bluuebunny/crossref_metadata_2025_split huggingface dataset:
Decentration After Refractive Surgery
Authors: Vinciguerra Paolo , Camesasca Fabrizio I 
Published: April 2021

ABSTRACT
PURPOSE: To examine factors useful in evaluation of suspect decentration after refractive surgery.
METHODS: We evaluated 148 cases (eyes) referred to us for recentering procedures by review of information obtainable by evaluation of pupil position, corneal topography, and corneal curvature gradient.
RESULTS: Only a minority of eyes (n=5, 3.4%) were truly decentered; in the remaining majority a high dioptric grathent with consequent focal scarring was present (n=107, 72.3%). In 28 eyes (18.9%), a drifting of the eye during treatment was responsible, and in eight eyes (5.4%), a central island was observed.
CONCLUSIONS: Proper corneal topographical diagnosis reduces the risk of improperly suspecting decentration, and for most cases, smoothing of the central cornea is a simple and efficacious solution. Recommendations for the prevention of decentration include proper patient positioning, special care in treating high myopes, preoperative check of pupil displacement nasally, evaluation of preoperative map with detection of high temporal curvature grathent, and use of the cross-cylinder technique in the treatment of astigmatism. [J Refract Surg 2001;17(suppl):S190-S191]
Clinical Results After Subepithelial Photorefractive Keratectomy (LASEK)
Authors: Kornilovsky Igor M 
Published: April 2021

ABSTRACT
PURPOSE: To study the results of photorefractive keratectomy (PRK) after creation of an epithelial flap and replacement of the flap after ablation (LASER).
METHODS: PRR was performed with the Nidek EC-5000 excimer laser. The technology of subepithelial PRK was developed in experiments in vitro in 10 pig eyes and six human eyes. The experiments in vivo were carried out in eight eyes of four rabbits. In patients, subepithelial PRK was carried out in 12 eyes with high myopia, best spectaclecorrected visual acuity of 20/30 and below. LASLK, ordinary PRR, or transepithelial PRK were performed in the second eye to act as a controL
RESULTS: The basic steps of subepithelial PRR include creation of an epithelial flap, refractive ablation, and subsequent repositioning of the epithelial flap. In the clinical trial, creation of an epithelial flap was easy in five (41.7%) eyes, moderate in four (33.3%) eyes, and difficult in three (25.0%) eyes. No pain occurred in six (50%) eyes, some discomfort in four (33.3%) eyes, and pain in two (16.7%) eyes. After subepithelial PRK, visual and refractive results were similar with both LASLK and PRK The common components of ordinary PRK, transepithelial PRK, and subepithelial PRK are removal of Bowman's layer and epithelium. The advantages and disadvantages of subepithelial PRR are considered.
CONCLUSION: Subepithelial PRR (LASER) has the potential for widespread use in clinical practice, but further development of special instruments and techniques would be helpful. [J Refract Surg 2001;17(suppl):S222-S223]
Evaluation of the Reliability of the Nidek MK-2000 Microkeratome for Laser in situ Keratomileusis
Authors: Naripthaphan Pichit , Vongthongsri Anun 
Published: April 2021

