bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrastructural and Immunohistochemical Findings after Linear Excimer Laser Keratectomy
Authors: Winter Martin , Behrendt Stephan , Binder Perry S , Duncker Gernot I W 
Published: April 2021

ABSTRACT
BACKGROUND: One human pathology specimen has been studied previously following the use of the excimer laser for the correction of astigmatism. We report histopathologic findings following linear corneal excisions with the excimer laser.
METHODS: A 193nm excimer laser was used to create symmetrical, transverse excisions in a human eye to correct astigmatism. Three months later, a full-thickness corneal transplant was performed due to unsatisfactory refractive results. The excised corneal button was examined with light microscopy, transmission electron microscopy and immunohistochemistry.
RESULTS: An area 10 to 20-µm wide was observed between the epithelial cells within the keratectomy and the sharply dissected stromal lamellae. This area stained positive for laminin and pro-collagen type III. Some epithelial cells showed processes reaching into this area. Descemet's membrane, immediately underneath the area of the keratectomy, contained atypically striated collagen fibers.
CONCLUSIONS: These findings demonstrate wound healing changes similar to those reported following diamond knife keratotomy and photorefractive keratectomy for myopia. The changes in the posterior cornea are similar to those previously reported when an excimer laser beam approached Descemet's membrane. [J Refract Surg 1997;13:60-68]
Clinical Effect of Blowing Nitrogen Gas across the Cornea during Photorefractive Keratectomy
Authors: Itoi Motozumi , Ryan Robert , Depaolis Michael , Aquavella James V 
Published: April 2021

ABSTRACT
OBJECTIVE: We evaluated the clinical effects of blowing nitrogen gas over the cornea during photorefractive keratectomy.
METHODS: We retrospectively compared clinical outcomes of 32 patients (37 eyes), divided into two groups who had photorefractive keratectomy with nitrogen gas blowing across the cornea (n=19) and without nitrogen gas (n=18). All photorefractive keratectomies were performed between April 1991 and August 1992. Ablation zone diameters were 5.0 or 5.5 mm. The average attempted correction was -3.47 ± 1.76 diopters (D) in the nitrogen gas group, and -3.48 ± 1.25 D in the non-nitrogen gas group.
RESULTS: The nitrogen gas group achieved more accurate corrections than the non-nitrogen gas group, but had a significantly greater amount of corneal haze at all postoperative examinations. Corneal haze was most evident at 1 month and gradually diminished thereafter in both groups. At 6 months, videokeratography revealed a central island in 2 eyes (11.1%) of the non-nitrogen gas group. Because of undercorrection (2 eyes) or central island (1 eye), 3 out of 18 eyes in the non-nitrogen gas group were reablated 6 months later.
CONCLUSIONS: The non-nitrogen gas group had more undercorrections and a higher frequency rate of central steep islands, but nitrogen gas blowing caused a greater amount of corneal haze. [J Refract Surg 1997;13:69-731
Patient Satisfaction after 5.0-mm Photorefractive Keratectomy for Myopia
Authors: Ben-Sira Ayala , Loewenstein Anat , Lipshitz Isaac , Levanon Daniela , Lazar Moshe 
Published: April 2021

