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Objective:To compare the characteristics of corneal stromal demarcation line after different surgical methods of riboflavin/ultraviolet A corneal collagen cross-linking (CXL) in early keratoconus, and analyze the influence of the demarcation line on the cross-linking effect.Methods:A non-randomized controlled clinical study was conducted.Sixty-nine eyes of 69 patients treated with riboflavin/ultraviolet A CXL in the Eye Hospital of Shandong First Medical University from May 2019 to February 2021 were included.According to the cross-linking methods, the patients were divided into epithelium-on treatment group (21 eyes) and epithelium-off treatment group (48 eyes). There were 25 eyes in 5.4 J energy group and 44 eyes in 7.2 J energy group.The morphology and changes of corneal stromal cross-linking reaction (corneal stromal demarcation line) were observed at 2 weeks, 1, 3 and 4 months after operation.Changes in the thinnest corneal thickness (TCT), uncorrected visual acuity (UCVA, LogMAR), best corrected visual acuity (BCVA, LogMAR) and corneal maximum curvature (Kmax) were recorded.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Eye Hospital of Shandong First Medical University (No.2019.05). Written informed consent was obtained from each subject.Results:Of the 69 eyes after operation, 44 eyes (63.77%) had demarcation lines, and 25 eyes (36.23%) had no demarcation lines.The occurrence rate of demarcation lines in the epithelium-on treatment group was 79.17%(38/48), which was significantly higher than 28.57%(6/21) in the epithelium-off treatment group ( χ2=16.186, P<0.01). The occurrence rate of demarcation line in 5.4 J energy group was 72.00%(18/25), and the 7.2 J energy group was 56.80%(25/44), with no significant difference ( χ2=1.565, P=0.302). Slit lamp microscopy and anterior segment-optical coherence tomography showed that the demarcation line appeared at 1-2 weeks after operation, gradually converged and strengthened after 1 month, turned diffuse, blurred and faded by degrees after 2-3 months, and basically disappeared after 4 months.The depth of the demarcation line reached 141-423 μm, with an average depth of (263.44±84.22)μm.Scanning laser confocal microscopy showed that corneal stromal cells were activated and light reflection was enhanced after CXL.Collagen fibers extended vertically and horizontally, crisscrossed, and were in a reticular arrangement.The TCT decreased from preoperative (458.69±38.28)μm to (443.86±36.54)μm at 4 months after operation, showing a statistically significant difference ( t=6.705, P<0.001). There was no significant difference in the TCT reduction between groups with and without demarcation lines ( t=1.684, P=0.100). At 4 months postoperatively, the UCVA of all eyes increased from preoperative 0.74±0.37 to 0.69±0.38, and the difference was statistically significant ( t=2.109, P=0.039). There was no significant difference in BCVA between before and after operation ( t=1.006, P=0.319). There was no significant difference in change of UCVA and BCVA between groups with and without demarcation lines ( t=0.065, P=0.949; t=0.346, P=0.730). There was no significant difference in Kmax in all patients between before and after operation ( t=0.050, P=0.950). There was no significant difference in the Kmax change between groups with and without demarcation lines ( t=-0.739, P=0.464). The change in TCT in the epithelium-off treatment group was significantly greater than that in the epithelium-on treatment group ( t=2.815, P=0.008). There was no significant difference in UCVA, BCVA and Kmax changes between epithelium-on and epithelium-off treatment groups (all at P>0.05). There was no obvious corneal scarring, infectious keratitis, corneal endothelial decompensation or other complications. Conclusions:The demarcation line after CXL may be a sign of the depth of cross-linking reaction, which is more prone to occur after the epithelium-off operation method.Both the epithelium-on and epithelium-off operation methods have similar therapeutic effects.Demarcation line after different cross-linking methods has no significant influence on the cross-linking effect in keratoconus.
