bluuebunny/crossref_metadata_2025_split huggingface dataset:
Understanding Vicarious Traumatization
Authors: Blair D Thomas , Ramones Valerie A 
Published: April 2021

I have this actual, physical reaction when I hear a helicopter, especially a Huey. If il gets close or loud, I feel this adrenaline rush. I shake and start breathing hard. I lose concentration and my mind tries to go off somewhere, oui I don't let it. Because it's embarrassing. If 1 hear helicopters from a distance, I have this compulsion to run outside and see where they are going.
We used to have a great sex life. Then she stopped letting me touch her genital area - she said it was 'like somebody probing her.' She used to like it. I tried being very gentle, but she wouldn't allow it. Then she slarted gelling all panicky and upset when we had intercourse, when I was on top. It gol so the only way we could have sex was if she was on top.
She got strange and wouldn't talk about it - she made me feel like I had done something wrong, or that I had hurt her or forced her in some way. It came from working in that clinic - she took all those stories to heart. She was really screwed up - it destroyed our relationship.
The worst thing that happened was when I was driving to work. Out of the clear blue sky, a utility worker was off to the side of the road working around a manhole. He made a gesture, like he was raising a rifle to shoot me. I flinched and moved away, and nearly ran into the car in the other lane. Looking back I saw he didn't have a weapon, he was just working. That bothered me. especially because I overreacted like that and almost had an accident.
The worst for me is that I can't enjoy watching the kids play sports. 1 just focus in on watching how the coaches and officials touch the children. This obsession ruins these activities for me, I can't seem to focus on the game itself. I know these people are probably really good people, and I admire their volunteering of their time. But they touch the children a lot during the game, and I can't seem to take my eyes away. I've got to keep watch for anything inappropriate.
Five-Year Results of Radial Keratotomy
Authors: Sawelson Harold , Marks Ronald G 
Published: April 2021

ABSTRACT: We present 5-year findings on 198 consecutive radial keratotomy surgeries. Follow-up was obtained on 134 (68%) of these eyes. Mean spherical equivalent (SE) was -4.3 diopters before surgery, average keratometry was 44,H D, and 75% of eyes had uncorrected distance acuity of 20/400 or worse, Average SE was -0.52 D for eyes seen at 5 years, which compares with -0.78 D for eyes examined at 18 months. Seventeen percent of eyes show at least a 1-D change in refraction from 18 months to 5 years compared with 13% between 18 months and 3 years. Fifty-six percent of eyes are within I D of emmetropia at 5 years, compared with 66% at 18 months. Uncorrected visual acuity was at least 20/40 in 62% of eyes seen at 5 years and in 73% of eyes seen at 18 months. Ten percent of eyes have lost at least two lines of best-corrected visual acuity from before surgery to 5 years later. Factors are identified that relate to loss of uncorrected and best corrected acuity over 5 years. Average keratometry at 5 years is 40.7 D, as compared with 41,2 D at 18 months.
Long-term keratometric results appear less stable than refractive results and a theory for this instability is presented, The results indicate radial keratotomy to be safe and effective for the vast majority of patients in this series for 5 years postoperatively, [Refractive & Corneal Surgery 1989; 5:8-20.]
Corneal Flattening by Shallow Circular Trephination in Human Eye Bank Eyes
Authors: Gilbert Michael L , Roth Allen S , Friedlander Miles H 
Published: April 2021

ABSTRACT: Recent reports documenting central keratometric changes after removal of failed epikeratoplasty lenticules, compared to preoperative keratometry measurements, suggest that the annular corneal wound alters corneal curvature. Central corneal steepening has also been reported following circular and hexagonal keratotomy. We performed standard epikeratoplasty trephination with a Hessburg-Barron suction trephine followed by a peripheral lamellar spreading keratotomy on seven human eye bank eyes to determine the effect of these incisions on corneal topography.
In seven human eye bank eyes, the mean acute central keratometric flattening from the shallow trephine incision was 2.81 D (SD 2.28, P = .017), with no significant change in keratometry due to peripheral lamellar spreading (P= .916). Computerized numeric and three-dimensional graphic analysis of the keratographs demonstrated this central topographic flattening. Further studies are needed to investigate the reversibility of host corneal changes induced by epikeratoplasty procedures. [Refractive and Corneal Surgery 1990; 6:113-116.]
Eight Years Experience With Permalens® Intracorneal Lenses in Nonhuman Primates
Authors: Werblin Theodore P , Peiffer Robert L , Binder Perry S , McCarey Bernard E , Patel Anil S 
Published: April 2021