ABSTRACT
PURPOSE: To examine patient satisfaction following photorefractive keratectomy (PRK) in a large number of subjects.
METHODS: We used a questionnaire to examine overall patient satisfaction in 173 patients (173 first-operated eyes) at least 1 year after they had undergone PRK. Mean preoperative spherical equivalent refraction was -7.05 ± 3.73 D (range, -1.50 to -15.00 D). Fifty-one patients had unilateral surgery and 122 had bilateral surgery, 60 of whom had follow-up of 1 year for both eyes. Visual and refractive results, the use of corrective lenses, and subjective side effects were also studied.
RESULTS: Eighty percent of 173 patients reported they were satisfied or very satisfied with the surgical outcome, while 19.7% reported they were dissatisfied. The average satisfaction score was 7.92 ± 2.22 out of a possible 10. After PRK, 77.5% reported improvement or great improvement in their general quality of life; 16.8% were very disturbed by subjective visual symptoms. Of the 51 bilateral patients, 85% required no corrective lenses after surgery. Patients who had bilateral operations were more satisfied than those who had unilateral ones. Statistically significant associations were found between patient satisfaction and initial refraction: as preoperative refraction increased, percentage of satisfied or very satisfied patients decreased.
CONCLUSION: Patient satisfaction after PRK was generally high, but subjective visual symptoms remain a problem. [J Refract Surg 1997; 13:129-134.]
Comparison of Two Microkeratome Systems
Authors: Binder Perry S , Moore Max , Lambert Robert W , Seagrist Debra McCoy 
Published: April 2021

ABSTRACT
BACKGROUND: Microkeratomes are currently used for keratomiluesis in situ (automated lamellar keratoplasty) for myopia and hyperopia and for laser in situ keratomileusis (LASIK). Visual and refractive complications have been reported with these refractive surgical procedures. We compared two microkeratomes in their ability to resect corneal lamellae to gain insight into possible mechanism(s) of refractive and visual complications following lamellar refractive procedures.
METHODS: Using an eyebank eye model, we performed automated lamellar keratoplasty to theoretically correct 10.00 diopters (D) of myopia using the Automated Corneal Shaper, manufactured by Chiron, Inc. and the MicroPrecision microkeratome, manufactured by Eye Technology, Inc. Diameters before (wet) and after fixation, thicknesses of excised tissue, and scanning electron microscopy were measured in a masked evaluation to compare instruments. Ultrasonic corneal pachymetry and a mechanical tissue compression gauge were also used to assess thickness of excised tissue.
RESULTS: The Chiron automated corneal shaper created blade chatter marks at the edges of all excisions, smaller than anticipated excision diameters, and a wide range of tissue thicknesses. In contrast, the MicroPrecision microkeratome created smoother resections of all tissues without creating blade marks; tissue diameters and thicknesses were closer to the intended dimensions compared to the Chiron automated corneal shaper.
CONCLUSION: Different microkeratomes create different morphologic features as they excise corneal tissue. Differences in instrument design, mechanics of the tissue excision and blade oscillation, and instrument traverse combined with surgical skill influence the configuration of lamellar keratotomies. [J Refract Surg 1997;13:142-153]
Excimer Laser Photorefractive Keratectomy for Hyperopia
Authors: Danjoux Jean-Pierre , Kalski Richard S , Cohen Peter , Lawless Michael A , Rogers Christopher 
Published: April 2021

ABSTRACT
OBJECTIVE: To prospectively study excimer laser correction of hyperopia, with a 1-year followup.
METHODS: Eleven consecutive hyperopic eyes (10 phakic and 1 aphakic) underwent correction of hyperopia using the Summit Technology SVS Apex Plus excimer laser. Data collection included cycloplegic refraction, spectacle-corrected visual acuity, contrast sensitivity, corneal haze, manual keratometry, and videokeratography. Prior to treatment the mean hyperopic spherical equivalent refraction (corneal plane) was +5.80 diopters (D)(SD 2.10). The mean attempted correction was +3.09 D at the corneal plane.
RESULTS: Refractive data for the group showed a mean overcorrection at 1 month of +3.18 D. This regressed slightly before stabilizing at 3 months, with a mean overcorrection of +1.88 D. Thereafter there was no statistically significant fluctuation in refraction ip = 0.67). The amount of overcorrection and regression was greater in eyes that received higher corrections. Changes in manual keratometry and videokeratography mirrored the attempted correction more closely than refraction, although stabilization did not occur until 6 months.
CONCLUSIONS: Because the hyperopic correction achieved when measured by refraction was greater than expected, algorithms should be adjusted. The hyperopic erodible disc and Axicon lens system is capable of treating low to moderate amounts of hyperopia. [J Refract Surg 1997; 13:349355]
Effect of Topical Tranilast and Corticosteroids on Subepithelial Haze after Photorefractive Keratectomy in Rabbits
Authors: Furukawa Hiroyuki , Nakayasu Kiyoo , Gotoh Toshiko , Watanabe Yasuo , Takano Toshiyuki , Ishikawa Takashi , Kanai Atsushi 
Published: April 2021

