bluuebunny/crossref_metadata_2025_split huggingface dataset:
Retrospective Comparison of Photorefractive Keratectomy and Radial Keratotomy
Authors: Hong Jeffrey C , Salz James J 
Published: April 2021

ABSTRACT
BACKGROUND: The efficacy and predictability of photorefractive keratectomy and radial keratotomy become increasingly relevant. This retrospective study compares one surgeon's experience with photorefractive keratectomy and radial keratotomy over a 3-year period from 1990 to 1993.
METHODSî Photorefractive keratectomy was performed on 103 eyes of 76 patients that met the inclusion criteria for the phase Hb, phase HI, and phototherapeutic keratectomy studies as delineated by the United States Food and Drug Administration. Radial keratotomy was performed on 117 eyes of 81 patients with up to 9.00 diopters (D) of myopia.
RESULTS: In the photorefractive keratectomy group, 83% of the eyes achieved uncorrected visual acuity of at least 20/40; 37% saw 20/20; 88% had a refraction within 1.00 D of emmetropia, and 63% within 0.50 D of emmetropia. For the radial keratotomy group, 85% of the eyes achieved an uncorrected visual acuity of 20/40 or better; 27% saw 20/20; 88% had a refraction within 1.00 D of emmetropia; and 55% within 0.50 D of emmetropia. There were no serious complications, and only one single eye in each of the photorefractive keratectomy and radial keratotomy groups lost two lines or more of spectacle-corrected visual acuity.
CONCLUSION: Photorefractive keratectomy and radial keratotomy are both effective procedures, and result in similar refractive outcomes for myopia of -1.00 to -9.00 D. [J Refract Surg. 1995;11:477-484.]
Long-Term Stability of Refraction After Intrastromal Suture Correction of Hyperopia Following Radial Keratotomy
Authors: Lyle W Andrew , Jin George J C 
Published: April 2021

ABSTRACT
BACKGROUND: Our first series of nine cases using circular and interrupted sutures for hyperopia from overcorrected radial keratotomy was reported 2 years ago. Additional cases and longterm follow up with this technique are presented here.
METHODS: Thirteen eyes of 12 patients with symptomatic hyperopia underwent corneal suturing with pursestring and interrupted sutures and were followed for 3 years. There were six original overcorrections and seven overcorrections after reoperation. The mean preradiai keratotomy refractive spherical equivalent refraction was -3.85±1.40 diopters (D).
RESULTS: The mean preoperative refractive spherical equivalent was +2.55±0.93 D (range -1-1.125 to +5.375 D). The mean follow up after the suturing procedure was 40±14.3 months with a range of 10 to 72 months. The change in refraction following suturing procedures averaged -1.84 D, resulting in an overall correction of 72% of the overcorrection. The mean increase of postoperative central keratometric power was 1.42*0.95 D. All eyes had reduction of hyperopia. Uncorrected visual acuity was improved from 0.367±0.11 (20/60) preoperatively to 0.712±0.25 (20/30+) postoperatively. The average improvement was 3.3 Snellen lines. Using the visual function score to assess the effectiveness of the procedure, we found 85% (11/13) of eyes obtained excellent or good results and 15% appeared fair or poor. In the 3 years since the study began, eight eyes had follow-up data from the previous study and the present study. During this period, an average change of refraction of only -0.19 D was observed. A refractive change less than 0.50 D was observed in 62.5% of the eyes, and all of the eyes had a refractive change within 1.00 D. There were no new complications and no loss of effect during the mean 43 months of follow up for those patients.
CONCLUSION: Based on the 3-year follow up, we concluded that intrastromal pursestring and interrupted techniques are stable, safe, and effective procedures for correcting hyperopia following radial keratotomy, especially for less than +3.00 D. [J Refract Surg. 1995;11:485-489.]
Laser in situ Keratomileusis for Myopic Astigmatism With the Nidek EC-5000 Laser
Authors: Payvar Saeed , Hashemi Hassan 
Published: April 2021

