bluuebunny/crossref_metadata_2025_split huggingface dataset:
Results of Photorefractive Keratectomy for Low, Moderate, and High Myopia
Authors: Tuunanen Tiina H , Tervo Timo T 
Published: April 2021

ABSTRACT
PURPOSE: To compare the predictability, safety, and stability of photorefractive keratectomy (PRK) in patient groups with low, moderate, and high myopia. The astigmatic component of these corrections was also evaluated.
METHODS: In 110 patients, 110 consecutive eyes were operated with a VISX 20/20 excimer laser using standard settings and a 6 mm ablation zone for PRK. The eyes were divided into three groups. In low myopia group (N=52) the intended correction ranged from -1.50 to -6.00 D (mean -4.28 ± 1.29 D), in the moderate myopia group (N=34) from -6.10 to -8.00 D (mean -7.05 ± 0.70 D), and in the high myopia group (N=24) from -8.10 to -11.50 D (mean -9.40 ± 1.13 D). Twenty-seven eyes had 0.75 D of preoperative myopic astigmatism. All patients were followed for 12 months and 36% (N=40) were available for the 24-month follow-up examination.
RESULTS: At 12 months the spherical equivalent manifest refraction was within 0.50 D of intended refraction in 58% (N=30) of eyes in the low myopia group, 50% (N= 17) in the moderate myopia group, and 29% (N=7) in the high myopia group. Eighty-seven percent (N=45) in low, 79% (N= 27) in moderate, and 67% (N=16) in the high myopia group were within 1.00 D of intended refraction. At 12 months, 88% (N=46) of the eyes with low myopia, 68% (N=23) with moderate myopia, and 68% (N=16) with high myopia achieved uncorrected visual acuity of 20/40 or better, while 6% (N=16) of the eyes lost and 4% (N=4) gained two or more lines of Snellen visual acuity. Uncorrected visual acuity of 20/20 or better at 12 months was achieved by 58% (N=30) of low myopes, 26% (N=9) of moderate myopes, and 33% (N=8) of high myopes; 20/25 or better by 71% (N=37) of low myopes, 39% (N=13) of moderate myopes, and 42% (N=IO) of high myopes. Overcorrection (>0.25 D) was detected at 12 months in 31% (N=16) with low, 38% (N=13) with moderate, and 67% (N=16) with high baseline myopia, with statistically significant differences between the low and high myopia groups.
CONCLUSION: In all groups, the safety of PRK was satisfactory, without major complications; in the high myopia group where corrections exceeded 8.0 D (mean -9.40 ± 1.13 D) the procedure was only slightly more unpredictable than in low and moderate myopia at 1 year. [J Refract Surg 1998;14:437-446J
Stability of Astigmatism Over 3 Years After Corneal Stretch Incision
Authors: Müller-Jensen Kei , Buchholz Andreas , BarIinn Björn 
Published: April 2021

ABSTRACT
PURPOSE: To assess long-term corneal stability of self-sealing clear corneal stretch incisions with implantation of 5 mm polymethylmethacrylate (PMMA) intraocular lenses.
METHODS: Two hundred consecutive eyes of 3500 cataract patients who had capsulorhexis, phacoemulsification, and preparation of a 1.5 to 2.0 mm corneal tunnel that had an external width of 4.0 to 4.1 mm and an internal width of 6.5 to 7.0 nun (stretch incision), and implantation of a 5 mm PMMA intraocular lens were evaluated clinically and statistically. Slit-lamp microscopy, keratometry, and corneal topography were performed preoperatively and postoperatively after 1 week, 1, 2, and 3 years.
RESULTS: The mean surgically induced astigmatism following superior corneal incision amounted to 1.59 ± 1.06 D after 3 years; following lateral corneal incision, mean surgically induced astigmatism was 0.84 ± 0.68 D. There were no corneal complications in the long-term follow-up study.
CONCLUSION: Our 5-year experience shows that the self-sealing clear corneal stretch incision in connection with implantation of a 5 mm polymethylmethacrylate intraocular lens induces approximately 1.00 D of astigmatism. We prefer the lateral incision and recommend the superior incision only for high preoperative with-the-rule astigmatism. [J Refract Surg 1998;14:455-458]
The Picosecond Laser for Nonmechanical Laser in situ Keratomileusis
Authors: Krueger Ronald R , Juhasz Tibor , Gualano Antonio , Marchi Vincenzo 
Published: April 2021

