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The stroma at a depth of about 200 μm including epithelium was examined at preoperation (a), 1 month (b), 3 months (c), and 6 months (d) after treatment. A dense network of fibrils described as trabecular patterned and hyper-reflecting phantom cells were observed in the deep corneal stroma
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Purpose:
To evaluate the microstructural modifications and safety of small incision lenticule extraction combined with accelerated cross-linking (SMILE Xtra) in high myopia and thin corneas by means of in vivo confocal microscopy (IVCM) and 3D-OCT after a 6-month follow-up.
Methods:
Forty-three eyes with high myopia and thin corneas were enrolle...
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Background
Corneal refractive surgery has become reliable for correcting refractive errors, but it can induce unintended ocular changes that alter refractive outcomes. This study is to evaluate the unintended changes in ocular biometric parameters over a 6-month follow-up period after femtosecond laser-assisted laser in situ keratomileusis (FS-LASI...
Citations
... Based on this idea, the SMILE Xtra procedure was developed, combining corneal collagen cross-linking with the SMILE procedure. Several publications show that the SMILE Xtra is a safe and effective procedure in the short-term period, but there is a lack of long-term safety data [18,[24][25][26]. e aim of SMILE Xtra is to deliver the least amount of energy that can stabilize the cornea. ...
Purpose:
To evaluate clinical outcome during 24 months follow-up between small incision lenticule extraction combined with cross-linking (SMILE Xtra) and small incision lenticule extraction (SMILE) only. Setting. Ophthalmology Division of San Rossore Medical Center, Pisa, Italy.
Design:
Retrospective comparative case series.
Methods:
The study comprised 70 eyes (35 patients); 40 eyes were corrected using SMILE and 30 eyes were corrected using SMILE Xtra using a low energy protocol. The outcomes were compared at 1, 6, 12, and 24 months postoperatively.
Results:
The mean spherical equivalent (SEQ) reduced from -7.18 ± 1.21 D to -0.01 ± 0.09 D in the SMILE group and from -6.20 ± 2.99 D to -0.04 ± 0.1 D postoperatively in SMILE Xtra (p < 0.05). At 24 months the mean SEQs were -0.01 ± 0.24 D for SMILE and -0.15 ± 0.33 D for SMILE Xtra (p > 0.05). At 1, 6, 12, and 24 months, there were no statistically significant differences between the SMILE and SMILE Xtra groups in logarithm of the minimum angle of resolution (logMAR) uncorrected distance visual acuity (UDVA), safety, and efficacy index (p > 0.05). The mean average keratometry (K-avg) at 1, 6, 12, and 24 months after surgery did not shown any statistically significant difference between SMILE and SMILE Xtra group (p > 0.05). The mean maximum keratometry (K-max) readings at 1, 6, 12, and 24 months were not statistically significant between SMILE and SMILE Xtra group (p > 0.05). The preoperative mean thinnest point pachymetry (TTP) was 543.90 ± 22.85 μm in the SMILE group and 523.40 ± 37.01 μm in the SMILE Xtra group (p < 0.05). At 1, 6, 12, and 24 months the mean TTP was not statistically significant between the SMILE and SMILE Xtra groups (p > 0.05). At 24 months, the TTP was 408.29 ± 38.75 μm for the SMILE group and 402.22 ± 37 μm for the SMILE Xtra group (p > 0.05). In the preoperative period, the mean maximum posterior elevation (MPE) was 8.63 ± 4.35 μm for SMILE and 8.13 ± 2.54 μm for SMILE Xtra (p > 0.05). After the surgical procedure, both groups showed a statistically significant increase of the MPE (p < 0.05). At 24 months, the MPE was 11.00 ± 4.72 μm for SMILE Xtra and 10.14 ± 3.85 μm for the SMILE group (p > 0.05). In the preoperative period, the means of the root mean square (RMS) of high-order aberration (HOA) were 0.08 ± 0.03 μm for the SMILE group and 0.08 ± 0.03 μm for the SMILE Xtra group (p > 0.05). At 24 months, the RMS of HOA was 0.13 ± 0.07 μm for the SMILE group and 0.14 ± 0.07 μm for the SMILE Xtra group (p > 0.05). In the preoperative period, the root mean square of coma aberration (RMS-Coma) aberration was 0.06 ± 0.09 μm for the SMILE group and 0.04 ± 0.03 μm for the SMILE Xtra group (p > 0.05). At 24 months, the coma aberration of SMILE group was 0.12 ± 0.21 μm and 0.16 ± 0.25 μm for SMILE Xtra group (p > 0.05).
