bluuebunny/crossref_metadata_2025_split huggingface dataset:
Management of Aniseikonia after Intraocular Lens Implantation or Refractive Surgery
Authors: Enoch Jay M 
Published: April 2021

ABSTRACT
BACKGROUND: Aniseikonia is a difference in perceived image size in the two eyes resulting in asthenopic symptoms and distortions of binocular space perception. This is a complication of refractive and implant surgery in patients with binocular vision. While many individuals adapt readily to modest aniseikonic errors, quite a number do not.
METHOD AND RESULTS: Few instruments exist to adequately test for aniseikonia. A means is described to determine if aniseikonia exists and a series of simple steps is suggested to minimize aniseikonia induced by refractive surgery or by surgery for removal of cataract and intraocular lens insertion. Also, using the proposed protocol, it is possible to determine if existing image size differences resulting from prior and/or induced aniseikonia are predominantly refractive or axial. A case report is presented.
CONCLUSIONS: The techniques described are not costly, provide no risk, take little time, and resolve or meaningfully reduce aniseikonia in many patients having non-extreme errors of this type. [J Refract Surg 1997;13:79-82]
Calibration of Trephine Blade Depth
Authors: Schor Paulo , Rocha Eduardo , Cheema Devinder P , Miller David 
Published: April 2021

ABSTRACT
PURPOSE: To assess the accuracy and precision of the Barron radial vacuum trephine as an instrument for corneal lamellar dissection.
METHODS: We describe a practical method to calibrate individual trephines prior to lamellar corneal procedures using the calibration microscope designed for diamond knives.
RESULTS: We observed that one turn (360°) of the trephine produced a mean blade displacement of 0.25mm. However, individual trephines demonstrated a significant range of variability.
CONCLUSION: For highly accurate trephination, it is useful to calibrate each individual trephine using the calibration microscope. [J Refract Surg 1997;13:89-90]
Effects of Topical Ketorolac and Diclofenac on Normal Corneal Sensation
Authors: Sun Ran , Gimbel Howard V 
Published: April 2021

ABSTRACT
BACKGROUND: A randomized, double-masked study was conducted to investigate the effects of 0.5% ketorolac tromethamine (Acular) and 0.1% diclofenac sodium (Voltaren) on normal human corneal sensation.
METHODS: Thirty normal volunteers were divided into two groups, (1) two-drop group, and (2) multiple-drop group. In the two-drop group, 15 volunteers randomly received two drops of 0.5% ketorolac tromethamine on one eye and two drops of 0.1% diclofenac sodium on the fellow eye. A masked investigator measured corneal sensation with the Cochet-Bonnet esthesiometer before applying the drops, and at 15, 30, and 60 minutes after using the eye drops. In the multiple-drop group, another 15 volunteers were randomly administered one drop of 0.5% ketorolac tromethamine or 0.1% diclofenac sodium in each eye, and the procedure was repeated every 5 minutes for 20 minutes. Corneal sensation was measured before, and 0, 15, 30 and 60 minutes after applying the drops.
RESULTS: In the two-drop group, neither of the eye drops had any effect on corneal sensation when only two drops were applied. In the multiple-drop group, corneal sensation was significantly reduced after multiple drops (p<0.05) and was subsequently effective for at least 1 hour.
CONCLUSION: Both 0.5% ketorolac and 0.1% diclofenac can significantly decrease corneal sensation in normal eyes when multiple drops are used. [J Refract Surg 1997;13:158-161]
Nocardial Keratitis after Laser in situ Keratomileusis
Authors: Pérez-Santonja Juan J , Sakla Hani F , Abad José L , Zorraquino Alfredo , Esteban Jaime , Alió Jorge L 
Published: April 2021

