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ABSTRACT Purpose: This study aimed to report an experiment designed to determine anatomical changes in porcine corneas following placement of a novel polymer implant into the cornea. Methods: An ex vivo porcine eye model was used. A novel type I collagen-based vitrigel implant (6 mm in diameter) was shaped with an excimer laser on the posterior surface to create three planoconcave shapes. Implants were inserted into a manually dissected stromal pocket at a depth of approximately 200 μm. Three treatment groups were defined: group A (n=3), maximal ablation depth 70 μm; Group B (n=3), maximal ablation depth 64 μm; and group C (n=3), maximal ablation depth 104 μm, with a central hole. A control group (D, n=3) was included, in which a stromal pocket was created but biomaterial was not inserted. Eyes were evaluated by optical coherence tomography (OCT) and corneal tomography. Results: Corneal tomography showed a trend for a decreased mean keratometry in all four groups. Optical coherence tomography showed corneas with implants placed within the anterior stroma and visible flattening, whereas the corneas in the control group did not qualitatively change shape. Conclusions: The novel planoconcave biomaterial implant described herein could reshape the cornea in an ex vivo model, resulting in the flattening of the cornea. Further studies are needed using in vivo animal models to confirm such findings.
RESUMO Objetivo: Relatar um experimento projetado para determinar alterações anatômicas em córneas porcinas após a colocação de um novo implante de polímero na córnea. Métodos: Foi utilizado olho de porco ex vivo. Um novo agente modelador biocompatível, de colágeno tipo 1, com 6mm de diâmetro foi moldado com excimer laser em sua face posterior, para criar três formatos planocôncavos. Os implantes foram inseridos dentro de um bolsão, dissecado manualmente, a 200 micrômetros (μm). Foram definidos três grupos de tratamento: grupo A (n=3), teve a profundidade máxima de ablação de 70 μm; o grupo B (n=3), profundidade máxima de ablação de 64 μm; e o grupo C (n=3), profundidade máxima de ablação de 104 μm, com buraco central. O grupo controle, D (n=3), foi incluído, com a criação do bolsão estromal, porém sem inserir o material. A avaliação desses olhos foi realizada por tomografia de coerência óptica (OCT) e por tomografia corneana. Resultados: A tomografia corneana mostrou uma tendência para diminuição da ceratometria média em todos os 4 grupos. A tomografia de coerência óptica mostrou córneas com implantes localizados no estroma anterior e aplanamento visível, enquanto as córneas não mudaram qualitativamente o formato no grupo controle. Conclusões: O novo implante de biomaterial planocôncavo descrito aqui foi capaz de remodelar a córnea em modelo de animal ex vivo, resultando no aplanamento corneano. Novos estudos são necessários usando modelos animais in vivo para confirmar tais achados.
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RESUMO O FemtoLasik é uma das técnicas mais empregadas em cirurgia refrativa, por seus bons resultados refracionais, sua previsibilidade, sua reprodutibilidade e sua segurança. Tem alto grau de satisfação, com rápida recuperação visual. Apesar de as taxas de complicações do FemtoLasik serem pequenas, intercorrências podem existir. O objetivo deste trabalho foi relatar um caso de uma complicação na dissecção da lamela por Lasik com laser de femtossegundo com consequente rasgadura da lamela, sendo aplicado Excimer Laser com mitomicina C 0,02%. O retratamento foi realizado com ablação de superfície (ceratectomia fotorrefrativa) guiada por frente de onda, evoluindo com boa qualidade visual final.
ABSTRACT Femtolasik is one of the most used techniques in refractive surgery due to good refractive results, predictability, reproducibility, and safety, achieving excellent results and a high degree of satisfaction. Although the complication rates are small, it is worth noting that there may be intercurrences. The objective of this work is to report a case of complication in the dissection of the lamella of laser in situ keratomileusis (Lasik) with Femtosecond laser, and subsequent lamella tear. Excimer Laser was applied with mitomycin 0.02% and re-approached with wavefront guided surgery, evolving with good final visual quality.