Conclusions:
SMILE Xtra procedure is a safe and simple procedure that can be offered to patients with high corneal ectasia risk because there were no differences in the indices of ectasia compared to the group treated only with SMILE which has a low corneal ectatic risk.
... e change in CCT was in line with that reported in Osman et al., who reported a statistically significant decrease from one to three months, which increased again after six months and was attributed to the compaction of the corneal stroma because of CXL [16]. A study based on in vivo confocal laser microscopy observed that typical honeycomb-like corneal edema was found on the surgical interface at one month after SMILE Xtra and disappeared gradually [22]. So, we speculated that dehydration may also account for further reduction of the CCT from three months to one month postoperatively. ...
... First, the stromal changes from lenticule extraction and CXL could result in consistent corneal epithelial hyperplasia and remodeling so as to uphold the integrity of the optical surface of the cornea [24,25]. Second, the increased reflectivity and density of the extracellular matrix stroma after SMILE Xtra indicated corneal stroma modification [22,26]. Correspondingly, the forward displacement of the posterior corneal surface gradually improved with the thickening of the cornea, especially in the posterior corneal elevation. ...
... is protocol proved safe and effective, as all eyes were exempted from complications. We did not routinely check the endothelial cell count as it has already been shown that no variation in cell count or the endothelial mosaic was observed after SMILE Xtra [22]. e advantage of this study was that we evaluated the changes in the corneal morphology on both the anterior and posterior surfaces and completed corneal biomechanics before and after SMILE Xtra. ...
Purpose:
To study the corneal morphology and biomechanics in cases of small incision lenticule extraction with prophylactic accelerated collagen cross-linking (SMILE Xtra).
Methods:
This study was a retrospective study. 28 eyes of 14 patients with moderate-high risk of postoperative ectasia according to the Randleman scoring system underwent SMILE Xtra procedure. Outcome data were recorded including uncorrected distance visual acuity (UDVA), manifest refraction spherical equivalent (MRSE), surface regularity index (SRI), surface asymmetry index (SAI), simulated keratometry (SimK), posterior axial curvature (PAC), anterior and posterior corneal elevations (ACE and PCE), central corneal thickness (CCT), corneal resistance factor (CRF), corneal hysteresis (CH), and cornea-compensated intraocular pressure (IOPcc). The follow-up period was 12 months.
Results:
There were 28, 26, 22, 12, and 10 eyes enrolled at postoperative 1st day and 1st, 3rd, 6th, and 12th months, respectively. The UDVA improved from 1.27 ± 0.18 logMAR preoperatively to -0.06 ± 0.04 logMAR postoperatively (P < 0.05). The MRSE improved from -5.05 ± 1.15 D preoperatively to -0.14 ± 0.30 D postoperatively (P < 0.05). SAI, SimK, PAC, PCE, and CCT all changed significantly at 1st month postoperatively (P < 0.05) and stabilized during the remainder of the follow-up (P > 0.05). There was no significant change in SRI or ACE before and after surgery (P > 0.05). CRF, CH, and IOPcc all decreased significantly at 1st month postoperatively (P < 0.05) and remained stable afterwards (P > 0.05).
Conclusions:
The changes in the corneal morphology and biomechanics remained stable after SMILE Xtra, and there was no sign of postoperative ectasia or refractive regression. Combined with the improvement of visual and refractive results, SMILE Xtra may be a promising method for corneal refractive surgeries in patients at risk.
... In contrast, Aragona et al. [54] described a significantly decreased keratocyte density in subjects with MG, examining 31 patients with MG, in Messina, Italy. Keratocyte density may be increased in keratitis [58][59][60][61][62], in autoimmune diseases [63], in some corneal dystrophies [58,[64][65][66][67][68], or following corneal surgeries such as crosslinking or corneal transplantation [69][70][71][72][73][74]. Nevertheless, keratocyte density decreases in ectatic corneal diseases [75][76][77][78][79], and congenital glaucoma [80]. ...
Background:
Corneal imaging may support an early diagnosis of monoclonal gammopathy. The goal of our study was to analyze corneal stromal properties using Pentacam and in vivo confocal cornea microscopy (IVCM) in subjects with monoclonal gammopathy.
