bluuebunny/crossref_metadata_2025 huggingface dataset:
Pediatric Ocular Trauma: A Retrospective Survey
Authors: Cascairo Mark A , Mazow Malcolm L , Prager Thomas C
Published: April 2021

ABSTRACT

A retrospective, cross-sectional survey was conducted of all pediatrie trauma cases seen by the ophthalmology department at our institution from January 1986 to December 1991. The study included 504 patients who were 15 years old or younger. The purpose of this study was to determine risk factors for ocular injury, especially injury resulting in severe visual impairment, and to identify trends and preventable causes. Our results were consistent with the findings of other similar studies: male patients predominated, penetrating Injuries resulted in poor visual outcomes, and many of the causes of severe visual deficit were preventable with more adequate adult supervision.
Health Locus of Control, Values, and Weight Reduction Behavior
Authors: Muhlenkamp Ann F , Nelson Arlene M
Published: April 2021

ABSTRACT

This study, in a natural setting, attempted to predict health-related behavior on the basis of the personality construct locus of control. Thirty-six participants in a weight reduction program completed the Multidimensional Health Locus of Control Scale (MHLC) and a value scale that included the values of "health" and "physical appearance." Subjects also were asked to determine their weight loss goal in pounds. Three months later their progress was assessed, and 22 of the subjects again completed the MHLC and value surveys. Consistent with the first hypothesis, those subjects who perceived their health status to be under the control of powerful others and valued health and/or physical appearance highly weighed in more frequently at the weight center than did the other subjects. Contrary to the second hypothesis, subjects did not become more "internal" as a result of sucessful weight loss. Subjects who valued physical appearance highly were found to have higher "external" control beliefs. Theoretical significance and practical applications of the findings are discussed.
Data on Young, Chronic, Mentally Ill Substance Abusers
Authors: Anonymous
Published: April 2021

Wanted:
Free Directory for the Elderly Available
Authors: Anonymous
Published: April 2021

Self-Help References
Role Playing
Authors: Wistrom Frances E
Published: April 2021

A Tool for the Prevention and Acceptance of Mental Illness
Psychiatric Hospital Admissions: Assessing Patients' Perceptions
Authors: Sebastian Linda
Published: April 2021

The admission process deserves our full attention as we attempt to enhance the therapeutic aspects of the patient's environment and treatment.
using play in psychiatric rehabilitation
Authors: Jack Lynette W
Published: April 2021

Play allows psychiatric clients to use cognitive skills and to experience in a non-threatening way the full range of emotions.
Medication: REASONS AND INTERVENTIONS FOR NONCOMPLIANCE
Authors: Forman Lisa
Published: April 2021

The causes of noncompliance include side effects, knowledge deficits, and patient/therapist relationships.
Corneoscleral Freehand Lamellar Keratoplasty in Terrien's Marginal Degeneration of the Cornea-Long-Term Results
Authors: Pettit Thomas H
Published: April 2021

ABSTRACT: Freehand corneoscleral lamellar grafts were used in the treatment of advanced Terrien's marginal degeneration of the cornea in four eyes of three patients followed over a period of 12 to 20 years. Anatomic reconstruction of the ectatic thinned peripheral cornea was achieved and irregular astigmatism eliminated in all four eyes. Corneal astigmatism secondary to the corneal ectasia was reduced by 4.00 to 9.00 diopters. The progressive increase in against-the-rule astigmatism associated with advancing Terrien's was arrested for up to 20 years. Gradual thinning of the lamellar graft was noted in all four eyes after 10 years, but the return of corneal ectasia and increasing astigmatism has not occurred. [Refractive and Corneal Surgery 1991;7:28-32.]
Corneal Complications of Cataract Surgery
Authors: Hwang David G , Smith Ronald E
Published: April 2021

ABSTRACT: The intraoperative and postoperative complications of cataract surgery that affect the cornea vary in etiology and severity. Principal complications include epithelial disruption, infections, sterile corneal ulceration, stromal melt, mechanical or toxic injury of the endothelium, vitreous touch, stripped Descemet's membrane, and epithelial and fibrous downgrowth. Meticulous cataract surgery with careful attention to protecting the cornea can prevent most serious corneal complications. Certain clinical situations warrant special note; patients with rheumatoid arthritis and dry eyes require extra lubrication to the epithelium to prevent disruption during surgery; patients with low endothelial cell counts benefit from the least possible surgical trauma to minimize cell loss; surgical clean-up of vitreous from the anterior segment remains an important principle; clinically significant Descemet's membrane tears or areas of stripping should be repaired at the time of cataract surgery. The clinical judgment and skills of the cataract surgeon should be equal to the type of cataract operation performed. [Refractive and Corneal Surgery 1991;7:77-80.]
Basic Surgical Principles of Penetrating Keratoplasty
Authors: Lanier Jeffrey Day
Published: April 2021

ABSTRACT: Surgical techniques of keratoplasty continue to be modified in an attempt to achieve ideal results, but basic surgical principles remain constant. Proper alignment of the donor graft is an important and consistent surgical principle in all types of keratoplasty. Closure of keratoplasty wounds should provide the most optimal environment for a secure water-tight wound, minimize contour distortion, and promote tissue healing. One provides the most ideal opportunity for desired surgical results by understanding and utilizing basic surgical principles.[Refractive and Corneal Surgery 1991;7:92-98.]
Immunogenicity of Epikeratophakia Tissue Lenses Containing Living Donor Keratocytes
Authors: Frantz Jonathan M , Gebhardt Bryan M , Reidy James J , McDonald Marguerite B
Published: April 2021