ABSTRACT
PURPOSE AND METHODS: Corneal interface central nodules appeared in a patient who underwent uncomplicated laser in situ keratomileusis (LASDX) retreatment for residual myopia.
RESULTS/CONCLUSIONS: Nocardia asteroides keratitis was confirmed by microbiologic studies, which guided treatment. Six months after the appearance of the keratitis, the patient's uncorrected visual acuity was 20/45, and spectacle-corrected visual acuity was 20/40. The postoperative refraction was +0.75 -0.75 X 95°, and slit-lamp examination revealed a clear cornea with a mild rounded scar in the central area. Night halos and starbursts were the main complaints in this patient. The immediate management of lifting the corneal flap for stromal bed scraping, fast microbial identification, and proper treatment was the key for the results in this patient. [J Refract Surg 1997;13:314-317]
The Suction Bridge for Radial Keratotomy May Avoid Late Hyperopic Shift
Authors: Krumeich Jorg H , Daniel Jan , Gast Robert 
Published: April 2021

ABSTRACT
BACKGROUND: Radial keratotomy may induce late hyperopic shift. We present data on 140 consecutive eyes with a follow-up of up to 3 years that underwent radial keratotomy with the RK suction bridge.
METHODS: We conducted a retrospective study of 140 consecutive eyes that had radial keratotomy between 1987 and 1994. Mean preoperative spherical equivalent was -5.21 D (range -2.00 to -9.75 D). All operations were performed by one surgeon (JHK) with the RK suction bridge. A suction ring maintaining physiological intraocular pressure immobilized the eye and left a peripheral rim of uncut cornea. The ring incorporated an eccentric bridge that guided the radial keratotomy knife. The knife setting was 90% of the central corneal thickness, measured by pachymetry. Spherical equivalent refraction and spectacle corrected visual acuity were measured at 1 week, 1, 3, 6 months, 1 year, and 3 years after radial keratotomy.
RESULTS: The mean preoperative spherical equivalent refraction of -5.21 D dropped to -0.43 D at 1 week (n=136), -0.71 D at 1 month (n=120), -0.85 D at 3 months (n=95), -0.74 D at 6 months (n=73), -0.77 D at 12 months (n=79), and -0.85 D at 3 years (n=67). Compared to 1 month spherical equivalent, at 3 years three eyes (4.4%) had moved > 1.00 D toward hyperopia. One eye (1.4%) shifted by 1.25 D. Paired f-tests of mean spherical equivalent refraction did not reveal significant shifts toward hyperopia. Mean preoperative spectacle-corrected visual acuity was slightly diminished at 1 week and was equal or better thereafter.
CONCLUSIONS; Our 3-year data suggest that a late hyperopic shift following radial keratotomy may be prevented if an intact peripheral rim is maintained and cutting depth does not exceed 90% of the lowest corneal thickness. [J Refract Surg 1997,13:367-373]
Radial Keratotomy Enhancements for Residual Myopia
Authors: Gayton Johnny L , Van Der Karr Michelle , Sanders Valerie 
Published: April 2021

ABSTRACT
BACKGROUND: A systematic method of performing radial keratotomy enhancements in undercorrected eyes may increase accuracy and predictability and decrease the number of procedures required. A consecutive series of 372 radial keratotomy procedures, including 110 eyes that received enhancements under a systematic protocol, was evaluated.
METHODS: Radial keratotomy was performed using the Reliable Keratotomy software, which uses the Thornton nomogram for primary radial keratotomy and provides a systematic method of performing enhancements.
RESULTS: Ninety eyes (24%) received one enhancement, 16 eyes (4%) received two enhancements, and four eyes (1%) received three enhancements. Mean final spherical equivalent refraction was -0.44 D (-4.00 to +1.875 D, SD 0.86) for eyes that did not receive enhancements and -0.44 D (-2.50 to +1.00 D, SD 0.61) for eyes that had enhancements. Mean final residual myopia for the entire cohort was -0.44 D (-4.00 to +1,875 D, SD 0.79). At final examination, 242 (65%) eyes had a refraction within ±0.50 D and 298 (80%) within ±1.00. Among eyes that received enhancements, 75 (68%) had a refraction within ±0.50 D, and 89 (81%) within ±1.00 D; 40 eyes (36%) had uncorrected visual acuity of 20/20 or better, 99 eyes (90%) 20/40 or better, and all but one eye (99%) 20/80 or better at the final postoperative examination. Among the entire cohort, 130 eyes (35%) had uncorrected visual acuity of 20/20 or better, 312 (84%) had 20/40 or better, and 350 (94%) had 20/80 or better. No eye lost more than one line of spectacle-corrected visual acuity.
CONCLUSION: A systematic approach to enhancement of undereorrected eyes after radial keratotomy, combined with accurate surgery, may reduce the need for multiple enhancements as well as the overcorrection rate, and provide improved uncorrected visual acuity. [J Refract Surg 1997;13:374-381]
Bilateral Cataract after Phakic Posterior Chamber Top Hat-style Silicone Intraocular Lens
Authors: Wiechens Burkhard , Winter Martin , Haigis Wolfgang , Happe Wilhelm , Behrendt Stephan , Rochels Rainer 
Published: April 2021