ABSTRACT
PURPOSE: We studied the efficacy, predictability, and safety of laser in situ keratomileusis (LASIK) for moderate to high simple and compound myopic astigmatism.
METHODS: Ninety-two eyes of 46 consecutive patients who had LASIK for myopic astigmatism (64 eyes, astigmatism 3.00 to 9.00 D; myopia 0 to -20.00 D), or simple myopia (28 eyes, myopia -4.00 to -20.00 D; astigmatism 0 to 0.50 D) were retrospectively studied. Mean baseline spherical equivalent refraction (SE) in the myopia group was -8.11 ± 3.94 D and in the astigmatism group, -8.55 ± 4.49 D. All eyes underwent LASIK using the Nidek EC-5000 laser by the same surgeon.
RESULTS: At 6 months after LASIK in the myopia group versus the astigmatism group, 24 eyes (85%) vs. 54 eyes (84%) were available for follow-up, 12 eyes (50%) vs. 13 eyes (24%) had uncorrected visual acuity (UCVA) of 20/20, 19 eyes (79%) vs. 44 eyes (81%) had UCVA of 20/40, 8 eyes (33%) vs. 18 eyes (33%) had SE within ±0.50 D, 15 eyes (62%) vs. 39 eyes (72%) had SE within ±1.00 D, and mean SE was -1.22 ± 1.17 D vs. -0.74 ± 1.46 D. Mean astigmatism (vertexed to the corneal plane) in the astigmatism group was 2.77 D at 0° before surgery and 0.32 D at 7° at 6 months. None of the myopic eyes and three of the astigmatic eyes (5%) lost ≥2 lines of best spectacle-corrected visual acuity.
CONCLUSION: LASIK with the Nidek EC-5000 laser for myopic astigmatism was reasonably effective, predictable, and safe. Astigmatism was undercorrected with the nomogram implemented in this study. [J Refract Surg 2002;18:225-233]
Treatment of Hyperopia: A New Ablation Profile to Reduce Corneal Eccentricity
Authors: Vinciguerra Paolo , Camesasca Fabrizio I 
Published: April 2021

ABSTRACT
PURPOSE: Hyperopic treatment normally increases corneal eccentricity (the measure of corneal asphericity). Information derived from treating corneal white scars occurring after hyperopic ablations suggests that reducing corneal eccentricity through central corneal flattening followed by smoothing eliminates scarring and prevents its recurrence.
METHODS: We treated two groups of patients; Group 1 included 18 eyes of 18 patients with whitish corneal scar due either to photorefractive keratectomy (PRK) (n=16, 88.9%) or laser in situ keratomileusis (LASEK) (n=2, 11.1%). Mean preoperative spherical equivalent refraction was +1.20 ± 2.30 D, and mean corneal eccentricity was +1.2 ± 0.8. We performed phototherapeutic keratectomy (PTK) to achieve central corneal flattening and decrease corneal eccentricity, coupled with smoothing» using the Nidek EC-5000 excimer laser. Group 2 included 27 eyes of 27 consecutive patients with mean preoperative spherical equivalent refraction of +2.40 ± 1.30 D; these patients had laser epithelial keratomiieusus (LASEK) with the Nidek EC-5000 excimer laser. A new Nidek aspheric ablation profile with a wider optical zone (6.7 mm) and transition zone (9.5 to 10.00 mm) was applied.
RESULTS: In Group 1 eyes, the apical scar disappeared in all eyes. Postoperative spherical equivalent refraction was +1.8 ± 1.02 D and mean postoperative eccentricity was +0.9. In Group 2 eyes after 9 months of follow-up, mean postoperative spherical equivalent refraction was -0.30 ± 0.30 D, with no loss of lines of BSCVA. Low corneal eccentricity values were maintained, which created a gradual change in the rate of curvature.
CONCLUSIONS: The new Nidek profile for hyperopia treatment allowed successful refractive correction and maintained low eccentricity values that approached those of a normal cornea. [J Refract Surg 2002;18(suppl):S315-S317]
Cleaning Solutions as a Cause of Diffuse Lamellar Keratitis
Authors: Nakano Eliane Mayumi , Nakano Kozo , Oliveira Marivaldo Castro , Portellinha Waldir , Simonelli Rosangela , Alvarenga Lênio Souza 
Published: April 2021