ABSTRACT: The purpose of this study was to compare the survival of epikeratophakia tissue lenses prepared with cryolathing and lyophilization (frozen lenses) and without (fresh lenses) in donorsensitized recipients with vascularized corneas. Fresh lenses placed in vascularized corneas of immune recipients were subjected to immune attack. Frozen lenses placed in vascularized corneas of immunized recipients did not elicit an immune reaction. Neither fresh nor frozen lenses elicited immune reactions in nonvascularized corneas of immune recipients or in nonvascularized, nonimmune recipients. These results indicate that although the fresh lenses are more antigenic than the lenses in which the cells have been killed by freezing and lyophilization, the fresh lenses prepared using the BKS-1000 technique containing living stromal keratocytes are not likely to stimulate allograft immune reactions in unsensitized patients with avascular graft sites. (Refract Corneal Surg 1991;7:141-145.)
Excimer Laser Myopic Photorefractive Keratectomy After Undercorrected Radial Keratotomy
Authors: McDonnell Peter J , Garbus Jenny J , Salz James J
Published: April 2021

ABSTRACT: Two patients, a 4 1 -year-old female diabetic and a 37-year-old male, were undercorrected after radial keratotomy (spherical equivalents of -3.25 diopters in each eye). Because they were unable to wear a coniaci lens and had uncorrected visual acuities of 20/400 and 20/100, respectively, they elected to undergo excimer laser photorefractive keratectomy to reduce the myopia by 3.00 D and 2.75 D, respectively. Three months postoperatively, both patients were within 0.50 D of emmetropia. Videokeratography demonstrated a fairly uniform zone of central flattening. The previous radial keratotomy surgery and the diabetes (in one patient) did not appear to complicate the surgery. Excimer laser photorefractive keratectomy appears to hold promise as a means of correcting eyes left undercorrected by radial keratotomy. (Refract Corneal Surg 1991;7:146-150.)
Optical Zone Size in Keratomileusis for Myopia: Computer-Assisted Evaluation and Correction of Myopic Keratomileusis
Authors: Asfour Osama M , El Shami H
Published: April 2021

ABSTRACT: In this article, we demonstrated the unexpected reduction of optical zone diameter in myopic keratomileusis and its causes. Mathematical evaluation of optical zone diameter was made possible through a module added to a computer program. Optical zone diameter was reduced more in smaller corrections than in higher corrections. Practical measurements were parallel to mathematical expectations except in some small corrections between -4.00 and -6.00 diopters, where it was even more reduced than calculated. We were able to enlarge the optical zone diameter using the same computer module. Refract Corneal Surg 1991:7:161-1 66.)
Comparison of Epikeratoplasty and Penetrating Keratoplasty for Keratoconus
Authors: Fronterre Aldo , Portesani Gian Paolo
Published: April 2021

ABSTRACT: We report the results obtained in two groups of 30 eyes surgically treated for keratoconus. The eyes in the first group underwent epikeratoplasty, and those in the second group, penetrating keratoplasty. All eyes had sutures removed and a follow-up period ranging from 3 to 6 years. In the epikeratoplasty group, mean postoperative uncorrected visual acuity was 20/52 ± 0.25; spectacle corrected, 20/23 ± 0.18; and contact lens corrected, 20/21 ± 0.17. In the penetrating keratoplasty group, mean postoperative uncorrected visual acuity was 20/63 ± 0.23; spectacle corrected, 20/22 ± 0. 1 1 ; and contact lens corrected, 20/20.5 ± 0.07. In the epikeratoplasty group, astigmatism (2.18 ± 1.48) and astigmatism reduction (- 4.16 ± 2.98) were comparable to the penetrating keratoplasty group (astigmatism; 3.16 ± 1.43 and astigmatism reduction; -4.2 ± 2.56). Among the advantages offered by epikeratoplasty were both the absence of immunologic complications and reduction of operative risk. Penetrating keratoplasty provided patients with higher reduction of the myopic defect and earlier improvement in both visual acuity and contrast sensitivity. (Refract Corneal Surg 1991;7:167-173.)
Relative Mydriasis After Photorefractive Keratectomy
Authors: Geerling Gerd , Neppert Birte , Wirbelauer Christopher , Laqua Horst
Published: April 2021

ABSTRACT

PURPOSE: To report the incidence of anisocoria after unilateral excimer laser photorefractive keratectomy (PRK) for myopia and subsequent corticosteroid therapy in a retrospective and prospective study and to explore possible etiologies.

METHODS: The horizontal pupil diameter was determined in 6 patients (6 eyes) at 21.8 ± 12.6 months after unilateral wide-field excimer laser PRK (retrospective group) as well as in 8 consecutive patients (8 eyes) before and 3.4 ± 2.9 months after unilateral PRK (prospective group). The Schwind-Keratom wide-field excimer laser was used. Measurements were done in an examination room using Rosenbaum card comparison pupillometry and with a Goldmann perimeter at 31.5 asb. In the prospective group, the effect of fitting a hard contact lens of zero diopter power and the application of 0.1% pilocarpine were evaluated.

RESULTS: Relative mydriasis was present in all treated eyes and the difference in pupil diameter between the two eyes measured 0.25 to 1.75 mrn (retrospective group: +0.56 ± 0.82 mm; prospective group: +0.72 ± 0.29 mm). At the time of pupil measurement, the retrospective group had a significantly longer mean postoperative follow-up (21 mo) than the prospective group (3.4 mo) and significantly more eyes still received topical corticosteroid treatment (retrospective group, 1 of 6 eyes; prospective group, 7 of 8 eyes). The amount of anisocoria did not correlate with the applied laser energy, ablation depth, or refractive change, but showed a negative correlation with increasing time after PRK. Neither hard contact lens fitting nor pilocarpine 0.1% reduced the amount of anisocoria significantly.

