healthy volunteers (n ¼ 22) aged 18-28 years whose refraction states were emmetropia or mild myopia, with astigmatism o1 diopter (D), were included in this study. After dilating the right pupil with 0.5% phenylephrine drops, the wavefront aberration of the right eye was measured continuously either without or with 1, 2, 3, 4, 5, or 6D accommodation stimuli (WFA1000B psychophysical aberrometer). The root mean square (RMS) values of the total wavefront aberrations, higher-order aberrations, and 35 individual Zernike aberrations under different accommodation stimuli were calculated and compared. Results The average induced accommodations using 1, 2, 3, 4, 5, or 6D accommodation stimuli were 0.848, 1.626, 2.375, 3.249, 4.181, or 5.085 D, respectively. The RMS of total wavefront aberrations, as well as higher-order aberrations, showed no significant effects with 1-3 D accommodation stimuli, but increased significantly under 4, 5, and 6 D accommodation stimuli compared with relaxed accommodation. Zernike coefficients of Z 0 4 significantly decreased with increasing levels of accommodation. Conclusion Higher-order wavefront aberrations in human eyes changed with increased accommodation. These results are consistent with Schachar's accommodation theory.

This prospective study assessed corneal flap morphology in 115 patients undergoing laser-assisted in situ keratomileusis (LASIK). Flaps were created using the Moria M2 90-μm or KM-5000D 110-μm microkeratomes. Flap thickness was measured using anterior segment optical coherence tomography at seven points in a 7-mm diameter zone 1 h, 1 day, 3 days, 1 week and 1 month after surgery. Flap accuracy, reproducibility, uniformity and changes over time were evaluated. The Moria M2 microkeratome created flaps with less accuracy in the centre than the KM-5000D microkeratome (114.06 ± 6.46 μm vs 128.39 ± 6.79 μm, respectively, at 1 week). For both microkeratomes, flap thickness varied between most of the peripheral areas and the central point. Both microkeratomes created flaps with good central predictability and reproducibility, but high variation and significant deviation from intended thickness were observed in peripheral flap thickness.

Background: Postradiation skull base osteoradionecrosis (ORN) is a severe complication that occurs after radiotherapy in patients with nasopharyngeal carcinoma (NPC) that can severely affect quality of life (QOL) and be life threatening. Only 13.4%–28.6% of patients can be cured by traditional repeated endoscopic debridement. Here, we introduced salvage endoscopic surgery for skull base ORN patients and evaluated its clinical efficacy. Methods: This was a prospective, observational, single-arm clinical study. Clinical data from 18 skull base ORN patients who underwent radical endoscopic necrectomy followed by reconstruction using a septal pedicled mucosal flap or temporal muscle flap were included in the study. The endpoint was an overall survival (OS) of 2 years. The numeric rating scale (NRS) scores for pain and foul odor were analyzed to determine the efficacy and safety of this surgery. Results: A total of 21 patients were recruited, 18 of whom completed the study and were analyzed. All surgeries were successfully performed. During the 2-year study, the OS rate of the entire cohort was 75%. The median NRS score for pain decreased from 6.44±2.62 to 0.50 ±0.71, and the NRS score for foul odor decreased from 1.89±1.08 to 1 after surgery. Conclusions: Salvage endoscopic necrectomy followed by construction using a septal pedicled mucosal flap or temporal muscle flap is a novel, safe, and effective treatment for ORN in patients with NPC. Clinical trial registration: This study was approved by the independent ethics committee of the Eye, Ear, Nose and Throat Hospital of Fudan University (IEC No. 2019095-1). Written informed consent was obtained from all patients. The study was registered with the Chinese Clinical Trial registry (ChiCTR2000029327).