ABSTRACT
BACKGROUND: New strategies have been developed for surgical treatment of high myopia. Recently, implantation of minus power posterior chamber intraocular lenses (IOL) into phakic eyes has been introduced.
METHODS: We report a 37 year-old female patient who developed bilateral anterior subcapsular cataract 7 years after minus-power, top hat-style silicone posterior chamber IOL implantation in Russia. The corrected visual acuity was right eye 20/200 and left eye 20/63. Because of the high myopia and the posterior chamber IOL in her phakic eyes, biometry for IOL calculation gave contradictory results. Both posterior chamber IOLs were found to be adherent to the crystalline lenses. After posterior chamber IOL explantation and phacoemulsification, intraoperative retinoscopy was performed. With this aphakic refraction, the IOL power was calculated and implanted. The explanted posterior chamber IOLs were examined by scanning electron microscopy.
RESULTS: After bilateral operation the corrected visual acuity increased to right eye 20/32 and left eye 20/40, respectively. On scanning electron microscopy, a membranous structure of unknown origin was noted on the entire surface of the explanted posterior chamber IOLS.
CONCLUSION: There is a potential risk of cataract formation after implantation of this top hat-style silicone posterior chamber IOL. If cataract extraction in this specific situation is needed, a different approach for calculating the aphakic IOL power is necessary, such as intraoperative retinoscopy. [J Refract Surg 1997;13:392-397]
Hyperopic Shift Induced by High Altitude after Radial Keratotomy
Authors: Creel Donnell J , Crandall Alan S , Swartz Mano 
Published: April 2021

ABSTRACT
BACKGROUND: The collagen fibrils embedded in the ground substance of the stromal lamellae provide the structural support for the cornea. When the stromal lamellae are cut in a radial keratotomy surgical procedure, the remaining uncut lamellae carry the tensile forces.
METHODS: We studied two expert climbers who had bilateral radial keratotomy before participating in six climbs of extreme altitude, including Mount McKinley and above 7500 m (24,606 ft) on Mount Everest.
RESULTS: Whenever either climber was exposed to altitudes greater than approximately 5000 m (16,405 ft) for more than a day, their refraction would become +3.00 D or more hyperopic and remain so as long as they were at or above this altitude. Visual acuity slowly returned to normal after descent.
CONCLUSION: It appears that in the presence of significantly reduced atmospheric pressure and/or oxygen there is a greater effect of radial keratotomy in some patients, making the cornea more vulnerable to changes in shape. The cornea appears to respond by further flattening, exacerbating the intended surgical effect and producing a refractive shift toward hyperopia. [J Refract Surg 1997;13:398400]
Photorefractive Keratectomy for Myopia and Photoastigmatic Keratectomy for Astigmatism
Authors: Ohashi Yuichi , Takahashi Keizo , Yorii Hidaki 
Published: April 2021