ABSTRACT
Background: For the past 8 years, three independent laboratories have been researching the biocompatibility and performance of Permalens® intracorneal lens implants in the corneas of nonhuman primates. Both myopic and hyperopic corrections have been achieved. This article describes the evolution of the intracorneal lens design and manufacturing process.
Methods: During this time period, 63 surgeries were performed on various species of nonhuman primates. Follow-up examination extended between 30 months and 8.2 years. Objective measures of refractive performance, as well as biocompatibility were made using slit lamp, retinoscopy, autorefractor, specular microscope, etc. Additionally, histopathology was performed on many of the specimens, both acute and chronic.
Results: Surgically successful implants were achieved in between 60% and 100% of eyes in the various series of lens implants outlined in the article. Levels of contamination in the preparation of hydrogels were felt to be responsible for many of the surgical failures. The removal of silicone and other contaminants seems to have significantly improved the biocompatibility of these materials within the cornea. The major histopathological finding was that there appeared to be some epithelial thinning over the implants, but in general excellent biocompatibility was obtained over the 8-year period outlined in this paper.
Conclusions: Although extensive studies of biocompatibility have been completed, the future of the performance of these materials remains to be proven in the human subject. Additionally, empirical relationships between lens implant power and refractive results will have to be determined in humans, prior to their general clinical usage. (Refract Corneal Surg 1992;8:12-22.)
Initial Human Experience With Permalens® Myopic Hydrogel Intracorneal Lens Implants
Authors: Werblin Theodore P , Patel Anil S , Barraquer Jose I 
Published: April 2021

ABSTRACT
Background: Previous nonhuman primate experimentation has demonstrated the successful use of Permalens® hydrogel intracorneal lens implants for the correction of hyperopic and myopic refractive errors. This article documents the first human experience with myopic Permalens hydrogel intracorneal lens implants.
Methods: In this article, we report an 18-month follow up on five patients implanted with minus power hydrogel intracorneal lenses. All surgery and follow-up examinations were performed in Bogota, Columbia. The mean preoperative spherical refraction was - 14.00 ± 5.00 diopters (range, -9.5 to -19.00 D).
Results: Corrections of up to 13.00 D were achieved. Corrections deviated from the predicted correction by a mean of -5.00 ± 2.10 D (range, -2.80 to -8.00 D). No significant surgical or postoperative complications were noted. Visual recovery was rapid, usually achieving maximum acuity within 1 month.
Conclusions: Successful myopic refractive changes were accomplished in all five human subjects. The major problem with the study to date has been a significant undercorrection of the preoperative refraction. We anticipate that further empirically derived relationships between hydrogel lens power and refractive change will allow a more accurate prediction of refractive result. Also, the ability to surgically interchange myopic hydrogel inlays should allow correction of any residual refractive errors. Refract Corneal Surg 1992;8:23-26.)
Results of Transverse Keratotomies for Astigmatism After Penetrating Keratoplasty: A Retrospective Study of 48 Consecutive Cases
Authors: Saragoussi Jean-Jacques , Abenhaim Alain , Waked Naji , Koster Harry R , Pouliquen Yves J M 
Published: April 2021