CONCLUSION: Unilateral PRK with wide-field excimer laser ablation and subsequent application of topical corticosteroids regularly resulted in a relative pupillary mydriasis. Neither an altered corneal profile nor parasympathetic denervation is responsible for this. Weakening of the pupillary sphincter of the treated eye may cause this phenomenon. [J Refract Surg 2000;16:69-74]
Evaluation of Corneal Flap Dimensions and Cut Quality Using the Automated Corneal Shaper Microkeratome
Authors: Behrens Ashley , Seitz Berthold , Langenbucher Achim , Kus Murat M , Rummelt Carmen , Küchle Michael
Published: April 2021

ABSTRACT

PURPOSE: To evaluate flap dimensions and cut deterioration with repeated blade use in an automated microkeratome.

METHODS: The Automated Corneal Shaper (Chiron-Adatomed, Munich, Germany), 160-/«m plate attached, was used to make a corneal flap in 90 pig cadaver eyes, reusing blades up to five times. Flap diameter was measured by planimetry and thickness was calculated by ultrasound pachymetry. Scanning electron microscopy of stromal beds and blade cutting edges was performed to assess cut deterioration after repeated blade use.

RESULTS: Mean flap central thickness was 125 ± 32 µt?. Mean vertical flap diameter was 7.6 ± 0.4 mm. No correlation was found between thickness and diameter (r = 0.15, P = .45). Progressive thinning of the flap was observed in the direction of the flap hinge. Smooth cuts (using new blades) with periodic chatter Unes at the keratectomy edge and in the stromal bed were observed with scanning electron microscopy. Increasing tissue remnants on the stromal bed and decreasing cut quality occurred with repeated blade use. Blades showed larger tissue remnants, nicks, and even folds on the cutting edge proportional to the number of times blades were used.

CONCLUSION: Satisfactory cut quality and reproducibility were obtained after a single use of stainless steel blades in the Automated Corneal Shaper microkeratome. Cut quality was degraded dramatically by repeated use of blades. [J Refract Surg 2000;16:83-89]
Photoastigmatic Refractive Keratectomy in Myopes
Authors: MacRae Scott M , Peterson Jan S , Koch Douglas D , Rich Larry F , Durrie Daniel S
Published: April 2021

ABSTRACT

PURPOSE: Photoastigmatic refractive keratectomy (PARK) was studied in a multi-center clinical trial. The Nidek EC-5000 excimer laser was evaluated for its effect on refraction, visual acuity, and safety measures as part of a U.S. Food and Drug Administration (FDA) regulated study.

METHODS: Eight U.S. centers enrolled adults with eyes having refractive astigmatism up to 4.00 D and a myopic spherical equivalent refraction up to -8.00 D. Results are reported for 749 eyes of 486 patients with at least 6 months follow-up. The rectangular beam scanning Nidek EC-5000 used a 5.5-mm-diameter treatment zone, a 7.0-mmdiameter peripheral blend zone, and a 40 Hz pulse rate for surface treatment of myopic astigmatism. Nomogram corrections to machine settings were required to achieve the desired results.

RESULTS: Preoperative average spherical equivalent refraction of -4.90 ± 1.74 D was reduced to -0.02 ± 0.79 D at 6 months. Refractive stability was established at 3 months. Over 62% of eyes were within ±0.50 D of desired correction at 6 months, with over 86% within ±1.00 D. Uncorrected visual acuity improved by an average of 10 Snellen lines; over 64% of eyes saw 20/20 or better uncorrected and over 93% saw 20/40 or better uncorrected at 6 and 12 months. PARK treatment effectively reduced astigmatism with little average axis error or magnitude error. Corneal haze and safety concerns were minimal.

CONCLUSIONS: Photoastigmatic refractive keratectomy using the Nidek EC-5000 excimer laser provided significant reduction of myopia and astigmatism, with minimal complications. [J Refract Surg 2000;16:122-132]
A Mathematical Model for Laser in situ Keratomileusis and Photorefractive Keratectomy
Authors: Lieberman David M , Grierson Jonathan W
Published: April 2021

ABSTRACT

PURPOSE: The purpose of ablation refractive surgery is to remove the refractive error from the inherently asymmetric aspheric cornea. Although the technique is gaining wide acceptance and popularity, some patients are left with irregular corneas. Our objective was to develop a methodology to analyze corneal shape, reduce the shape to arcs, modify the local arc value to the desired new arc value, and render a new continuous Euclidean surface without discontinuity.

METHODS: The method to reconstruct the corneal surface consists of importing scanner output elevation data points into a computer-aided design (CAD) application to form the surface model. The corneal arc measurements are derived at 5° increments and centered about the Gauss point of symmetry. Each arc is manipulated to adjust the corresponding arc on the proposed corneal surface to reflect the new arc value, correcting for the refractive error. The method determines the amount of corneal tilt and ablation depth at a given diameter required for the refractive error with a smooth transition zone to the base cornea.

RESULTS: The case example is a patient who began with a spherical refraction of -8.75 D and after LASDX was emmetropic, but had irregular astigmatism and 20/30 best spectacle-corrected Snellen visual acuity. The proposed mathematical model compares the achieved surface shape to the mathematically planned surface contour. An enhancement procedure to remove the LASIK-induced corneal irregularity was designed.

