To investigate the efficacy and safety of wavefront guided (WG) LASIK for the myopia and astigmatism.This study is a randomized control trial. 42 cases (78 eyes) were collected in the study through the routine examinations and wavefront analysis, which were divided into two groups (A and B). The value of Z (3, -1) being less than -0.15 microm was evaluated as Group A (24 cases, 45 eyes); The value of Z (3, -1) being more than +0.15 microm was as Group B (18 cases, 33 eyes). Both A and B were also divided into two subgroups (test and control). WG-LASIK was performed in tested groups, and classic LASIK was performed in control group. Visual quality, wavefront examination, and CSF were analyzed after surgery 3-6 months compared with that of preoperation.In the earlier period of post-operation time, diopters of the two groups were both slightly overcorrected, and then began to decrease slightly later and the diopters of both tested and control groups were corrected perfectly. RMSh of tested group increased higher than that of control group when Z (3, -1) was negative and the CSF in control group was better than that in test group after WG-LASIK in Group A. RMSh of tested group increased lower than that of control group when Z (3, -1) was positive and the CSF in tested group was better than that in control group after WG-LASIK in Group B.These results suggest that retaining negative vertical coma and removing positive vertical coma were beneficial to the visual function after the WG-LASIK, which could save the corneal tissue reasonably in order to improve visual quality effectively.
Objective
To examine parameters of the cornea, retina, intraocular pressure, and visual electrophysiology of three-year-old rhesus monkeys.
Methods
In this descriptive study, 8 three-year-old rhesus monkeys were selected for measurement of intraocular pressure (IOP), spherical equivalent (SE), anterior chamber depth (ACD), lens thickness (LT), vitreous chamber depth (VCD), axial length (AL), central corneal thickness (CCT), retinal thickness, choroidal thickness (under fovea and 500, 1 000, 1 500 μm nasal or temporal from fovea), and flash electroretinogram (f-ERG). The measurements were made by TonoVet tonometry, A-scan ultrasonography, optical coherence tomography (OCT), and visual electrophysiology. Paired t-tests were used to analyze differences between left and right eyes. Repeated ANOVA was used to analyze differences of choroidal thickness at different locations.
Results
The IOP of three-year-old rhesus monkeys was 16.9±3.1 mmHg, the SE was +0.6±1.0 diopter(D), the ACD was 3.4±0.4 mm, the LT was 3.8±0.2 mm, the VCD was 12.3±0.5 mm, the AL was 19.5±0.6 mm, the CCT was 537.6±50.8 μm, the foveal retinal layer thickness was 206.8±16.0 μm, and the foveal choroidal thickness was 186.6±17.2 μm. There were significant differences of choroidal thickness among all locations (F=10.966, P<0.001). There was a significant difference between foveal choroidal thickness and choroidal thickness at all extrafoveal locations (P<0.05).The amplitude of the dark-adapted rod-response b-wave was 170.3±41.7 μV. The amplitude of standard combined ERG a-wave was 195.4±37.4 μV, and the b-wave was 373.0±70.1 μV. The amplitude of cone-response a-wave was 26.1±6.6 μV and the b-wave was 105.4±35.7 μV. There were no statistically significant differences in any of the measured ocular biometry values between left and right eyes.
Conclusion
The reliable and complete ocular parameters of three-year-old rhesus monkeys will lay the foundation for future ocular research.
Key words:
Macaca mulatta; Intraocular pressure; Retina; Choroid; Visual electrophysiology
Purpose: To report the design, methods and baseline data of the Anyang Childhood Eye Study (ACES), aiming to determine the prevalence, incidence and risk factors of myopia and other ocular diseases in children in central China.Methods: The ACES was a school-based cohort study conducted in Anyang city. Students have been examined and will be followed-up annually for 3–5 years. Ocular examinations included visual acuity, identification of amblyopia and strabismus, ocular biometry, optical coherence tomography, retinal photography, cycloplegic autorefraction, accommodative response, peripheral refraction, visual perception and so on. A questionnaire survey was performed to collect risk factors for myopia including near work, outdoor activity, parental myopia, birth history, habits of wearing spectacles and reading, living habits, food habits and so on.Results: Of 3112 grade 1 and 2363 grade 7 students eligible for the ACES, 2893 (93.0%) and 2267 (95.9%) participated in the study, with a mean age of 7.1 years (range 5.7–9.3 years) and 12.7 years (range 10.0–15.9 years), and proportions of male to be 57.8% and 50.0%, respectively. The prevalence rates of myopia, high myopia, emmetropia and hyperopia were 3.9%, 0.1%, 72.9% and 23.3% in grade 1, and 67.3%, 2.7%, 31.4% and 1.2% in grade 7, respectively. Similar data were found in the children confined in 6-year-old and 12-year-old ages.Conclusions: The ACES is the first large-scale cohort study in China with baseline response rates over 90%. Continuous documentation of changes and risk factors of refractive errors in these cohorts would provide new insights into myopia control in school-aged children.