ABSTRACT
BACKGROUND: Tranilast (trade name Rizaben), an anti-allergic drug with anti-inflammatory effects, is thought to inhibit synthesis of extracellular matrix of fibroblasts through the suppression of TGF-ß. We evaluated the effect of topical tranilast on the subepithelial haze that developed after excimer laser keratectomy and its effect was compared with that of betamethasone eye drops
METHODS: Excimer laser keratectomy (phototherapeutic keratectomy mode) was performed with the Nidek EC-5000 excimer laser on 16 rabbit corneas (eight rabbits). From the second postoperative day, topical 2% tranilast was instilled in the right eye and the control solution in the left eye, four times daily. Until the fourth week after the operation, we measured the densitometric values of scattered light intensity of the subepithelial haze with an anterior ocular analyzer, EAS-1000 (Nidek). At the fifth postoperative week, light and electron microscopy and immunohistochemistry with an antibody to TGF-ß were also performed.
RESULTS: Densitometric values of the subepithelial haze in the corneas treated with 2% tranilast were slightly less than those of the subepithelial haze in the control corneas. However, the values of the subepithelial haze in the betamethasonetreated corneas were significantly less than those in control corneas. Histochemical examinations revealed that topical tranilast had a small effect on the subepithelial haze after excimer laser keratectomy in rabbits.
CONCLUSION: Topical 0.1% betamethasone can limit the amount of subepithelial haze and tranilast may inhibit development of subepithelial haze by the suppression of TGF-ß. [J Refract Surg 1997; 13(suppl):S457-S458]
Corneal Asphericity in Eye Bank Eyes Implanted with the Intrastromal Corneal Ring
Authors: Burris Terry E , Holmes-Higgin Debby K , Silvestrini Thomas A , Scholl John A , Proudfoot Robert A , Baker Phillip C 
Published: April 2021

ABSTRACT
OBJECTIVE: To evaluate the effects of the intrastromal corneal ring, a device developed to reduce myopia, on corneal asphericity in a large set of eye bank eyes.
METHODS: Forty-one deturgesced eye bank eyes were implanted with intrastromal corneal rings of five different thicknesses, ranging from 0.25 mm to 0.45 mm. Corneal asphericity, before and after implantation, was examined using two different metrologies. Corneal asphericity profiles were produced from dioptric power data collected from videokeratography. To statistically assess the corneal asphericity differences between exam times for each intrastromal corneal ring thickness, dependent sample confidence intervals (95%) were calculated for the mean differences between preoperative and postoperative measures for each topographic diameter zone. Laser holographic interferometry was used to inspect corneal asphericity in one eye bank eye case study for four intrastromal corneal ring sizes. Wave unit map and geometric zonal spot ray tracing analyses derived from laser holographic interferometry topography were surveyed.
RESULTS: Videokeratographic analysis suggested that preoperative corneal shape was prolate, ie, flattened from central to paracentral cornea. Corneal shape became more prolate with intrastromal corneal ring implantation for all intrastromal corneal ring thicknesses. Laser holographic interferometry demonstrated that prolate asphericity was preserved with the intrastromal corneal ring sizes tested and that optical collection efficiency of the cornea was not diminished.
CONCLUSION: Using two different measurement techniques, this eye bank eye study demonstrated that intrastromal corneal rings maintain prolate corneal asphericity. [J Refract Surg 1997;13:556-567]
Dichlorotriazinyl Aminofluorescein Inhibits Human Keratocyte Proliferation in Vitro
Authors: Rofougaran Roya , Pakkar Alireza , Wee Won Ryang , McDonnell Peter J 
Published: April 2021

