bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of Laser in situ Keratomileusis and Photorefractive Keratectomy to Correct Myopia from -1.25 to -6.00 Diopters
Authors: Wang Zheng , Chen Jiaqi , Yang Bin 
Published: April 2021

ABSTRACT
BACKGROUND: We evaluated the safety and efficacy of laser in situ keratomileusis (LASIK) for the correction of low to moderate amounts of myopia (-1.25 to -6.00 D).
METHODS: Photorefractive keratectomy (PRK) was performed on 432 eyes and LASEK on 137 eyes with a Chiron Keracor 116 excimer laser. Uncorrected and corrected visual acuity, corneal sensitivity, contrast sensitivity, and corneal topography were examined before and after surgery.
RESULTS: One-year follow-up of 307 eyes in the PRK group and 103 eyes in the LASLK group was achieved. At 1 year, 83% (85 of 103) of LASLK eyes and 72% (221 of 307) of PRK eyes had an uncorrected visual acuity of 1.0 or better. Eighty-nine percent (92 of 103) of LASLK eyes and 83% (255 of 307) of PRK eyes had a refractive error within ±1.00 D of emmetropia; 71% (73 of 103) of LASLK eyes and 61% (188 of 307) of PRK eyes were within ±0.50 D of emmetropia. Contrast sensitivity and corneal sensitivity were reduced in both groups at the early postoperative stage but gradually returned to preoperative values; their recovery took about 3 months in LASIK eyes and 6 to 12 months in PRK eyes.
CONCLUSION: LASIK is safe and more predictable than PRK to correct low to moderate amounts of myopia. Recovery from LASLK is faster than after PRK. [J Refract Surg 1997;13:528-534]
Mesopic Contrast Sensitivity Function After Excimer Laser Photorefractive Keratectomy
Authors: Montés-Micó Robert , Charman W Neil 
Published: April 2021

ABSTRACT
PURPOSE: To evaluate contrast sensitivity under mesopic conditions in patients who had undergone uncomplicated excimer laser photorefractive keratectomy (PRK) for myopia.
METHODS: Monocular contrast sensitivity function was measured with the Stereo Optical ?A.C.T. chart in 26 patients who had received PRK using the Nidek EC-5000 excimer laser system. Mean preoperative refractive error was -6.23 ? 1.69 D (range, -4.00 to -8.25 D); postoperatively, mean refractive error was -0.36 ? 0.58 D (range, -0.75 to +0.50 D). Contrast sensitivity function was measured 6 months after surgery using four different chart luminances: 85, 5.0, 2.5, and 0.1 cd/m2, the first being a photopic level and the rest mesopic. A control group of eight emmetropic subjects was also studied to allow comparison of results for statistical purposes.
RESULTS: Logarithmic values of contrast sensitivity at each spatial frequency were used for statistical analysis and normalized values were used for graphical representation. The results showed a statistically significant reduction (P<.01) in contrast sensitivity for the PRK patients in comparison with the control group under mesopic conditions for each spatial frequency tested (1.5, 3, 6, 12, and 18 c/deg), although no significant contrast sensitivity differences were observed between PRK and control groups at the photopic (85 cd/m2) level (P>.01 for all frequencies).
CONCLUSION: Photorefractive keratectomy can induce significant reductions in contrast sensitivity under mesopic conditions, even though the photopic contrast sensitivity function is normal. [J Refract Surg 2002;18:9-13]
Image Quality and Visual Performance in the Peripheral Visual Field Following Photorefractive Keratectomy
Authors: Montés-Micó Robert , Charman W Neil 
Published: April 2021

