Journal of refractive and corneal surgery最新文献

{"title":"Rotating brush for fast removal of corneal epithelium.","authors":"I G Pallikaris,&nbsp;A D Karoutis,&nbsp;S E Lydataki,&nbsp;D S Siganos","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Background: </strong>A simple new device is proposed for safe and very fast epithelial removal of the cornea. This is a rotating plastic brush that removes the corneal epithelium within a few seconds under irrigation, without causing any mechanical damage to the stromal surface.</p><p><strong>Methods: </strong>Comparative SEM and TEM studies on rabbit corneas were carried out following epithelial removal by rotating brush and by a Beaver knife blade. Epithelial removal time and reepithelialization time after photorefractive keratectomy were evaluated in a series of 40 human sighted eyes treated with the brush.</p><p><strong>Results: </strong>The rotating brush-abraded surface was smoother compared to the blade-abraded one. Additionally, the brush provoked no damage to the basal lamina of the rabbit corneal epithelium. In human photorefractive keratectomy, the mean time needed for removal of the corneal epithelium by the rotating brush was only 3 sec (range, 2-5 sec). Reepithelialization time following photorefractive keratectomy did not exceed 3 days.</p><p><strong>Conclusion: </strong>Experimental and preliminary clinical studies suggest that the new rotating plastic brush is a safe and fast method for removing the corneal epithelium.</p>","PeriodicalId":79348,"journal":{"name":"Journal of refractive and corneal surgery","volume":"10 4","pages":"439-42"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18534992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prostaglandin E2 production after lamellar keratectomy and photorefractive keratectomy.","authors":"K D Szerenyi,&nbsp;M Campos,&nbsp;P J McDonnell","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Purpose: </strong>To compare the levels of prostaglandin E2 (PGE2) in corneal tissue after 193-nanometer excimer laser keratectomy and mechanical keratectomy with a microkeratome.</p><p><strong>Methods: </strong>Four rabbits underwent 193-nanometer excimer laser phototherapeutic keratectomy on one eye, and lamellar keratectomy with the microkeratome on the fellow eye. The corneas were harvested at 10 hours after the treatment and quantitated for PGE2 levels using an enzyme-linked immune assay. Control levels of PGE2 in untreated corneas were obtained from a previous study.</p><p><strong>Results: </strong>Unoperated control corneas had low levels of PGE2 (1.79 +/- 1.0 pg/mL). Both surgical techniques resulted in a significant (p < .01) increase in PGE2. Corneas ablated mechanically with the microkeratome had an average PGE2 level of 15.48 +/-5.36 pg/mL, which represented an 8.6-fold increase compared to control; there was an additional 330% mean increase in PGE2 concentration in the laser-ablated corneas (51.29 +/- 36.08 pg/mL) compared to the corneas treated with mechanical lamellar keratectomy (p = .014).</p><p><strong>Conclusions: </strong>Mechanical and photochemical superficial keratectomies induce production of an inflammatory mediator, PGE2. The 193-nanometer excimer laser irradiation causes a greater increase of PGE2 production in the corneal tissue than does keratectomy with the microkeratome; this observation may support a role for cyclo-oxygenase inhibitors in postoperative therapy.</p>","PeriodicalId":79348,"journal":{"name":"Journal of refractive and corneal surgery","volume":"10 4","pages":"413-6"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18537822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nonfreeze myopic keratomileusis for myopia in 158 eyes.","authors":"L. Laroche, L. Gauthier, J. C. Thenot, F. Lagoutte, J. Nordmann, P. Denis, V. Borderie, P. Giral, H. Saraux","doi":"10.3928/1081-597X-19940701-05","DOIUrl":"https://doi.org/10.3928/1081-597X-19940701-05","url":null,"abstract":"BACKGROUND\u0000A prospective evaluation of non-freeze myopic keratomileusis is reported.\u0000\u0000\u0000METHODS\u0000One hundred and fifty-eight eyes of 98 consecutive patients underwent nonfreeze myopic keratomileusis, with BKS 1000 (Eyetech-M.V.A.A.G, Balzers, Liechtenstein) refractive set. The preoperative myopia ranged from -6.25 to -28.00 D. Mean follow up was 591.3 days (range, 90 to 1500 days).\u0000\u0000\u0000RESULTS\u0000The logarithmic mean preoperative spectacle-corrected visual acuity was 0.48 +/- 0.31 (20/40), and 0.44 (20/50) +/- 0.30 after 2 years and longer, whereas mean uncorrected visual acuity was 0.32 +/- 0.28 (20/70) in 34 of 82 (41.5%) eyes. After 2 years and longer, 21 of 82 (25.6%) eyes were within 1.00 D of emmetropia, and 43 of 82 (52.4%) were within 2.00 D. The subjective spherical equivalent refraction confidence interval at 90% was 9.28 D (-6.85 to +2.43 D). No refractive instability was detected during follow-up. We detected a trend toward improvement of spectacle-corrected visual acuity with time. However, after 2 years and longer, there was an increase in astigmatism of more than 1.00 D, when compared to the preoperative values, and 14 of 82 (17%) eyes lost two or more lines of spectacle-corrected visual acuity (statistically significant: p < .01).