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A aterectomia coronária com Excimer Laser melhorou significativamente nos últimos anos, utilizando emissão ultravioleta de alta energia e comprimento de onda curto, com menor penetração e menor emissão de calor, resultando em menos danos aos tecidos e menos complicações. Descrevemos o caso de um paciente do sexo masculino, 66 anos, ex-tabagista, hipertenso, diabético, dislipidêmico. Foi submetido a múltiplas intervenções coronárias percutâneas na artéria descendente anterior com stents não farmacológicos e farmacológicos. Na última intervenção coronária percutânea, o stent foi subexpandido, e o paciente apresentou trombose aguda do stent e reestenose recorrente do stent. Foram realizadas novas intervenções coronárias percutâneas com aterectomia coronária com Excimer Laser adjuvante, devido à angina refratária, com uso de carga progressiva e injeção de soro fisiológico, seguidas de posterior insuflação de balão de alta pressão e implante de stent farmacológico, com resultado excelente. No acompanhamento de 8 meses, o paciente se manteve assintomático.
Excimer Laser coronary atherectomy has improved significantly in recent years, emitting high-energy ultraviolet and short wavelength with less penetration and heat emission, ultimately leading to less tissue damage and fewer complications. We described a case of a 66-year-old male patient, former smoker and suffering from hypertension, diabetes mellitus, and dyslipidemia. He underwent multiple percutaneous coronary interventions in the left anterior descending artery with bare metal and drug-eluting stents. In the last percutaneous coronary intervention, the stent was underexpanded and the patient presented acute stent thrombosis and recurrent stent restenosis. New percutaneous coronary interventions with adjunctive Excimer Laser coronary atherectomy were undertaken due to refractory angina, using progressive load and saline injection, followed by subsequent high-pressure balloon inflation and drug-eluting stent implantation with an excellent result. At 8-month follow-up, the patient was asymptomatic.
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Objective:To explore the clinical efficacy of excimer laser atherectomy (ELA) in the treatment of diabetic foot with infrapopliteal arteriopathy.Methods:The clinical data of 36 patients (40 limbs) with diabetic foot complicated with inferior knee artery disease treated by ELA in Xinjiang Uygur Autonomous Region People′s Hospital from December 2019 to May 2021 were analyzed retrospectively. The success rate of ELA in the treatment of diabetic inferior genicular artery disease, ankle-brachial index (ABI), limb salvage rate and Visual Analogue Scale (VAS) score at 3 days and 3 and 6 months after operation was observed.Results:All the 36 patients were operated successfully, including 2 cases of flow-limiting dissection, 2 cases of arterial embolism and 1 case of hematoma at the puncture point. The ABI of patients 3, 6 months after operation was significantly higher than that before operation (all P<0.05), and the VAS score 3, 6 months after operation was significantly lower than that before operation (all P<0.05). The rate of limb (toe) salvage were 92.5%(37/40), 82.5%(33/40) at 3 d, 3 months and 77.5%(31/40) at 6 months after operation. Conclusions:ELA is safe and effective in the treatment of diabetic foot infrapopliteal arteriopathy, and the recent efficacy is fair.
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Objective:To compare the accuracy and stability between corneal topography-guided femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) and small incision lenticule extraction (SMILE) for myopic astigmatism by vector analysis.Methods:A non-randomized controlled clinical trial was performed.One hundred and twenty patients (214 eyes) with myopic astigmatism who underwent the FS-LASIK or SMILE in Henan Eye Hospital from January 2020 to July 2020 were enrolled.The patients were divided into FS-LASIK group (58 cases, 105 eyes) and SMILE group (62 cases, 109 eyes) according to different surgeries.The visual acuity, refraction, intraocular pressure and corneal topography were examined before and 1 week, 1 month and 3 months after operation.The results of vector analysis between the two groups were compared, including target induced astigmatism vector (TIA), surgically induced astigmatism vector (SIA), magnitude of error (ME), angle of error (|AE|), difference vector (|DV|), correction index (CI), and index of success (IOS) 3 months after operation.This study protocol adhered to the Declaration of Helsinki and was approved by an Ethics Committee of Henan Eye Hospital (No.HNEECKY-2020[25]). Written informed consent was obtained from each patient before operation.Results:Three months after surgery, no astigmatism was found in 11 eyes (10.5%), and with the rule (WTR) astigmatism was in 23 eyes (21.9%), and against the rule (ATR) and oblique astigmatism were in 71 eyes (67.6%) in FS-LASIK group.In SMILE group, no astigmatism was detected in 35 eyes (32.1%), and WTR astigmatism was in 58 eyes (53.2%), and ATR and oblique astigmatism were in 16 eyes (14.7%), showing a statistically significant difference between them ( χ2 =48.20, P<0.05). The postoperative SIA, |AE|, |DV|, CI and IOS values in the SMILE group were lower than those in the FS-LASIK group, showing statistically significant differences between them (all at P<0.05). The ME was -0.20 (-0.37, 0.00)D in FS-LASIK group and 0.20 (0.00, 0.25)D in SMILE group.Within 3 months after operation, there was no significant difference in ME among different time points in the FS-LASIK group (all at P>0.05) and in spherical equivalent (SE) among different time points in the SMILE group (all at P>0.05). There was significant difference in the results of vector analysis among different time points in the two groups (all at P<0.05). Conclusions:Both FS-LASIK and SMILE are effective in the correction of myopic astigmatism.Astigmatism is slightly overcorrected by FS-LASIK and slightly undercorrected by SMILE.The axial error is smaller and the SE is more stable after SMILE within 3 months postoperatively.