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AIM: To observe the epithelial remodeling of femtosecond laser-assisted stromal lenticule addition keratoplasty combined with corneal collagen cross-linking(SLAK-CXL)in patients with progressive keratoconus, investigate the remodeling rules of corneal epithelial and influencing factors, and provide clinical data for further refractive correction.METHODS: Retrospective and observational study. A total of 28 keratoconus patients(29 eyes)who received SLAK-CXL from September 2020 to October 2021 were included. Preoperative and postoperative visual acuity, intraocular pressure(IOP), diopter, keratometry and corneal epithelial thickness(CET)were recorded. The trend of CET change was observed. The factors affecting CET were analyzed according to the thickness and depth of the lenticule.RESULTS: Flattest meridian keratometry(Kf)and steepest meridian keratometry(Ks)at 1mo postoperatively were significantly larger than those preoperatively(P<0.05). The thinnest corneal thickness(TCT)at 1, 2, 6mo and 1a postoperatively were significantly larger than preoperative(P<0.05). The CET changed with time, with the central CET showing a larger variation tendency. The CET of superior, superior nasal, nasal, superior temporal in paracentral area were thinned, the CET of superior, temporal, superior temporal in midperipheral area were thinned, while the CET of superior nasal was thickened in peripheral area at 1, 2, 6mo and 1a postoperatively. The variation of CET was not correlated with the thickness or depth of lenticule at 1a postoperatively(P>0.05).CONCLUSIONS: It is firstly found that the corneal morphology has changed after SLAK-CXL. CET decreases and then increases and then decreases again. At 1a postoperatively, the CET of the central and paracentral areas is thinner, while the CET of the midperipheral and peripheral areas is thicker. The degree of epithelial remodeling is not correlated with lenticule thickness or depth.
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@#AIM:To investigate the clinical efficacy and safety of trans-epithelial accelerated corneal collagen cross-linking in the treatment of progressive keratoconus.METHODS: A prospective before-after self-control study. A total of 47 eyes of 37 patients with progressive keratoconus who underwent trans-epithelial accelerated corneal collagen cross-linking in our hospital from August 2016 to November 2019 were collected. Uncorrected visual acuity(UCVA), best corrected visual acuity(BCVA), refractive status, corneal transparency, maximum keratometry value of the anterior corneal surface, thinnest corneal thickness, corneal endothelial cell counts and intraocular pressure(IOP)were analysed preoperatively and at 1, 3, 6 and 12mo postoperative.RESULTS: UCVA of patients 1, 3, 6 and 12mo after surgery was higher than that before surgery, but there was no difference(<i>F</i>=1.372, <i>P</i>=0.261). BCVA at 1, 3, 6 and 12mo after surgery was higher than that before surgery, the difference was statistically significant(<i>F</i>=3.308, <i>P</i>=0.019). There were no differences in the spherical and cylindrical power, Kmax and thickness of the thinnest point of cornea at 1, 3, 6 and 12mo postoperatively compared with those before surgery(<i>F</i>=0.293, 1.378, 2.448, 1.970; <i>P</i>=0.881, 0.258, 0.061, 0.116). There was no difference in corneal endothelial cell counts between 1mo after surgery and before surgery(<i>t</i>=1.156, <i>P</i>=0.25). There was no difference in IOP at all postoperative time points compared with that before surgery(<i>F</i>=1.221, <i>P</i>=0.321). The corneal Haze(grade 1-2)appeared in 7 eyes after surgery, and subsided in 5 eyes from 3-6mo after surgery, and the corneal transparency recovered. The corneal nebula remained in 1 eye, and the corneal central stroma linear opacity existed in 1 eye, but the visual acuity of both eyes was not affected.CONCLUSION: Trans-epithelial accelerated corneal collagen cross-linking can significantly improve BCVA, stabilize refractive status, corneal morphology and thickness, prevent or delay the progression of keratoconus, and enable patients to obtain better visual function. At the same time, the operation time is short, postoperative complications are less, and the operation has good safety.