ABSTRACT
PURPOSE: A theoretical and experimental study was performed to assess the possible effects of photorefractive keratectomy (PRK) on retinal image quality and thresholds in the peripheral visual field.
METHODS: Simple optical calculations suggest that although the quality of the retinal image at the fovea of the postoperative PRK eye may be comparable to that in an emmetropic eye, images in the peripheral field may be markedly worse, since peripheral ray bundles may pass partly through ablated and partly through unablated cornea, giving a simultaneous-vision bifocal effect. This would be expected to create an annular zone of confusion, so that light from two different directions in object space arrives at the same point on the retina. The position of this zone and its width are a function of the ablation zone geometry, the attempted correction, and the pupil diameter, but the major effects typically occur at field angles between about 40° and 60°. To explore this effect, Goldmann static quantitative perimetry was carried out along the 0° to 180° meridian in six patients who had undergone myopic PRK and eight emmetropes.
RESULTS: The results showed that thresholds for the PRK group at field angles from 40° to 60° were significantly higher than those of the emmetropic group (P<.01). These findings arise because the retinal images in the peripheral field of originally myopic, postoperative PRK patients are, in general, significantly degraded in comparison with those of emmetropes.
CONCLUSION: Although under photopic conditions, retinal image quality close to the visual axis in patients who have been corrected by PRK is similar to that in emmetropes, it may be markedly worse in the peripheral visual field. [J Refract Surg 2002;18:14-22]
Management of Corneal Ectasia After Laser in situ Keratomileusis With INTACS
Authors: Siganos Charalambos S , Kymionis George D , Astyrakakis Nikos , Pallikaris Ioannis G 
Published: April 2021

ABSTRACT
PURPOSE: To evaluate the safety and efficacy of intrastromal corneal ring segments (ICRS, INTACS, Keravision) for the correction of corneal ectasia after laser in situ keratomileusis (LASIK).
METHODS: In this prospective, noncomparative case series, INTACS were implanted in three eyes (two patients) that were ectatic after LASIK. Mean follow-up was 8.7 months (range, 8 to 10 mo).
RESULTS: No intraoperative complications occurred. After INTACS implantation, uncorrected visual acuity ranged from 20/20 to 20/25 at 6 months and remained stable until 9 months. Mean postoperative spherical equivalent refraction was 0.50 D at 1 month and no significant changes appeared up to 9 months after LNTACS implantation. After INTACS implantation, no eye lost any lines of Snellen spectacle-corrected visual acuity and two eyes gained from one to two lines. There was an increase in topographical regularity in all three eyes.
CONCLUSION: Implantation of LNTACS in eyes with corneal ectasia after LASLK resulted in good refractive outcome, absence of complications, and improvement in visual acuity. [J Refract Surg 2002;18:43-46]
Tear Secretion Following Excimer Laser in situ Keratomileusis
Authors: Siganos Dimitrios S , Popescu Corina N , Siganos Charalambos S , Pistola Georgia 
Published: April 2021

ABSTRACT
PURPOSE: To evaluate the effect of laser in situ keratomileusis (LASIK) on tear secretion.
METHODS: A non-consecutive series of 42 eyes of 42 patients had LASIK for the correction of myopia and myopic astigmatism. The fellow eye served as a control. The mean preoperative spherical equivalent refraction was -5.25 ? 1.00 D (range, -1.75 to -11.00 D). Attempted correction aimed at emmetropia. Schirmer I and II, and tear break-up time (BUT) tests were performed preoperatively and at 1, 3, and 6 months postoperatively. All tests were correlated to the amount of the attempted correction.
RESULTS: Preoperatively, mean values were Schirmer 1: 16.2 mm, Schirmer II: 11.6 mm, and BUT. 16.3 sec. One month after LASEK, mean values were Schirmer 1: 12.8 mm, Schirmer II: 9.2 mm, and BUT: 13.3 sec. At 3 months, mean values were Schirmer I: 15.76 mm, Schirmer II: 11.3 mm, and BUT: 14.15 sec. At 6 months, mean values were Schirmer I: 15.96 mm, Schirmer II: 11.66 mm, and BUT: 16.3 sec. No correlation to the amount of attempted correction was found. Fellow eye tests were not affected at any interval.
CONCLUSIONS: Tear secretion following LASIK was decreased during 3 months after surgery and was normalized by 6 months. [J Refract Surg 2002;18:124-126]
Comparison of TGF-β1 in Tears Following Laser Subepithelial Keratomileusis and Photorefractive Keratectomy
Authors: Lee Jae Bum , Choe Chul-Myong , Kim Hyon S , Seo Kyoung Yul , Seong Gong Je , Kim Eung Kweon 
Published: April 2021