ABSTRACT
PURPOSE: To assess the capability of two microkeratome cleaning solutions in causing diffuse lamellar keratitis (DLK) in a rabbit model of laser in situ keratomileusis (LASIK).
METHODS: Two cleaning solutions (Palmolive 2:100 and Cidezyme 2:250) were tested. These solutions were diluted with balanced salt solution according to directions from the Hansatome microkeratome manual. Two additional solutions were prepared using an additional ten-fold dilution, creating a total of four study solutions. A LASffi flap was created in one eye each of 25 rabbits using the ALK Chiron microkeratome. The rabbits were divided into five study groups. The flaps were reflected and a drop of one of the study solutions (or BSS, control group) was placed on the interface. After 1 minute, the solution was washed out from the interface and the flap was repositioned. The eyes were examined at the slit lamp on postoperative days 1, 2, 3, 5, and 7.
RESULTS: In 12 eyes, a flap displacement was identified. Four eyes showed flap retraction and five others, epithelial ingrowth in flap margins. The incidence of these events did not differ among groups. Thirteen eyes were then evaluated for DLK. No DLK-like interface inflammation was seen in the studied eyes.
CONCLUSION: The cleaning solutions, when diluted as recommended by the microkeratome manufacturer, when in contact with the corneal stroma, and provided that the interface was washed with BSS did not cause DLK interface inflammation in rabbit LASDX models. [J Refract Surg 2002;18(suppl):S361-S363]
Butterfly Laser Epithelial Keratomileusis for Myopia
Authors: Vinciguerra Paolo , Camesasca Fabrizio I 
Published: April 2021

ABSTRACT
PURPOSE: Decreased epithelial viability is a postoperative complication of standard laser epithelial keratomileusis (LASEK) that hampers rapid recovery, and causes reduced visual acuity as well as discomfort. We present a new LASEK technique that, by increasing epithelial viability, reduces the occurrence of these complications.
METHODS: In a preliminary series of patients, conventional LASEK was performed in one eye, and "Butterfly LASEK in the fellow eye. In Butterfly LASEK, a thin paracentral epithelial line, from 8 to 11 o'clock was removed, and 20% alcohol plus BSS 'solution was placed in contact with the cornea for 5 to 30 seconds. A specially designed spatula allowed separation of epithelium from Bowman's layer, proceeding from center to periphery on both sides. A special retractor was used to move the two flaps of loose epithelium toward the limbus. After drying the surface, excimer laser ablation was performed with the Nidek EC-5000 excimer laser. Smoothing with masking solution was then carried out, followed by flap replacement and overlapping.
RESULTS: We treated 70 eyes of 35 patients with Butterfly LASEK. Preoperative mean spherical equivalent refraction was -5.30 ± 3.70 D. At 12 months after surgery, mean spherical equivalent refraction was -0.10 ± 0.40 D, and no lines of BSCVA were lost. Ninety percent of patients preferred Butterfly LASEK to conventional LASEK because of increased comfort. At 12 months, no patient had more than trace haze, and in 96.2%, corneas were completely clear.
CONCLUSIONS: Butterfly LASEK is aimed at preserving the Iimbal connection of epithelial stem cells and Iimbal vascular connections. Improved epithelial viability is thus achieved, with faster postoperative recovery. [J Refract Surg 2002; 18(suppl):S371-S373]
Corneal Pharmacodynamics After Photorefractive Keratectomy and Laser in situ Keratomileusis in Rabbits
Authors: Maitchouk Dmitri , Smirennaia Elena , Kourenkov Vyacheslav 
Published: April 2021

ABSTRACT
PURPOSE: To evaluate changes in corneal pharmacodynamics after PRK and LASIK in rabbits.
METHODS: Two groups of five rabbits (10 eyes) each received PRK and LASIK, and an unoperated third group was used as a control. Dexamethasone, efflumidex, diclofenac, and tobramycin were applied. Anterior chamber aqueous was collected every 20 minutes and analyzed by spectrophotometry. Histological studies were performed to find drug deposits in the cornea.
RESULTS: The coefficient of diffusion after PRK was determined for dexamethasone (3.2x10"* cm/min), efflumidex (1.4x10a4), diclofenac (7.4x10^), and tobramycin (5.4x10*). After LASIK, the coefficient of diffusion for dexamethasone was 3.4x1o*5; efflumidex, 1.7x10**; diclofenac, ß.ß???"6; and tobramycin, 2.4x1?-8 cm/min. Total time of passing through the cornea after PRK and LASIK was also measured: dexamethasone 45 and 70 min, efflumidex 50 and 115 min, diclofenac 60 and 200 min, and tobramycin 335 and 690 min. Histologically a drug deposit area was found in corneas after LASIK under the flap. In the control group, coefficient of diffusion for dexamethasone was 1.2x10 5 cm/min, efflumidex 1.5x10a8, diclofenac 6.4xl0"e, and tobramycin 2. Ix 10a*. Total time of passing through the cornea for the control group for dexamethasone was 60 min, efflumidex 105 min, diclofenac 160 min, and tobramycin 540 min.
CONCLUSIONS: Coefficient of diffusion increased after photorefractive surgery. [J Refract Surg 2002:18(suppl):S382-S384]
Higher Order Aberrations in Normal, Dilated, Intraocular Lens, and Laser in situ Keratomileusis Corneas
Authors: Miller Joseph M , Anwaruddin Raana , Straub Jochen , Schwiegerling Jim 
Published: April 2021