ABSTRACT
PURPOSE: Dichlorotriazinyl aminofluorescein (DTAF) has been used to stain corneal stromal collagen as part of in vivo experimentation. Toxicity of this drug, if present, might alter the observed wound healing. To determine if this drug has any deleterious effect on keratocytes, we evaluated it in vitro.
METHODS: Human keratocytes in 96 well plates were exposed to different concentrations of DTAF (10e-7, 10e-6, 10e-5, 10e-4, 10e-3, 10e-2, and 1Oe-I mg/ml of media). Exposure times of 1 and 24 hours at each concentration of DTAF were evaluated. The cell number was measured 1 and 3 days after exposure to the drug using a coulter-counter and a hemocytometer.
RESULTS: The proliferation of keratocytes after 24 hours of exposure to the drug was inhibited in a dose dependent manner by DTAF, but 1 hour exposure of keratocytes to the drug did not inhibit keratocyte proliferation.
CONCLUSION: These results suggest that DTAF has inhibitory effects on human keratocyte proliferation after 24 hours of exposure, while exposure limited to 1 hour does not induce such a change. [J Refract Surg 1997;13:568-570]
Photorefractive Keratectomy For Hyperopia and Aphakia with a Scanning Spot Excimer Laser
Authors: Sener Bozkurt , Özdamar Akif , Aras Cengiz , Yanyali Ates 
Published: April 2021

ABSTRACT
OBJECTIVE: To study the safety, efficacy, predictability, and stability of photorefractive keratectomy (PRK) for hyperopia and aphakia.
METHODS: Fifteen eyes of 15 patients (mean age, 33 ± 5.95 yrs) were enrolled in the study and divided into three groups. The first group was comprised of six eyes that had hyperopia ranging from +1.75 to +4.75 D; the second group had seven hyperopic eyes ranging from +5.00 to +9.75 D; the third group included two eyes of two aphakic patients. All eyes had PRK with a 193 nm argon fluoride excimer laser (Chiron-Technolas, Keracor 116) with a 10 Hz repetition rate and a fluence of 120 mJ/cm2. The total follow-up time in all eyes was 12 months.
RESULTS: In the lower hyperopia group, 0% eyes were within ±0.50 D and 66% (N=4) of eyes were within ±1.00 D of emmetropia with the other two eyes between +1.00 and +2.00 D at 1 year after PRK In the higher hyperopia group, all eyes had at least +3.00 D of hyperopia at 1 year. In the aphakic group, both eyes achieved less than 50% of the target correction of +10.00 D at 1 year. Final uncorrected visual acuity ranged from 20/20 to 20/30 in the lower hyperopia group, 20/30 to 20/50 in the higher hyperopia group, and count fingers in the aphakic group.
CONCLUSIONS: PRK is a relatively safe, stable, and effective procedure with reasonably good predictability for eyes with less than +5.00 D of baseline hyperopia, and poor predictability for eyes with more than +5.00 D of baseline hyperopia. PRK is ineffective in the correction of aphakia. [J Refract Surg 1997;13:620-6231
Endotoxin Levels in Steam and Reservoirs of Table-top Steam Sterilizers
Authors: Whitby James L , Hitchins Victoria M 
Published: April 2021