\u0000\u0000\u0000CONCLUSION\u0000The nonfreeze myopic keratomileusis procedure, with BKS 1000, substantially reduces moderate to high myopia, but predictability of refractive outcome is only fair, and the frequency of optical complications including irregular astigmatism is higher than desired.","PeriodicalId":79348,"journal":{"name":"Journal of refractive and corneal surgery","volume":"10 4 1","pages":"400-12"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70145678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nonfreeze myopic keratomileusis for myopia in 158 eyes.","authors":"L Laroche,&nbsp;L Gauthier,&nbsp;J C Thenot,&nbsp;F Lagoutte,&nbsp;J P Nordmann,&nbsp;P Denis,&nbsp;V Borderie,&nbsp;P Giral,&nbsp;H Saraux","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Background: </strong>A prospective evaluation of non-freeze myopic keratomileusis is reported.</p><p><strong>Methods: </strong>One hundred and fifty-eight eyes of 98 consecutive patients underwent nonfreeze myopic keratomileusis, with BKS 1000 (Eyetech-M.V.A.A.G, Balzers, Liechtenstein) refractive set. The preoperative myopia ranged from -6.25 to -28.00 D. Mean follow up was 591.3 days (range, 90 to 1500 days).</p><p><strong>Results: </strong>The logarithmic mean preoperative spectacle-corrected visual acuity was 0.48 +/- 0.31 (20/40), and 0.44 (20/50) +/- 0.30 after 2 years and longer, whereas mean uncorrected visual acuity was 0.32 +/- 0.28 (20/70) in 34 of 82 (41.5%) eyes. After 2 years and longer, 21 of 82 (25.6%) eyes were within 1.00 D of emmetropia, and 43 of 82 (52.4%) were within 2.00 D. The subjective spherical equivalent refraction confidence interval at 90% was 9.28 D (-6.85 to +2.43 D). No refractive instability was detected during follow-up. We detected a trend toward improvement of spectacle-corrected visual acuity with time. However, after 2 years and longer, there was an increase in astigmatism of more than 1.00 D, when compared to the preoperative values, and 14 of 82 (17%) eyes lost two or more lines of spectacle-corrected visual acuity (statistically significant: p < .01).</p><p><strong>Conclusion: </strong>The nonfreeze myopic keratomileusis procedure, with BKS 1000, substantially reduces moderate to high myopia, but predictability of refractive outcome is only fair, and the frequency of optical complications including irregular astigmatism is higher than desired.</p>","PeriodicalId":79348,"journal":{"name":"Journal of refractive and corneal surgery","volume":"10 4","pages":"400-12"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18537821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Misalignment of videokeratoscope produces pseudo-keratoconus suspect.","authors":"C. M. Silverman","doi":"10.3928/1081-597X-19940701-16","DOIUrl":"https://doi.org/10.3928/1081-597X-19940701-16","url":null,"abstract":"","PeriodicalId":79348,"journal":{"name":"Journal of refractive and corneal surgery","volume":"10 4 1","pages":"468"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70145918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Topical diclofenac following excimer laser: effect on corneal sensitivity and wound healing in rabbits.","authors":"N. Loya, S. Bassage, S. Vyas, M. D. del Cerro, S. B. Park, J. Aquavella","doi":"10.3928/1081-597X-19940701-08","DOIUrl":"https://doi.org/10.3928/1081-597X-19940701-08","url":null,"abstract":"BACKGROUND\u0000Diclofenac is a nonsteroidal antiinflammatory drug (NSAID) that is widely used systemically and topically. We studied the effect of diclofenac on corneal reepithelialization and corneal sensitivity after excimer laser treatment in rabbits.\u0000\u0000\u0000METHODS\u0000Twelve New Zealand white rabbits were divided into four groups (A, B, C, and D). Groups A and B received diclofenac four times and eight times daily, respectively, following a central 5-millimeter epithelial debridement. Groups C (control) and D (diclofenac four times daily) underwent excimer laser ablation (30-micrometer depth) following manual debridement. Wound healing was compared between groups A and B and groups C and D. Sensitivity was recorded preoperatively and postoperatively 1 to 5 and 14 days in groups C and D until normal values were reestablished.\u0000\u0000\u0000RESULTS\u0000Total time for corneal wound healing and epithelial migration rates was not delayed in any group receiving diclofenac (A, B, and D). Sensitivity after laser ablation reached a minimum of 15% to 20% in both groups C and D by day 2 and returned to normal (100%) by day 8. The decrease in sensitivity between group C, the controls, and group D, receiving diclofenac four times daily, was not statistically significant.