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@#AIM: To compare the change of refractive power and corneal high-order aberrations after femtosecond laser-assisted excimer laser <i>in situ</i> keratomileusis(FS-LASIK)and FS-LASIK combined with accelerated corneal cross-linking(FS-LASIK Xtra)for high myopia correction, and to evaluate the early effects of two surgical methods to correct high myopia. <p>METHODS:Retrospective case-control study. Totally 42 patients(84 eyes)with high myopia underwent FS-LASIK Xtra and FS-LASIK in our hospital from April 2019 to April 2020 were followed up for 3mo, including 21 patients in each group(42 eyes). The uncorrected visual acuity(UCVA), spherical equivalent(SE), astigmatism and corneal high-order aberration of the two groups were analyzed and compared.<p>RESULTS: The UCVA of the FS-LASIK Xtra group was significantly lower than that of the FS-LASIK group at 1d after surgery(<i>P</i><0.01), there was no statistical difference in UCVA at the other time points after surgery between the two groups(<i>P</i>>0.05). The postoperative SE of the two groups was significantly lower than that before surgery, at 3mo after surgery, 38 eyes(90%)in the FS-LASIK Xtra group and 41 eyes(98%)in the FS-LASIK group had SE within ±1.00D. In both groups, 35 eyes(83%)had residual astigmatism within 0.50D after surgery. The total corneal high-order aberrations, spherical aberrations, coma and clover aberrations in the two groups were increased at 3mo after surgery, the total high-order aberration and clover aberration in the FS-LASIK Xtra group were greater than those in the FS-LASIK group(all <i>P</i><0.05).<p>CONCLUSION:FS-LASIK and FS-LASIK Xtra have good effectiveness and predictability in correcting high myopia in the early postoperative period, the total high-order aberrations of the cornea both increased in the early postoperative period, and the patients who underwent FS-LASIK Xtra were increased significantly.
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PURPOSE: To report a case of corneal collagen cross-linking for corneal ulcer caused by the Moraxella group.CASE SUMMARY: A 77-year-old male had decreased visual acuity for several days in his right eye. The patient showed severe stromal ring infiltrates with a corneal epithelial defect measuring (5.0 × 7.0 mm), a corneal endothelial plaque, and a hypopyon measuring less than 1.0 mm in height in the anterior chamber of the right eye. There was no abnormal finding in the right eye using B-scan ultrasonography. Before starting treatment, a corneal culture was conducted. The culture tests showed the presence of the Moraxella group. Because the patient was diagnosed with a corneal ulcer caused by the Moraxella group, corneal collagen cross-linking (CXL) was performed. The antimicrobial susceptibility test confirmed that this Moraxella group was sensitive to ceftazidime, so the patient was treated with 5% ceftazidime eye drops and 0.5% moxifloxacin eye drops every 2 hours for 9 months after corneal collagen CXL. The uncorrected visual acuity was 0.1 in the right eye, and there was almost no corneal stromal melting on anterior segment optical coherence tomography.CONCLUSIONS: This is the first known case of a corneal ulcer, in the Republic of Korea, caused by the Moraxella group and treated with corneal collagen CXL. Corneal collagen CXL should be considered as a surgical treatment for patients who have an impending corneal perforation due to a corneal ulcer because it is a simple procedure and causes fewer serious complications than other treatments.
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Aged , Humans , Male , Anterior Chamber , Ceftazidime , Collagen , Cornea , Corneal Perforation , Corneal Ulcer , Freezing , Moraxella , Ophthalmic Solutions , Republic of Korea , Tomography, Optical Coherence , Ultrasonography , Visual AcuityABSTRACT
@#Corneal collagen cross-linking(CXL)is a new treatment for corneal diseases such as primary or secondary keratoconus, infectious keratitis and bullous keratopathy. CXL is used to increase the biomechanical stability of the stromal tissue and prevent the progression of keratopathy based on Laws of Photochemistry, which is widely used in clinical practice at present. Currently, commonly used method in clinical practice is the traditional “epithelium-off” corneal cross-linking method(dresden protocol), but the classical method takes a long time, and there may be postoperative complications such as poor healing of the corneal epithelium and infection. In recent years, a number of studies have improved the classical method, such as the choice of riboflavin solution immersed in the cornea, increasing the energy of ultraviolet light to shorten the accelerated cross-linking time of irradiation and cross-epithelial CXL. Thus, this paper reviews clinical and basic researches of the current use of non-classical CXL in the treatment of keratoconus.