ABSTRACT
Background: High astigmatism is still a common complication of penetrating keratoplasty which often limits the final corrected visual acuity. Surgical correction of high astigmatism persistent after suture removal remains rather controversial. In our present study, we used the technique of transverse keratotomies for the surgical correction of high astigmatism following penetrating keratoplasty because of its simplicity and corrective potential.
Methods: We present a retrospective clinical study based on the results of 48 consecutive transverse keratotomy procedures performed on the graft. Three eyes were operated on twice, for a total of 51 procedures. The astigmatism had to be stable for at least 6 months after suture removal, with poor corrected visual acuity with spectacles or contact lenses. The operative protocol (number of incisions, optical zone size) was decided based on the degree of astigmatism. The mean postoperative observation period was 5.11 ± 3.93 months (range, 1 to 24 months).
Results: The mean preoperative cylinder was 8.96 ± 2.22 diopters and 4.91 ± 1.79 D postoperatively. The mean cylindrical change was 4.51 ± 2.77 D. The spherical equivalent remained unchanged in most cases. In a majority of cases, the corrected visual acuity for distance and near vision was improved. No cases of persistent graft edema caused by immunologic rejection or endothelial failure were observed. Moreover, in no case was there worsening of the best corrected visual acuity.
Conclusions: The technique of transverse incisions in the graft to correct or reduce high postkeratoplasty astigmatism is simple, efficient, and relatively safe. The main problem was poor predictability. (Refract Corneal Surg 1992;8:33-38.)
Numerical Modeling of Radial, Astigmatic, and Hexagonal Keratotomy
Authors: Pinsky Peter M , Datye Deepak V 
Published: April 2021

ABSTRACT
Background: A mechanical model of the human cornea is proposed and employed in a finite element formulation for simulating the effects of keratotomy on the cornea.
Methods: The formulation assumes that the structural behavior of the cornea is governed by the properties of the stroma which is modeled as a thick membrane. The tensile forces in the cornea are resisted by the collagen fibrils embedded in the ground substance of the stromal lamellae. When the stromal lamellae are cut, as in keratotomy, it is assumed that they no longer carry any tensile forces, and the forces in the cornea are then resisted only by the remaining uncut lamellae. A constitutive model, which represents the anisotropy and inhomogeneity in the membrane rigidity induced by the incisions, has been employed in a geometrically nonlinear finite element membrane formulation for small strains with moderate rotations. This preliminary model is restricted to linear material behavior with no time dependency.
Results: A number of numerical examples are presented to illustrate the effectiveness of the proposed constitutive model and the finite element formulation for computing the immediate postoperative shift in corneal power resulting from radial, astigmatic, and hexagonal keratotomy. Surgical changes computed using the proposed model compare well with surgical corrections predicted by expert surgeons.
Conclusions: The proposed computational model of the cornea and the effects of sugical procedures on it is based on a number of important simplifying assumptions regarding the mechanical properties and structure of the corneal tissue at the ultrastructure level. The encouraging results found with present model suggest that further development and refinement will be useful. (Refract Corneal Surg 1992;8:164-172.)
On the Computer-Aided and Optimal Design of Keratorefractive Surgery
Authors: Velinsky Steven A , Bryant Michael R 
Published: April 2021

ABSTRACT
Background: Several recent papers have discussed the use of engineering-based computer methods for the analysis of keratorefractive surgical procedures. What has been lacking is a broader view of the role of engineering analysis in keratorefractive surgery. This article demonstrates how these various analysis methods can be coupled to provide a comprehensive methodology for the design of refractive surgical procedures.
Methods: A structural model of the eye, based on a linearly elastic, transversely isotropic finite element formulation is coupled to a full-eye optical model. The optical errors due to refractive keratotomy are estimated by ray tracing through the optical model and measuring the position of the resulting focal plane relative to the retina. Computer-based optimization methods are employed to determine the surgical parameters necessary to correct myopia for a given set of surgical design goals.
Results: Results based on a hypothetical eye demonstrate agreement with clinical trends. Radial keratotomies are designed that eliminate refractive error while minimizing invasiveness in one case and maximizing the optical zone size in another. It is also shown that there is significant potential to customize this process on a patient-by-patient basis using clinically measured data.
Conclusions: We present an overview of the research necessary to bring this approach to fruition. While only a first step, the methodology presented in this article has the potential to increase the predictability of keratorefractive surgery by substantially increasing both the quality and the quantity of the information available to the refractive surgeon preoperatively. (Refract Corneal Surg 1992;8:173-182.)
A Thin-Shell Model of the Cornea and Its Application to Corneal Surgery
Authors: Howland Howard C , Rand Richard H , Lubkin Sharon R 
Published: April 2021