Patients and methods:
In our cross-sectional study, patients with monoclonal gammopathy (130 eyes of 65 patients (40.0% males; age 67.65 ± 9.74 years)) and randomly selected individuals of the same age group, without hematological disease (100 eyes of 50 control subjects (40.0% males; age 60.67 ± 15.06 years)) were included. Using Pentacam (Pentacam HR; Oculus GmbH, Wetzlar, Germany), corneal stromal light scattering values were obtained (1) centrally 0-2 mm zone; (2) 2-6 mm zone; (3) 6-10 mm zone; (4) 10-12 mm zone. Using IVCM with Heidelberg Retina Tomograph with Rostock Cornea Module (Heidelberg Engineering, Heidelberg, Germany), the density of hyperreflective keratocytes and the number of hyperreflective spikes per image were manually analyzed, in the stroma.
Results:
In the first, second and third annular zone, light scattering was significantly higher in subjects with monoclonal gammopathy, than in controls (p ≤ 0.04). The number of hyperreflective keratocytes and hyperreflective spikes per image was significantly higher in stroma of subjects with monoclonal gammopathy (p ≤ 0.012).
Conclusions:
Our study confirms that increased corneal light scattering in the central 10 mm annular zone and increased keratocyte hyperreflectivity may give rise to suspicion of monoclonal gammopathy. As corneal light scattering is not increased at the limbal 10-12 mm annular zone in monoclonal gammopathy subjects, our spatial analysis provides evidence against the limbal origin of corneal paraprotein deposition. Using IVCM, stromal hyperreflective spikes may represent specific signs of monoclonal gammopathy.
... They concluded that SMILE may have less ectasia risk potential than LASIK when both used prophylactic CXL simultaneously in the refractive treatment. In a similar research line, Zhou et al. [28] reported microstructural modifications measured with in vivo confocal microscopy in 43 eyes with SMILE and CXL. They found a demarcation line depth at 296.12 µm, an increase in hyperreflectivity, and no variations in the endothelium. ...
Purpose:
To analyze the efficacy, safety, predictability, and stability in myopic and astigmatic small-incision lenticule extraction (SMILE) with simultaneous prophylactic corneal crosslinking (CXL) in thin corneas.
Methods:
A total of 48 eyes from 24 patients who underwent myopic and astigmatism SMILE with simultaneous prophylactic CXL were included in this retrospective study. All patients had a 24-month follow-up. A femtosecond laser was performed with VisuMax (Carl Zeiss Meditec). CXL treatment was applied when the predicted stromal thickness was less than 330 μm.
Results:
The patients' mean age was 31.58 ± 6.23 years. The previous mean spherical equivalent was - 6.85 ± 1.80 (-9.75 to - 2.00) D. The postoperative mean spherical equivalent was - 0.50 ± 0.26 (-1.00 to + 0.25) D; 60% of the eyes had 20/20 or better; 19% lost one line; 58% were within ± 0.50 D; and 8.3% of the eyes changed 0.50 D or more between 3 and 24 months.
Conclusion:
Prophylactic CXL with simultaneous SMILE for myopia and astigmatism femtosecond laser surgery technique appears to be partially effective, safe, predictable, and stable after 24 months of follow-up.
... One year after the operation, 94% of the eyes obtained an uncorrected distance visual acuity of 20/30 or above, and the biomechanics was significantly higher than that with traditional SMILE. Zhou et al. [61] observed corneal morphological changes after SMILE Xtra by optical coherence tomography and in vivo confocal microscopy. In their study, the ultraviolet radiation of riboflavin was carried out under a cap with a thickness of 110-120 μm and a diameter of 7-7.8 mm. ...
Small incision lenticule extraction (SMILE) is an "all-in-one" surgical method for refractive correction. An advantage of the SMILE over traditional surgery is that it depends on the corneal cap’s design. This review discusses the morphological evaluation of the corneal cap, selection of the corneal cap with different thickness and diameters, influence of the corneal cap design on retreatment, and management of corneal cap-related complications. The following points should be recognized to define the correct morphology and design of the operation-related parameters of the corneal cap during SMILE: (1) the thickness and diameter of the corneal cap are predictable and influence postoperative visual quality, (2) the change in anterior surface curvature of the corneal cap should be considered in the design of nomogram value, (3) for patients with moderate myopic correction, early visual quality is better with a 6.9-mm than with a 7.5-mm diameter corneal cap, (4) there is no significant difference in visual quality or biomechanics among corneal caps with different thickness; (5) primary corneal cap thickness plays an important role in the SMILE retreatment, (6) a 7.78-mm diameter corneal cap has a greater risk of suction loss than a 7.60-mm diameter corneal cap, (6) if suction loss occurs when lenticular scanning exceeds 10%, then SMILE can be continued by changing corneal cap thickness, (7) preventive collagen cross-linking with SMILE caps are 90–120 μm thick and 7–7.8 mm in diameter, and (8) properly treating SMILE-related complications ensures better postoperative results. The data presented herein shall deepen the understanding of the importance of the corneal cap during SMILE and provide diversified analysis for personalized operational design of corneal cap parameters.