ABSTRACT
BACKGROUND: We conducted a clinical trial to evaluate the efficacy and safety of excimer laser photorefractive keratectomy (PRK) and photoastigmatic refractive keratectomy (PARK) using the Nidek EC-5000 excimer laser.
METHODS: A total of 67 eyes from 47 patients whose average age was 35 years were enrolled in the study. The mean spherical equivalent of the manifest refraction before surgery was -7.50 diopters (D). Patients were followed for at least 6 months. One year after surgery, uncorrected visual acuity improved in 98% of the eyes, while spectaclecorrected visual acuity had not deteriorated in any patient. The achieved corrections were within ±1.00 D of attempted correction in 72.5% of eyes. Predictability was poor in eyes in which the correction was more than 10.00 D. Subepithelial haze occurred in all eyes to minimal extent, and disappeared gradually.
CONCLUSION: Photorefractive keratectomy and photoastigmatic refractive keratectomy, performed with the Nidek EC-5000 excimer laser, is a reliable and adequately safe procedure to correct myopia of a limited range. [J Refract Surg 1997;13(suppl):S452-S453]
Effects of Topical Corticosteroids after Photorefractive Keratectomy
Authors: Chatterjee Anupam , Shah Sunil , Galway Gavin 
Published: April 2021

ABSTRACT
PURPOSE: To assess the effects of topical corticosteroids (fluoromethalone) following photorefractive keratectomy (PRK).
METHODS: Both eyes of 654 patients had PRK with a minimum of 4 months between treatments. Topical corticosteroids were prescribed for one eye only. Endpoints were assessed by comparing the ratio of intended to actual refractive change in the corticosteroid treated eye with the fellow eye (no corticosteroid use).
RESULTS: The corticosteroid treated eyes showed a mean percentage correction of 95.7% compared to the untreated fellow eyes, which achieved a percentage correction of 103.3%- statistical significance of ? = 0.00001. There was more of a trend toward regression in the corticosteroid treated eyes despite intervention with fluoromethalone.
CONCLUSION: Topical corticosteroids showed very little positive effect on regression of effect after PRK [J Refract Surg 1997;13(suppl):S454-S455]
Photorefractive Keratectomy for Hyperopia after Radial Keratotomy
Authors: Venter Jan A 
Published: April 2021

ABSTRACT
BACKGROUND: Progressive hyperopia is a common complication following radial keratotomy.
METHODS: Ten eyes of ten consecutive patients with hyperopia after radial keratotomy between +1.75 and +4.00 diopters (D) were treated with the hyperopia module of the Nidek Model EC-5000 excimer laser. The mean preoperative uncorrected visual acuity was 0.38 (20/60+).
RESULTS: After excimer laser photorefractive keratectomy (PRK), mean uncorrected visual acuity improved to .72 (20/30+). No complications occurred with the exception of one eye with haze greater than 2+.
CONCLUSION: PRK for hyperopia is a valuable method for correcting hyperopia after radial keratotomy. [J Refract Surg 1997;13(suppl):S456]
Excimer Laser in situ Keratomileusis for Myopia
Authors: Pesando Paolo M , Ghiringhello Maria P , Tagliavacche Paolo 
Published: April 2021

ABSTRACT
PURPOSE: To evaluate the efficacy, safety, and predictability of excimer laser in situ keratomileusis (LASIK) for the correction of myopia.
METHODS: Forty-six consecutive eyes that had LASIK with the VISX 20/20B laser and Chiron corneal shaper were evaluated. Mean spherical equivalent of the preoperative manifest refraction was -9.40 ± 3.78 diopters (D) (range, -3.50 to -19.75 D). The refractive effect (postoperative refraction minus baseline refraction), residual refractive error (refractive effect minus planned correction) and uncorrected and spectaclecorrected visual acuity were examined.
RESULTS: Mean follow-up was 6.1 months (range, 3 to 9 mo). Spectacle-corrected visual acuity was unchanged in 39 eyes (84.78%), significantly improved in five eyes (10.86%), and worse in two eyes (4.34%). Uncorrected visual acuity was 20/20 or better in 15 eyes (32.6%) and 20/40 or better in 39 eyes (84.78%). Thirteen eyes (28.26%) had a postoperative spherical equivalent refraction within ±0.50 D and 36 eyes (78.26%) within ±1.00 D of attempted correction. No intraoperative complication occurred. Postoperative complications were few and not severe: three eyes (6.52%) developed regular astigmatism, two eyes (4.34%) had interface deposits, and three eyes (6.52%) had small epithelial cysts in the interface.
CONCLUSION: LASIK with the VISX 20/20B laser is safe, moderately effective, and relatively predictable for correcting myopia from -3.50 to -19.50 D. Predictability decreases with increasing myopia. [J Refract Surg 1997;13:521-527]
Three Multizone Photorefractive Keratectomy Algorithms for Myopia
Authors: Alpins Noel A , Taylor Hugh R , Kent David G , Lu Yi , Liew Mary , Couper Terry , McGough Virginia 
Published: April 2021