ABSTRACT
Background: We present a thin-shell, analytical model of the vertebrate cornea to study the changes in shape resulting from surgical operations (eg, radial keratotomy).
Methods: A simple closed-form solution is derived for a thin linearly elastic spherical model of the cornea. We assume that the shell is symmetrical about a central axis and that the modulus of elasticity is the same in all directions. The surgery is modeled by allowing the modulus of elasticity (or equivalents the thickness) of the shell to depend upon position, measured as an angle from the axis of symmetry.
Results: The analytical nature of the solution allows us to compute the principal curvatures of the cornea explicitly. For example, for representative parameters, the model predicts the average corneal curvature changes from about 43 diopters before keratotomy to about 38 D after keratotomy.
Conclusions: The model is used to estimate Young's modulus from experimental data reported previously by Thomas et al (Invest Ophthalmol Vis Sci 1991;32:1000), as well as to investigate the effect of surgery on corneal flattening and the associated sensitivity to intraocular pressure changes. (Refract Corneal Surg 1992;8:183-186.)
A Comparison of Corneal Stromal Edema Induced From the Anterior or the Posterior Surface*
Authors: Cristol Stephen M , Edelhauser Henry F , Lynn Michael J 
Published: April 2021

ABSTRACT
BACKGROUND: Many differences between the anterior and posterior corneal stroma have been reported. The physiological and mechanical properties of the cornea are a summation of these properties across each of the corneal regions. This article investigates corneal stromal swelling that is experimentally induced through each surface.
METHODS: Corneal stromal swelling was induced in human and rabbit corneas through either the anterior or posterior surface. The rate of stromal swelling was analyzed with a linear regression model.
RESULTS: Swelling in the rabbit stroma was 3.65 × faster when induced through the posterior surface than through the anterior surface (p < .0001), while the human stroma swelled 13.1 × faster through the posterior surface (p < .0001). The hydration of the stroma increased during swelling through the posterior surface, but paradoxically decreased during swelling through the anterior surface.
CONCLUSIONS: These experiments showed that stromal swelling occurs more rapidly through the posterior corneal surface than through the anterior surface. These results may have implications for the refractive surgeon performing laser ablative procedures on the anterior surface of the cornea. Refract Corneal Surg 1992;8:224-229.)
Report on Psychosocial Findings and Satisfaction Among Patients 1 Year After Excimer Laser Photorefractive Keratectomy
Authors: Kahle Gunther , Seiler Theo , Wollensak Josef 
Published: April 2021

ABSTRACT
BACKGROUND: The first 26 patients who underwent photorefractive keratectomy with an excimer laser in our clinic with a 1-year follow up voluntarily answered a questionnaire.
METHODS: It was intended to get information about their social status, motivation, expectations, and satisfaction with myopic excimer laser photorefractive keratectomy.
RESULTS: All patients wore corrective lenses before surgery; 74% wore no optical correction after the photorefractive keratectomy. "To improve general vision" was the highest ranked motivation while "looking better" was only of minor importance. Seventy-two percent reported that their subjective vision became better; 28% felt that it didn't change, but none reported deterioration of subjective vision. Seventy-five percent of the patients reported improvement of their lifestyle after surgery, whereas 21% reported no change and one patient stated that his lifestyle got worse. On a scale ranging from 1 to 5, early postoperative course was painful with a mean score of 2.25; the treatment itself was considered as professional (1.42 ± 0.8) and well done (1.54 ± 0.8). Eighty-four percent of the patients reported that they were satisfied with the overall results.
CONCLUSIONS: All patients would decide again to have photorefractive keratectomy for myopic correction. [Refract Corneal Surg 1992;8:286-289.)
Facilitation of Ab Interno Radial Keratotomy by Air Keratoplasty
Authors: Mansour A M 
Published: April 2021

ABSTRACT
BACKGROUND: Ab interno radial keratotomy is a keratorefractive procedure with radial incisions made by externalizing a blade inserted in the deep stroma. A major limitation of the procedure is the technical inability to establish a safe preDescemetic stromal entry of the blade with subsequent suboptimal depth of the radial incisions. A technique to delineate Descemet's membrane was investigated to obtain deeper incisions with the ab interno radial keratotomy.
METHODS: Air was injected with a 30-gauge needle mounted on a 3-milliliter syringe and entering the deep stroma at the limbus in human donor eyes. The injection was done in a pulse fashion with the needle tip advanced 3 mm away from the limbus. Ab interno radial keratotomy was then performed with and without air injection.
RESULTS: Bubbles were localized to the preDescemet region. The depth of the radial keratotomy incisions increased from 57.7% (SD = 1 1 .5%) without air injection, to 83.0% (SD = 10.6%) with air injection.
CONCLUSIONS: Deep stromal air injection delineates the pre- Descemet space, allowing deeper radial incisions with the ab interno radial keratotomy. [Refract Corneal Surg 1992;8:385-388.)
Circumferential Block Resection to Reduce Myopia
Authors: Buzard Kurt A 
Published: April 2021