ABSTRACT
PURPOSE: To evaluate the performance of the Nidek MK-2000 microkeratome in eorneal flap creation for laser in situ keratomileusis (LASIK) in Asian eyes and the simplicity of its use for the beginner.
METHODS: A prospective study of 200 Asian eyes was performed. The corneal flaps were created using the Nidek MK-2000 microkeratome 130-µm and 160-µm thickness plates with 8.5- and 9.5-mm suction rings. Ease of obtaining suction was evaluated and measurements were done for flap thickness, flap diameter, hinge size, and hinge-to-center-of-pupil distance.
RESULTS: Subjectively, even in small eyes, the procedure of obtaining the required suction and creating a good flap was easy and reliable with the Nidek MK-2000 microkeratome. Average flap thickness was 120.52 ± 16.49 µm (range, 84 to 162 µm) for the 130-µm thickness plate with the 8.5-mm suction ring. Mean flap diameter was 9.16 ± 0.43 mm, mean hinge size was 4.96 ± 0.36 mm, and mean hinge-tocenter-of-pupil distance was 4.16 ± 0.28 mm. With the 9.5-mm suction ring, mean flap thickness was 122.06 ± 18.54 µm (range, 84 to 149 µm), mean flap diameter was 9.85 * 0.35 mm, mean hinge size was 5.28 ± 0.36 mm, and mean hinge-to-center-of-pupil distance was 4.49 ± 0.27 mm. For the 160-µm plate with a 8.5-mm suction ring, the flap thickness was 172.71 ± 27.49 µm (range, 121 to 203 µm), flap diameter was 9.13 + 0.37 mm, mean hinge size was 5.02 ± 0.29 mm and mean hinge-to-center-of-pupil distance was 4.21 ± 0.29 mm. There were no complications of corneal flap creation.
CONCLUSION: The Nidek MK-2000 microkeratome was effective, safe, and reliable, even in small eyes. [J Refract Surg 2001;17(suppl): S255-S258]
Morphology of the Stromal Surface and Endothelium Using Two Different Microkeratomes
Authors: Frueh Beatrice E , Eggli Peter , Böhnke Matthias 
Published: April 2021

ABSTRACT
PURPOSE: To compare stromal surface and endothelial morphology after keratectomies and after laser in situ keratomileusis (LASIK), using two different microkeratomes.
METHODS: Keratectomies (lGO-µm and 400-µm) were performed on 82 enucleated porcine eyes using the Chiron Automated Corneal Shaper (52 eyes) and the Microtech Turbokeratome (30 eyes). LASIK procedures of -9.00 D, -27.00 D, and -36.00 D were performed with a Schwind excimer laser. The corneas were immediately fixed in glutaraldehyde or stained with alizarin red and trypan. Scanning electron microscopy was then performed.
RESULTS: All keratectomies performed with the Chiron microkeratome displayed a relatively smooth surface. The quality of the keratectomies with the manually advanced Microtech microkeratome was variable, with a high incidence (4 of 9) of incomplete cuts and irregular surfaces. In the eyes in which the stromal laser ablation was performed, a thin layer of condensed stroma (pseudomembrane formation) was seen. Vital staining did not indicate endothelial damage.
CONCLUSIONS: The surface morphology was unacceptable for one of the microkeratomes tested. Keratectomies of 160 to 400 µm and LASIK up to -36.00 D did not acutely alter endothelial morphology in porcine eyes. [J Refract Surg 2001;17:428-432]
Diffuse Lamellar Keratitis Associated With Recurrent Corneal Erosions After Laser in situ Keratomileusis
Authors: Harrison Devin A , Periman Laura M 
Published: April 2021

ABSTRACT
PURPOSE: Diffuse lamellar keratitis (DLK) is marked by the presence of diffuse or multifocal infiltrates confined to the laser in situ keratomileusis (LASDX) interface. These infiltrates are culturenegative, and the etiology is thought to be noninfectious. Most cases of DLK occur within the first week or two following surgery.
METHODS: We describe one case of diffuse lamellar keratitis that occurred 3 months after LASLK. The patient developed a spontaneous corneal erosion in one eye. Over the next 2 days while the erosion was being treated, there was rapid development of DLK. Slit-lamp biomicroscopy and in vivo scanning slit confocal microscopy were performed. The patient was treated with intensive topical corticosteroids.
RESULTS: Scanning slit confocal microscopy revealed numerous, highly-reflective round bodies consistent with a polymorphonuclear infiltrate located at the flap interface. Treatment with topical 1.0% prednisolone acetate was instituted, with rapid improvement in patient symptoms, visual acuity, and slit-lamp biomicroscopy.
CONCLUSIONS: Diffuse lamellar keratitis may occur months after LASlK as a result of a spontaneous recurrent corneal epithelial erosion. [J Refract Surg 2001;17:463-465]
Phototherapeutic Keratectomy in Patients With Recurrent Corneal Epithelial Erosions
Authors: Rashad Khaled M , Hussein Hussein A , El-Samadouny M Alaa , El-Baha Samir , Farouk Hisham 
Published: April 2021