CONCLUSION: A mathematical technique to plan myopic ablative surgery to make the corneal surface regular and symmetric is proposed. [J Refract Surg 2000;16:177-186]
Mycobacterium Keratitis After Laser in situ Keratomileusis
Authors: Gelender Henry , Carter Harvey L , Bowman Bradley , Beebe Walter E , Walters George R
Published: April 2021

ABSTRACT

PURPOSE: The authors report two cases of Mycobacterium keratitis following LASIK.

METHODS: The case reports are based on a retrospective review of clinical history and associated findings.

RESULTS: Two patients developed infectious keratitis after undergoing laser in situ keratomileusis (LASLK). In case #1, the infection developed after manipulation of the lamellar flap to remove epithelium from the stromal bed. In case #2, prior radial keratotomy may have been a contributing factor to development of the infection. Corneal infiltrates appeared as focal, white, stromal deposits. Cultures isolated Mycobacterium fortuitum from case #1 and Mycobacterium chelonae from case #2. Topical fortified amikacin, clarithromycin, tobramycin, and ciprofloxacin eventually controlled the infection. Topical prednisolone acetate and bandage contact lenses were necessary to control inflammation and pain. Infiltrates were slow to resolve until focal necrosis eroded through the flaps leading to rapid clearing of the infiltrates; however, scarring of the cornea developed at the site of necrosis. Visual recovery was good in the first case but limited in the second.

CONCLUSIONS: Mycobacterium keratitis complicating LASIK may be difficult to eradicate until the sequestered stromal infiltrate drains. Rapid recognition of the causative organism and aggressive medical and surgical management of the infection may improve the outcome. [J Refract Surg 2000;16:191-1951
Laser in situ Keratomileusis for Anisometropic Amblyopia
Authors: Dedhia Niteen C , Behl Seema
Published: April 2021

ABSTRACT

PURPOSE: To evaluate the efficacy and benefit of laser in situ keratomileusis (LASIK) for correction of anisometropic amblyopia.

METHODS: LASER was performed in 21 eyes of 21 anisometropic amblyopes with a mean age of 27.71 ± 12.24 years. Three patients were less than 18 years of age. LASIK was performed in the more myopic and amblyopic eye using the Chiron Automated Corneal Shaper microkeratome and the Nidek EC-5000 excimer laser system.

RESULTS: Results of 3-month follow-up are presented. Preoperative mean manifest spherical equivalent refraction was -13.20 ± 3.84 D (range, -5.25 to -20.00 D). Mean attempted correction was -12.28 ± 3.47 D. Mean postoperative refraction at 3 months was -0.78 ± 1.63 D. Postoperative uncorrected visual acuity improved by 2 or more lines in all patients and was the same or better than preoperative best spectacle-corrected visual acuity in 95.2% of eyes. Best spectacle-corrected visual acuity improved by 1 or more lines in 61.9% of eyes. The 12-year-old child had a gain of more than 4 lines of uncorrected visual acuity.

CONCLUSION: LASIK was a good alternative to contact lenses in adults for anisometropia and resulted in a gain of best spectacle-corrected visual acuity. In children it may be an alternative method of treatment for amblyopia. [J Refract Surg 2000;16(suppl):S264-S267]
Holmium Laser Thermal Keratoplasty for Hyperopia and Astigmatism After Photorefractive Keratectomy
Authors: Eggink Catharina A , Meurs Piet , Bardak Yavuz , Deutman August F
Published: April 2021

ABSTRACT

PURPOSE: To report results of holmium laser thermal keratoplasty used to treat induced hyperopia and induced, as well as pre-existing astigmatism after photorefractive keratectomy.

METHODS: Sixteen eyes of 16 patients were included in this study. Contact holmium laser (Technomed Holmium 25) was used in 7 patients to correct hyperopia (8 spots at 8 or 9 nun) and in 9 patients to correct astigmatism (4 spots at 7, 8, or 9 mm). Follow-up evaluation was done after at least 6 months. The effectiveness, stability, and safety of the procedure were investigated.

RESULTS: Spherical correction was ineffective (1.00 D or less) when applied at the 9-mm diameter treatment zone. Spherical correction applied at the 8-mm diameter treatment zone was ineffective in 1 eye. Three eyes achieved 1.00 to 2.00 D change, but 2 of these eyes showed an induced astigmatic change as well. Correction of astigmatism at the 7-mm diameter treatment zone resulted in a 0 to 4.00 D cylinder component change. Treatment at the 8-mm diameter treatment zone showed a 0 to 1.50 D effect and at the 9-mm treatment zone, 0.25 to 1.50 D. All eyes that achieved significant improvement (1.00 D or more change in cylinder component) showed significant overcorrection in the first postoperative phase. There were no sight threatening complications.

CONCLUSION: Holmium laser thermal keratoplasty can be useful for the treatment of overcorrection and induced as well as pre-existing astigmatism after photorefractive keratectomy. However, predictability is low and astigmatism can be induced with the attempted spherical correction. [J Refract Surg 2000;16:317-322]
A Model to Explain the Difference Between Changes in Refraction and Central Ocular Surface Power After Laser in situ Keratomileusis
Authors: Patel Sudi , Alió Jorge L , Pérez-Santonja Juan J
Published: April 2021

ABSTRACT

PURPOSE: After refractive surgery, changes in central ocular surface power are usually less than actual changes in refraction. The aim of this paper was to examine the theoretical changes in the radius of the epithelial-stromal interface and corneal stromal refractive index which could take place to account for some of the empirical findings.

