The biomechanical properties of 21 white New Zealand rabbits' corneas after Laser in situ keratomileusis (LASIK) were tested by use of one-dimension tensile test and creep test in the INSTRON 5544 mechanical machine. The cornea-related data from the experiments of one-dimension tensile test and creep test for an hour were obtained; a standard linear solid model was adopted to analyse the data, and the least square method was used to fit the viscoelastical coefficients of creep experiment on different corneas. We noticed there was certain difference between the LASIK groups and the normal group in respect to the corneal modulus of elasticity, the stiffness coefficients diminished with the increase of ablation depth; the anti-tensile ability of corneas also displayed some reduction. These findings indicate that the deeper the ablation goes, the easier will be the deformation after LASIK.
Animals ; Biomechanical Phenomena ; Cornea ; physiopathology ; surgery ; Elasticity ; Keratomileusis, Laser In Situ ; methods ; Lasers, Excimer ; therapeutic use ; Rabbits

PURPOSE: To compare changes of anterior corneal aberration (Pentacam(R)) and ocular aberration (aberrometer, LADARWave(R)) after laser refractive surgery. METHODS: Sixty-six eyes underwent laser refractive surgery and were retrospectively reviewed. Anterior corneal aberration and ocular aberration were measured by Pentacam(R) and an aberrometer (LADARWave(R)) respectively. Changes of root mean square (RMS) values of coma, spherical aberration, and total high order aberration (HOA) were evaluated before, 1 month, and 3 months after surgery RESULTS: Ocular aberrations displayed low preoperative values, but after laser refractive surgery, anterior corneal aberration and ocular aberration increased equally. There were no statistically significant differences of internal optics aberration values (ocular aberration minus anterior corneal aberration) in coma, spherical aberration, and total HOA. Anterior corneal aberration and ocular aberration showed statistically significant correlations at 1 and 3 months after surgery. CONCLUSIONS: Internal optics aberration compensated the anterior corneal aberration effectively before surgery, but the increase of anterior corneal aberration after laser refractive surgery exceeded the compensation of internal optics. As a result, anterior corneal aberration and ocular aberration increased equally. The correlation between anterior corneal aberration and ocular aberration after surgery was statistically significant due to the increased proportion of anterior corneal aberration in ocular aberration.
Adult ; Cornea/*physiopathology ; Corneal Topography ; Humans ; Lasers, Excimer/*therapeutic use ; Myopia/surgery ; Photography ; Refraction, Ocular/*physiology ; Refractive Errors/*physiopathology ; *Refractive Surgical Procedures ; Retrospective Studies

Objective: To explore the safety and efficacy of excimer laser coronary angioplasty (ELCA) for the treatment of degenerated great saphenous vein graft (SVG). Methods: This is a single-center, prospective, single-arm study. Patients, who were admitted to the Geriatric Cardiovascular Center of Beijing Anzhen Hospital from January 2022 to June 2022, were consecutively enrolled. Inclusion criteria were recurrent chest pain after coronary artery bypass surgery (CABG), and coronary angiography confirmed that the SVG stenosis was more than 70% but not completely occluded, and interventional treatment for SVG lesions was planned. Before balloon dilation and stent placement, ELCA was used to pretreat the lesions. Optical coherence tomography (OCT) examination was performed and postoperative index of microcirculation resistance (IMR) were assessed after stent implantation. The technique success rate and operation success rate were calculated. The technique success was defined as the successful passage of the ELCA system through the lesion. Operation success was defined as the successful placement of a stent at the lesion. The primary evaluation index of the study was IMR immediately after PCI. Secondary evaluation indexes included thrombolysis in myocardial infarction (TIMI) flow grade, corrected TIMI frame count (cTFC), minimal stent area and stent expansion measured by OCT after PCI, and procedural complications (Ⅳa myocardial infarction, no reflow, perforation). Results: A total of 19 patients aged (66.0±5.6) years were enrolled, including 18 males (94.7%). The age of SVG was 8 (6, 11) years. The length of the lesions was greater than 20 mm, and they were all SVG body lesions. The median stenosis degree was 95% (80%, 99%), and the length of the implanted stent was (41.7±16.3)mm. The operation time was 119 (101, 166) minutes, and the cumulative dose was 2 089 (1 378, 3 011)mGy. The diameter of the laser catheter was 1.4 mm, the maximum energy was 60 mJ, and the maximum frequency was 40 Hz. The technique success and the operation success rate were both 100% (19/19). The IMR after stent implantation was 29.22±5.95. The TIMI flow grade of patients after ELCA and stent implantation was significantly improved (all P>0.05), and the TIMI flow grade of all patients after stent implantation was Grade Ⅲ. The cTFC decreased significantly after ELCA (33.2±7.8) and after stent placement (22.8±7.1) than preoperative level (49.7±13.0) (both P<0.001). The minimum stent area was (5.53±1.36)mm², and the stent expansion rate was (90.0±4.3)%. Perforation, no reflow, type Ⅳa myocardial infarction and other complications were not observed. However, postoperative high-sensitivity troponin level was significantly increased ((67.937±33.839)ng/L vs. (5.316±3.105)ng/L, P<0.001). Conclusion: ELCA is safe and effective in the treatment of SVG lesions and could improve microcirculation and ensure full expansion of stent.
Male ; Humans ; Aged ; Prospective Studies ; Percutaneous Coronary Intervention ; Lasers, Excimer/therapeutic use* ; Saphenous Vein/transplantation* ; Constriction, Pathologic ; Atherectomy, Coronary/methods* ; Myocardial Infarction ; Coronary Angiography ; Stents ; Treatment Outcome