ABSTRACT
PURPOSE: To compare the release of tear fluid transforming growth factor-?l (TGF-?l) of 15 patients who underwent photorefractive keratectomy (PRK) in one eye and laser subepithelial keratomileusis (LASEK) in the other eye.
METHODS: Tear fluid samples were collected with scaled microcapUlary tubes preoperatively (day 0) and on the first, second, and seventh postoperative days. We calculated the release of TGF-β1 (tear fluid flow-corrected concentrations of TGF-β1) by multiplying the concentration by capillary tear fluid flow and also evaluated corneal haze at 1, 3, and ? months after PRK or LASEK.
RESULTS: The median TGF-βl release values were: Day 0: 50.6 pg/min (range 0 to 101.6 pg/min) for PRK and 56.7 pg/min (range 0 to 121.8 pg/min) for LASEK (P=.496); Day 1: 240.6 pg/min (range 56.6 to 1120.2 pg/min) for PRK and 155.2 pg/min (range 45.1 to 480.4 pg/min) for LASEK, which showed a significant difference between the two procedures (P=.041); Day 2: 395.7 pg/min (range 92.3 to 1150.7 pg/min) for PRK and 185.2 pg/min (range 41.4 to 872.5 pg/min) for LASEK (P=.004); and Day 7: 91.3 pg/min (range 0 to 225.4 pg/min) for PRK and 74.3 pg/min (range 0 to 187.1 pg/min) for LASEK, (P=.244). The mean corneal haze score at 1 month after PRK was 0.88 ± 0.50 and 0.53 ± 0.29 after LASEK, and a statistically significant difference was noted between the two groups (P=.005). At 3 months (P=.083) and 6 months (P=.157) after the procedures, there were no statistically significant differences.
CONCLUSIONS: A lower amount of tear fluid transforming growth factor-?l was released in the early postoperative days following LASEK than in PRK. The lower grade of corneal haze seen in LASEK than PRK in the early postoperative period may come from a decreased release of TGF-?l, which may have a role in wound healing. [J Refract Surg 2002;18:130-134]
Laser in situ Keratomileusis for Hyperopia and Hyperopic Astigmatism Using the Meditec MEL 70 Spot Scanner
Authors: Ditzen Klaus , Fiedler Joachim , Pieger Stefan 
Published: April 2021

ABSTRACT
PURPOSE: To evaluate safety, predictability, efficacy, and stability of laser in situ keratomileusis (LASIK) for spherical hyperopia and hyperopia with astigmatism
METHODS: In this retrospective study we analyzed the results of 23 eyes of 23 patients who had LASIK for spherical hyperopia (preoperative cylinder SS0.75 D) and 44 eyes of 44 patients who had LASIK for hyperopia with astigmatism; (Bausch & Lomb Hansatome microkeratome with a 180-/*m plate and a suction ring for a 9.5-mm flap diameter; Asclepion-Meditec MEL 70 G-scan flying spot laser with a 1.8-mm Gaussian beam).
RESULTS: In Group 1 (spherical hyperopia), mean preoperative spherical equivalent refraction was +4.88 ? 2.13 D (range +2.13 to +9.63 D); in Group 2 (hyperopic astigmatism), +4.33 ? 2.15 D (range +0.50 to +9.50 D). One year after LASIK, mean spherical equivalent refraction was +0.30 ? 0.90 D (range -0.75 to +2.50 D) in Group 1 and +0.29 ? 1.27 D (range -3.25 to +3.25 D) in Group 2. In Group 1, 78%, and in Group 2, 42% were within ?0.50 D. In Group 1, no eyes lost two or more lines, and one eye (6%) lost one line of best spectacle-corrected visual acuity at 1 year. In Group 2, one eye (4%) lost one line and one eye (4%) lost more than two lines at 1 year. Uncorrected visual acuity of 20/40 or better was achieved in 83% (Group 1) vs. 62% (Group 2) at 1 year; these values improved to 100% vs. 71% for corrections up to +6.00 D.
CONCLUSIONS: LASBK with the M?dit?e MEL 70 G-Sean flying spot laser seemed to be safe and effective for hyperopia and hyperopia with astigmatism for corrections up to +6.00 D. Large flap diameters are necessary to avoid epithelial ingrowth. [J Refract Surg 2002;18:430-434]
An Informal Satisfaction Survey of 200 Patients After Laser in situ Keratomileusis
Authors: Hill John C 
Published: April 2021