ABSTRACT
PURPOSE: To compare repeated measures of Zernike polynomial higher-order aberrations in 29 normal, 13 dilated normal, 11 intraocular lens (IOL), 11 laser in situ keratomileusis (LASER), and one refractive keratectomy (RK)ZIOL subject.
METHODS: At least three Shack-Hartmann images were obtained from each subject, and higher order (uncorrectable by spectacles) Zernike representation was determined. For each subject, confidence intervals for each Zernike coefficient were determined as a function of pupil size. Significant (P<.05) coefficients were averaged within groups, and group means were compared to normal subjects.
RESULTS: No differences were seen between the normal and dilated groups at P=.05. The patients with prior LASEK and IOL surgery showed statistically significant elevation of 4th order spherical aberration and total wavefront variance for pupil sizes greater than 5 mm, compared to normals.
CONCLUSION: Both IOL and LASEK surgery elevate spherical aberration and wavefront variance, with increasing magnitude of effect with increasing pupil size, although pupillary dilation alone did not produce statistically different changes, as compared to normal subjects. These findings demonstrate that IOL implantation can produce more net aberrations than LASEK, and demonstrate a new opportunity to optimize surgical results. [J Refract Surg 2002;18:S579-S583]
Biomechanical Response of the Cornea to Phototherapeutic Keratectomy When Treated as a Fluid-filled Porous Material
Authors: Katsube Noriko , Wang Rentong , Okuma Emiko , Roberts Cynthia 
Published: April 2021

ABSTRACT
PURPOSE: Surgical effect on corneal deformation has been traditionally analyzed based on the solid material assumption. We examine the validity of this assumption by treating the cornea as a fluidfilled porous material and separately modeling the solid and fluid constituents inside the cornea. In particular, the internal sub-atmospheric fluid pressure is treated as an important part of the mechanical loading in addition to the intraocular pressure.
METHODS: Finite element simulations of phototherapeutic keratectomy (PTK) were conducted with the cornea treated as a fluid-filled porous material, and through-the-thickness difference in swelling phenomena was taken into account. The results were compared with the same PTK simulations based on the solid material assumption of the cornea.
RESULTS: The PTK simulation results based on the fluid-filled porous material assumption demonstrated a significantly higher amount of unintended hyperopic shift compared to the results based on the traditional solid material assumption. The proposed approach qualitatively matched experimental observations.
CONCLUSIONS: The internal sub-atmospheric pressure significantly influenced corneal deformation. The simulation results based on the fluid-filled porous material assumption raise serious questions regarding the validity of existing models in corneal surgery, where the effect of the internal sub-atmospheric pressure on corneal deformations is neglected. [J Refract Surg 2002;18:S593-S597]
Aberration Generation by Contact Lenses With Aspheric and Asymmetric Surfaces
Authors: López-Gil Norberto , Castejón-Mochón José Francisco , Benito Antonio , Marín José María , Lo-a-Foe George , Marin Gildas , Fermigier Bruno , Renard Dominique , Joyeux Denis , Château Nicolas , Artal Pablo 
Published: April 2021

ABSTRACT
PURPOSE: We explored the potential of aberration correction in the human eye by using a new generation of soft contact lenses with aspheric and asymmetric surfaces.
METHODS: Soft contact lens samples were designed with one asymmetrical surface (front) and one spherical (back) to produce predetermined amounts of desired pure defocus, astigmatism, trefoil, coma, and spherical aberration. Contact lens wavefront aberrations were measured ex vivo using a Fizeau-Tolanski interferometer and compared with the in vivo wavefronts obtained by subtracting the aberrations of the eye with and without the contact lenses. These second set of measurements were obtained using a Snack-Hartmann sensor.
RESULTS: We found that an aberration-free contact lens sample induced in the eye a small amount of residual aberration. We obtained a good match between the ex vivo and in vivo wavefront measurements for most of the samples of the contact lenses.
CONCLUSIONS: The aberrations generated by soft contact lenses on the eye were predictable. Rotations and translations of the contact lenses with respect to correct position on the eye were, however, the main limitation for precise correction of the ocular aberrations. [J Refract Surg 2002;18:S603-S609]
First Results With Wavefront-guided Photorefractive Keratectomy for Hyperopia
Authors: Nagy Zoltán Z , Palágyi-Deák Ilona , Kovács Andrea , Kelemen Edit , Förster Werner 
Published: April 2021