Objective To investigate the effects of scleral collagen cross-linking (SXL) using riboflavin and ultraviolet A (UVA) light on the scleral thickness of different regions and expression of matrix metalloproteinase 2 (MMP-2) and membrane-type MMP-1 (MT1-MMP) in guinea pigs with lens-induced myopia. Methods Forty-eight 4-week-old guinea pigs were assigned to three groups (n = 16 per group): SXL group, lens-induced myopia (LIM) group, and control group. The sclera of the right eye of the guinea pig in the SXL group was surgically exposed, riboflavin was dropped on the treatment area for 10 minutes before the 30-minute UVA irradiation. The same surgical procedure was performed in the LIM group without UVA irradiation. The -10.00 D lenses were then placed on the right eyes of guinea pigs in the SXL and LIM groups for six weeks. The control group received no treatment. The left eyes were untreated in all groups. The ocular axial length (AXL) and refraction were measured at 4 weeks and 10 weeks of age. 10-week-old guinea pigs were sacrificed, and the right eyes were enucleated and evenly divided for preparation of hematoxylin and eosin (HE) stained sections, quantitative real-time polymerase chain reaction (qPCR) and western blotting. The scleral thickness of different regions was measured on HE stained sections. The temporal half of the sclera was harvested to measure the expression of MMP-2 and MT1-MMP by qPCR and western blotting. Results The AXL was significantly shorter, and the degree of myopic refraction was significantly lower in the SXL group than those in the LIM group at 10 weeks of age. The scleral thickness of the cross-linked area was significantly greater in the SXL group than that of the corresponding area in the LIM group, while the scleral thickness of the untreated nasal side was not significantly different between the SXL group and the LIM group. The expression of MMP-2 and MT1-MMP of the cross-linked sclera was significantly downregulated compared with that of the corresponding area in the LIM group. Conclusion Riboflavin/UVA SXL could slow myopia progression and thicken the cross-linked sclera in guinea pigs, which might be related to the downregulation of MMP-2 and MT1-MMP expression during the scleral remodeling process.
Purposes: To (i) evaluate various methods for preserving refractive lenticules (RLs) from myopic eyes following small-incision lenticule extraction (SMILE), in order to (ii) establish a sound, standard storage RL preservative for clinical uses. Methods: In this prospective study, we compared freshly excised post-SMILE RLs (control group) with post-SMILE RLs (experimental group). Experimental group RLs were preserved in one of several preservatives: glycerol, allochroic silicagel desiccant, or Optisol. Following preservation in one of these three media, samples were evaluated by light microscopy (LM), and transmission (TEM) and scanning (SEM) electron microscopy on days-1, -3, -7, and -14. Results: Changes in cellular morphology were observed at all time points. Compared with fresh control-group RLs, there were significant histological changes in RLs preserved in glycerol and allochroic silicagel, but not Optisol. Comparison of the three methods revealed Optisol to be the best, followed by allochroic silica gel desiccant, followed by glycerol. RLs preserved in Optisol maintained the highest degree of viability and integrity. And the RLs viability and collagen density decreased with prolongation of storage time all. Conclusions: Optisol is a midterm corneal storage medium, which can maintain post-SMILE corneal RLs for 14 days, is a feasible and effective method for tissue storage.