ABSTRACT
PURPOSE: To evaluate the outcome of phototherapeutic keratectomy (PTK) in the management of recurrent corneal erosions, refractory to other forms of treatment.
METHODS: Phototherapeutic keratectomy was performed on 43 eyes of 41 patients with recurrent corneal erosions. The corneal epithelium was debrided, and laser ablation was performed to a depth of 6 µm with an ablation zone of 7 to 9 mm, using the Technolas Keracor 117C PlanoScan excimer laser. Follow-up time was 12 to 48 months (mean, 23.3 ±9.1 mo).
RESULTS: After PTK, patients were free of symptoms in 31 eyes (72.1%), and eight eyes (18.6%) had occasional mild symptoms of irritation and photophobia upon awakening. Recurrence of painful corneal erosions occurred in four eyes (9.3%). After PTK retreatment, these patients did not report any further episodes and were free of symptoms for 12 to 30 months (mean, 21.0 ± 7.7 mo). The mean spherical equivalent manifest refraction was changed by +0.15 ± 0.39 D in the hyperopic direction at 1 year after PTK. Thirty-three eyes (76.7%) were within ±1 line of preoperative best spectacle-corrected visual acuity (BSCVA). BSCVA was improved by two or more lines in 10 eyes (23.3%). There were no significant complications.
CONCLUSION: Excimer laser PTK with the Technolas Keracor 117C excimer laser was a safe and effective procedure for the treatment of recurrent corneal erosions. Excimer laser PTK can also be useful in improving the visual acuity in these patients. A small percentage of patients may require a second PTK to prevent further episodes of corneal erosions. [J Refract Surg 2000; 17: 511-518]
Two-year Corneal Endothelial Cell Assessment Following INTACS Implantation
Authors: Azar Ramzy G , Holdbrook Mark J , Lemp Michael , Edelhauser Henry F 
Published: April 2021

ABSTRACT
PURPOSE: To evaluate the 2-year effects of intrastromal corneal ring segments (INTACS) on the corneal endothelium.
METHODS: Non-contact specular microscopy was performed as a subgroup test in a Phase III clinical trial. Endothelial cell images were collected before surgery and at 6, 12, and 24 months after surgery at the central and peripheral (6 and 10 o'clock) regions. Images were recorded and analyzed later by a central reading center. Cell density, coefficient of variation, and percent hexagonal cells were determined.
RESULTS: There were no clinically significant changes in the endothelial cell structure at 6, 12, and 24 months (102 eyes). There was a gain of 5 cells/mm2 (6 months) and 3 cells/mm2 (12 months) at the central region of the cornea and a loss of 28 cells/mm2 at 24 months. At the 6 o'clock region of the cornea, there was a loss of 0, 24, and 92 cells/mm2 at 6, 12, and 24 months. At the 10 o'clock region of the cornea, there was a loss of 14, 30, and 94 cells/mm2 at 6, 12, and 24 months. INTACS did not statistically affect the central cell density at 6 and 12 months, however, there was a slight loss centrally at 24 months. At 24 months, all corneal regions had a slight decrease in cell density. In all eyes, mean central and peripheral endothelial cell counts remained above 2495 cells/mm2. Coefficient of variation improved and percent hexagonal cells remained unchanged.
CONCLUSION: Endothelial cell density changes at 2 years after INTACS implantation were not clinically significant and endothelial cell remodeling was present. [J Refract Surg 2001;17:542-548J
Keratolysis Following Excimer Laser Phototherapeutic Keratectomy in a Patient With Keratoconus
Authors: Lahners William J , Russell Buddy , Grossniklaus Hans E , Stulting R Doyle 
Published: April 2021

