ObjectiveTo evaluate the effectiveness of using a six-dimensional eye-tracking system during femtosecond laser-assisted sub-Bowman keratomileusis (FS-SBK) surgery to correct myopia and astigmatism. MethodsA total of 23 patients (36 eyes) with ametropia undergoing FS-SBK were retrospectively analyzed and divided into the static cyclotorsion control (SCC) group (11 patients, 20 eyes) and the non-SCC group (12 patients, 16 eyes). According to the static eyeball rotation degrees, the SCC group was further divided into three subgroups: within ±2° group (5 patients, 9 eyes), ±2°-±5° group (4 patients, 7 eyes), and above ±5° group (2 patients, 4 eyes). The preoprative and postoperative one-month uncorrected visual acuity, best corrected visual acuity, diopter of spherical power, diopter of cylindrical power, corneal curvature, and the rotating degree in SCC were observed; the root-mean-square values of the total higher-order aberrations, spherical aberration, coma, Strehl ratio, etc. when the pupil diameter was 6.5 mm were extracted; and the therapeutic efficacy was observed. ResultsNo severe intraoperative or postoperative complications occurred in any subject. The effectiveness index of the SCC group was 0.947±0.145, and that of the non-SCC group was 1.005±0.141, with no statistically significant difference (P>0.05). Compared with the preoperative levels, in the two groups, the postoperative uncorrected visual acuity was significantly elevated; the postoperative diopter of spherical power, diopter of cylindrical power, and corneal curvature difference were reduced; the postoperative total higher-order aberrations, spherical aberration, and coma increased; all the differences mentioned above were statistically significant (P<0.05). In the SCC group, the difference between the preoperative and the postoperative Strehl ratio was statistically significant (P<0.05). There was no significant difference in postoperative indicators between the SCC group and the non-SCC group (P>0.05). The difference in postoperative increment of coma between the SCC group and the non-SCC group was statistically significant (P<0.05). In the SCC group, no statistically significant difference was found in postoperative increment of any indicator among the three subgroups (P<0.05). ConclusionsFS-SBK of six-dimensional eye-tracking system is effective in correcting myopia and astigmatism. FS-SBK can reduce lower-order aberrations while introducing higher-order aberrations, and whether SCC is performed intraoperatively is meaningless.
Meibomian gland dysfunction (MGD) is a common ocular surface disease, and the pathogenesis of MGD is closely related to the alteration of meibomian gland morphology and (or) function. At present, the treatment strategy for MGD consists of physical therapy, artificial lubricants, topical and systemic antibiotics and anti-inflammatory agents, topical steroids and Ω-3 dietary supplementation. Recently, the thermal pulsation system (LipiFlow) has been used clinically, which allows heat to be applied to the palpebral surfaces of the upper and lower eyelids directly over the meibomian glands, while simultaneously applying pulsatile pressure to the outer eyelid surfaces. Due to its specific design, the cornea and eyeball can successfully avoid the potential damage from overheating and improper expression, which will greatly improve the safety during the clinical application and patients’ compliance. Studies have showed that the effectiveness of LipiFlow when treating MGD is at least as well as twice-daily lid warming and massage for 3 months, which displays a broad application prospect. At present, the application of LipiFlow in China has not been fully developed, and only some hospitals have experimental applications. This paper summarizes the research progress of LipiFlow treatment in MGD.