OBJECTIVETo assess the efficacy and safety of the 308 nm excimer laser for the treatment of vitiligo.

METHODSWe treated 170 patients with stable vitiligo by using the 308 nm excimer laser. The lesions of vitiligo were treated one to two times per week for 10-30 times. Efficacies were evaluated every 7 days and 3 days after the treatments were completed. Patients were followed up for two months.

RESULTSThe rates of "remarkably improved" and "cured" were 67.97% and 32.03% in faces, 54.55% and 27.27% in necks, 63.26% and 26.53% in trunks, 38.84% and 15.70% in limbs, and 0 and 0 in hands and feet. The areas of faces had a better response than those of necks, trunks, or limbs (P < 0.01), and the areas of trunks or limbs had better response than that of hands and feet (P < 0.01).

CONCLUSIONThe 308 nm excimer laser is safe and effective in treating stable vitiligo and the efficacy varies in different lesion sites.

Adolescent ; Adult ; Child ; Female ; Humans ; Lasers, Excimer ; therapeutic use ; Low-Level Light Therapy ; instrumentation ; methods ; Male ; Middle Aged ; Risk Assessment ; Treatment Outcome ; Vitiligo ; radiotherapy ; Young Adult

PURPOSE: To determine effectiveness of laser-assisted in situ keratomileusis (LASIK) in the treatment of astigmatism following penetrating keratoplasty (PK). METHODS: We performed a retrospective review of medical records of patients who underwent LASIK following PK and had over 1 year of follow-up data. RESULTS: Twenty-six patients (26 pairs of eyes) underwent LASIK following PK. Mean age of the patients at the time of LASIK was 40.7 years (range, 26 to 72 years). Following LASIK, the mean cylinder was reduced by 2.4 diopters and mean reduction of cylinder after LASIK was 65.4% from the preoperative values at the last follow-up visit. Uncorrected visual acuity became 20 / 50 or better in 69.2% of the eyes after LASIK. Best-corrected visual acuity became 20 / 50 or better in 73.1% of the eyes after LASIK. All of them were intolerable to contact lenses before LASIK. After LASIK, 6 pairs (23.1%) did not need to use contact lenses and 18 pairs (69.2%) were tolerable to using contact lenses or spectacles. There were no significant endothelial cell density changes 12 months after LASIK (p = 0.239). CONCLUSIONS: LASIK is effective in the treatment of astigmatism following PK and increases contact lens and spectacle tolerance.
Adult ; Aged ; Astigmatism/etiology/physiopathology/*surgery ; *Contact Lenses/utilization ; Corneal Topography ; Female ; Humans ; Keratomileusis, Laser In Situ/*methods ; Keratoplasty, Penetrating/*adverse effects ; Lasers, Excimer/*therapeutic use ; Male ; Middle Aged ; Refraction, Ocular/physiology ; Retrospective Studies ; Vision, Binocular/physiology ; Visual Acuity/physiology

PURPOSE: To evaluate the changes of higher order aberrations (HOAs) before and after laser subepithelial keratomileusis (LASEK) and to analyze the influence of tear film instability on HOAs of the corneal surface after LASEK. METHODS: In this cross-sectional study, 31 patients who underwent LASEK were divided into dry eye (16 patients, 32 eyes) and non-dry eye groups (15 patients, 30 eyes). Uncorrected distance visual acuity, spherical equivalent refraction, ablation depth, tear film parameters and Ocular Surface Disease Index (OSDI) questionnaire scores were evaluated in both groups. Total HOA root mean square (RMS), third-order coma, third-order trefoil and fourth-order spherical aberration (SA) of the corneal surface immediately and at 10 seconds after blinking were measured before and after surgery. RESULTS: The total HOA RMS, coma, trefoil and SA significantly increased after LASEK compared with preoperative values in both groups. In the dry eye group, total HOA RMS, coma and trefoil significantly increased except for SA at 10 seconds after blinking compared with those measured immediately after blinking. In addition, the changes of total HOA RMS, coma and trefoil were negatively correlated with tear film break-up time (R = -0.420, -0.473 and -0.439, respectively), but positively correlated with OSDI score (R = 0.433, 0.499 and 0.532, respectively). In the non-dry eye group, there were no significant differences between HOAs measured at 10 seconds after blinking and those measured immediately after blinking. CONCLUSIONS: The HOAs including coma, trefoil and SA significantly increased after LASEK. The tear film instability in the dry eye can be associated with more deterioration of the optical quality after LASEK, due to more significant increase of total HOA RMS, coma and trefoil.
Adult ; Cornea/*physiopathology ; Corneal Wavefront Aberration/*etiology/physiopathology ; Cross-Sectional Studies ; Dry Eye Syndromes/*physiopathology ; Female ; Humans ; Keratectomy, Subepithelial, Laser-Assisted/*adverse effects ; Lasers, Excimer/*therapeutic use ; Male ; Surveys and Questionnaires ; Tears/*physiology ; Visual Acuity/physiology ; Young Adult