ABSTRACT
PURPOSE: Patient satisfaction following laser in situ keratomileusis (LASIK) is commonly reported as high. This paper reviews the outcome of LASIK both in terms of visual results and satisfaction.
METHODS: Two-hundred patients were surveyed telephonically to establish their degree of satisfaction with LASIK and to enquire about postoperative use of glasses, and symptoms of light sensitivity and of night vision problems. Patient anonymity was assured.
RESULTS: The majority of patients (95%) never wore distance glasses after LASIK. Reading glasses were used by 49 (24.5%), related to age and presbyopia. Light sensitivity was not a problem or was unchanged from baseline in 73% of patients; 27% said they were worse; a few (5J>%) said their symptoms were better. Night vision was not a problem or was unchanged from baseline in 76% of patients; 24% said they were worse; 17% said their symptoms were better. One hundred ninety-five patients (97.5%) were extremely happy with their results and 197 (98.5%) would have the procedure again.
CONCLUSION: After LASErL 95% of 200 patients wore no distance optical correction; 99% would have the procedure again; and light sensitivity and night vision problems bothered a significant number of patients. [J Refract Surg 2002;18:454-459]
Anterior Lamellar Keratoplasty With a Microkeratome: A Method for Managing Complications After Refractive Surgery
Authors: Hafezi Farhad , Mrochen Michael , Fankhauser Franz , Seiler Theo 
Published: April 2021

ABSTRACT
PURPOSE: To demonstrate a technique of anterior lamellar keratoplasty with standardized and automated preparation of surface-parallel cuts in both donor and recipient appropriate for addressing several problems after laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK).
METHODS: We report a noncomparative series of ten eyes with complications after LASIK and PRK. Lamellar cuts were performed in donor and recipient eyes by means of an automated microkeratome. Lamellar grafts were fixed by only four single sutures. In two eyes, a re-lift LASLK was performed after 6 months.
RESULTS: Surgery was uneventful and visual acuity was improved in all eyes. Residual irregular astigmatism and refractive error were corrected in two eyes by means of excimer laser computerassisted ablation and resulted in a further improvement of uncorrected and best spectaclecorrected visual acuity.
CONCLUSIONS: Anterior lamellar keratoplasty with a microkeratome can be used for the management of certain complications of PRK and LASIK. [J Refract Surg 2003;19:52-57]
Laser in situ Keratomileusis for Compound Myopic Astigmatism Using the Meditec MEL 70 G-Scan Excimer Laser
Authors: Uçakhan Ömür Ö 
Published: April 2021