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As a relatively new procedure, femtosecond laser small incision lenticule extraction (SMIIE) is still in its initial stage.Despite the safety, efficacy, predictability and stability it has showed in refractive error correction, there are still reports of intraoperative complications resulting in different clinical outcomes in SMILE.SMILE includes the production of lenticule by femtosecond laser, the separation and extraction of lenticule, and intraoperative complications may occur in every step.The production of the lenticule is completely dependent on the femtosecond laser, so complications related to femtosecond lasers are inevitable, such as suction loss, opaque bubble layer and black spots.Separation and extraction of the lenticule relies on the experience and surgical skills of surgeon, during which, torn corneal cap, difficult lenticule extraction, lenticule remnants, bleeding and lenticule decentration may occur.In this article, the categories, reasons, management and effects of intraoperative complications on outcome in SMILE were summarized to improve the ability of ophthalmologists to handle intraoperative incidents and enhance surgical safety.
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Objective:To evaluate the effectiveness and safety of transepithelial photorefractive keratectomy (TransPRK) assisted by smart pluse technology (SPT) for the correction of high myopia.Methods:An observational case series study was conducted.Sixty high myopic patients (107 eyes) with spherical equivalent (SE)≥-6.0 D who received TransPRK assisted by SPT from January to December 2016 in Eye Hospital of Wenzhou Medical University were enrolled.Uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) of the patients were examined and recorded in logarithm of the minimum angle of resolution (LogMAR) units, and refraction was examined with a subjective refractometer.The healing of corneal epithelium and corneal haze was observed with a slit lamp.Intraocular pressure (IOP) was measured with the non-contact tonometer.Safety index (SI) and efficacy index (EI) were analyzed.The follow-up time was 12 months.This study protocol adhered to the Declaration of Helsinki and was approved by an Ethics Committee of Eye Hospital of Wenzhou Medical University (No.2019-197-k-177). Written informed consent was obtained from each patient prior to any medical examination.Results:The mean epithelial healing time was (3.77±1.02) days.There were statistically significant differences in UCVA and BCVA between before and after surgery ( Z=380.812, 267.313; both at P<0.001). And the 7-day, 6-month, and 12-month postoperative BCVA were better than preoperative BCVA, showing statistically significant differences (all at P<0.05). Mean SI was 1.10±0.12, and mean EI was 1.05±0.17 at 12 months after surgery.There was no significant difference between the attempted SE before surgery (-8.02±1.36)D and the achieved SE at 12 months after surgery (-8.04±1.51)D ( P=0.523). SE in the predictive range within ±0.50 D accounted for 79% (85/107) and that within ±1.0 D accounted for 92% (98/107). The IOP was slightly increased in 3 eyes at 7 days and 7 eyes at 1 month after surgery, respectively, which returned to normal after the use of ophthalmic solution for lowing IOP.The incidence of haze severer than grade 1 was less than 1% (1 eye), and haze gradually disappeared after application of drugs. Conclusions:TransPRK assisted by SPT for high myopia shows good safety, effectiveness and predictability.It is an ideal corneal surface surgery to correct high myopia.