\u0000\u0000\u0000CONCLUSIONS\u0000Diclofenac can be used up to eight times daily in the rabbit without causing changes in corneal wound healing or epithelial migration rate. There was no significant, long-term reduction of sensitivity, and recovery was not affected by diclofenac.","PeriodicalId":79348,"journal":{"name":"Journal of refractive and corneal surgery","volume":"116 1","pages":"423-7"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70145764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Radial keratotomy and excimer laser photorefractive keratectomy for the correction of myopia.","authors":"P. Binder","doi":"10.3928/1081-597X-19940701-12","DOIUrl":"https://doi.org/10.3928/1081-597X-19940701-12","url":null,"abstract":"PURPOSE\u0000To compare our current knowledge of the two most common current refractive surgical procedures for the correction of myopia.\u0000\u0000\u0000METHODS\u0000I reviewed the scientific literature and my personal experience with radial keratotomy and excimer laser photorefractive keratectomy to compare these two modalities.\u0000\u0000\u0000RESULTS\u0000Both radial keratotomy and photorefractive keratectomy are capable of permanently correcting myopic refractive errors. However, each procedure has its individual advantages and disadvantages, with the greatest concern currently being the effect of wound healing on refractive outcome. The procedures are not mutually exclusive.\u0000\u0000\u0000CONCLUSIONS\u0000Both radial keratotomy and photorefractive keratectomy will be used to surgically correct myopia for the next several years until newer technology is developed to improve the predictability and stability of refractive results currently achieved with each procedure.","PeriodicalId":79348,"journal":{"name":"Journal of refractive and corneal surgery","volume":"10 4 1","pages":"443-64"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70145825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photoablation of gelatin with the free-electron laser between 2.7 and 6.7 microns.","authors":"B Jean,&nbsp;T Bende","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Background: </strong>Photoablation in the infrared (IR) is an option for future refractive and corneal surgery; its basic principles have not yet been investigated systematically. For the first time, the free electron laser allows the dynamic study of photoablation over a wide range of wavelengths with variable combinations of pulselength and energy. The goal of this study is to use the free electron laser as a tool to describe photoablation in the IR quantitatively. We studied the function of wavelength as it is related to target material spectroscopy and the effects of corneal hydration and the pulse repetition rate.</p><p><strong>Methods: </strong>Surface absorption spectroscopy of the human cornea and of gelatin as a proven model of the cornea was performed between 2.7 and 6.7 microns. Gelatin probes of well-defined thickness (140 +/- 5 microns) and controlled hydration (wet/dry weight 1 to 4.5) served as target material. Photoablation was performed with the Vanderbilt University free electron laser (Nashville, Tenn) in September 1992 at a fluence of 1.27 J/cm2, and a macropulse of 4 microseconds, composed of 2 ps micropulses at a 2.9 GHz pulse repetition rate. Wavelength was tunable between 2.7 and 6.7 microns at stable beam profiles. Ablation experiments were performed as a function of energy, hydration, and pulse repetition rate. Ablation rates were assessed by a) perforation experiments, and b) direct measurements using confocal laser topometry (UBM, Ettlingen, FRG).</p><p><strong>Results: </strong>Ablation rate, assessed by perforation experiments and topometry, correlated well with the corresponding measured absorbencies of the target material: maximal ablation rate at maximal target absorption, around the 3- and 6-micrometer water absorption bands. The ablation threshold at 6.2 microns was 0.7 +/- 0.05 J/cm2 (perforation) and 0.55 +/- 0.08 J/cm2 for depth measurements. Ablation rate as a function of hydration increased to 2.3 (wet/dry weight) with a decrease for higher hydrations. Ablation rate as a function of the pulse repetition rate showed an increase of up to 20 Hz, where it was found to be 60% higher.</p><p><strong>Conclusion: </strong>The first systematic use of free electron laser technology positively correlated ablation efficiency with target material absorption, thus identifying a \"new\" promising wavelength at around 6.2 microns for materials with a high water content such as corneal tissue.</p>","PeriodicalId":79348,"journal":{"name":"Journal of refractive and corneal surgery","volume":"10 4","pages":"433-8"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18534991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corneal sensation following excimer laser photorefractive keratectomy in humans.","authors":"T Ishikawa,&nbsp;S B Park,&nbsp;C Cox,&nbsp;M del Cerro,&nbsp;J V Aquavella","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Background: </strong>For the correction of myopia, small amounts of corneal tissue--including corneal nerves--are removed, resulting in flattening of the central cornea.