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@#AIM: To Study the anti-fungal effect of corneal collagen cross-linking combined with natamycin <i>in vivo</i> and <i>in vitro</i>, so as to provide the treatment and experimental basis for the treatment of clinical fungal keratitis. <p>METHODS: Three common pathogenic fungi(<i>Aspergillus flavus</i>, <i>Fusarium Solani</i> and <i>Candida albicans</i>)were used. The experimental group was divided into cross-linking combined natamycin group, natamycin combined riboflavin group, natamycin combined UVA irradiation group, cross-linking group and natamycin group as the control group. The drug was added to the center of the Sabouraud dextrose agar(SDA)plate coated with liquid with each fungal spores with the same maid turbidity of 1.5. Ten minutes later, it was irradiated with collagen cross-linking instrument for 10min and cultured at 28℃ for 36h, and then the inhibition zone size was measured and analyzed statistically. The rabbit model of <i>Fusarium Solani</i> corneal infection was prepared. The model rabbits were randomly divided into model control group, cross-linking treatment group, natamycin treatment group, cross-linking combined natamycin group, 5 rabbits in each group. And another 5 normal rabbits were taken as control, and five rabbits were irradiated in accordance with corneal collagen cross-linking therapy. The results were observed by anterior segment photography, corneal scraping and confocal microscopy, and the ultra micro structural changes of the corneas were observed by electron microscope after the treatment.<p>RESULTS: Corneal collagen cross-linking alone had shown no effect on each fungus <i>in vitro</i>. Corneal collagen cross-linking combined with natamycin produced significant anti-fungal effect(<i>P</i><0.05). However, the anti-fungal effect of natamycin combined riboflavin group and natamycin combined ultraviolet light group showed no statistical difference(<i>P</i>>0.05)comparing with the control group. For the model of rabbit fungal infection, the course of disease was about 14d in the natamycin group and CXL combined with natamycin group, and it was about 21d in CXL group. After the treatment, all the groups healed. There were no defects in the corneal epithelium, no mycelium in the corneas, except for more corneal neovascularization. The results of the anterior segment photography showed that the treatment effect of the cross-linking combined natamycin group was better than other groups, with fewer scar tissue, better corneal healing and relatively short course of disease.<p>CONCLUSION: Corneal collagen cross-linking combined with natamycin treatment is able to enhance anti-fungal effect, promote corneal healing, and shorten the course of disease. So it is a promising therapeutic technique for the clinical treatment of fungal keratitis.
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@#AIM: To evaluate the efficacy of FS-LASIK combined with rapid corneal collagen cross-linking in treatment of high myopia.<p>METHODS: A prospective self-control study. Totally 42 patients(81 eyes)with high myopia treated by FS-LASIK combined with rapid corneal collagen cross-linking in our hospital from June to September 2017 were followed up for 6mo. The uncorrected visual acuity(UCVA), spherical equivalent(SE), corneal morphological parameters, corrected intraocular pressure and complications were observed.<p>RESULTS: At 6mo after operation, the UCVA(LogMAR)increased from 1.44±0.18 before operation to -0.03±0.04, the SE degree reduced from -8.01±1.23D to -0.06±0.54D, the steepest corneal curvature(Steep K)decreased from 44.23±0.80D to 37.39±1.17D at 6mo after operation, the flattest corneal curvature(Fleep K)decreased from 42.87±0.61D before operation to 36.84±0.99D after operation. And the thinnest point thickness of cornea decreased from 525.33±30.42μm to 402.12±28.04μm, the corrected intraocular pressure decreased from 17.77±2.16mmHg to 16.69±0.41mmHg. There were no significant changes in the posterior surface height of thinnest cornea and the endothelial cell density. No corneal infections, serious non-infectious inflammation and complications related to corneal flaps were found during follow-up.<p>CONCLUSION: FS-LASIK combined with rapid corneal collagen cross-linking is safe and effective in treatment of high myopia. The corneal morphology and refraction are relatively stable after surgery.