ABSTRACT
PURPOSE: We report a case of keratolysis following phototherapeutic keratectomy (PTK) for a subepithelial nodule in a patient with keratoconus.
METHODS: A 29-year-old male with keratoconus who became contact lens intolerant because of a raised subepithelial nodule was treated with excimer laser phototherapeutic keratectomy (PTK).
RESULTS: The epithelium failed to heal postoperatively, and progressive keratolysis led to a central descemetocele by the eighth postoperative day. The patient was managed with a penetrating keratoplasty.
CONCLUSIONS: Excimer laser phototherapeutic keratectomy has been shown to be an effective treatment for subepithelial nodules in patients with keratoconus. Rapidly progressive keratolysis is a potential complication of this procedure. [J Refract Surg 2001;17:555-558]
Dehiscence of Radial Keratotomy Wounds Without Globe Rupture Following Explosion Injury
Authors: Bouchard Charles S , Vaziri Boyd 
Published: April 2021

ABSTRACT
PURPOSE: To report a case of explosive trauma to a patient with a history of radial keratotomy (RK), which resulted in multiple wound dehiscences but not globe rupture.
METHODS: A 29-year-old male underwent radial keratotomy 1 year before he sustained facial trauma from a gasoline tank explosion. Corneal abrasions were treated with copious irrigation, topical antibiotics, corticosteroids, and scopolamine. He did not have a ruptured globe in either eye.
RESULTS: The incision sites from radial keratotomy had evidence of anterior dehiscence in both eyes. One month following the injury, the patient had corrected visual acuity of 20/20-1 in the right eye and 20/25+1 in the left eye. At that time, the RK wounds were well healed with minimal irregularity over the incision sites.
CONCLUSION: This case demonstrates the excellent recovery of visual acuity in a patient with a partial thickness traumatic wound rupture 12 months following radial keratotomy. [J Refract Surg 2001;17:561-563]
Wavefront Customized Ablations With the WASCA Asclepion Workstation
Authors: Panagopoulou Sophia I , Pallikaris Ioannis G 
Published: April 2021

ABSTRACT
PURPOSE: WASCA (Wavefront Aberration Supported Cornea Ablation) is a method for wavefront-guided ablation. This new method records all existing eye aberrations with the Asclepion Wavefront Aberrometer and calculates the customized pattern for laser correction. We measured the low and high order aberrations of eyes before and after PRK and LASIK, as well as before and after flap creation.
METHODS: The Asclepion Shack-Hartmann aberrometer was used to measure wavefront aberrations. Preoperative and postoperative measurements were made following both PRK and LASIK performed with conventional software, modified Aberration-free Profile (AFA) software, and specially designed WASCA software. Surgery was performed with the Meditec MEL-70 G-scan excimer laser. Additionally, measurements were made before and after flap creation only (10 eyes).
RESULTS: There was a significant difference between preoperative and 1 -month postoperative high order aberrations, with notable increases following conventional PRK and LASIK and less increase following modified AFA PRK and LASIK. Flap creation only changed the higher order aberrations slightly, and caused a shift toward hyperopia. In the eyes that received WASCA correction with PRK or LASIK, at 3 months postoperative the high order aberrations averaged an increase of 1.3 times for PRK and 1.8 times for LASIK. Both the AFA and WASCA treatments demonstrated improved outcomes in comparison to conventional PRK and LASIK.
CONCLUSION: Wavefront mapping of the eye and wavefront-guided ablation with the Asclepion Aberrometer can be used for optimizing the results and fine-tuning visual performance after laser vision correction. WASCA PRK appeared to result in better outcomes than WASCA LASIK. [J Refract Surg 2001;17:S608-S612]
Iris-claw Phakic Intraocular Lens for High Myopia
Authors: Landesz Monika , van Rij Gabriel , Luyten Gregorius 
Published: April 2021