... Y. Zhou и соавт. модифицировали ранее описанную методику и подтвердили безопасность ее проведения [40]. Недавние исследования на кроликах продемонстрировали, что кросслинкинг-обработанная лентикула (ее диаметр составлял 2,5 мм) усиливает переднюю кривизну и стабилизирует рефракцию роговицы через 8 нед. ...
Purpose. To identify the problems of using lenticular tissue, its storage, obtaining cell-free scaffolds in corneal tissue engineering, and the possibility of predicting refraction. The unique advantage of Relex Smile technology is that it is a potentially reversible procedure that allows preserve the extracted lenticules and opens up broad possibilities for the use of lenticules in ophthalmic practice in the future. Research in this area demonstrated the potential for implanted autologous and allogeneic lenticules after creating an intracorneal pocket for treating diseases such as presbyopia, corneal perforation, corneal keratectasia, progressive pterygium, progressive keratoconus. In addition, this article presents the results of recent studies describing protocols for cryopreservation and decellularization of lenticules as the most promising methods in tissue engineering in conditions a shortage of donor's cornea. Key words: Relex Smile, lenticule, implantation, cryopreservation, decellularization, tissue engineering.
... Los tratamientos de sonrisa gingival, realizados en odontología, se basan en correcciones quirúrgicas en la mayoría de los casos, invasivas, mientras que otros medios aplicados fuera del área de práctica del cirujano dental también se tienen en cuenta y pueden cambiar la rutina en la clínica dental (BOTOX® y Acupuntura) (36). Estos no son procedimientos tan complejos pero ventajosos, en otras palabras, hay una gama de opciones de tratamiento para la corrección de esta característica de sonrisa, y la multidisciplinaria en el tratamiento es extremadamente beneficiosa (37). ...
El análisis facial y dental debe integrarse con todos los tratamientos dentales, donde la estética y la función deben ser los principales objetivos, ya que la cara es la base principal del equilibrio estético y la odontología debe estar sincronizada con ella. El objetivo de este trabajo es una revisión de la literatura para identificar los factores que deben considerarse en un análisis estético del paciente cuando se somete a un tratamiento den-tal. La percepción de una cara equilibrada es posible, existe un concepto diversificado de belleza facial, y esto varía según el paciente, el tratamiento estético debe ser siempre una función aliada, para que pueda mejorar la armonía facial con la sonrisa, devolver la estética positiva significa satisfacer las expectativas y dar una ima-gen positiva de sí mismo. La percepción de una cara equilibrada es posible, existe un concepto diversificado de belleza facial, y esto varía según el paciente. Se concluye que la percepción de un rostro equilibrado es posible, existe un concepto diversificado de belleza facial y esto varía según el paciente.
... There are several studies in the literature that investigate the results of other refractive surgery procedures such as photorefractive keratectomy (PRK) or laser in situ keratomileusis (LASIK) on patients with thinnest corneal thickness (CCT) less than 500 µm [14][15][16][17][18][19]. There are also studies about the clinical results and morphologic results of small incision lenticule extraction (SMILE) when combined with accelerated crosslinking [20,21]. However, to the best of our knowledge, there is a lack of data in the literature focusing SMILE results on thin cornea eyes alone. ...
To report the refractive and visual outcomes of small incision lenticule extraction (SMILE) with the thinnest corneal thickness (CCT) of less than 500 µm and evaluate it in terms of safety and efficacy.
Setting
Refractive Surgery Clinic of University of Health Sciences Beyoglu Eye Training and Research Hospital, Istanbul, Turkey.
Design
Retrospective case series.
Methods
The pre-and-postoperative examinations of all patients with thin corneas (preoperative CCT <500 µm) who underwent the SMILE procedure and had a minimum of 24 months of follow-up records were reviewed from medical files. The main outcome measures of the refractive and visual outcomes and the effect on corneal high order aberrations (HOAs) were evaluated.