ABSTRACT
PURPOSE: To introduce the clinical use of the Nd:YLF picosecond laser as a nonmechanical microkeratome.
METHODS: A commercially available Nd:YLF picosecond laser (25 µJ/pulse, 30 psec, 1053 nm) was used to deliver intrastromal pulses of focused high power laser light to generate a flap for laser in situ keratomileusis (LASIK) and perform picosecond laser keratomileusis (PLK) in two partially sighted patients with high myopia.
RESULTS: Case #1: A 6 mm, 150 µp? flap for LASIK was successfully created and the underlying stroma treated with an excimer laser for a target correction of -15.00 D of myopia. Good corneal clarity and a refractive change of -14.00 D was recorded 2 months postoperatively. Case #2: Both eyes of a high myope (-22.00 D right eye, -21.50 D left eye) underwent picosecond laser keratomileusis, removing a 3.2 mm diameter lenticule of 120 urn thickness under a 200 µp? flap. Postoperative refraction was -2.00 D at 7 months in the right eye and -0.75 D at 2 months in the left eye with improvement of spectacle-corrected visual acuity from 20/200 to 20/70 in each eye.
CONCLUSION: The Nd:YLF picosecond laser can be safely used in creating a corneal flap for LASIK and in performing picosecond laser keratomileusis for high myopia. Future refinements in the laser will include a larger flap diameter and femtosecond pulsing capability. [J Refract Surg 1998;14:467-469]
Ultrasound Biomicroscopic Imaging of Posterior Chamber Phakic Intraocular Lens
Authors: Trindade Fernando , Pereira Frederico , Cronemberger Sebastião 
Published: April 2021

ABSTRACT
BACKGROUND: Phakic intraocular lens (IOL) implantation represents a major technique for the correction of high myopia. The STAAR collamer posterior chamber phakic IOL- trade named Implantable Contact Lens- is an emerging technology in refractive surgery. We studied the relative position of the posterior chamber phakic IOL using ultrasound biomicroscopy.
METHODS: The posterior chamber phakic intraocular lens was inserted in 9 eyes of 8 patients with high myopia. Ultrasound biomicroscopy was performed before and after implantation of the phakic IOL to assess its relative position in the anterior segment of the eye. The parameters measured and compared were anterior chamber depth, angle opening distance 500 urn from the scleral spur, iris-crystalline lens contact distance, iris-IOL contact distance, and K)L- crystal Ii ne lens distance.
RESULTS: Ultrasound biomicroscopy showed contact between the iris and the IOL in all eyes and between the IOL and the crystalline lens in 8 eyes. Reduction in the anterior chamber depth and localized narrowing of the angle opening were observed in all eyes.
CONCLUSION: IOL-iris touch, IOL-crystalline lens touch, and anterior chamber shallowing raise concerns of pigmentary dispersion, cataractogenesis, and narrow angle glaucoma following posterior chamber phakic intraocular lens implantation. Clinical data are needed to determine if these problems occur. [J Refract Surg 1998;14:497-503]
Astigmatism Outcomes Following Spherical Photorefractive Keratectomy for Myopia
Authors: Al-Abdulla Nael A , Jabbur Nada S , O'Brien Terrence P 
Published: April 2021

ABSTRACT
BACKGROUND: Our aim was to examine the change in astigmatism after spherical photorefractive keratectomy (PRK). These effects are essential to optimizing photoastigmatic refractive keratectomy (PARK) to correct astigmatism to within fractions of a diopter.
METHODS: We retrospectively reviewed 98 eyes of 178 patients with mild to moderate myopia and cylinder «1.00 diopter (D) treated with spherical PRK (VISX 20/20 STAR excimer laser system); 31 eyes had epithelium removed mechanically with a blade and 67 eyes by a laser-scrape technique.
RESULTS: Refractive astigmatism was reduced by greater than 0.25 D in 27 eyes (28%); refractive astigmatism was induced by greater than 0.25 D in 31 eyes (32%); the average vector-corrected difference between an eye's astigmatism before and after surgery was 0.01 ± 0.52 D (P=.85). Eyes with high topographic astigmatism but low refractive cylinder before PRK showed an average of 0.07 ± -0.60 D change in refractive cylinder after PRK. Refractive astigmatism of more than 0.25 D was induced in 16 eyes (44%) that received manual removal of epithelium versus 15 eyes (24%) that received laser removal of epithelium (odds ratio 2.51, P<01).
CONCLUSIONS: When using PRK for astigmatism correction, refractive cylinder before surgery rather than topographic astigmatism may be the most appropriate method for targeting the astigmatism correction, especially when the two values are discordant. An unpredictable mild increase or decrease in astigmatism may be expected. [J Refract Surg 1998;14:610-614]
Radial Keratotomy Clear Zone Diameter Errors
Authors: Grimmett Michael R , Ogawa Gregory S H 
Published: April 2021