ABSTRACT
BACKGROUND: The surgical treatment of excessive myopia following penetrating keratoplasty has been largely ignored. Oversized corneal grafts can induce myopia and the Troutman wedge (block) resection has been used to correct astigmatism by removing tissue in a single corneal semimeridian. This study explores the use of block resections in opposing semimeridians to reduce myopia caused by a steep cornea.
METHODS: Six eyes received three different operations. One eye received 60-degree block resections in semimeridians located 90° (procedure 1), two eyes received 0.5-millimeter semicircumferential (180°) block resections (procedure 2), and three eyes underwent 0.5-millimeter 360degree circumferential block resections (procedure 3). All patients were followed for at least 1 year.
RESULTS: Procedure 1 (two 60-degree block resections) developed approximately 2.75 D of myopic correction at 1 year. The average reduction of spherical equivalent was 4.50 D for procedure 2 (one 180-degree block resection) and 10.50 D for procedure 3 (one 360-degree block resection) at 1 year. Although all eyes regained best spectacle-corrected visual acuity, the postoperative course was prolonged by irregular astigmatism.
CONCLUSIONS: Circumferential and semicircumferential block resections can reduce myopia after penetrating keratoplasty and in naturallyoccurring myopia, but the postoperative course can be prolonged, especially because of irregular astigmatism. Early removal of sutures results in regression of myopic correction. Refract Corneal Surg 1993;9:283-292.)
Intraoperative Intraocular Endoscopy in Transscleral Suture Fixation of Posterior Chamber Lenses: Consequences for Suture Technique, Implantation Procedure, and Choice of PCL Design
Authors: Althaus Christoph , Sundmacher Rainer 
Published: April 2021

ABSTRACT
BACKGROUND: Transscleral suture fixation of posterior chamber lenses (PCLs) in the absence of capsular support causes minimal long-term alteration of the blood-aqueous barrier, if two requirements are fulfilled: 1) the transscleral suture has to penetrate exactly through the ciliary sulcus, and 2) the PCL haptics have to be directed into the sulcus and secured there.
METHODS: The surgical results of our standard techniques were controlled intraoperative^ by means of intraocular endoscopy in every patient since May 1991. Different alterations were necessary to improve the incidence of sulcus penetration and implantation.
RESULTS: With our conventional suture techniques, the needle penetrated the ciliary processes in the majority of eyes. Best results were achieved by passing the needle from the outside into the eye before opening the globe. When the eye was already hypotonic, the ciliary processes tended to prolapse in front of the needle tip, resulting in pars plicata fixation. With perforating keratoplasty, passing the needle from the inside out by feeling one's way into the sulcus with the needle tip gave good results. Even correct needle penetration through the sulcus did not guarantee correct positioning of the PCL haptics in the sulcus.
CONCLUSIONS: Selecting a suitable PCL design and a new implantation technique which reduces the angle of PCL implantation, the rate of correctly positioned PCLs in transscleral suture fixation is increased considerably. Refract Corneal Surg 1993;9:333-339.)
RÉSUMÉ
INTRODUCTION: La fixation des lentilles intraoculaires de chambre postérieure avec des sutures trans-sclérales, sans l'appui capsulaire, entraine très peu de changement de la barrière sang-aqueuse à condition que 1) la suture transsclérale pénètre exactement dans le sulcus ciliaire et 2) que les anses soient dirigées dans le sulcus et y être suturées.
MÉTHODES: Nos techniques chirurgicales furent contrôlées pendant l'opération par endoscopie intra-oculaire chez chaque patient depuis mai, 1991. Plusieurs changements furent nécessaires afin d'améliorer l'incidence de pénétration et d'implantation dans le sulcus ciliaire.