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Objective@#To evaluate the efficacy of compound Qinjiao Pill in the treatment of pustulosis palmaris and plantaris and the effect on the neutrophil-to-lymphocyte ratio (NLR).@*Methods@#A total of 100 patients with palmoplantar pustulosis who met the inclusion criteria from June 2017 to June 2018 were randomly divided into two groups, 50 in each group. The control group was treated with 308 nm excimer laser twice a week, and the treatment group was treated with one compound Qinjiao Pill once and twice a day. Both groups were treated for 8 weeks and followed up for 3 months. The disease severity was evaluated by the Palmoplantar pustulosis area and severity index (PPPASI), the quality of life was evaluated by the dermatology life quality index (DLQI), the changes of serum NLR were observed, and the clinical efficacy was evaluated.@*Results@#The total effective rate was 88.0% (44/50) in the treatment group and 70.0% (35/50) in the control group. The PPPASI scores (t=6.813, 3.091, 3.582, 5.622) and DLQI scores (t=5.713, 4.616, 6.262, 1.824) in the treatment group were significantly lower than those in the control group (P<0.01). After treatment, NEU (4.13 ± 1.42 ×109/L vs. 6.56 ± 1.65 ×109/L, t=7.893), NLR (1.75 ± 0.98 vs. 2.60 ± 0.87, t=4.592). During the treatment, the incidence of adverse reactions was 20.0% (10/50) in the treatment group and 18.0% (9/50) in the control group (χ2=1.680, P=0.089). The recurrence rate of the treatment group was 9.1% (4/44) and that of the control group was 20.0% (7/35). The difference between the two groups was statistically significant (χ2=2.893, P=0.003).@*Conclusions@#Compound Qinjiao Pill combined with 308 nm excimer laser can reduce the NLR in peripheral blood, improve the clinical efficacy and reduce the risk of recurrence.
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Laser corneal refractive surgery is currently the most mainstream surgery to correct refractive errors.In recent years,the laser corneal refractive surgery has been developed rapidly in China.Femtosecond laser small incision lenticule extraction (SMILE) and the femtosecond laser flap laser in situ keratomileusis (LASIK) are greatly improving the safety of the laser lamellar corneal refractive surgery,and trans-epithelial photorefractive keratectomy (Trans PRK) is also taking the surface ablation of excimer laser to a new level.Compared with traditional excimer laser corneal refractive surgery,the above methods are more safe,stable and reliable.Trans PRK,SMILE and femtosecond flap LASIK combined with riboflavin corneal cross-linking provides a safe guarantee for the myopicpatients with thin cornea and abnormal corneal topography.As rapid progress and upgrading of laser corneal refractive surgery technologies,selection of operation methods is a new challenge.Ophthalmologists should comprehensively evaluate the corneal anatomical characteristics,individual needs of patients,performance of operating equipment andindications of different surgeries to pay more attention to the precise and personalized selection of laser corneal refractive surgery to improve the postoperative visual quality of patients with ametropia.
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Requirements for cataract surgery have gradually increased from the original rehabilitation procedure to personalized refraction surgery.Femtosecond laser-assisted cataract surgery is being widely used because of its precision of incision,accuracy of capsule cutting and high efficiency of nuclear fracturing in recent year.Currently some operating systems of femtosecond laser-assisted cataract surgery include LenSx,Catalys,LenSAR and Victus,and they are different in the design of contact interfaces,video and operating bed and therefore present different working methods.Ophthalmologists should be aware of the differences of these operating systems and accurate assess the clinical findings of patients in order to consider the preciseness,accuracy,efficiency of incision,capsulorhexis and nucleus fragmentation to avoid the intraoperative and postoperative complications.
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Objective To investigate the efficacy and safety of 308-nm excimer laser compared to high-intensity ultraviolet radiation for the treatment of active localized vitiligo,and to observe changes in skin lesions before and after the treatment by confocal laser scanning microscopy.Methods Sixty patients with 203 skin lesions of active localized vitiligo and were enrolled into this study,and the vitiligo disease activity (VIDA) score of these patients ranged from 2 to 3.We selected more than 3 skin lesions from a same anatomical site of each patient,one of lesions served as a control and the other skin lesions (≥ 2) were randomly treated with 308-nm excimer laser (laser group) or high-intensity ultraviolet radiation (ultraviolet group).The treatment was conducted twice a week for 25 sessions,and a 3-month follow-up was performed.Results A total of 48 patients with 169 skin lesions completed the trial.The marked response rate was significantly higher in the laser group [66.15％ (43/65)] than in the ultraviolet group [44.64％ (25/56),x2 =8.28,P ＜ 0.01].The patients with a VIDA score of 2 showed a significantly higher marked response rate [67.69％(44/65)] compared with those with a VIDA score of 3 [44.64％(25/56),x2 =6.80,P ＜ 0.01].During the 3-month follow-up,no relapse was observed.Confocal laser scanning microscopy showed that the number of inflammatory cells increased at the dermal-epidermal junction of the intra-and extra-marginal lesional skin.After treatment,the number of inflammatory cells markedly decreased and returned to normal level in lesions.Conclusion Both 308-nm excimer laser and high-intensity ultraviolet radiation are effective in the treatment of active localized vitiligo,but the 308-nm excimer laser shows a more rapid onset of action and a better therapeutic effect.