ABSTRACT
PURPOSE: To examine the variability of achieved clear zone diameters following radial keratotomy and to determine if refractive outcomes are correlated to clear zone diameter errors.
METHODS: Twenty-six patients with radial keratotomy (51 eyes) were studied retrospectively. The central clear zone diameter for each radial incision meridian was measured using a slit-lamp and a photograph. The achieved clear zone diameters were statistically compared to the intended clear zone sizes and to the refractive outcomes.
RESULTS: Twenty-nine of the 51 eyes met various exclusion criteria. Ninety individual slit-lamp clear zone measurements were obtained for the remaining 22 eyes. Sixty-two of 90 (69%) achieved clear zone diameters were more than 0.25 mm different than the intended clear zone size. A maximum difference of ±0.80 mm from the intended clear zone marker size was observed. The average clear zone diameter error did not statistically differ between the three refractive outcome groups (undercorrection, emmetropia, and overcorrection).
CONCLUSIONS: In selected cases of centripetal radial keratotomy, the achieved clear zone diameter can vary widely from the intended clear zone size despite extensive surgeon experience. [J Refract Surg 1998;14:623-630]
Microbiological Examination of Bandage Soft Contact Lenses Used in Laser Refractive Surgery
Authors: Detorakis Efstathios T , Siganos Dimitrios S , Houlakis Vasilios M , Kozobolis Vasilios P , Pallikaris Ioannis G 
Published: April 2021

ABSTRACT
BACKGROUND: Disposable soft contact lenses are known to be colonized by bacteria and play a key role in bacterial keratitis pathogenesis. Such lenses, commonly used after laser refractive surgery procedures in which postoperative corneal infiltrations are sometimes observed, are potentially a substrate for bacterial inoculation. This study evaluates the extent of such a contamination.
METHODS: Sixty disposable lenses collected from 60 eyes of patients who underwent photorefractive keratectomy (PRK), photoastigmatic refractive keratectomy (PARK), or laser in situ keratomileusis (LASK) for the treatment of myopia or hyperopia were collected under sterile conditions over 4 months and cultured in various media. Results were statistically analyzed and the correlation with clinical and epidemiological data was examined.
RESULTS: Eleven (18.3%) of the examined lenses were contaminated with Staphylococcus epidermidis. No other bacteria or fungi were found. Contamination was significantly more common among female patients (P=.036). Correlation with the other clinical or operative parameters examined was statistically insignificant.
CONCLUSIONS: Contamination was independent of the surgical procedure and females who were frequent users of eyelid cosmetics displayed higher contamination frequencies, suggesting that bacteria possibly originate from eyelid flora. The isolation of Staphylococcus epidermidis requires close postoperative surveillance, since it is a known cause of keratitis. Prophylactic postoperative treatment with tobramycin, gentamycin, or sulphonamides could be indicated. [J Refract Surg 1998;14:631-635]
Refractive Results of Radial Keratotomy After 10 Years
Authors: Charpentier Dominique Y , Garcia Philippe , Grunewald Franck , Brousse Dominique , Duplessix Michel , David Thierry 
Published: April 2021

ABSTRACT
BACKGROUND: We analyzed retrospectively the refractive and visual resulte of a cohort of patients who underwent radial keratotomy for myopia 10 years ago.
METHODS: Radial keratotomies using centripetal incisions were performed by the same surgeon in 1986 and 1987 to correct myopia of -0.75 to -10.00 diopters (D). Refractive and visual results were evaluated at 1 month and on average 10 years after surgery.
RESULTS: Thirty-nine patients (71 eyes) underwent radial keratotomy. Mean spherical equivalent refraction before surgery was -3.90 D and after surgery was -0.50 D at 1 month and +0.13 D at 10 years after surgery. At last examination, 41 eyes (43.7%) had a spherical equivalent refractive error within ±1.00 D of emmetropia (24 eyes [34%] ±0.50 D) and 32.4% of eyes were overcorrected by more than 1.00 D. Between 1 month and 10 years after surgery, a hyperopic shift greater than 1.00 D occurred in 34.1% of eyes with a single procedure. Ten years after surgery, 59 eyes (83%) had uncorrected distance visual acuity of 20/40 or better (22 eyes [31%] with uncorrected visual acuity of 20/20 or better).
CONCLUSION: This retrospective evaluation confirms that radial keratotomy is an effective procedure to correct myopic error, but the hyperopic shift produces an unstable, less predictable refraction in one-third of eyes at 10 years. [J Refract Surg 1998;14:646-648]
Intrastromal Corneal Ring Segments: Reversibility of Refractive Effect
Authors: Asbell Penny A , U¸akhan Ömür Ö , Abbott Richard L , Assil Kerry A , Burris Terry E , Durrie Daniel S , Lindstrom Richard L , Schanzlin David J , Verity Steven M , Waring George O 
Published: April 2021