ABSTRACT
OBJECTIVE: To compare the efficacy and complications of three different excimer laser algorithms for multizone photorefractive and photoastigmatic keratectomy.
METHODS: Three different software algorithms were applied to treat myopia and myopic astigmatism with the VTSX 20/20 excimer laser. Each algorithm had a maximum ablation zone of 6 mm but differed in the number of zones employed, the proportion of the total treatment allocated to each ablation zone, and the treatment of astigmatism. The Melbourne multizone technique equally divided myopia correction into a maximum of three ablation zones. The Pop multizone technique biased myopia treatment into the smaller diameter zones to a maximum of six ablation zones, with one central island pretreatment. The Alpins multizone technique equally divided myopia treatment through all zones up to a maximum of six, with one central island pretreatment.
RESULTS: A total of 585 patients (780 eyes) were treated and 625 eyes (80%) were followed for more than 6 months. The mean baseline spherical equivalent refractive error was -5.63 D (-1.00 to -19.50 D). Between 71 and 79% of eyes were treated for astigmatism. There was no statistically significant difference in baseline refractive error or other characteristics among the three groups. At 6 months, the Alpins multizone algorithm had more eyes with a refractive error within ±1.00 D of emmetropia (p=0.01) and more within ±2.00 D of emmetropia (p<0.01). This new algorithm produced more eyes with an uncorrected visual acuity of 20/20 or better at 6 months (p<0.01). When multiple logistic regression was used to correct for any differences in baseline myopia among the three groups, this algorithm also had a higher odds ratio for achieving 20/20 or better uncorrected visual acuity (OR=1.58).
CONCLUSION: At 6 months, all three algorithms were effective in the reduction of myopia. Significantly better visual acuity and refractive results were achieved with the Alpins multizone algorithm that spread the total treatment over a larger number of ablation zones, with an equal number of diopters of treatment in each zone. [J Refract Surg 1997,13:535-544]
Iris Claw Phakic Intraocular Lens for High Myopia
Authors: Menezo José L , Aviño Juan A , Cisneros Angel , Rodriguez-Salvador Vicente , Martinez-Costa Rafael 
Published: April 2021

ABSTRACT
BACKGROUND: The implantation of a WorstFechner iris claw intraocular lens (IOL) is one of the surgical procedures used for the correction of high myopia. This technique reduces myopia with stähle refractive results; however, its potential long-term risks have not been evaluated. We report results in 94 eyes with a minimum follow -up of 3 years.
METHODS: We studied 94 eyes of 62 patients with myopia 5= -7.00 diopters (D) who underwent Worst-Fechner IOL implantation. Lens decentration, permeability of the blood-aqueous barrier by iris angiography, and changes in corneal endothelial density were analyzed.
RESULTS: Mean follow-up time was 48.9 months (range 36 to 72 mo). Three years after surgery, 58 eyes (61%) had an uncorrected visual acuity s* 20/40, and 77 eyes (82%) gained two or more lines of spectacle-corrected visual acuity with respect to the preoperative value; 75 eyes (79%) were within ±1.00 D of emmetropia and 46 eyes (48%) were within ±0.50 D of emmetropia. The mean endothelial cell loss was 17.9% at 5 years after surgery, while the percentage of hexagonality and the coefficient of cell variation tended toward preoperative levels. No vision threatening complications were seen.
CONCLUSIONS: The implantation of a WorstFechner iris claw phakic IOL reduced high myopia with a stable refractive outcome. Endothelial cell damage was within acceptable limits. The absence of major complications makes this procedure an acceptable method for correcting high myopia. [J Refract Surg 1997;13:545-555]
The Effect of Topical Corticosteroids on Refractive Outcome and Corneal Haze after Photorefractive Keratectomy
Authors: Baek Seung-Hee , Chang Jin-Ho , Choi Sang-Yul , Kim Woo-Jung , Lee Jin-Hak 
Published: April 2021