METHODS: The parameters of an aspheric human eye model featuring grathent index optics was modified using data from a clinical study evaluating effects of laser in situ keratomileusis (LASIK) for correction of moderate to high myopia. Computations were performed to determine: 1) theoretical postoperative radius of the epithelialstromal interface and hence distribution of epithelial thickness, and 2) refractive index of the stroma when the epithelium was of fixed uniform thickness.

RESULTS: Within the central 2-mm diameter refractive zone of the cornea after LASIK for myopia, either of two factors could account for the difference between changes in central ocular surface power and the actual change in ocular refraction: 1) a steepening of the epithelial-stromal interface resulting from a 400% centrifugal increase in epithelial thickness, or 2) a reduction in stromal refractive index from an average of 1.376 to 1.364.

CONCLUSION: The difference between the observed changes in refraction and central ocular surface power could be explained by reduction in stromal refractive index and this could be secondary to a 6.5% increase in water content of the stroma during the postoperative period. The epithelial-stromal interface after LASIK is unlikely to steepen by the extent predicted by our model. This surface is not the source of the difference between the change in refraction and change in central ocular surface power. [J Refract Surg 2000;16:330-3351
Corneal First Surface Optical Aberrations and Visual Performance
Authors: Applegate Raymond A , Hilmantel Gene , Howland Howard C , Tu Elmer Y , Starck Tomy , Zayac E Joseph
Published: April 2021

ABSTRACT

PURPOSE: Wavefront analysis has demonstrated that refractive surgery-induced corneal first surface aberrations are large, are dominated by symmetric aberrations (spherical-like aberrations), and are correlated to measures of visual performance. It is not clear whether the correlation between corneal first surface aberrations and visual performance can be generalized to other corneal conditions where large asymmetric aberrations (coma-like aberrations) may dominate the aberration structure. The purpose of the research reported here was to determine the general utility of corneal first surface wavefront analysis in predicting visual performance.

METHODS: Patients were 13 normals and 78 patients with a variety of corneal conditions including surgically removed pterygia, penetrating keratoplasty, keratoconus, radial keratotomy, laser in situ keratomileusis, and others. Videokeratographs were taken for all patients and used to calculate corneal first surface wavefront variance for 3 and 7 mm pupils. Similarly, visual performance was quantified by measurements of contrast sensitivity and high and low contrast acuities through both 3 and 7 mm pupils.

RESULTS: Statistically significant correlations existed between all three measures of visual performance and the corneal wavefront variance. All relationships were stronger for the 7 mm diameterpupil condition than the 3 mm pupil.

CONCLUSION: Regardless of the cause, corneas with increased wavefront variance showed a quantifiable decrease in visual performance that was pupil size dependent. [J Refract Surg 2000; 16: 507-514]
Measurement of Corneal Thickness By Videopachymetry: Preliminary Results
Authors: Franco Sandra , Almeida José B , Parafita M
Published: April 2021

ABSTRACT

Corneal thickness measurements find applications in areas such as diagnosis and management of corneal disorders and corneal surgery. We present a technique for the measurement of corneal thickness using a CCD camera mounted on a slit-lamp biomicroscope and common image processing software. Thickness measurements were performed on three RGP contact lenses of known thickness with an average error of 5 µm, SD of 8 µm. Measurements of a living cornea yielded a thickness of 505 µm and a SD of 8 µm for 10 consecutive measurements; this is an acceptable value. [J Refract Surg 2000;16:S661-S663]
Geometric Ray Tracing Analysis of Visual Acuity After Laser in situ Keratomileusis
Authors: del Cotero Jose N Fernández , Moreno Fernando , Ortiz Dolores , Vélez Enrique , González Francisco , Saiz Jose M , Velarde Jose I , De Valentín-Gamazo Luis , García-Antón Paula
Published: April 2021

ABSTRACT

PURPOSE: Using a geometric ray tracing model, we explain the increase in visual acuity observed in myopic patients after laser in situ keratomileusis (LASIK).

METHODS: This study included 37 eyes of 23 patients who underwent LASIK. All patients had myopia and a spectacle-corrected visual acuity of 0.95 or worse. Clinical tests included biometry, corneal topography, pachymetry, and refraction (with and without cycloplegia). Calculations were made by tracing rays through all the refractive surfaces of the eye based on a Le Grand-type theoretical model of the whole eye.

RESULTS: Comparison of spectacle-corrected visual acuity of the eye before surgery, the size of the blur circle calculated by ray tracing, and the magnification for the ocular system facilitated a numerical criterion to assess visual acuity by geometric calculation. This criterion was applied to myopic eyes that underwent LASIK, and the maximum increase in spectacle-corrected visual acuity was predicted. An actual increase in visual acuity of approximately 40% of the predicted maximum was observed in patients.

CONCLUSIONS: With geometric ray tracing, it was possible not only to obtain an estimate of the visual acuity before LASIK but also to assess the value of the maximum and probable increases in visual acuity after LASIK. [J Refract Surg 2001;17:305-309]
Epithelial and Stromal Changes Induced by Intacs Examined by Three-dimensional Very High-frequency Digital Ultrasound
Authors: Reinstein Dan Z , Srivannaboon Sabong , Holland Simon P
Published: April 2021

ABSTRACT

PURPOSE: To examine epithelial and stromal layers by three-dimensional very high-frequency (VHF) digital ultrasound scanning before and after implantation of Intacs (intracorneal ring segments [ICRS]).

METHODS: Three-dimensional scanning was performed in five eyes before and 3 months after Intacs insertion. Digital signal processing techniques provided high-resolution B-scan imaging and I-scan traces for high-precision (1-µm) three-dimensional pachymetry. Thickness maps of individual corneal layers were constructed of the epithelium, stroma, and full cornea before and after surgery. Difference maps for epithelium and stroma were produced to examine anatomical changes in the thickness profile induced in each layer and correlate these to refractive changes.