ABSTRACT
PURPOSE: To evaluate the reversibility of refractive effect following removal of the ICRS (intrastromal corneal ring segments; Intacs).
METHODS: Data from 34 eyes from which ICRS were removed during United States FDA Phase II and III clinical trials were evaluated with regard to segment size, loss or change of best spectacle-corrected visual acuity (BSCVA), any change of uncorrected visual acuity (UCVA), manifest spherical equivalent refraction, manifest cylinder refraction, stability of manifest cylinder refraction, and subjective visual symptoms.
RESULTS: Out of 725 initial or contralateral eyes placed with the ICRS during Phase II and III clinical trials, segments were removed from 34 eyes (4.7%). Other than one (1/725, 0.1%) safety related ICRS removal, 30/725 (4.1%) were due to visual symptoms. ICRS removal was accomplished under topical anesthesia without complications in all eyes. The mean length of time the segments remained in the cornea after initial surgery was 10.3 ± 5.4 months. At 3 months after ICRS removal, 21 eyes had monitored data available and were within ±1 line or 10 letters of their preoperative BSCVA. Twenty eyes (20/21, 95%) returned to within ±1.00 D of their preoperative manifest spherical equivalent refraction. All eyes had a stable refraction at the 3-month examination after removal, and a manifest spherical equivalent refraction within ±1.00 D of their 1-month examination after removal. Nineteen eyes (19/21, 90%) returned to within ±2 lines and 16 eyes (16/21, 76%) returned to within ±1 line of preoperative UCVA.
CONCLUSION: The ICRS (Intacs) was easily and safely removed, and eyes returned to preoperative refractive status within 3 months. [J Refract Surg 2001;17:25-31]
Posterior Chamber Phakic Intraocular Lenses to Correct High Myopia: A Comparative Study Between Staar and Adatomed Models
Authors: Menezo José L , Peris-Martínez Cristina , Cisneros Angel , Martínez-Costa Rafael 
Published: April 2021

ABSTRACTPURPOSE: To determine the feasibility of using posterior chamber phakic intraocular lenses (PIOLs) to treat high myopia, comparing two different models, Staar and Adatomed.METHODS: Twenty-four eyes from 12 patients were studied prospectively. A phakic Staar IOL was implanted in one eye of each patient, and the other eye received a phakic Adatomed IOL. Patients with uveitis or ocular trauma prior to ocular surgery, diabetic retinopathy, or capsular pseudoexfoliation were excluded. The mean preoperative spherical equivalent refraction was -16.00 ± 5.05 D for the Staar group and -15.39 ± 2.83 D for the Adatomed group. Average follow-up was 32.4 months (range, 19 to 46 mo) for the Adatomed group and 18.3 months (range, 11 to 21 mo) for the Staar group and included evaluation of intraocular pressure, intraocular lens pigment deposits, lens decentration, anterior subcapsular cataract, and visual acuity.RESULTS: Spectacle-corrected and uncorrected visual acuity improved in all eyes in both groups. No statistically significant differences in visual acuity gain were observed with the two materials (Student t-test, P = .08 for the Staar group and P = .6 for the Adatomed group), although the gain in visual acuity was somewhat greater with the Staar PIOLs. The difference in mean intraocular pressure before surgery and at last follow-up was 1.5 mmHg for the Staar group and 2.3 mmHg for the Adatomed group (P = .36). The incidence of lens pigment deposits was the same in both groups (41.66%), with deposits in 5 of the 12 eyes in both groups. The incidence of lens decentration was higher in the Adatomed group (5/12; 41.66%) than in the Staar group (2/12; 16.7%). Anterior subcapsular cataract was higher in the Adatomed group (4/12; 33.3%) than in the Staar group (3/12; 25%).CONCLUSIONS: There was a higher incidence of lens decentration and anterior subcapsular cataract in the Adatomed group than in the Staar group. [J Refract Surg 2001;17:32-42]
Correlation Between Refractive and Corneal Topographic Changes After Photorefractive Keratectomy for Myopia
Authors: Rosa Nicola , Cennamo Giovanni , Rinaldi Michele 
Published: April 2021