ABSTRACT
BACKGROUND: The effect of topical corticosteroids after excimer laser photorefractive keratectomy (PRK) remains a matter of some controversy. Refractive effects may be different according to the amount of myopia and timing of instillation.
METHODS: Two groups of patients were studied: Study A consisted of 215 eyes (128 patients) with PRK (mean baseline myopia, -6.53 ± 2.22 D) that received no corticosteroids (No Corticosteroid Group) unless significant regression or corneal haze appeared (Delayed Corticosteroid Group), and in Study B, we randomly assigned eyes to the Initial Corticosteroid Group (mean baseline myopia, -6.39 ± 1.84 D) or the No/delayed Corticosteroid Group (mean baseline myopia -5.78 ± 2.02 D). Clinical results after PRK for low-to-moderate and high myopia were compared.
RESULTS: In the first group, 70.9% (73 eyes) of moderately myopic eyes (mean, -4.56 ± 1.10 D) belonged to the No Corticosteroid Group that had a mean refraction of -5.39 ± 1.77 D. Delayed Corticosteroid Group eyes were more myopic (mean, -7.52 ± 2.10 D), and showed more severe haze than those in the No Corticosteroid Group. In study B, only in high myopes with more than -6.00 D (mean, -7.76 ± 1.15 D) did refraction and corneal haze outcomes show significant difference between the Initial Corticosteroid Group and the No/delayed Corticosteroid Group.
CONCLUSIONS: The effects of topical corticosteroids after PRK were less in moderate myopes compared to high myopes. Delayed instillation of corticosteroids did not reverse the regression or haze whereas initial instillation showed a beneficial effect on high myopes but not on moderate myopes. [J Refract Surg 1997;13:644-652]
Tracker-assisted Versus Manual Ablation Zone Centration in Laser in situ Keratomileusis for Myopia and Astigmatism
Authors: Pineros Oscar E 
Published: April 2021

ABSTRACT
PURPOSE: Eye tracker systems have been developed concomitantly with small scanning beams to theoretically reduce ablation zone decentration and for accurate registration of all the laser pulses on the cornea. The purpose of the study was to compare the tracker-assisted with the manual centration method.
METHODS: Twenty-five patients (48 eyes) with myopia and/or astigmatism had laser in situ keratomileusis (LASIK) between August 1998 and February 1999 with the Technolas 117C laser. Twenty patients (38 eyes, 80%) were available for follow-up at 3 months after surgery. Eyes were assigned randomly to one of two ablation zone centration methods: Group 1: Tracker- assisted (20 eyes), Group 2: Manual (18 eyes).
RESULTS: Mean distance between the ablation zone center and the pupillary center in the trackerassisted centration group was 0.55 ? 0.30 mm (range, 0.10 to 1.4 mm), and in the manual centration group, 0.43 ? 0.23 mm (range, 0.10 to 1.0 mm) (P=.177). There was no statistically significant difference in postoperative contrast sensitivity, glare, and Topographical Corneal Surface Regularity Index (SRI) between the two groups.
CONCLUSIONS: We obtained good results with both centration methods. We did not find superiority of the tracker-assisted over manual regarding ablation zone centration, vision quality, or regularity of the ablation. [J Refract Surg 2002:18:37-42]