ABSTRACT
PURPOSE: To determine the safety, efficacy, predictability, and stability of laser in situ keratomileusis (LASIK) in treating patients with myopic astigmatism using the Meditec MEL 70 G-Scan excimer laser.
METHODS: Seventy-four eyes of 42 patients with myopia ranging from -4.50 to -9.88 D and astigmatism ranging from 0.50 to 4.00 D who underwent LASIK with the Meditec MEL 70 G-Scan excimer laser and the Summit Krumeich-Barraquer microkeratome were studied. Patients were followed for 1 year.
RESULTS: Mean baseline spherical equivalent refraction was -7.12 ± 1.70 D and cylinder was 1.62 ± 1.72 D. At 12 months, mean postoperative spherical equivalent refraction was -0.49 ± 0.57 D and mean refractive cylinder was 0.59 ± 0.32 D. Mean change in spherical equivalent refraction between 1 and 12 months after surgery was -0.09 ± 0.31 D, toward myopia. At baseline, no eyes had best spectaclecorrected visual acuity (BSCVA) of 20/20 or better, and 65% had 20/40 or better. At 12 months after surgery, 10% of eyes had BSCVA of 20/20 or better and 88% of eyes had 20/40 or better. The unusually low postoperative BSCVA results were thought to be due to amblyopia or existence of a higher percentage of some optical aberrations in this group of eyes. Mean uncorrected visual acuity was -1.38 ± 0.42 LogMAR units (20/400) at baseline and -0.29 ± 0.25 LogMAR units (20/40) at the 12-month postoperative examination. No eyes lost two or more lines of spectacle-corrected visual acuity. No vision threatening complications were observed.
CONCLUSIONS: LASIK with the Meditec MEL 70 G-Scan excimer laser appeared to be safe, effective, reasonably predictable, and stable for correction of myopic astigmatism with a spherical component between -4.25 and -8.25 D and a cylindrical component between 0.50 and 4.00 D. However, astigmatism was slightly undercorrected with the algorithm used. [J Refract Surg 2003;19:124-130]
Bilateral Marginal Sterile Infiltrates and Diffuse Lamellar Keratitis After Laser in situ Keratomileusis
Authors: Ambrósio Renato , Periman Laura M , Netto Marcelo V , Wilson Steven E 
Published: April 2021

ABSTRACT
PURPOSE: To report cases of acute bilateral catarrhal infiltrates in the early postoperative period after laser in situ keratomileusis (LASIK).
METHODS: Retrospective review of both eyes of two patients.
RESULTS: Two patients developed acute bilateral, marginal, catarrhal infiltrates in the early postoperative period after LASIK. Both patients had moderate to severe chronic meibomian gland dysfunction preoperatively. One patient (both eyes) developed grade 3 diffuse lamellar keratitis (DLK) that required both flaps to be lifted for irrigation and cleaning on postoperative day 5. Fungal and bacterial cultures were negative in both eyes of both patients. The condition resolved with intensive topical corticosteroids and fortified antibiotics. Regression of refractive error and the need for enhancement was encountered in all eyes. There was mild recurrence in one eye of each patient with pretreatment with topical corticosteroids prior to enhancement.
CONCLUSIONS: Endogenous factors such as chronic blepharitis and meibomian gland dysfunction may trigger inflammation resulting in sporadic cases of catarrhal infiltrates after LASIK. These patients may have chronic inflammatory milieus that can trigger sporadic cases of catarrhal infiltrates after LASIK, with accompanying diffuse lamellar keratitis. (J Refract Surg 2003;19:154-158)
Outcomes After Laser in situ Keratomileusis Retreatment in High Myopes
Authors: Rani Alka , Balasubramanya Ramamurthy , Sharma Namrata , Tandon Radhika , Vajpayee Rasik B , Dada Vijay K , Singh Rajvir 
Published: April 2021

ABSTRACT
PURPOSE: To evaluate the refractive and visual performance after laser in situ keratomileusis (LASIK) retreatment.
METHODS: A retrospective study was performed on 33 eyes of 23 patients who underwent LASIK (Bausch & Lomb Technolas 217C) retreatment for residual myopia with or without astigmatism. Parameters evaluated were uncorrected and best spectacle-corrected visual acuity, spherical equivalent refraction, contrast sensitivity, glare acuity, and pachymetry, preoperatively and at 1, 3, and 6 months postoperatively.
RESULTS: The mean spherical equivalent refraction before primary LASIK was -9.89 ± 4.00 D and before retreatment was -2.85 ±2.17 D. Although contrast sensitivity and glare acuity decreased significantly after primary LASIK (P<.05), no significant change in these parameters was observed after retreatment. Smaller ablation zones were associated with decreased contrast sensitivity and glare acuity after primary LASIK as well as following retreatment. Contrast sensitivity and glare acuity following primary LASIK were significantly better in eyes with ablation zones 5=5 mm than those with <5 mm (P<.05). Eyes in which the ablation zone was the same as that for primary LASIK had significantly better contrast sensitivity than those with different ablation zones (increased or decreased) during retreatment. Attempted refractive correction during primary LASIK and retreatment had a significant negative correlation with contrast sensitivity and glare acuity following primary LASIK as well as retreatment.
CONCLUSION: The ablation zones following primary LASIK and retreatment should be 5=5.00 mm and remain unchanged to improve visual performance. [J Refract Surg 2003;19:159-164]
Reduction of Spherical Aberration With the Nidek NAVEX Customized Ablation System
Authors: Vinciguerra Paolo , Camesasca Fabrizio I , Urso Rosario 
Published: April 2021