RESULTS: B-scan examination revealed stromal and epithelial anatomy anterior and adjacent to the Intac. Ring depth could be measured topographically. There was stromal lamellar displacement by the ring segments that produced a concave anterior stromal groove within an annulus central to the ring. Epithelial filling of this concavity was shown in three dimensions in such a way as to produce orthogonally asymmetrical flattening of the corneal surface, thus potentially accounting for induced astigmatism. Mapping of the central stroma demonstrated thickening, potentially also accounting for astigmatic changes ascribable to orthogonal asymmetry.

CONCLUSIONS: VHF digital ultrasound scanning provided imaging and three-dimensional thickness mapping of corneal layers, enabling anatomical evaluation of the changes induced in the cornea by Intacs. [J Refract Surg 2001;17:310-318]
Complications of Laser in situ Keratomileusis: Etiology, Prevention, and Treatment
Authors: Ambrósio Renato , Wilson Steven E
Published: April 2021

ABSTRACT

PURPOSE: To review the etiology, prevention, and management of laser in situ keratomileusis (LASIK) complications.

METHODS: Review of literature and the experience of the authors.

RESULTS: Careful preoperative screening is critical to prevention of many potential complications of LASIK. Flap complications that occur during surgery are typically managed by replacement of the flap and repeating the surgery or applying special methods such as transepithelial photorefractive keratectomy weeks to months following the initial procedure. A common source of serious complications is the use of a microkeratome that functions after improper assembly. Timely treatment of postoperative complications such as diffuse lamellar keratitis, flap striae, and infection is critical to an optimal outcome.

CONCLUSION: Most complications of LASIK can be treated effectively and have minimal effect on the final outcome after surgery, if appropriate methods are used for management. [J Refract Surg 2001;17:350-379]
Tips on Irritations and Aspirations in Ophthalmology
Authors: Paton David
Published: April 2021

SUMMARY

This paper confronts philosophical issues concerning information gaps in the knowledge explosion, systems of medical education, and professional ethics.
A "Part-Time" Locking Needle Holder
Authors: Berger Ronald O , White Marcia
Published: April 2021

SUMMARY

We have coupled a Serrafine clamp with a non-locking needle holder to enable the surgical assistant to have two hands free after loading the next suture. This permits more effective utilization of the surgical assistant.
Orbital Aspergillosis
Authors: Dortzbach Richard K , Segrest David R
Published: April 2021

SUMMARY

We treated a 40-year-old male who had orbital aspergillosis and presumed early intracranial extension with limited orbital exenteration and adjunctive amphotericin B. Forty-two months later the patient is alive without recurrence. Our patient illustrates the typical presentation of orbital aspergillosis with severe periorbital pain and proptosis; however, he did not have the usual concomitant sinusitis. Aggressive surgical and antifungal therapy in this case was successful in preventing further intracranial extension, which usually has a high mortality rate.
Surgery for Involutional Entropion
Authors: Jackson Steven T
Published: April 2021

SUMMARY

Surgery for involutional entropion must correct horizontal eyelid laxity, vertical laxity, and overriding of the tarsus by the infra-tarsal tissues. The surgery should give lasting functional and pleasing cosmetic results. These goals are achieved with: 1) a blepharoplasty incision and reflection of a skin-muscle flap; 2) excision of a wedge of eyelid tissue at the lateral canthus; 3) barrier sutures or tuck of the retractors; 4) reattachment of the lid to the lateral orbital rim; and 5) excision of excess skin.
Cryotherapy and Photocoagulation in the Management of Retinoblastoma: Treatment Failure and Unusual Complication
Authors: Margo Curtis , Hidayat Ahmed A , Marshall Charles F , Renaldo Donald P
Published: April 2021

SUMMARY

Ophthalmologists treating children with retinoblastoma need to be aware of the limitations of new forms of therapy and their complications. For this reason the following case of a child with a small peripheral retinoblastoma that failed to respond to treatment with both cryotherapy and photocoagulation is recorded. The development of a rapidly growing juxta papillary lesion prompted immediate enucleation. Histological examination revealed viable tumor cells remaining in the areas that were previously treated. The juxtapapillary mass consisted of optic nerve and detached peripapillary retina that were "dragged" towards the tumor by a thick fibrocellular membrane containing many myofibroblasts.
Surgical Therapy of Traumatic Hyphema
Authors: Weiss Jayne S , Parrish Richard K , Anderson Douglas R
Published: April 2021

SUMMARY

The usual management of traumatic hyphemas in our institution has been to avoid or delay surgery until absolutely demanded by the clinical course. Despite this, most (73%) of our in-patients with total hyphema underwent surgery before leaving the hospital. In those who required surgery, 43% developed corneal staining. Optic nerve damage occurred in half of the patients whose surgery was performed eight or more days after the hyphema occurred, but was absent in those undergoing earlier surgery.