ABSTRACT
PURPOSE: To document endotoxin levels in "Statim" cassette sterilizer reservoirs and in steam delivered to the cassette in the unwrapped instrument cycle. To document endotoxin levels in sterilizer reservoir water using different management protocols.
METHODS: Endotoxin levels were determined using the Limulus Amebocyte Lysate test. Endotoxin preparations were from Escherichia coli and Ralstonia pickettii. All samples were collected in depyrogenated glassware and stored at -20°C until assayed.
RESULTS: The majority of water samples contained <1.0 Endotoxin Unit (EU)/mL The highest level found in sterilizers in clinical use was 5.3 EU/ml. Endotoxin was not detected in steam condensate within the limits of the assay. When the endotoxin level in the reservoir water was experimentally enhanced to 200 EU/ml, cassette steam condensate endotoxin levels were from 0.5% to 5% of the reservoir level. Daily and weekly emptying of the cassette reservoir consistently yielded low endotoxin levels as did monthly emptying, but with the latter there was a trend toward higher levels that favors weekly emptying as a precautionary measure.
CONCLUSIONS: Endotoxin levels in the reservoirs of 23 sterilizers involving 240 samplings were never high enough to yield detectable endotoxin levels in steam in the sterilizer cassette. Regular weekly emptying of sterilizer reservoirs would eliminate the risk of endotoxin transfer during steam sterilization. [J Refract Surg 2002;18:51-57]
Comparison of Placido-based, Rasterstereography, and Slit-scan Corneal Topography Systems
Authors: Guarnieri Fabio A , Guarnieri José C 
Published: April 2021

ABSTRACT
PURPOSE: Elevation-based topography systems have received growing recognition. We compared a Placido-based (EyeSys), a rasterstereography (PAR), and a slit-scan system (Orbscan) for human subjects.
METHODS: Measurements were obtained from 221 eyes of 119 human subjects. We made statistical comparisons central curvature, keratometric curvatures, and meridians between the three systems. We also compared the optical pachymetry of the slit-scan system with an ultrasonic device. We analyzed cases of subclinical keratoconus, central island, photorefractive keratectomy for myopia, and hyperopia correction with arcuate keratotomy.
RESULTS: The statistical comparison showed better correlation between the Placido-based and the rasterstereography systems in measurement of central curvature (R=0.95). The slit-scan system showed better correlation with the Placido system in the preoperative and postoperative radial keratotomy group (R=0.73) than in the group that included postoperative PRK eyes (R=0.69). Similar results were obtained for keratometric curvatures and meridians. The Orbscan pachymetry correlation with ultrasonic was R=0.69 and increased when the postoperative PRK eyes were excluded (R=0.95).
CONCLUSIONS: Slit-projection topography and pachymetry seemed to be affected by hydration in the postoperative PRK group. The pachymetric map was useful in predicting the final outcome of refractive surgery and in the diagnosis of keratoconus. [J Refract Surg 2002;18:169-176]
Anterior Corneal Surface After Nidek EC-5000 Multipass and Multizone Photorefractive Keratectomy for Myopia
Authors: Rosa Nicola , Lanza Michele , De Rosa Giuseppe , Romano Antonio 
Published: April 2021

ABSTRACT
PURPOSE: To evaluate the correlation between the presence of irregularities in corneal ablation and the number of ablation zones with multipass and multizone photorefractive keratectomy (PRK).
METHODS: The differential maps obtained from corneal topography performed before and 1 month after PRK in 62 eyes that had undergone PRK with the Nidek EC-5000 excimer laser were assessed for irregularities. PRK treatment ranged from -1.00 to -16.00 D (mean -5.25 ? 2.72 D), and the number of zones ranged from one to five.
RESULTS: Of 62 differential maps, 27 had an irregular pattern according to the Hersh classification, with a non-significant correlation with the number of treatment zones (chi2 = 5.09, P>.1).
CONCLUSION: Our results suggest that corneal topography irregularities arising from multizone PRK were not related to the amount of treatment or to the number of ablation zones. [J Refract Surg 2002;18:460-4621
Enlargement of the Temporal Clear Corneal Cataract Incision to Treat Pre-existing Astigmatism
Authors: Rao Sanjay N , Konowal Alexandra , Murchison Allison E , Epstein Randy J 
Published: April 2021