ABSTRACT
PURPOSE: Spherical aberration is the most frequent optical aberration induced by refractive surgery, reducing visual acuity and causing halos. We present preliminary results of Custom Ablation Transition Zone (CATz), which we developed for Nidek's Final Fit software, part of the Nidek NAVEX customized ablation system.
METHODS: We studied 55 eyes of 51 patients (31 males, 20 females) who underwent refractive surgery. Mean preoperative spherical equivalent refraction was -5.50 ± 3.30 D (range -12.00 to +4.50 D). Mean age was 35 years (range 23 to 47 yr). All patients underwent complete preoperative ophthalmologic examination, including aberrometry and topography, then surgery with laser epithelial keratomileusis, and OPD-based refractive treatment with the Nidek EC-5000 excimer laser. The Nidek Final Fit software with the CATz feature was always used. Postoperatively, all patients repeated the ophthalmologic examination inclusive of aberrometry at day 30, 60, and 90.
RESULTS: The 3-month follow-up rate was 21.8%. Mean postoperative spherical equivalent refraction was -0.33 ± 0.91 D (range -0.75 to +0.75 D), with a mean sphere of -0.23 ± 0.78 D (range -2.50 to +0.75 D) and a mean cylinder of -0.21 ± 0.33 (range -1.00 to 0 D). At 3 months, 43% of eyes achieved 20/15 or better UCVA, and 43% achieved 20/20 or better UCVA; 63% achieved 20/15 or better BSCVA and 25% achieved 20/20 or better BSCVA. Postoperative spherical aberration was unchanged for a 3-mm pupil.
CONCLUSION: Customized ablation with the Nidek NAVEX system provided excellent refractive results. The CATz algorithm of the Nidek Final Fit software appeared to prevent induction of spherical aberration. [J Refract Surg 2003;19(suppl): S195-S201]
Comparison of Conventional Versus Wavefront-guided Laser in situ Keratomileusis in the Same Patient
Authors: Phusitphoykai Nutharin , Tungsiripat Tulaya , Siriboonkoom Janpen , Vongthongsri Anun 
Published: April 2021

ABSTRACT
PURPOSE: To verify whether there is any difference in visual outcome, including higher order aberrations, after performing laser in situ keratomileusis (LASEK) with conventional ablation and wavefront-guided ablation in myopic eyes of the same patient.
METHODS: This was a prospective randomized study of 20 myopic eyes (10 patients) who had LASIK using the Nidek NAVEX excimer laser system. Wavefront-guided customized ablation was used in the first eye of the patient (study group) and the other eye of the same patient was operated with conventional ablation (control group). Mean refractive error was similar between left and right eyes of the same patient. Preoperative examination included higher order aberration by Nidek OPDScan. Uncorrected and best spectacle-corrected visual acuity and higher order aberrations were recorded postoperatively.
RESULTS: Preoperative and postoperative best spectacle-corrected visual acuity was better than 20/40 (100%) after LASEK in both the conventional ablation and wavefront-guided customized ablation groups. Postoperative refraction was within ±0.50 D of emmetropia: 90% in the conventional group and 100% in the wavefront-guided group. No statistically significant difference in postoperative higher order aberrations was found between groups.
CONCLUSION: Postoperative visual outcome with both conventional LASIK and wavefrontguided customized ablation was not significantly different. Higher order aberrations did not significantly increase postoperatively in either group. [J Refract Surg 2003;19(suppl):S217-S220]