Results
The study included 55 eyes of 39 patients. The mean preoperative uncorrected visual acuity (UDVA) was 1.3 ± 1.5 logMAR, and the mean postoperative UDVA was significantly improved to 0.05 ± 0.80 logMAR at the last visit (p < 0.001). At the last follow-up, 84% of the eyes were within ± 0.50D, and 96% of the eyes were within ±1.00D of attempted SE refraction. The HOAs of coma (p < 0.001), secondary astigmatism (p = 0.015), spherical aberration (p < 0.001), and RMS (p < 0.001) aberrations increased significantly from the baseline to the postoperative last visit. The increase in trefoil was not significant (p = 0.32). No sight threatening complications or ectasia were observed during the follow-up time.
Conclusion
SMILE is a safe and effective technique with long-term stability for treatment of myopia in eyes with a thin cornea, and satisfactory results can be obtained if candidates for surgery are selected carefully with particular emphasis on normal preoperative corneal topography.
... 14 suggested that patients were to be older than 18 years. [37][38][39][40][41] There is no clear-cut evidence for setting a guideline for age. Since younger patients are at risk for post-refractive surgery corneal ectasia, prophylactic CXL is advised at the time of refractive surgery. ...
... Previous studies on SMILE Xtra enrolled eyes with CCT ≥450μm 37 or >460 μm, 39 but recommended that RST should be between 250 and 290 μm. 39 In general, surgeons are relatively conservative on the minimal RST value, almost same as that in refractive surgery. ...
... The central cornea is irradiated with UVA. 39 Ng et al 38 created an additional 2 mm incision at the opposite site to allow for complete irrigation of the riboflavin solution. ...
Corneal refractive surgery is one of the most common approaches for correction of refractive errors. Combined corneal refractive surgery and corneal crosslinking (CXL) has been proposed as a method to achieve better refractive stability and to prevent iatrogenic corneal ectasia. However, there are concerns regarding its indications, surgical safety, standardization of protocols, and long‐term effect on corneal tissue. This review article aims to discuss the current knowledge and recent updates on combination of CXL and refractive surgery. This article is protected by copyright. All rights reserved.
... 38 LASIK Xtra and SMILE Xtra have not been studied in detail with IVCM; however a hypocellular interface and keratocyte apoptosis to a depth of 60 lm below the interface have been found following LASIK Xtra and SMILE Xtra. 39,40 In conclusion, to our knowledge this is the first study to show that, for the same myopic refractive correction, SMILE may have less potential than LASIK to induce ectasia. Concomitant CXL in this biological animal model had a protective effect, as LASIK Xtra cases showed the least potential for ectasia. ...
Purpose:
We investigate whether small incision lenticule extraction (SMILE) is associated with less ectasia than laser-assisted in-situ keratomileusis (LASIK) and whether concomitant collagen cross-linking (CXL) is protective in SMILE Xtra and LASIK Xtra.
Methods:
Using an established LASIK rabbit ectasia model, we performed -5 diopter (D) LASIK on six eyes and -5 D SMILE on six eyes; five eyes had -5 D LASIK Xtra, five eyes -5 D SMILE Xtra. Anterior segment optical coherence tomography and corneal topography were performed preoperatively and 2, 4, and 6 weeks postoperatively. Mean (standard deviation [SD]) values of postoperative keratometry (K), maximum posterior elevation (MPE) and minimum corneal thickness (CT) were compared to preoperatively and among the surgical groups (paired t-test, analysis of variance).
Results:
Mean (SD) K values decreased significantly following SMILE, SMILE Xtra, LASIK, and LASIK Xtra. The MPE increased significantly (P < 0.05) following LASIK, SMILE, and SMILE Xtra, but not following LASIK Xtra (P = 0.12). The MPE was less following SMILE than LASIK, but not statistically significant (week 2, 17.73 [5.77] vs. 22.75 [5.05] μm; P = 0.13); post-LASIK Xtra MPE was less than that following LASIK (week 2. 13.39 [3.05] vs. 22.75 [5.05] μm; P < 0.001). CT decreased significantly in all surgical groups; no differences were detected among the groups.
Conclusions:
SMILE may have less potential than LASIK to induce ectasia. LASIK Xtra and SMILE Xtra showed the smallest increase in MPE.
Translational relevance:
Concomitant CXL may be protective following keratorefractive surgery and may reduce further the risk of ectasia.