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@#AIM: To observe the safety and efficacy of epithelium-off corneal collagen cross-linking(CXL)combined with rigid gas permeable contact lens(RGPCL)in treatment of progressive keratoconus.<p>METHODS: From January 2015 to January 2017, 51 cases(51 eyes)of patients diagnosed with keratoconus and epithelium-off CXL treatment at the Eye Hospital of Nanjing Medical University were collected. The patients were divided into two groups according to whether they wore RGPCL or not after treatment. Group A: 30 eyes, epithelium-off CXL was removed and wear a framed mirror after treatment; Group B: 21 eyes, epithelium-off CXL was removed and RGPCL was worn after the condition was stable. Observed the best corrected visual acuity(BCVA), spherical equivalent(SE), minimum keratometry of the anterior corneal surface(K1), maximum keratometry of the anterior corneal surface(K2), mean keratometry(Km), maximal keratometry(Kmax), corneal vertex thickness, thinnest corneal thickness(TCT)before and 12mo after treatment.<p>RESULTS: No statistically significant differences were found before the therapy between the two groups in BCVA, SE, K1, K2, Km, Kmax, corneal vertex thickness, and TCT between the two groups(<i>P</i>>0.05). 12mo after treatment, BCVA in group B was significantly higher than that in group A(0.11±0.03 <i>vs</i> 0.26±0.16), the corneal vertex thickness of group B was lower than that of group A(431.8±14.41μm <i>vs</i> 461.38±32.68μm)(<i>P</i><0.05), there was no significant difference in other parameters between the two groups.<p>CONCLUSION: Epithelium-off CXL can effectively delay or control the progression of keratoconus. Wearing RGPCL after treatment can effectively improve BCVA.
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Objective This study was to assess the efficacy of corneal collagen cross-linking treatment on fungal keratitis.Methods Eighty SPF male C57BL/6 mice aged 6-8 weeks were selected for the experiment.Fusarium solani infected model was established on the left eyes of all 80 mice.Forty mice were distributed randomly into sham operation group,model control group,scraped epithelium group and corneal collagen cross-linking (CXL)group (treated with epithelium scraped and CXL).Three days after modeling,the levels of the corncal disease sevcrity were scored by slit lamp microscopy.The fungal activity was confirmed by plate counts.The left 40 mice were divided randomly into sham operation group,model control group,scraped epithelium group and CXL group (treated with epithelium scraped and CXL).In 1 day and 2,3,4,5,6,7,14 days after modeling,the corneas were examined under the slit lamp microscope.The corneal pathological examination of each group were conducted with hematoxylin and eosin staining at postoperative 14 days.The animal feeding and use was in accordance with the standards set by the ARVO,and the experiment was approved by the Ethic Committee for Experimental Animal of Henan Eye Institute.Results The colony-forming units (CFUs) of fungal solutions in culture significantly decreased with CXL treatment (F =11.97,P =0.00).The Pearson correlation analysis of CFU and clinical scores in CXL group showed that inflammatory cells infiltration was positively correlated with corneal disease severity (r =0.723,P =0.043).Corneal inflammatory score was significantly lower in the CXL group in various time points,with a significant differences among the groups and time points (Fgroup =34.44,P=0.00;Ftime =17.49,P=0.00).Corneal lesion and the depth of ulceration in scraped epithelium group and CXL group were remarkably lower than that in the model control group (all at P ＜ 0.05).Histopathology revealed that the degree of corneal collagen fibers destruction and the ratio of inflammatory cells infiltration in scraped epithelium group (59.33％) and CXL group (11.29％) were much lower than that in the model control group (73.65％).Conclusions CXL can inhibit the fungal activity effectively in the cornea of mice,and reduce the fungal induced keratitis reaction.
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· AIM:To evaluate the safety and efficacy at early stage after femtosecond laser-assisted excimer laser in situ keratomileusis (FS-LASIK) combined with collagen cross-linking.· METHODS:Totally 30 myopia patients (60 eyes) received FS-LASIK combined with collagen cross-linking from July 2016 to August 2017 in our hospital were tested the uncorrected visual acuity (UCVA),Ks,Kf,surface regular index (SRI),surface asymmetry index (SAI) by corneal topography (TMS) preoperatively,1,3mo after operation.The corneal compensated intraocular pressure (IOPcc),Goldmann correlated IOP value (IOPg),corneal resistance factor (CRF),corneal hysteresis (CH) tested by ocular response analyzer (ORA) were also observed.Ziemer Galilei Dual Scheimpflug Analyzer detected the anterior diopter and the corneal thickness.Endothelial cell density were examined.· RESULTS:The postoperative UCVA remained beyond 0.8 including 26 eyes (43％) of 1d,55 eyes (92％) of 1mo,50 eyes (83％) of 3mo.IOPcc,IOPg,CRF,CH at postoperative 1mo significantly decreased comparing with preoperative (P＜0.01).IOPcc,IOPg,CRF,CH at postoperative 3mo did not change significantly comparing with 1mo (P＞0.05).The corneal topographic map parameters of Ks and Kf significantly decreased at postoperative 1mo (P ＜ 0.01),while SRI and SAI increased significantly (P＜0.01) on comparison of 1mo and preoperative.Ks of postoperative 3mo was significantly higher than that of 1 mo (P＜0.05),while Kf did not change significantly (P＞ 0.05).There was a significant decrease in SRI and SAI between 3mo and 1mo after operation (P＜ 0.05).In Galileo analysis on comparison of 3mo and 1mo,Sim Ks,Sim Kf had 0.94D,0.95D growth and the front and back surface value of Kf increased more at 3mo postoperative (P＜0.01),while Ks was no significant difference (P＞ 0.05).There was no statistically significant difference in corneal thickness between the central point and the thinnest point (P＞ 0.05).There was no significant endothelial cell loss throughout follow up (3059.95±247.87/mm2 vs 3052.87± 267.71/mm2;t=0.279,P＞0.05).· CONCLUSION:Refractive corneal surgery combined with collagen cross linking for high degree,thin cornea,uneven thickness of the cornea,topographic anomalies except for the patients with keratoconus,play a role in stabilizing corneal shape and increasing corneal biomechanics early.