Children and adolescents' myopia is a major public problem. Although the clinical effect of various interventions has been extensively studied, there is a lack of national-level and integral assessments to simultaneously quantify the economics and effectiveness of comprehensive myopia prevention and control programs. We aimed to compare the cost-effectiveness between traditional myopia prevention and control strategy, digital comprehensive myopia prevention and control strategy and school-based myopia screening program in China.A Markov model was used to compare the cost-utility and cost-effectiveness among school-based myopia screening, traditional myopia prevention and control strategy, and digital comprehensive myopia prevention and control strategy among 6 to 18-year-old rural and urban schoolchildren. Parameters were collected from published sources. The primary outcomes were quality-adjusted life-year, disability-adjusted life-year, incremental cost-utility ratio, and incremental cost-effectiveness ratio. Extensive sensitivity analyses were performed to test the robustness and sensitivity of base-case analysis.Compared with school-based myopia screening strategy, after implementing digital comprehensive myopia prevention and control strategy, the prevalence of myopia among 18-year-old students in rural and urban areas was reduced by 3.79% and 3.48%, respectively. The incremental cost-utility ratio per quality-adjusted life-year gained with the digital myopia management plan ($11,301 for rural setting, and $10,707 for urban setting) was less than 3 times the per capita gross domestic product in rural settings ($30,501) and less than 1 time the per capita gross domestic product in urban settings ($13,856). In cost-effectiveness analysis, the incremental cost-effectiveness ratio produced by digital comprehensive myopia management strategy ($37,446 and $41,814 per disability-adjusted life-year averted in rural and urban settings) slightly exceeded the cost-effectiveness threshold. When assuming perfect compliance, full coverage of outdoor activities and spectacles satisfied the cost-effectiveness threshold, and full coverage of outdoor activities produced the lowest cost ($321 for rural settings and $808 for urban settings).Health economic evidence confirmed the cost-effectiveness of promoting digital comprehensive myopia prevention and control strategies for schoolchildren at the national level. Sufficient evidence provides an economic and public health reference for further action by governments, policy-makers and other myopia-endemic countries.National Natural Science Foundation of China, NSFC (82171051), Beijing Natural Science Foundation (JQ20029), Capital Health Research and Development of Special (2020-2-1081), National Natural Science Foundation of China, NSFC (82071000), National Natural Science Foundation of China, NSFC (8197030562).
Objective To evaluate the quality of vision after implantation of a Verisyse phakic intraocular lens (PIOL) and laser in situ keratomileusis (LASIK) for correcting high myopia,and to evaluate a rational surgical approach for high myopia.Methods This was a prospective non-randomized control trial.Thirty eyes (30 patients) underwent LASIK and 30 eyes (30 patients) were implanted with Verisyse IOLs.Preoperative spherical equivalents were-15.41 ±4.68 D and-16.94±5.42 D,respectively.Wavefront aberrations were measured using a subjective aberrometer (WFA1000B)preoperatively and 6 months postoperatively.Higher-order aberrations (HOAs) were recorded and compared.Patient satisfaction (photic phenomena,overall satisfaction) was assessed by a subjective questionnaire.The data from the two groups was statistically analyzed by a t or x2 test.Results Six months after surgery,uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) had improved.Postoperative UCVA was equal to or better than preoperative BCVA in 70％(21/30) in the Verisyse group and 43.3％(13/30) in the LASIK group.The difference between the groups was statistically significant (x2=4.34,P＜0.05).3rd to 7th order and total HOAs increased in both groups after surgery,especially in the LASIK group.In the Verisyse group,3rd order aberrations were the predominant postoperative HOA and horizontal coma increased significantly (t=2.12,P＜0.05); in the LASIK group,3rd and 4th order aberrations were the predominant postoperative HOA,and coma and spherical aberrations increased significantly (t=-6.55,-7.37,P＜0.05).Each order and total HOAs in the LASIK group were higher than that in the Verisyse group,and the difference was statistically significant.Patient satisfaction was 60％ in the LASIK group and 83.3％ in the Verisyse group (x2=4.02,P＜0.05).Conclusion PIOL and LASIK surgery were found to be comparatively safe and effective for high myopia.But when quality of vision is taken into account,UCVA was better with PIOL implantation and it resulted in a smaller increase in HOAs and higher patient satisfaction compared to LASIK.Therefore,PIOL implants may be considered as the first choice for high myopia.
Key words:
Myopia,degenerative; Higher-order aberration; Keratomileusis,laser in situ; Phakic intraocular lenses; Iris-fixated
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