ABSTRACT
PURPOSE: To evaluate the effect of enlarging the temporal clear corneal cataract incision on preexisting against-the-rule astigmatism.
METHODS: We performed a prospective study of 21 eyes of 21 consecutive patients with astigmatism greater 3*1.75 D, who underwent temporal clear corneal cataract surgery by phacoemulsification. Patients were divided into two groups. The first group, with medium astigmatism, consisted of 14 patients (14 eyes) with 1.75 to 2.74 D of againstthe-rule astigmatism, and had an incision enlarged to 4.5 mm. The second group, with higher astigmatism, consisted of seven patients (seven eyes) with 2.75 to 3.75 D of against-the-rule astigmatism and had an incision enlarged to 5.5 mm. Corneal topography was performed preoperatively and 24 months postoperatively on all eyes. Surgically induced cylinder changes were compared by examining preoperative and postoperative keratometric power using vector analysis.
RESULTS: Mean preoperative cylinder in the medium against-the-rule astigmatism group was 2.10 ± 0.23 D and mean postoperative cylinder at 3 months was 1.17 ± 0.29 D. Using vector analysis, mean change in cylinder in the medium group was 0.93 ± 0.42 D (P<001). In the higher against-the-rule astigmatism group, mean preoperative cylinder was 2.85 ± 0.10 D and mean postoperative cylinder at 3 months was 1.63 ± 0.38 D. Mean change in cylinder in the higher astigmatism group was 1.34 ± 0.58 D (P<001). For both groups, Student's f-test showed that the postoperative decrease in cylinder was statistically significant (P=.005).
CONCLUSION: By enlarging the size of the standard (2.8 to 3.5 mm) temporal clear corneal cataract incision, pre-existing against-the-rule astigmatism was reduced. [J Refract Surg 2002;18:463-467]
Artisan Phakic Iris Claw Intraocular Lens for High Primary and Secondary Hyperopia
Authors: Alió Jorge L , Mulet M Emilia , Shalaby Ahmad M M 
Published: April 2021

ABSTRACT
PURPOSE: To evaluate the efficacy, predictability, and safety of the Artisan iris claw phakic intraocular lens for the correction of high primary and secondary hyperopia.
METHODS: Fifty-seven eyes were divided into two groups: 29 eyes had primary hyperopia (mean refraction 6.06 ± 1.26 D, and 28 eyes had secondary hyperopia, (mean refraction 5.88 ± 1.88 D) induced or residual following a previous corneal refractive procedure. Consecutive implantation of the Artisan iris claw phakic intraocular lens was performed. Main outcome measures recorded were BSCVA, UCVA, refraction, and astigmatic change, intraocular inflammation, and endothelial cell loss.
RESULTS: Primary hyperopic group: Preoperatively, mean UCVA was 0.4 ± 0.7 and mean BSCVA was 0.2 ± 0.6. After implantation, mean UCVA was 0.3 ± 0.6 and BSCVA was 0.1 ± 0.6. Mean cycloplegic residual spherieal refractive error after surgery was 0.10 ± 0.57 D (range -1 to +2 D). Mean surgically induced astigmatism was 1.48 ± 0.89 D. Safety index was 1.11. Efficacy index was 0.83. Secondary hyperopic group: Preoperatively, mean UCVA was 0.5 ± 0.7 and mean BSCVA was 0.2 ± 0.6. Postoperatively, mean UCVA was 0.4 ± 0.7 and mean BSCVA was 0.2 ± 0.6. Mean cycloplegic residual spherical refractive error was 0.55 ± 1.49 D. Mean surgically induced astigmatism was 1.85 ± 1.19 D. Safety index was 1.05. Efficacy index was 0.7. Postoperative iridocyclitis was observed in one eye (3.4%) in the primary group and in three eyes (10.7%) in the secondary group. Overall corneal endothelial cell loss at 1 year of follow-up was 9.4%.
CONCLUSION: The Artisan iris claw phakic intraocular lens was reasonably safe and predictable for correcting high hyperopia. [J Refract Surg 2002;18:697-707]