AIM： To investigate the long term（≥5 y） efficacy, predictability, and safety of laser in situ keratomileusis（LASIK） in eyes with thin corneas [central corneal thickness（CCT） 〈500 μm]. METHODS： A total of 33...AIM： To investigate the long term（≥5 y） efficacy, predictability, and safety of laser in situ keratomileusis（LASIK） in eyes with thin corneas [central corneal thickness（CCT） 〈500 μm]. METHODS： A total of 339 patients met the criteria of this study. Finally, 175 eyes of 89 patients who had thin corneas and underwent LASIK≥5 y ago returned to our clinic and included in this study. Preoperative parameters recorded included uncorrected visual acuity（UCVA）, corrected distance visual acuity（CDVA）, manifest refraction, CCT and corneal topography. At returning visits, in addition to visual acuity and manifest refraction, ultrasound CCT and corneal topography were performed. Optical coherence tomography was used to measure the CCT, LASIK flap thickness, and residual stromal bed thickness（RSBT）. Safety index, efficacy index, percentage of eyes within ±0.5 D and ±1.0 D of refraction, percent tissue altered（PTA）, and percentage stromal bed thickness（PSBT） were calculated. RESULTS： The safety index was 1.09 and efficacy index was 0.99. The percentages of eyes within ±0.5 D and ±1.0 D were 71.2% and 87.7%, respectively. The mean PTA was 40%±6%（range 20% to 55%）; 76 eyes（43.4%） had PTA 〈40% and 99 eyes（56.6%） had PTA≥40%. The mean RSBT was 303±27 μm（range 240 to 390 μm）, and 2 eyes had RSBT〈250 μm. The mean PSBT was 61%±9%（range 51% to 85%）. No eyes developed ectasia. CONCLUSION： In this cohort with the PSBT of 50% or more, LASIK is safe with follow-up for at least 5 y.展开更多
AIM:To investigate and compare the visual and refractive outcomes of small incision lenticule extraction(SMILE),laser assisted sub-epithelial keratomileusis(LASEK),and LASEK combined with corneal collagen cross-linkin...AIM:To investigate and compare the visual and refractive outcomes of small incision lenticule extraction(SMILE),laser assisted sub-epithelial keratomileusis(LASEK),and LASEK combined with corneal collagen cross-linking(LASEKCXL)surgery in patients with less than 500μm of central corneal thickness(CCT).METHODS:The retrospective medical records review was conducted on the patients with CCT less than 500μm treated with SMILE,LASEK,and LASEK-CXL.There was a total of 172 eyes,76 eyes were in the SMILE group,53 eyes in the LASEK group,and 43 eyes in the LASEK-CXL group.Uncorrected distance visual acuity(UDVA),spherical equivalent refraction(SE),and corneal haze were followed up in the three groups for 12 mo.RESULTS:At 12 mo postoperatively,there were no statistically significant differences in UDVA and in the absolute value of SE between the three groups.The predictability within±0.50 D in the SMILE group(85.5%)was significantly higher than in both the LASEK group(64.2%,P<0.01)and the LASEK-CXL group(69.8%,P=0.04).The efficacy index and safety index were not significantly different among the three groups.Corneal haze at 12 mo postoperatively was higher in the LASEK-CXL group(27.9%)than in the SMILE group(2.6%,P<0.01)and in the LASEK group(7.5%,P<0.01).CONCLUSION:In patients with CCT less than 500μm,SMILE,LASEK,and LASEK-CXL appear to be effective for myopic correction.Among them,SMILE surgery shows the highest predictability.展开更多
Corneal collagen cross-linking(CXL)is a therapeutic procedure aiming at increasing the corneal stiffness in the keratoconus eyes by induction of cross-links within the extracellular matrix.It is achieved by ultraviole...Corneal collagen cross-linking(CXL)is a therapeutic procedure aiming at increasing the corneal stiffness in the keratoconus eyes by induction of cross-links within the extracellular matrix.It is achieved by ultraviolet-A(370 nm)irradiation of the cornea after saturation with the photosensitizer riboflavin.In the conventional CXL protocol,a minimum de-epithelialized corneal thickness of 400μm is recommended to avoid potential irradiation damage to the corneal endothelium.In advanced keratoconus,however,stromal thickness is often lower than 400μm,which limits the application of CXL in that category.Efforts have been undertaken to modify the conventional CXL procedure to be applicable in thin corneas.The current review discusses different techniques employed to achieve this end and their results.The overall safety and efficacy of the modified CXL protocols are good,as most of them managed to halt the progression of keratectasia without postoperative complications.However,the evidence of safety and efficacy in the use of modified CXL protocols is still limited to few studies with few patients involved.Controlled studies with long-term follow-up are required to confirm the safety and efficacy of the modified protocols.展开更多