</p><p><strong>Methods: </strong>We studied the changes in corneal sensation in five regions of the cornea following photorefractive keratectomy at varying depths. We examined and compared the recovery of sensation in 17 sighted myopic eyes, with preoperative refractive ranges from -1.00 to -7.25 D. Eyes were divided into shallow (0 to 30 microns) or deep (31 to 70 microns) ablation groups depending on the attempted laser correction. Corneal sensation was measured in the central ablated area and the temporal, inferior, nasal, and superior unablated regions preoperatively and at 1, 3, and 6 months postoperatively.</p><p><strong>Results: </strong>Central and inferior sensation were significantly reduced in the deep ablations at 1 month and continued in the central cornea 6 months postoperatively. There were no overall differences in the sensations in the unablated nasal, temporal, and superior regions between either group or over time. There was a significant second order trend (p = .034) in these three regions, indicating a sharper increase in sensation from baseline in the deeper group at 1 month than the gradual upward trend of the shallow group.</p><p><strong>Conclusions: </strong>Corneal sensation of both the central ablated area and the unablated peripheral cornea is decreased after deep anterior stromal excimer laser ablations and does not recover within 1 month. Although the deeper group showed isolated areas in the periphery of significant second order trends in sensation, the overall trends were not large, indicating no significant anesthetic effect. Fluctuations in sensation can be detected in the five regions even 6 months after excimer laser keratectomy. The clinical importance of these data remain to be defined.</p>","PeriodicalId":79348,"journal":{"name":"Journal of refractive and corneal surgery","volume":"10 4","pages":"417-22"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18537823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photoablation of gelatin with the free-electron laser between 2.7 and 6.7 microns.","authors":"B. Jean, T. Bende","doi":"10.3928/1081-597X-19940701-10","DOIUrl":"https://doi.org/10.3928/1081-597X-19940701-10","url":null,"abstract":"BACKGROUND\u0000Photoablation in the infrared (IR) is an option for future refractive and corneal surgery; its basic principles have not yet been investigated systematically. For the first time, the free electron laser allows the dynamic study of photoablation over a wide range of wavelengths with variable combinations of pulselength and energy. The goal of this study is to use the free electron laser as a tool to describe photoablation in the IR quantitatively. We studied the function of wavelength as it is related to target material spectroscopy and the effects of corneal hydration and the pulse repetition rate.\u0000\u0000\u0000METHODS\u0000Surface absorption spectroscopy of the human cornea and of gelatin as a proven model of the cornea was performed between 2.7 and 6.7 microns. Gelatin probes of well-defined thickness (140 +/- 5 microns) and controlled hydration (wet/dry weight 1 to 4.5) served as target material. Photoablation was performed with the Vanderbilt University free electron laser (Nashville, Tenn) in September 1992 at a fluence of 1.27 J/cm2, and a macropulse of 4 microseconds, composed of 2 ps micropulses at a 2.9 GHz pulse repetition rate. Wavelength was tunable between 2.7 and 6.7 microns at stable beam profiles. Ablation experiments were performed as a function of energy, hydration, and pulse repetition rate. Ablation rates were assessed by a) perforation experiments, and b) direct measurements using confocal laser topometry (UBM, Ettlingen, FRG).\u0000\u0000\u0000RESULTS\u0000Ablation rate, assessed by perforation experiments and topometry, correlated well with the corresponding measured absorbencies of the target material: maximal ablation rate at maximal target absorption, around the 3- and 6-micrometer water absorption bands. The ablation threshold at 6.2 microns was 0.7 +/- 0.05 J/cm2 (perforation) and 0.55 +/- 0.08 J/cm2 for depth measurements. Ablation rate as a function of hydration increased to 2.3 (wet/dry weight) with a decrease for higher hydrations. Ablation rate as a function of the pulse repetition rate showed an increase of up to 20 Hz, where it was found to be 60% higher.\u0000\u0000\u0000CONCLUSION\u0000The first systematic use of free electron laser technology positively correlated ablation efficiency with target material absorption, thus identifying a \"new\" promising wavelength at around 6.2 microns for materials with a high water content such as corneal tissue.","PeriodicalId":79348,"journal":{"name":"Journal of refractive and corneal surgery","volume":"10 4 1","pages":"433-8"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70145809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}