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RESUMEN El auge de la cirugía refractiva con excimer láser en las últimas dos décadas se ha reflejado en que un grupo creciente de pacientes con antecedente de este procedimiento necesitan ahora cirugía de catarata. Debido a las modificaciones generadas en la córnea por la fotoablación con el láser, la determinación del poder corneal necesario para el cálculo del poder del lente intraocular a implantar en la cirugía de catarata, es difícil. Teniendo en cuenta estos aspectos se hace una revisión de las causas de estos errores de medición y los abordajes existentes para minimizar su impacto. MÉD.UIS. 2017;30(1):99-105.
ABSTRACT The rise of excimer laser refractive surgery in the last two decades has been reflected in a growing group of patients with a history of this procedure who now need cataract surgery. Because the generated modifications to the cornea with the laser photoablation, determining the corneal power, necessary for calculating the power of the intraocular lens to be implanted during the cataract surgery, is difficult. We review the causes of these errors of measurement and existing approaches to minimize its impact. MÉD.UIS. 2017;30(1):99-105.
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Humans , Lasers, Excimer , Cataract , Photorefractive Keratectomy , Cornea , Corneal Topography , Multifocal Intraocular LensesABSTRACT
Background Recently,small incision lenticule extraction (SMILE) procedure is used to correct myopia.The clinical safety and efficiency of SMILE have been approved,but its predictability to corneal ablation depth is brought into focus.Objective This study was to compare the predictability of ablation depth in central cornea between SMILE and femtosecond laser-assisted in situ keratomileusis (FS-LASIK) for myopia.Methods A nonrandomized controlled clinical study was performed.Two hundred and seventy eyes of 135 myopic patients who were going to receive corneal refractive surgery were included in Beijing Tongren Hospital from October 2015 to May 2016.SMILE and FS-LASIK were performed on 138 eyes of 69 patients and 132 eyes of 66 patients matched in demography respectively under the informed consent.Central corneal thickness was measured by RTVue FD-OCT before and 1 week after surgery.The refractive power,actual ablation depth (difference of central corneal thickness before and after surgery) and central corneal cutting error (difference between theoretically expected ablation depth and real ablation depth) were intergrouply compared,and the correlation of real ablation depth with theoretically expected ablation depth was assessed.Results No significant difference was found in spherical power,astigmatic power and spherical equivalent after surgery between SMILE group and FS-LASIK group (t =-1.826,-1.405,-1.420,all at P＞0.05).The actual ablation depth was (76.96± 15.27)μm in the SMILE group,which was significant lower than (96.76± 16.52) μm of theoretically expected ablation depth (t =-23.016,P ＜ 0.01);however,there was no significant difference in the FS-LASIK group between actual and expected ablation depth ([77.92 ± 18.69] μm versus [77.42± 15.60] μm) (t =-0.604,P =0.547).The central corneal cutting error was (20.55 ± 8.51) μm in the SMILE group and (7.17±5.97) μm in the FS-LASIK group,showing a significant difference between them (t=14.950,P＜0.01).The positive linear correlations were seen between actual and expected ablation depth in both SMILE group and FS-LASIK group (r=0.799,0.867,both at P＜0.01).The actual ablation depth was increased over expected ablation depth,with the regression equations of Y=3.892+0.749X in the SMILE group and Y=3.443 + 0.957X in the FS-LASIK group.Conclusions The actual corneal ablation depth is less than expected corneal ablation depth in SMILE procedure,while in FS-LASIK procedure,the actual corneal ablation depth appears to be consistent with the expected one,inferring a good predictability in corneal ablation depth in FS-LASIK surgery.
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In recent years,corneal refractive surgery continues to develop with becoming to be one of the most prevalent utilizations of correction of many patients and brings about better visual quality for ametropic patients.Meanwhile,some patients are subjected to optical complications,and poor night vision is one of the most serious problems which are complained by sufferers after refractive surgery,such as glare,halo and reduce of contrast sensitivity,and the affective factors include age,pupil diameter,high order aberation,scattering,pre-estimated diopter,corneal healing,individual sensitivity to surgery,which are supposed to attract the attention of the majority of clinicians and researchers,at the same time.Ophthalmic clinical doctors and researchers only fully understand the mechanism of the above factors and explore the corresponding measures in order to purposefully treat these complications.In addition,ophthalmologists should be aware of the interaction of these factors and their relationship with individual sensitivity and explore the impact of postoperative visual impairment and the way to avoid them in clinical practice inorder to improve the visual quality by controlling the postoperative optical complications.