ABSTRACT
PURPOSE: To compare videokeratographic and refractive data obtained before and after photorefractive keratectomy (PRK) for myopia.
METHODS: Seventy-four eyes underwent PRK for myopia ranging from -2.50 to -17.00 D (mean, -7.76 ± 3.17 D). All patients had videokeratography with the EyeSys instrument before, and 1 and 6 months after PRK, and the changes in three corneal power measurements (center of the ablation, apex, and effective refractive power) were compared with refractive changes.
RESULTS: Changes obtained in the three corneal power measurements at 1 and 6 months were well correlated with manifest refraction (Pearson's coefficient ranged from 0.71 to 0.84).
CONCLUSION: Power measurements obtained with corneal topography, as described above, are a reliable and objective method for the evaluation and follow-up of PRK, provided addition of an approximate 25% correcting factor. [J Refract Surg 2001;17:129-133]
Laser in situ Keratomileusis Results of DOS and Windows Software Versions for the Nidek EC-5000 Excimer Laser Using the Same Nomogram
Authors: Vongthongsri Anun , Hanutsaha Prut , Naripthapan Pichit , Lerdvitayasakul MD Rungroj 
Published: April 2021

ABSTRACT
PURPOSE: To compare the results of laser in situ keratomileusis (LASDK) correction for myopia and myopic astigmatism between the previous DOS software version and the Windows software version for the Nidek EC-5000 excimer laser, using the same nomogram.
METHODS: This retrospective review included 2021 eyes (980 patients) after LASIK using the Nidek EC-5000 excimer laser. Of these, 1632 eyes were corrected with the DOS software version and the other 389 eyes were corrected with the Windows software version of the laser. Both groups were treated with the same surgical nomogram. Minimum follow-up time was 6 months. Patients were classified into range of myopia: low, moderate, and high.
RESULTS: Postoperative uncorrected visual acuity was not statistically significantly different between the two groups in any range of refractive error. There was no loss of best spectacle-corrected visual acuity for any patient. Uncorrected visual acuity equal to or better than 20/40 was achieved in 96.3% of eyes in the Windows version group and 94.9% in the DOS version.
CONCLUSION: Results for the correction of myopia or myopic astigmatism were similar using the Nidek EC-5000 excimer laser with either the DOS software version or Windows software version, with the same surgical nomogram. [J Refract Surg 2001;17(suppl):S242-S245]
Changes in Intraocular Pressure After Laser in situ Keratomileusis
Authors: Rashad Khaled M , Bahnassy Ahmed A 
Published: April 2021

ABSTRACT
PURPOSE: To evaluate changes in intraocular pressure (IOP) measurements by Goldmann applanation tonometry after laser in situ keratomileusis (LASIK) for myopia and myopic astigmatism, and to assess the accuracy of Goldmann applanation tonometry measurements after LASIK in these eyes.
METHODS: LASIK was performed on 166 eyes of 93 patients for correction of myopia and myopic astigmatism. Intraocular pressure was measured by Goldmann applanation tonometry at the central and temporal parts of the cornea before and at 1, 3, 6, and 12 months after LASIK. The amount of change in IOP was computed and its relation to different variables was evaluated by regression analysis.
RESULTS: Intraocular pressure measured at the center of the cornea was reduced by a mean of 3.69 ± 1.63 mmHg after LASIK Multiple regression analysis showed that the decrease in IOP was related to the preoperative IOP and the change in central corneal thickness after LASHC Measurements of IOP at the temporal part of the cornea were also reduced by a mean of 2.39 ± 1.71 mmHg. There was wide variability in the amount of difference between the temporal and central measurements after LASHi (temporal measurements were higher than central by 0 to +4 mmHg).
CONCLUSION: LASIK for myopia produced underestimation of IOP measured by Goldmann applanation tonometry at the central part of the cornea by a mean of 3.69 ?1.63 mmHg. The decrease of IOP was related to preoperative IOP and the change in central corneal thickness after LASHi. Temporal Goldmann applanation tonometry measurements, although decreased after LASHi, were less reliable. [J Refract Surg 2001;17:420-427]