A rare case of bilateral scleromalacia perforans, bilateral peripheral corneal thinning (contact lens cornea) and unilateral orbital inflammatory disease in a 50 year old female patient with an indolent form Wegener&#...A rare case of bilateral scleromalacia perforans, bilateral peripheral corneal thinning (contact lens cornea) and unilateral orbital inflammatory disease in a 50 year old female patient with an indolent form Wegener's granulomatosis(WG) involving lungs and sinuses is reported. The patient survived for 12 years after the initial diagnosis of systemic disease. There was perforation of left globe following trauma and no perforation of the right globe till the last follow up of the patient.展开更多
AIM: To report the 3mo outcomes of collagen crosslinking(CXL) with a hypo-osmolar riboflavin in thin corneas with the thinnest thickness less than 400 μm without epithelium.METHODS: Eight eyes in 6 patients with age ...AIM: To report the 3mo outcomes of collagen crosslinking(CXL) with a hypo-osmolar riboflavin in thin corneas with the thinnest thickness less than 400 μm without epithelium.METHODS: Eight eyes in 6 patients with age 26.2±4.8y were included in the study. All patients underwent CXL using a hypo-osmolar riboflavin solution after its de-epithelization. Best corrected visual acuity, manifest refraction, the thinnest corneal thickness, and endothelial cell density were evaluated before and 3mo after the procedure.RESULTS: The mean thinnest thickness of the cornea was 408.5 ±29.0 μm before treatment and reduced to369.8 ±24.8 μm after the removal of epithelium. With the application of the hypo-osmolar riboflavin solution, the thickness increased to 445.0 ±26.5 μm before CXL and recover to 412.5 ±22.7 μm at 3mo after treatment, P =0.659). Before surgery, the mean K-value of the apex of the keratoconus corneas was 57.6 ±4.0 diopters, and slightly decreased(54.7±4.9 diopters) after surgery(P =0.085). Mean best-corrected visual acuity was 0.55 ±0.23 logarithm of the minimal angle of resolution, and increased to 0.53±0.26 logarithm after surgery(P =0.879).The endothelial cell density was 2706.4 ±201.6 cells/mm2 before treatment, and slightly decreased( 2641. 2 ±218.2 cells/mm2) at last fellow up(P =0.002).CONCLUSION: Corneal collagen cross-linking with a hypo-osmolar riboflavin in thin corneas seems to be a promising treatment. Further study should be done to evaluate the safety and efficiency of CXL in thin corneas for the long-term.展开更多
AIM:To assess early visual outcomes and corneal stability following small incision lenticule extraction(SMILE)in eyes with a pre-planned residual stromal thickness(RST)ranging from 280 to 300μm.METHODS:This retrospec...AIM:To assess early visual outcomes and corneal stability following small incision lenticule extraction(SMILE)in eyes with a pre-planned residual stromal thickness(RST)ranging from 280 to 300μm.METHODS:This retrospective study was designed to evaluate 82 eyes from 82 patients,all of whom had a pre-planned RST of 280 to 300μm and normal corneal topography prior to undergoing SMILE surgery.The mean preoperative spherical equivalent(SE)was-4.82±1.30 D.A standard follow-up protocol was conducted between 1 to 6mo postoperatively.Visual outcomes were recorded using uncorrected visual acuity(UCVA)and subjective refraction.The curvature of the anterior and posterior corneal surfaces,as well as the posterior elevation at the thinnest point(PTE)were derived from the Pentacam system.RESULTS:At the final follow-up,the efficacy index was 1.14±0.15,the safety index was 1.20±0.13.The mean preoperative UDVA was 0.78±0.16 logMAR,which improved significantly to-0.07±0.06 logMAR postoperatively(P<0.001).The preoperative mean SE was-4.82±1.30 D,which decreased to-0.14±0.30 D by the last visit.The curvature of the anterior cornea at the flat meridian(AK1)were 42.62±1.02 D preoperatively,38.56±1.37 D and 38.59±1.39 D at 1 and 6mo after operation,respectively.Corresponding measurements at the steep meridian(AK2)were 43.55±1.14 D preoperatively,39.18±1.46 D and 39.22±1.50 D at 1 and 6mo after operation,respectively.Both AK1 and AK2 remained stable at 1 and 6-mo postoperative intervals(P=0.126 and 0.082,respectively).There were no observed changes in the curvature of the posterior cornea at the flat meridian or at the steep meridian,or the PTE before and after surgery.CONCLUSION:SMILE represents a safe and effective procedure for the correction of myopia and astigmatism in eyes featuring a pre-planned RST ranging from 280 to 300μm accompanied by normal corneal topography,on the premise of strict control of surgical indications.展开更多