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Background The current evaluation of corneal optical quality after small incision lenticule extraction (SMILE) is based on the single factor,such as scattering,diffraction or aberration,and all of them are not comprehensive and objective methods.Modulation transfer function (MTF) and Strehl ratio (ST) are novel parameters of corneal optical quality,which can be used to assess the optical quality comprehensively.Objective This study was to evaluate the change of MTF and SR under the photopic and scotopic environment (3 mm and 6 mm pupil size,respectively) after SMILE procedure.Methods The study protocol was approved by Ethic Committee of Tianjin Eye Hospital,and written informed consent was obtained from each patient before any medical procedure.A series cases-observational study with self-control design was carried out.Sixty-three eyes of 32 myopia or myopic astigmatism patients who underwent SMILE surgery in Tianjin Eye Hospital were included from December 2013 to March 2014.The uncorrected visual acuity (UCVA),best corrected visual acuity (BCVA) (LogMAR),the effective index (postoperative UCVA/preoperative BCVA) and refractive diopter were examined,and the MTF,SR and root mean square (RMS) on the anterior corneal surface were measured under the 3 mm and 6 mm pupil size at different spatial frequencies (10,20,30,40,50 and 60 c/d) by Sirius anterior analyzer before surgery and 1 week,1 month and 3 months after surgery,respectively.Results UCVA was ≥0.8 in 59,62 and 63 eyes in 1 week,1 month and 3 months after SMILE,with the percentage of 93.65％,98.41％ and 100％,and the effective index was 1.104± 0.128,1.126±0.145 and 1.158±0.208,respectively.The refractive diopter was normal in the eyes at postoperative 3 months.The MTFs of various spatial frequencies on the vertical and horizontal meridian under the 3 mm pupil size after SMILE were significantly higher than those before SMILE,while under the 6 mm pupil size,the MTFs were higher only on vertical meridian and 10,20,30 and 40 e/d,and there were not significant differences on the horizontal meridian (all at P＜0.05).The SRs under the 3 mm and 6 mm pupil size showed increasing softly after surgery in comparison with before surgery,and the SRs were higher under the 3 mm pupil size than those under the 6 mm pupil size at various time points (all at P＜0.05).There were not significant differences in RMS among different time points under both 3 mm pupil size and 6 mm pupil size (3 mm pupil size:F =1.348,P =0.184;6 mm pupil size:F=1.990,P=0.137).Conclusions SMILE provides a great improvement in corneal optical quality for myopia or myopic astigmatism patients,which is more distinct in photopic condition than that in scotopic condition.
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Background Corneal reinnervation of subbasal nerve plexus have been found after small incision lenticule extraction(SMILE).However,there were few reports about corneal reinnervation mode and dynamic changes at the corneal cap in different time points postoperation.Objective The aim of this study was to evaluate the corneal reinnervation at the cap margin after SMILE.Methods The clinical data of 32 myopic eyes of 16 patients who received SMILE incision lenticule extraction surgery in Affiliated Eye Hospital of Shandong Medical College from April 2014 to April 2015 were retrospectively analyzed.The following-up was carried in 1 week,1 month,3 months and 6 months after surgery,and in-vivo confocal microscopy was used to acquire images of the central corneal subbasal nerve plexus before and after surgery,with the scan range of 0.4 mm×0.4 mm,from which nerve density and nerve tortuosity were evaluated using Image-Pro Plus imaging analysis software.The overall length of nerve fibers at the central cornea was measured to assess the subbasal nerve density,and the repair of nerve fibers at cap was observed.Results The corneal subbasal nerve density was (19 687.45 ± 1 147.59),(10 500.46 ± 1 056.22),(12 833.40-± 1 047.98),(13 564.04-± 1 173.01) and (14 661.35-±941.92) μm/mm2 in preoperation and postoperative 1 week,1 month,3 months,6 months,respectively,with a significant difference among different time points (F =319.44,P=0.000),and the corneal subbasal nerve densitis in postoperative time points were significantly reduced in comparison with the preoperation,and corneal subbasal nerve densities were gradually increased after surgery as the extending of time,showing significant differences between different time points (all at P＜ 0.01).Abundant corneal subbasal nerve fibers were seen with the near normal morphology after surgery.However,the fragments and disaggregation of nerve fibers were found at the incision of cap margins,and some nerve fibers extended toward the inner cap at the non-incision of cap margins 1 week after surgery.In 3-6 months after SMILE,the continuous extension of nerve fibers was exhibited under the confocal microscope.Conclusions Six months after surgery,less invasive SMILE technique can remain the superficial corneal nerve fibers.Corneal innervation shows a radiate mode from peripheral cornea outside toward inside of the cap.The subbasal never fiber density is gradually increased with the extending of time after SMILE.