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AIM:To compare the early results of different kinds of transepithelial corneal collagen cross-linking (TE-CXL) in the treatment of progressive keratoconus.METHODS:Retrospective study.Twenty four patients (34 eyes) who were diagnosed with progressive keratoconus were divided into three groups.And 10 eyes in hypotonic CXL group received the treatment of hypotonic corneal collagen cross-linking;14 eyes in Ⅰ-CXL 5min group received the treatment of iontophoresis corneal collagen cross-linking for 5min,and 10 eyes from the Ⅰ-CXL 10min group received the treatment of iontophoresis corneal collagen cross-linking for 10min.Uncorrected distance visual acuity,corrected distance visual acuity,Pentacam,in vivo scanning laser confocal microscopy and anterior segment optical coherence tomography were examined before and after 1wk,1,3 and 6mo postoperatively.RESULTS:Six months postoperatively,corrected distance visual acuity (CDVA) (LogMAR) in Ⅰ-CXL 10min group increased by-0.21 ± 0.23 (t =2.735,P=0.026);Kmax decreased by 2.32± 5.21D (t=1.40,P=0.193),but the differences were not statistically significant.Uncorrected distance visual acuity (UDVA),CDVA and Kmax in hypotonic CXL group and Ⅰ-CXL 5min group were stable,the differences were not statistically significant.The depth of demarcation line was 152.7±42.9μ m in hypotonic CXL group,213.6±42.3μ m in Ⅰ-CXL 5min group and 237.0±46.4μ m in Ⅰ-CXL 10min group 1wk after the surgery,the differences among groups were statistically significant (F =7.111,P =0.006).The phenomenon of stroma cell apotosis-activate regeneration in Ⅰ-CXL 10min group was the most significant after the surgery.The changes of corneal thinnest thickness and endothelial cell density in three groups were stable.CONCLUSION:Three kinds of transepithelial CXL can halt the progression of keratoconus,among which the reaction of corneal tissue in iontophoresis CXL for 10min is the most obvious.
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Objective To observe the clinical outcomes of corneal collagen cross-linlIng (CLX) and laser-assisted in situ keratomileusis (LASIK) for refractive error.Methods Together 100 patients (200 eyes) with myopia and/or astigmatism who underwent LASIK were admitted from December 2015 to January 2016,and divided into treatment group (50 patients,100 eyes),in which patient received CXL-LASIK,and control group (50 patients,100 eyes),in which the controls were given LASIK alone.Then the optical variables,including visual acuity,diopter,cornea endothelium cell counting,corneal transparency,corneal collagen cross-linking line,were examined and analyzed before operation and 1 week,1 month,3 months,6 months and 12 months after opera tion.Results As for postoperative time points,the uncorrected visual acuity after operation was better than the best corrected visual acuity before surgery in the two groups,but the differences in diopter between the two groups were statistically significant (all P ＜ 0.05).There was no significant difference in diopter 1 month and 12 months postoperatively in the treatment group (t =0.021,P =0.070),while its difference in the control group 1 month and 12 months postoperatively(t =4.857,P =0.010).The differences of the cornea endothelium cell counting in the treatment group between before and after surgery were not statistically significant (F =1.163,P =0.327).Moreover,slightly opacification apPeared in anterior corneal stromal in the early stage after surgery in the treatment group,and the average thickness of corneal collagen cross-linking line was 210.00-340.00 (270.48 + 37.80) μm 1 month postoperatively,accounting for 63％ of the central cornea thickness.There were not flap-related complications in the treatment group,but the control group had corneal flap wrinkle in 3 eyes and displacement in 1 eye in the controls.Conclusion Corneal collagen cross-linlIng and laser-assisted in situ keratomileusis for refractive error can obtain better outcomes,including sound uncorrected visual acuity and stable diopter after surgery,without the loss of the corneal endothelial cells.