基金Supported in part by the National Natural Science Foundation of China(No.11402161)the Programs for Science and Technique Development of Shanxi Province,China(No.20120313025-3)+1 种基金the Science and Technology Research Projects of the Shanxi Provincial Health Department,China(No.201201018)an unrestricted grant from Research to Prevent Blindness,New York,NY,USA
文摘AIM： To investigate the long term（≥5 y） efficacy, predictability, and safety of laser in situ keratomileusis（LASIK） in eyes with thin corneas [central corneal thickness（CCT） 〈500 μm]. METHODS： A total of 339 patients met the criteria of this study. Finally, 175 eyes of 89 patients who had thin corneas and underwent LASIK≥5 y ago returned to our clinic and included in this study. Preoperative parameters recorded included uncorrected visual acuity（UCVA）, corrected distance visual acuity（CDVA）, manifest refraction, CCT and corneal topography. At returning visits, in addition to visual acuity and manifest refraction, ultrasound CCT and corneal topography were performed. Optical coherence tomography was used to measure the CCT, LASIK flap thickness, and residual stromal bed thickness（RSBT）. Safety index, efficacy index, percentage of eyes within ±0.5 D and ±1.0 D of refraction, percent tissue altered（PTA）, and percentage stromal bed thickness（PSBT） were calculated. RESULTS： The safety index was 1.09 and efficacy index was 0.99. The percentages of eyes within ±0.5 D and ±1.0 D were 71.2% and 87.7%, respectively. The mean PTA was 40%±6%（range 20% to 55%）; 76 eyes（43.4%） had PTA 〈40% and 99 eyes（56.6%） had PTA≥40%. The mean RSBT was 303±27 μm（range 240 to 390 μm）, and 2 eyes had RSBT〈250 μm. The mean PSBT was 61%±9%（range 51% to 85%）. No eyes developed ectasia. CONCLUSION： In this cohort with the PSBT of 50% or more, LASIK is safe with follow-up for at least 5 y.
文摘AIM:To investigate and compare the visual and refractive outcomes of small incision lenticule extraction(SMILE),laser assisted sub-epithelial keratomileusis(LASEK),and LASEK combined with corneal collagen cross-linking(LASEKCXL)surgery in patients with less than 500μm of central corneal thickness(CCT).METHODS:The retrospective medical records review was conducted on the patients with CCT less than 500μm treated with SMILE,LASEK,and LASEK-CXL.There was a total of 172 eyes,76 eyes were in the SMILE group,53 eyes in the LASEK group,and 43 eyes in the LASEK-CXL group.Uncorrected distance visual acuity(UDVA),spherical equivalent refraction(SE),and corneal haze were followed up in the three groups for 12 mo.RESULTS:At 12 mo postoperatively,there were no statistically significant differences in UDVA and in the absolute value of SE between the three groups.The predictability within±0.50 D in the SMILE group(85.5%)was significantly higher than in both the LASEK group(64.2%,P<0.01)and the LASEK-CXL group(69.8%,P=0.04).The efficacy index and safety index were not significantly different among the three groups.Corneal haze at 12 mo postoperatively was higher in the LASEK-CXL group(27.9%)than in the SMILE group(2.6%,P<0.01)and in the LASEK group(7.5%,P<0.01).CONCLUSION:In patients with CCT less than 500μm,SMILE,LASEK,and LASEK-CXL appear to be effective for myopic correction.Among them,SMILE surgery shows the highest predictability.
文摘Corneal collagen cross-linking(CXL)is a therapeutic procedure aiming at increasing the corneal stiffness in the keratoconus eyes by induction of cross-links within the extracellular matrix.It is achieved by ultraviolet-A(370 nm)irradiation of the cornea after saturation with the photosensitizer riboflavin.In the conventional CXL protocol,a minimum de-epithelialized corneal thickness of 400μm is recommended to avoid potential irradiation damage to the corneal endothelium.In advanced keratoconus,however,stromal thickness is often lower than 400μm,which limits the application of CXL in that category.Efforts have been undertaken to modify the conventional CXL procedure to be applicable in thin corneas.The current review discusses different techniques employed to achieve this end and their results.The overall safety and efficacy of the modified CXL protocols are good,as most of them managed to halt the progression of keratectasia without postoperative complications.However,the evidence of safety and efficacy in the use of modified CXL protocols is still limited to few studies with few patients involved.Controlled studies with long-term follow-up are required to confirm the safety and efficacy of the modified protocols.