OBJECTIVE: To evaluate the efficacy and influential factors for 308 nm excimer laser in the treatment of stable vitiligo patients.
 METHODS: A total of 207 stable vitiligo patients with 1 763 patches were treated with 308 nm excimer laser. Open-label study was carried out to investigate the efficacy and safety regarding the treatment with 308 nm excimer laser, and to compare the response under different conditions including gender, age, duration, lesion location, and hair color.
 RESULTS: After treatment, 560 (31.8%) patches achieved 100% repigmentation, 650 (36.9%) lesions showed 75%-99% repigmentation, 189(10.7%) showed 50%-75% repigmentation, 231(13.1%) showed 25%-49% repigmentation, 108(6.1%) showed 1%-24% repigmentation, 25(1.4%) displayed no response. The rates of total excellent response (50%-100% repigmentation) in underage patients was 86.9%, much higher than that in adult patients (P<0.001). Total excellent response rates was 90.6% in disease duration <2 years, and 40.7% in disease duration ≥2 years. Lesions on the faciocervical region responded better than trunk and limbs, showing 95.4%, 70.3%, and 41.7% total excellent response, respectively. Patients with poliosis showed 54.9% in total excellent response rate, much lower than 84.5% in patients without poliosis(P<0.001). No significant response differences in gender were found.
 CONCLUSION 308 nm excimer laser is effective and safe in treatment of vitiligo. Aging, disease duration, lesion location, and hair color in lesion may be the influential factors for 308 nm excimer laser in treatment of vitiligo patients.
Adolescent ; Adult ; Age Factors ; Extremities ; pathology ; radiation effects ; Face ; pathology ; radiation effects ; Female ; Hair Color ; Humans ; Lasers, Excimer ; therapeutic use ; Male ; Skin Pigmentation ; radiation effects ; Torso ; pathology ; radiation effects ; Treatment Outcome ; Vitiligo ; therapy

This research focuses on four cases of patients having undergone eximer laser photorefractive surgery who were diagnosed with adenoviral keratoconjunctivitis during the postoperative period and who later developed epidemic keratoconjunctivitis (EKC)-like keratitis. Two of the patients had undergone laser-assisted subepithelial keratectomy (LASEK), one had undergone laser in situ keratomileusis and one had photorefractive keratectomy. After the surgery adenoviral keratoconjunctivitis and recurrent late-developing EKC-like keratitis were observed in the patients. Recurrent late-developing EKC-like keratitis occurred in one of the patients, who had received LASEK as many as three times. The others had only one or two episodes.The corneal infiltrates of keratitis mainly occurred in the central cornea. Successful resolution of recurrent late-developing EKC-like keratitis was achieved through the use of topical steroids without sequelae and the final best-corrected visual acuity was as good as the base line. These keratitis infiltrates have been presumed to represent an immune response to the suspected adenoviral antigens deposited in corneal stroma during the primary adenoviral infection. Previous reports argued that patients with a history of adenoviral ketatoconjunctivitis were succeptible to adenoviral keratoconjunctivitis becoming reactivated; however, in our research, our patients had their first adenoviral infections after the eximer laser photorefractive surgery and reactivation was confirmed. We recommend that attention be paid to adenoviral infection after laser refractive operations, because these patients seem to have more frequent recurrences.
Adenovirus Infections, Human/diagnosis/drug therapy/*etiology ; Adult ; Conjunctivitis, Viral/diagnosis/drug therapy/*etiology ; *Corneal Surgery, Laser ; Eye Infections, Viral/diagnosis/drug therapy/*etiology ; Female ; Glucocorticoids/therapeutic use ; Humans ; Keratectomy, Subepithelial, Laser-Assisted ; Keratitis/diagnosis/drug therapy/*etiology ; Keratomileusis, Laser In Situ ; Lasers, Excimer/therapeutic use ; Photorefractive Keratectomy ; *Postoperative Complications ; Recurrence ; Young Adult