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Objective To observe the clinical outcomes of corneal collagen cross-linlIng (CLX) and laser-assisted in situ keratomileusis (LASIK) for refractive error.Methods Together 100 patients (200 eyes) with myopia and/or astigmatism who underwent LASIK were admitted from December 2015 to January 2016,and divided into treatment group (50 patients,100 eyes),in which patient received CXL-LASIK,and control group (50 patients,100 eyes),in which the controls were given LASIK alone.Then the optical variables,including visual acuity,diopter,cornea endothelium cell counting,corneal transparency,corneal collagen cross-linking line,were examined and analyzed before operation and 1 week,1 month,3 months,6 months and 12 months after opera tion.Results As for postoperative time points,the uncorrected visual acuity after operation was better than the best corrected visual acuity before surgery in the two groups,but the differences in diopter between the two groups were statistically significant (all P ＜ 0.05).There was no significant difference in diopter 1 month and 12 months postoperatively in the treatment group (t =0.021,P =0.070),while its difference in the control group 1 month and 12 months postoperatively(t =4.857,P =0.010).The differences of the cornea endothelium cell counting in the treatment group between before and after surgery were not statistically significant (F =1.163,P =0.327).Moreover,slightly opacification apPeared in anterior corneal stromal in the early stage after surgery in the treatment group,and the average thickness of corneal collagen cross-linking line was 210.00-340.00 (270.48 + 37.80) μm 1 month postoperatively,accounting for 63％ of the central cornea thickness.There were not flap-related complications in the treatment group,but the control group had corneal flap wrinkle in 3 eyes and displacement in 1 eye in the controls.Conclusion Corneal collagen cross-linlIng and laser-assisted in situ keratomileusis for refractive error can obtain better outcomes,including sound uncorrected visual acuity and stable diopter after surgery,without the loss of the corneal endothelial cells.
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@#AIM:To present the outcomes of early treatment with corneal collagen cross-linking with riboflavin in patients with mild to moderate keratoconus.<p>METHODS:It is a prospective interventional study at tertiary eye care center. Forty-seven eyes of 38 patients with mild to moderate keratoconus who underwent collagen cross linking with riboflavin were enrolled. Preoperative data included eye involved, presenting visual acuity, intraocular pressure(IOP), pachymetry and corneal topography. Postoperative data included the best-corrected visual acuity(BCVA), IOP, pachymetry, corneal topography and postoperative complications.<p>RESULTS:Study comprised of 47 eyes of 38 patients aged between 16-30y. The average preoperative vision was 0.58±0.40 logMAR which significantly improved to 0.40±0.27logMAR at 2y follow up(<i>P</i>=0.005). The average preoperative keratometry readings were 50.5±4.6 D which significantly decreased during the subsequent follow up and the average keratometry readings at 2y was 48.2±4.1 D(<i>P</i>=0.011). The average IOP significantly increased postoperatively and at 2y follow up was 15.1±3.0mmHg compared to preoperative IOP(12.9±2.5 mmHg)(<i>P</i>=0.035). The average preoperativepachymetry was 467.9±38.8 μm, which decreased significantly and was 465.0±39.3 μm at 2y follow up. No complications were noted in any of our cases.<p>CONCLUSION:Early treatment with collagen cross-linking with riboflavin provide good long term visual outcomes in patients with mild to moderate keratoconus without awaiting for progression of the keratoconus.