ABSTRACT
PURPOSE: To evaluate the efficacy, safety, predictability, and stability of implanting a polymethylmethacrylate (PMMA) phakic intraocular lens (PIOL) (the Artisan myopia lens) to correct high myopia.
METHODS: An Artisan myopia lens was implanted in 78 consecutive eyes of 49 patients with preoperative myopia that ranged from -6.25 to -28.00 D. Mean patient age was 42.4 years. Mean follow-up was 10.7 months and all patients were followed for at least 6 months; 45 eyes had follow-up of 12 months, and 10 eyes had 24 months. The desired outcome was emmetropia in all eyes except for those eyes with preoperative myopia greater then -23.00 D.
RESULTS: Fifty-three eyes (67.9%) had a postoperative refraction at the last follow-up examination within ?1.00 D of emmetropia, and 39 eyes (50.0%) had a postoperative refraction ?within 0.50 D of emmetropia. The postoperative refraction remained stable during the entire follow-up period. Mean spectacle-corrected visual acuity improved from 20/32 preoperatively to 20/25 postoperatively. Mean postoperative uncorrected visual acuity was 20/32. There was no significant change in endothelial cell density from baseline. We did not encounter major complications.
CONCLUSION: Implantation of the Artisan myopia lens to correct high myopia resulted in a stable and fairly predictable refractive outcome. A significant endothelial cell change was not detected. [J Refract Surg 2001,1 7:634-640]
Effect of Acute Biomechanical Changes on Corneal Curvature After Photokeratectomy
Authors: Dupps William J , Roberts Cynthia 
Published: April 2021

ABSTRACT
PURPOSE: Unintended hyperopia shift; is a common yet poorly understood complication of phototherapeutic keratectomy (PTK) that raises fondamental questions about the etiology of corneal curvature change in PRK and LASIK. We investigated the relative contributions of ablation profile and peripheral stromal thickening to intraoperative PTK-indueed central flattening, and propose a biomechanical model of the acute corneal response to central ablation.
METHODS: Fourteen de-epithelialized eye bank globes from seven donors underwent either broadbeam ablation (~100-??? depth, no programmed dioptric change) or sham photoablation in pairedcontrol fashion. Peripheral stromal thickness changes and the pattern of thickness loss across each ablation zone were evaluated by optical section image analysis as predictors of acute corneal flattening.
RESULTS: Relative to sham ablation, keratectomy caused significant anterior corneal flattening (-6.3 ? 3.2 D, P = .002). Concomitant peripheral stromal thickening (+57 ? 43 ??\, P = .01) was a significant predictor of acute hyperopic shift (r = 0.68, P - .047). Ablation pattern bias did not consistently favor hyperopia and was a poor lone predictor of hyperopic shift.
CONCLUSIONS: Unintended keratectomyinduced hyperopic shift is replicable in a human donor model and is associated with significant thickening of the unablated peripheral stroma. This biomechanical response may have a considerable impact on early refractive outcomes in PTK, PRK, and LASIK [J Refract Surg 2001;17:658-669]
Microwave Thermal Keratoplasty for Myopia: Keratoscopic Evaluation in Porcine Eyes
Authors: Trembly B Stuart , Hashizume Natsuko , Moodie Karen L , Cohen Kenneth L , Tripoli Nancy K , Hoopes P Jack 
Published: April 2021

ABSTRACT
PURPOSE: Microwave thermal keratoplasty applies microwave energy to elevate the temperature of the paracentral stroma of the cornea to its thermal shrinkage temperature of about 600C. A suitable pattern of shrinkage in the paracentral cornea can flatten the central cornea. A surface cooling system preserves the epithelium during the procedure.
METHODS: Fourteen enucleated porcine eyes were treated with a prototype microwave thermal keratoplasty applicator that heated in a ring pattern with inner diameter of 3.2 mm and width of 0.7 mm. The change in corneal power was quantified by a videokeratoscope. Slit-lamp microscope examinations and histological assessments were made.
RESULTS: The 3-mm simulated keratometry reading showed an average of 6.60 ? 6.00 D (standard deviation) of flattening. The region of opacity associated with shrinkage extended to 62% (?26%) of the corneal thickness. The epithelium was intact in all eyes.
CONCLUSIONS: Microwave thermal keratoplasty applied in the paracentral cornea may flatten the central cornea. [J Refract Surg 2001;17:682-688]
Image Quality in Myopic Eyes Corrected With Laser in situ Keratomileusis and Phakic Intraocular Lens
Authors: Sarver Edwin J , Sanders Donald R , Vukich John A 
Published: April 2021