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Background Laser in situ keratomileusis (LASIK) for myopia and/or myopic astigmatism still is one of primary surgeries.Femtosecond laser (FS)-LASIK offers several advantages over microkeratomes for flap creation including better safety,reproducibility,and predictability.However,the visual performance after FS-LASIK is of high clinical concern.Objective This study was to compare the visual performance between Intralase FS60 femtosecond laser flap and mechanical microkeratome Moria M2 flap in LASIK.Methods A prospective nonrandomized controlled study was performed.Two hundred and four myopic eyes of 102 patients were enrolled in this study and divided into two groups according to patients’ opinion,with matched demography between the two groups.LASIK with FS60 femtosecond laser flap was performed on 100 eyes of 50 myopia and/or myopic astigmatism in the FS group,and Moria M2 flap LASIK was performed on 104 eyes of 52 patients in the microkeratomes group.Zernike coefficients and the root-mean-square (RMS) of higher order aberrations were measured by Wavescan wavefront aberrometer before and 3,6 and 12 months after surgery,and the contrast sensitivity (CS) in different spatial frequencies under the scotopia and scotopia + glare background was detected using Optec 6500 visual function instrument before and 3,6,12 months after surgery.This study protocol was approved by Ethic Committec of Beijing Tongren Hospital,and written informed consent was obtained from each patient prior to surgery.Results The uncorrected visual acuity (UCVA) levels after surgery reached or was superior to the preoperative best corrected visual acuity (BCVA) in 95.1％,94.2％ and 93.9％ patients in the FS group and in 94.2％,93.8％ and 93.2％ patients in the microkeratomes group 3,6,12 months after surgery,respectively.The mean spherical equivalent (SE) was (-6.37 ±2.06)D,(-0.26±0.45)D and (-0.45± 0.51)) in the FS group,(-6.25± 2.43) D,(-0.44± 0.64) D and (-0.35±0.59)D in the microkeratomes group before surgery and 3,12 months after surgery,respectively.There were no significant differences in the SE in various time points between the two groups (u =1.194,1.429;both at P＞ 0.05).The root means square high order (RMSh) and RMS3-6 in the FS group were significantly lower than those in the microkeratomes group 3,6 and 12 months after surgery (all at P＜0.05).Under the background of scotopia or scotopia+glare,the LogCS values under different spatial frequencies were significantly higher in the FS group than those in the microkeratomes group 3 and 6 months after surgery (all at P＜0.05).In 12 months after surgery,no significant difference was found in the LogCS under the 1.5 c/d in the background of scotopia between FS group and microkeratomes group (P＞0.05),and the LogCS values under the 12.0 c/d and 18.0 c/d in the background of scotopia or scotopia+glare in the FS group were better than those in the microkeratomes group (all at P＜0.05).Conclusions Femtosecond laser assistant LASIK has better visual performance and lower higher-order aberrations than microkeratomes assistant LASIK.