The usual procedure used in this series was a trabeculectomy with iridectomy and gentle irrigation of the anterior chamber, and no surgical complications occurred. We believe that surgery, being relatively safe, should be performed early in cases of total hyphema unless the elevated intraocular pressure is controlled medically and spontaneous resolution is clearly imminent. For cases in which surgery is nearly inevitable, we suggest that earlier surgery might reduce the incidence of optic nerve damage and corneal staining.
Management of an Intact Vitreous Face in Penetrating Keratoplasty
Authors: Schanzlin David J , Smith Ronald E
Published: April 2021

SUMMARY

Recent evidence suggests that the manipulation of the vitreous face may be a factor in increasing the incidence of cystoid macular edema. Since a bulging vitreous face at the ti me of penetrating keratoplasty may cause complications with the corneal transplant, we have devised a technique of pars plana vitrectomy that allows for an adequate vitrectomy while maintaining an intact vitreous face.
Conjunctivodacryocystorhinostomy With Mucous Membrane Graft
Authors: Campbell Charles B , Shannon Gerard M , Flanagan Joseph C
Published: April 2021

SUMMARY

Eleven patients with obstructed lacrimal canaliculi underwent conjunctivodacryocystorhinostomy modified by lining the fistula with buccal mucosa at the time of surgery. Four patients had the tube removed after six months. All four have patent mucous membrane lined fistulas with follow-up ranging from ten to 13 months. One patient removed his tube on the second post-operative day. His fistula closed immediately.

For comparison, the remaining six patients retain their tubes. They are free from epiphora but suffer from some of the complications of the tube itself, namely tube extrusion, tube migration, and chronic conjunctival irritation and discharge.

The surgical technique is described, histopathologic material is presented, and the initial results are discussed.
Variation in the Pathophysiology of Involutional Entropion and its Treatment
Authors: Schaefer Arthur J
Published: April 2021

SUMMARY

It is essential to understand the anatomy in detail, the normal physiology and pathophysiology of the lower eyelid to properly correct an involutional entropion surgically.

The fact that 50% of involutional entropion cases show an actual defect (dehiscence or complete detachment) of the retractor aponeurosis of the lower eyelid is important. The surgeon must be cognizant of the high rate of occurrence of these defects and look for them during the surgical repair. The direct external approach of the imbrication procedure makes it easy to identify these aponeurotic retractor defects.

The pathophysiologic changes can vary with each case and are as follows: involutional changes (attenuation, dehiscence, detachment) taking place in the lower lid retractors; atony of the lateral and medial canthal tendons may be present and must be recognized; enophthalmus of the aging is present; the septal orbicularis loses it firm attachment to the orbital septum.

It is paramount that the pathophysiologic changes present in each case be recognized and surgically corrected to prevent recurrences.
Treatment of Lower Lid Retraction by Tarsal-Conjunctival and Skin-Muscle Transposition Flaps
Authors: Wiggs Eugene O
Published: April 2021

SUMMARY

A method of alleviating full thickness lower eyelid retraction is described. Transposition flaps of tarsus-conjunctiva and skin-muscle are transposed from the ipsilateral upper lid into an infratarsal transverse blepharotomy in the retracted lower lid.
Combined Penetrating Keratoplasty, Extracapsular Cataract Extraction, and Posterior Chamber Intraocular Lens Implantation
Authors: Busin Massimo , Arffa Robert C , McDonald Marguerite B , Kaufman Herbert E
Published: April 2021

ABSTRACT

We reviewed 22 cases of triple procedure in the last two years at our Institution. Six months postoperatively 21 of the 22 transplanted corneas were clear. One graft for herpetic corneal scarring failed. Best corrected visual acuity was 20/40 or better in 14 patients. The average refractive error was -1.31 ± 230 diopters. Refractive astigmatism was 4 diopters or less in 80% of patients. These results, which compare favorably with previous series, indicate the efficacy and safety of this procedure.
Vitrectomy and Fluid Infusion in the Treatment of Delayed Suprachoroidal Hemorrhage After Combined Cataract and Glaucoma Filtration Surgery
Authors: Davison James A
Published: April 2021

ABSTRACT

I report the successful treatment of one case of massive, delayed suprachoroidal hemorrhage that occurred after combined intracapsular cataract extraction and trabeculectomy. Significant vitreous incarceration in the filtration site and consequent vitreoretinal traction were present so that a limbal approach anterior vitrectomy was necessary before choroidal drainage could be accomplished safely. An infusion of balanced salt solution through a limbal infusion cannula was employed during vitrectomy and also during drainage of suprachoroidal blood. The simultaneous intravitreal infusion helped to create an efficient, controlled choroidal drainage procedure. In addition to relieving vitreoretinal traction, this technique helps prevent the periods of extreme hypotony experienced when choroidal drainage and anterior chamber reformation are accomplished serially in step-wise fashion. This use of this method also obviates the compromised view of the peripheral retina which occurs when air is introduced into the vitreous cavity.
Visual Field Improvement After Neodymium: YAG Laser Puncture of Miotic Cysts
Authors: Schrems Wolfgang , Tomlinson Craig P , Belcher C Davis
Published: April 2021

ABSTRACT

This case report describes the use of a Q-switched neodymium: YAG laser to puncture miotic cysts. Fifteen shots of 0.06 mJ were needed. The pupil dilated more widely following this procedure, resulting in an improvement in the patient's visual field. Intraocular pressure (IOP) was not able to be controlled medically, however, and Altering surgery 20 days post laser treatment was required. IOP control had been poor prior to the laser-treatment, and did not appear to be more following treatment.
Photodynamic Therapy of Human Ocular Cancer
Authors: Sery Theodore W , Shields Jerry A , Augsburger James J , Shah Harshad G
Published: April 2021