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Corneal collagen cross-linking (CXL) is a photochemotherapy for keratoconus, keratectasias and infectious keratitis.Corneal collagen fiber infiltrated with riboflavin, a photosensitizer which generates reactive oxygen species when activated by UVA at 370nm, was induced to form the crosslinks in corneal stroma.Corneal collagen cross-linking alone or combined with medicine therapy could be used to treat fungal keratitis, improve the cure rates, and reduce the complications and the demands of corneal transplantation surgery.The purpose of this paper is to review the basic principle, procedure, laboratory researches, clinical applications and the safety about this treatment.
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Background Keratoconus is a progressive corneal thinning and protrusion disease that develop in the age of puberty,resulting in a certain extent impairment of visual function.Corneal collagen cross-linking (CXL) increases the stiffness of the cornea through the photooxidation of ultraviolet A (UVA) and riboflavin,with the aim to postpone and prevent the progression of keratoectasia.Objective This study was to evaluate the safety and efficacy of transepithelial CXL in the treatment of pediatric keratoconus.Methods Ten eyes of 9 pediatric patients with keratoconus undergoing transepithelial CXL were enrolled from February 2010 to March 2013 in Affiliated Eye Hospital of Wenzhou Medical University,with the mean age was (15± 1) years (range from 13 years to 17 years).After topical anesthesia (0.1％ tetracaine) for 15 minutes,0.5％ riboflavin was applied until it was saturated in the anterior chamber,then UVA with the intensity of 3 mW/cm2 was performed on the cornea for 30 minutes.The uncorrected distance visual acuity (UDVA),corrected distance visual acuity (CDVA),refractive error,topography,corneal thinnest thickness were measured 7 days,1 month,3 months,6 months and 1 year after operation.Endothelium cell density (ECD) was measured 7 days afier operative.Results The mean corneal reepithelization time was (1.4±0.8) days.The UDVA and CDVA were significantly improved from preoperative 1.02±0.16 and 0.34±0.20 to postoperative 0.77±0.18 and 0.25 ±0.15,respectively (t =4.251,3.750;both at P＜0.05).The refractive sphere and spherical equivalent significantly changed from preoperative (-7.15±3.00)D and (-9.26±3.23)D to postoperative (-5.28±2.05) D and (-7.05±2.08) D 1 year,respectively (t =-2.515,-2.597;both at P＜0.05).Maximum Kvalue (Kmax) was significantly decreased from preoperative (64.1 ± 11.9) D to postoperative (61.8 ± 10.4) D (t =2.304,P＜0.05).The refractive cylinder,corneal thinnest thickness and ECD showed no significant differences between preoperation and postoperation (t =-1.331,0.328,1.205;all at P＞0.05).Stromal opacity was observed in 2 eyes 3 months and 6 months after operation,respectively.Conclusions Transepithelial CXL is safe and effective in prolonging or halting progression in adolescent keratoconus.
ABSTRACT
Objective: The primary objective of this study was to quantify the visual improvement and the reduction of corneal curvature achieved through association of Mini Asymmetric Radial Keratotomy (MARK) and Corneal Collagen Cross-linking (CXL). Design: Retrospective clinical trial. Methods: Sixteen eyes (sixteen patients) were included. Computerized corneal topography and Scheimpflug camera equipment were used to measure higher order corneal aberrations before treatment and during follow-up. Outcome parameters, including uncorrected visual acuity and best corrected visual acuity, have been measured as well. Examinations were performed at 3, 6, 12 and 24 months following both MARK and CXL. Results: A sharp reduction of both corneal curvature and corneal aberrations was observed after MARK surgery, followed by a smaller improvement following CXL treatment. Conclusion: The combination of MARK with CXL offers a significant improvement of visual acuity and a reduction of corneal curvature along with the corneal reinforcement provided by CXL.
ABSTRACT
?Corneal collagen cross-linking ( CXL ) could increase the mechanical strength, biological stability and halt ectasia progression due to covalent bond formed by photochemical reaction between ultraviolet - A and emulsion of riboflavin between collagen fibers in corneal stroma. Corneal melting is an autoimmune related noninfectious corneal ulcer. The mechanism of corneal melting, major treatment, the basic fundamental of ultraviolet- A riboflavin induced CXL and the clinical researches status and experiment in CXL were summarized in the study.