ABSTRACT
PURPOSE: To compare image quality due to higher-order aberrations following laser in situ keratomileusis (LASIK) or implantation of phakic intraocular lens (PIOL) to correct high myopia.
METHODS: Postoperative wavefront examinations, normalized to a pupil size of 5.5 mm, were obtained for 19 LASLK and 20 PIOL eyes for the same surgeon over the same time period. Higherorder aberrations and simulated retinal images were compared.
RESULTS: For this small sample, the LASLK eyes yielded an average three times more spherical aberration and two times more coma than PIOL eyes. The effects of these differences were visualized using the simulated retinal images.
CONCLUSION: Spherical aberration and coma are the major differences between postoperative LASIK and PIOL higher-order aberrations, and simulated retinal images can be used to visualize these effects. [J Refract Surg 2003,19:397-404]
Technical Improvements in Photorefractive Keratectomy for Correction of High Myopia
Authors: Cennamo Giovanni , Rosa Nicola , Breve Maria Angelica , di Grazia Maria 
Published: April 2021

ABSTRACT
PURPOSE: To evaluate the effects of hardware and software improvements in photorefractive keratectomy (PRK) for the treatment of highly myopic eyes.
METHODS: A retrospective study was carried out in 554 patients (582 eyes) with myopia between -7.00 and -17.00 D (mean -11.20 ± 3.60 D) who had undergone PRK using the Aesculap Méditée laser. Group 1 with a 5-mm-diameter single ablation zone; Group 2 with a 5-mm-diameter single zone surrounded by a 2-mm tapered transitional zone; Group 3 and Group 4, same as Group 2 but with the laser upgraded with a smoke aspiration control system (Group 3), and with a computer-controlled fluenee (Group 4).
RESULTS: In Group 1 at 2 years after PRK (50 eyes), 10 eyes (20%) were within ±1.00 D of attempted correction and 13 eyes (26%) were within ±2.00 D. In Group 2 at 2 years (118 eyes), 42 eyes (36%) were within ±1.00 D of attempted correction and 65 eyes (55%) were within ±2.00 D. In Group 3 at 2 years (43 eyes), 18 eyes (42%) were within ±1.00 D of attempted correction and 28 eyes (65%) were within ±2.00 D. In Group 4 at 2 years (47 eyes), 25 eyes (53%) were within ±1.00 D of attempted correction and 29 eyes (62%) were within ±2.00 D.
CONCLUSIONS: Software and hardware improvements facilitated PRK correction of high myopia with reasonable predictability, especially if a tapered transition zone was used. At 12 and 24-month follow-up, only the use of a tapered transition zone was associated with a statistically significant improvement in predictability. [J Refract Surg 2003;19:438-442]
Influence of Ablation Parameters on Refractive Changes After Phototherapeutic Keratectomy
Authors: Ginis Harilaos S , Katsanevaki Vikentia J , Pallikaris Ioannis G 
Published: April 2021

ABSTRACT
PURPOSE: The aim of the current study was to control the hypothetical effects of decreased laser energy delivered to the peripheral cornea during phototherapeutic keratectomy (PTK) and provide quantitative calculation of induced low and high order aberrations.
METHODS: We employed a model eye to simulate the refractive effect of homogeneous laser corneal irradiation, as in PTK, for different laser fluences (range 125 to 225 mJ/cm2) and treatment depths up to 200 pm.
RESULTS: The hyperopic shift induced by the relatively lower energy delivered at the peripheral ablation zone during PTK was proportional to the treatment depth and inversely proportional to the energy fluence. The hyperopic shift calculated using the above ablation parameters was lower compared to previously reported clinical results. Higher order wavefront aberration (total root mean square) changes were of minimal significance for treatment depths up to 200 urn.
CONCLUSIONS: After PTK, a hyperopic shift cannot be attributed to the energy delivery method alone. Modification of laser energy delivery algorithms may only minimize PTK-induced hyperopia. [J Refract Surg 2003;19:443-448]