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Background Keratectasia after laser in situ keratomileusis (LASIK) is a rare but severe complication,which threatens the visual acuity and corneal strength.Corneal collagen crosslinking (CXL) is a new therapy that increases the security and decreases the risk of complication.However,the effectiveness and safety of LASIK-CXL is still need to be concerned.Objective This study was to evaluate the safety of LASIK-CXL for myopia and astigmatism with thin cornea.Methods A prospective cohort study was designed.A total of 128 eyes of 64 patients with thin corneal and myopic astigmatism enrolled in Beijing Tongren Eye Center from January 2014 to January 2015.The patients were assigned to LASIK group (74 eyes of 37 patients) and LASIK-CXL group (54 eyes of 27 patients).Refractive surgery was performed by Visumax femtosecond lasrer and VISX S4 excimer laser.Eyes of LASIK-CXL group applied accelerated CXL immediately after LASIK.The follow-up was 6 months.Manifest refraction,uncorrected (UDVA) and corrected distance visual acuity (CDVA),average keratometry values (AveK),anterior segment OCT (AS-OCT),corneal hysteresis (CH) and corneal resistance factor (CRF) were examined before and after operation.This research passed through Ethics Committee of Beijing Tongren Hospital.Results The spherical equivalent (SE) of the LASIK group and LASIK-CXL group were (-6.49 ±2.41)D and (-6.97 ±2.41) D before operation and decreased to (-0.68 ±0.88) D and (-0.75 ±0.94) D 6 months after operation.The UDVA (LogMAR) was 1.18±0.28 and 1.05±0.38 before operation and elevated to-0.06±0.09 and-0.03±0.186 months after operation in the LASIK group and LASIK-CXL group.The preoperative AveK values were (44.37 ±1.46) D and (44.47± 1.50)D in the LASIK group and LASIK-CXL group and reduced to postoperative (39.30±2.06) D and (38.66± 1.80) D.The preoperative SRI of LASIK group and LASIK-CXL group were 0.25 ±0.21 and 0.24±0.22,which increased to 0.29±0.24 and 0.28±0.24.The SAI values were 0.36±0.16 and 0.39±0.15 before operation,which increased to 0.57 ±0.31 and 0.75 ±0.376 months after operation,and the SAI value of the LASIK-CXL group was significantly higher than that of LASIK (F =10.220,P--0.002).CRF values of LASIK and LASIK-CXL were (8.44±1.44)mmHg and (8.63±1.35) mmHg in preoperation,which decreased to (5.74±1.31) mmHg and (6.25± 1.24) mmHg in postoperation.The result of LASIK-CXL was higher than that of LASIK (F=8.650,P =0.040).CH values were 8.78 ± 1.51 and 8.69 ± 1.62 in preoperation,which decreased to (7.23 ± 1.08) mmHg and (6.50±1.32)mmHg.The value of LASIK-CXL was lower than that of LASIK (F =5.860,P =0.017).The mean depth of demarcation line was (228.45±28.24) μm (range 165 to 310 μm) on OCT,which was presented in 45 eyes (81.82％) at 1 month in postoperation.Conclusions Accelerated CXL with FS-LASIK is effective and safe in improving visual acuity in myopic astigmatism patients with thin cornea,which also can increase the rigidity of the cornea.
ABSTRACT
Safety,efficacy and predictability of corneal refractive surgery have greatly improved as the advancement of the operating technology and equipment.Laser corneal refractive surgeries include excimer laser photorefractive keratectomy (PRK),laser-assisted subepithelial keratomileusis (LASEK),laser in situ keratomileusis (LASIK) and small incision lenticule extraction (SMILE).No matter what kind of operation method,its ultimate goal is to increase the comfort level and improve visual quality.With the surgery skills improving,retinal drug use is a primary factor affecting the safety of laser corneal refractive surgery.Ophthalmologists should strictly master indications and administration of commonly used drugs in postoperative eyes to prevent drug-related eye diseases.In addition,eye doctors also should understand the postoperative complications and topical administration of eye drops.It is important to pay attention to the standard surgical operation and rational drug use after corneal refractive surgery,which can enhance the visual quality and comfort and reduce the complication.
ABSTRACT
Objective To determine the efficiency of microwave heating of the conjunctival sac flushing liquid combined with disposible blood transfusion device to prepare for laser-assisted in situ keratomileusis (LASIK).Methods A total of 150 healthy myopia patients undergoing LASIK in Myopia Treatment Center of our hospital from February to August 2013 were divided into two groups randomly according to operation date,75 patients in each group.The observation group used a microwave oven to heat the flushing liquid connected with a disposable blood transfusion device.The control group used a hot water bath to heat the flushing liquid,which was then connected to a disposable infusion device.The heated liquid by both methods was applied to conjunctival sac flushing before LASIK.The time required for liquid heating was recorded and the outcome of the conjunctival sac flushing was compared between the two groups.Results The time required by the observation group and the control group of heating flushing fluid from 5,10,15,20,25 and 30 ℃ to (36.0±1.0) ℃ was 124,104,84,64,44,24 s and 372,312,252,192,132,72 s,respectively.The conjunctival sac flushing effect comparison between the observation group and the control group was as follows:in four indicators such as the operation cooperation,conjunctiva congestion,spasm of eyelid,eye pain,there was no significant difference between two groups; for tear fat deposition,there was significant difference between two groups (4 cases vs.15 cases,x2=7.292,P ＜ 0.01).Conclusions Microwave heating of the conjunctival sac flushing liquid connected with a disposable blood transfusion device is efficient,safe and easy to operate.Therefore,it gains approvement and high opinion of medical workers and is worth being popularized in clinic.