文摘A rare case of bilateral scleromalacia perforans, bilateral peripheral corneal thinning (contact lens cornea) and unilateral orbital inflammatory disease in a 50 year old female patient with an indolent form Wegener's granulomatosis(WG) involving lungs and sinuses is reported. The patient survived for 12 years after the initial diagnosis of systemic disease. There was perforation of left globe following trauma and no perforation of the right globe till the last follow up of the patient.
文摘AIM: To report the 3mo outcomes of collagen crosslinking(CXL) with a hypo-osmolar riboflavin in thin corneas with the thinnest thickness less than 400 μm without epithelium.METHODS: Eight eyes in 6 patients with age 26.2±4.8y were included in the study. All patients underwent CXL using a hypo-osmolar riboflavin solution after its de-epithelization. Best corrected visual acuity, manifest refraction, the thinnest corneal thickness, and endothelial cell density were evaluated before and 3mo after the procedure.RESULTS: The mean thinnest thickness of the cornea was 408.5 ±29.0 μm before treatment and reduced to369.8 ±24.8 μm after the removal of epithelium. With the application of the hypo-osmolar riboflavin solution, the thickness increased to 445.0 ±26.5 μm before CXL and recover to 412.5 ±22.7 μm at 3mo after treatment, P =0.659). Before surgery, the mean K-value of the apex of the keratoconus corneas was 57.6 ±4.0 diopters, and slightly decreased(54.7±4.9 diopters) after surgery(P =0.085). Mean best-corrected visual acuity was 0.55 ±0.23 logarithm of the minimal angle of resolution, and increased to 0.53±0.26 logarithm after surgery(P =0.879).The endothelial cell density was 2706.4 ±201.6 cells/mm2 before treatment, and slightly decreased( 2641. 2 ±218.2 cells/mm2) at last fellow up(P =0.002).CONCLUSION: Corneal collagen cross-linking with a hypo-osmolar riboflavin in thin corneas seems to be a promising treatment. Further study should be done to evaluate the safety and efficiency of CXL in thin corneas for the long-term.
文摘AIM:To assess early visual outcomes and corneal stability following small incision lenticule extraction(SMILE)in eyes with a pre-planned residual stromal thickness(RST)ranging from 280 to 300μm.METHODS:This retrospective study was designed to evaluate 82 eyes from 82 patients,all of whom had a pre-planned RST of 280 to 300μm and normal corneal topography prior to undergoing SMILE surgery.The mean preoperative spherical equivalent(SE)was-4.82±1.30 D.A standard follow-up protocol was conducted between 1 to 6mo postoperatively.Visual outcomes were recorded using uncorrected visual acuity(UCVA)and subjective refraction.The curvature of the anterior and posterior corneal surfaces,as well as the posterior elevation at the thinnest point(PTE)were derived from the Pentacam system.RESULTS:At the final follow-up,the efficacy index was 1.14±0.15,the safety index was 1.20±0.13.The mean preoperative UDVA was 0.78±0.16 logMAR,which improved significantly to-0.07±0.06 logMAR postoperatively(P<0.001).The preoperative mean SE was-4.82±1.30 D,which decreased to-0.14±0.30 D by the last visit.The curvature of the anterior cornea at the flat meridian(AK1)were 42.62±1.02 D preoperatively,38.56±1.37 D and 38.59±1.39 D at 1 and 6mo after operation,respectively.Corresponding measurements at the steep meridian(AK2)were 43.55±1.14 D preoperatively,39.18±1.46 D and 39.22±1.50 D at 1 and 6mo after operation,respectively.Both AK1 and AK2 remained stable at 1 and 6-mo postoperative intervals(P=0.126 and 0.082,respectively).There were no observed changes in the curvature of the posterior cornea at the flat meridian or at the steep meridian,or the PTE before and after surgery.CONCLUSION:SMILE represents a safe and effective procedure for the correction of myopia and astigmatism in eyes featuring a pre-planned RST ranging from 280 to 300μm accompanied by normal corneal topography,on the premise of strict control of surgical indications.