ABSTRACT

Photodynamic therapy (PDT), also known as photoradiation therapy, was employed in five patients with ocular tumors that had been photosensitized to hematoporphyrin derivative (HPD). In each case more conventional treatment had failed to control the tumor, or the patient was considered a poor candidate for surgical intervention because of advanced age or general health. Intravenous administration of 2.5-3.0 mg/kg HPD was followed by PDT 2-4 days later, using a dye laser tuned to a wavelength of 632 nm. Laser light was delivered either by a fiber optic probe maintained at a fixed distance, or via a slit lamp system, for intervals of up to 20 minutes. The levels of energy applied were mainly below 420 Joules/cm
p 2
, but for tumors less than 1 mm diameter energy levels were as high as 3000 J/ cm
p 2
with a conservative power value as low as 20 mW/cm2. Tumor response to PDT was disappointing. Although substantial superficial tumor necrosis occurred in several cases, it did not extend to the deeper levels of tumor tissue. In each instance surgical intervention became necessary. Deficiencies in the procedure are discussed.
Neodymium: YAG Laser Treatment of Persistent Pupillary Membrane
Authors: Vega Luis F , Sabates Roland
Published: April 2021

ABSTRACT

A 16-year-old girl had a cosmetically unappealing persistent iridopupillary membrane in the left eye. Her best corrected visual acuity was 20/60, but this improved to 20/40 with pupillary dilation. Neodymium:YAG laser membranectomy resulted in 20/20 vision. This is the first reported case of persistent pupillary membrane treated with the Neodymium:YAG laser.
Macrocystic Enlargement of Orbital Dermis-Fat Grafts
Authors: Patrinely James R , Anderson Richard L , Shore John W
Published: April 2021

ABSTRACT

Acquired cysts represent an unusual but significant complication of orbital dermis-fat grafts. We report two cases of late postoperative enlargement of dermisfat grafts: First, macrocystic enlargement occurring in both orbits with severe microphthalmia; second, cystic enlargement occurring in a dermis-fat graft for anophthalmia following an earlier evisceration. Both graft enlargements were due to epithelial-lined cysts that developed within the graft tissue. These cysts were treated by excising the cyst walls and allowing the resultant cavity to heal spontaneously. Light microscopy of the excised tissue revealed that the clear cysts were lined by a non-keratinizing, stratified squamous epithelium. The histogenesis of the cysts is unclear, but most likely they are the result of incompletely removed or implanted conjunctival or corneal epithelium. Several other possibilities are discussed. Due to the difficulty of removing all corneal and conjunctival epithelium, cystic complications of dermis-fat grafts make unattractive their use for volume enhancement in patients with microphthalmia or following evisceration.
Vertical Rupture in Posterior Corneal Layers After Cataract Extraction
Authors: Wolter J Reimer , Sugar Alan
Published: April 2021

ABSTRACT

The histopathological description of a 3 mm vertical cut in the posterior layers of a corneal button removed for pseudophakic bullous keratopathy is presented. The corneal complications became clinically evident several weeks after extracapsular cataract extraction with placement of a posterior chamber lens implant. Outstanding histological features were: wall-like elevation of the borders of the cut with swelling of the posterior stromal layers; rolled-in edges of Descemet's membrane; double interruption of Descemet's membrane on one side; regional endothelial atrophy; and total lack of any signs of endothelial regeneration.
Inhibition of Pseudophakic Endophthalmitis in a Rabbit Model
Authors: Elliott Ross D , Katz Harold R
Published: April 2021

ABSTRACT

A clear lens extraction with insertion of a posterior chamber intraocular lens (PC-IOL) was performed in one eye of each of 20 rabbits. An intracameral injection of 50,000 organisms of gentamicin-sensitive Staphylococcus aureus was given before completion of the surgical procedure. At the completion of surgery, a sub-conjunctival injection of either gentamicin (20 mg) or gentamicin vehicle was administered randomly, in a masked fashion, to the operative eye. Rabbits were observed daily for signs of endophthalmitis. Vitreous taps were performed on all operative eyes. Ninety percent (p = .001) of control eyes became clinically infected and 80% (p = .007) of control eyes grew S. aureus from their vitreous aspirate. None of the gentamicin-treated eyes became clinically or microbiologically infected with S. aureus.
Treatment of Mooren's and Mooren's-like Ulcer by Lamellar Keratectomy: Report of Six Eyes and Literature Review
Authors: Martin Neil F , Stark Walter J , Maumenee A Edward
Published: April 2021

ABSTRACT

Three cases of Mooren's ulcer (four eyes) and one case of marginal corneal ulcer associated with relapsing polychondritis (two eyes) are presented with decrease in ocular inflammation following extensive lamellar keratectomy or lamellar keratoplasty. Tissue adhesive was needed in two cases to maintain ocular integrity. The procedure may work by the removal of a corneal antigenic stimulus to a self-perpetrating autoimmune phenomenon that causes corneal melting. More cases are needed to evaluate the therapeutic efficacy of lamellar keratectomy for Mooren's and Mooren's-like corneal ulcers.
Clinicopathologic Study of Eyes Obtained Postmortem From a Patient 6 and 2 Years After Operative Choroidal Hemorrhage
Authors: Haynes Jeffrey H , Payne John W , Green W Richard
Published: April 2021

ABSTRACT

We present the clinicopathologic features of a patient who developed bilateral choroidal hemorrhage during cataract surgery and who regained 20/30+ vision in each eye. Consequences related to the operative procedure and choroidal hemorrhage included iris and vitreous incarceration with inferior peripheral fractional retinoschisis, retained lens cortex, and an anterior capsule fragment lodged in the anterior chamber angle. A recent choroidal hemorrhage associated with a thrombosed vortex vein was observed in one eye.

The favorable outcome was likely due both to preplaced sutures that allowed immediate tamponade of the hemorrhage and to the additional possible tamponading effect of an intact posterior capsule in the left eye. The possible role of venous stasis leading to vortex vein thrombosis as a cause of recent choroidal hemorrhage is discussed.