ABSTRACT
PURPOSE: To compare the results of traditional laser photoablation and wavefront-supported customized ablation (WASCA) in hyperopic photorefractive keratectomy (H-PRK).
METHODS: This was a prospective study, comparing two treatment groups, each comprising 40 eyes of 20 patients. Wavefront aberrations were examined using a Shack-Hartmann aberrometer. Preoperative refraction was similar in the two groups; in the traditional H-PRK group (Group 1) it was +3.10 ± 0.85 D, and in the WASCA-guided group (Group 2) it was +2.90 ± 0.80 D. H-PRK was performed with the Asclepion-Meditec MEL 70 flying-spot excimer laser. The follow-up time was 6 months.
RESULTS: In Group 1, mean postoperative refraction was +0.14 ± 0.24 D, and in Group 2, -0.10 ± 0.25 D; mean uncorrected visual acuity was 0.92 ± 0.16 in Group 1 and 0.95 ± 0.18 in Group 2. Mean best spectacle-corrected visual acuity was 0.96 ± 0.04 in Group 1 and 1.06 ± 0.13 in Group 2. In Group 1, 67.5% (27 of 40 eyes), and in Group 2, 85% (34 of 40 eyes) were within ±0.50 D of target refraction. Regarding change of spectacle-corrected visual acuity in Group 1, 5% (2 of 40 eyes), and in Group 2, 20% (8 of 40 eyes) gained one Snellen line compared to the preoperative; in Group 1, 10% (4 of 40 eyes), and in Group 2, 12.5% (5 of 40 eyes) lost two Snellen lines. In Group 2, the root mean square value for the higher order aberration increased from the initial 0.134 to 0.257 µ?? at 6 months after surgery.
CONCLUSIONS: WASCA-guided hyperopic-PRK treatment was found to be safe and predictable. The results were better than those achieved with traditional PRK performed using the same flyingspot type excimer laser. [J Refract Surg 2002;18:S620-S623]
Measuring Corneal Thickness With a Rotary Scanning System
Authors: Franco Sandra , Almeida José B , Parafita Manuel 
Published: April 2021

ABSTRACT
PURPOSE: Recently the authors presented a technique that allows measurement of the corneal thickness along a vertical meridian from optical sections obtained using a slit-lamp microscope. We present a new system that allows rotary scanning of the cornea and consequent measurement of the corneal thickness along any meridian.
METHOD: The corneal thickness along two perpendicular meridians was measured from optical sections obtained with a new rotary scanning system. To obtain the optical sections, the cornea is illuminated with a light beam that is previously expanded in a fan by a small cylindrical lens rotated on a plane-containing axis to explore the cornea. The light diffused by both corneal surfaces is collected by two video cameras placed at an angle with the light beam. The axes of the two cameras define, with the visual axis, two planes normal to each other. After image acquisition, a processing algorithm is applied in order to compute the corneal thickness along the two meridians.
RESULTS: Some preliminary results for the vertical and the horizontal meridians of one eye are shown, as well as all the intermediate computations.
CONCLUSIONS: With this system, we expect to be able to measure corneal topography and thickness along an arbitrary meridian. The rotary scanning of the cornea is mechanically simple and will eventually allow automated scanning. [J Refract Surg 2002;18:S630-S633]
Self-Curing Methyl Methacrylate: Is It Safe?
Authors: Anderson Richard L , Stasior Orkan George 
Published: April 2021

ABSTRACT
Self-curing methyl methacrylate has been recently abandoned by some ophthalmic surgeons because of more than 20 deaths associated with its use in orthopedic surgery. The mechanism of cardiovascular collapse noted in orthopedic cases appears to relate to the surgical procedure as well as a direct vasodilation caused by free monomer. There are no reported cardiovascular complications with the facial uses of self-curing methyl methacrylate. Toxicities to this substance are noted. Ophthalmologists should be aware of these problems and their management Careful preoperative cardiovascular evaluation, intraoperative patient monitoring, and a well-ventilated operating room are recommended with its use. The review finds no evidence to condemn the ophthalmic uses of self-curing methyl methacrylate because of cardiovascular complications. The search for more inert synthetic compounds should continue.
Anterior Segment Ischemia and Sector Iris Atrophy: After Strabismus Surgery In A Patient With Chronic Lymphocytic Leukemia
Authors: Jacobs Donald S , Vastine David W , Urist Martin J 
Published: April 2021

SYNOPSIS-ABSTRACT
A 69-year-old woman with chronic lymphocytic leukemia developed segmental iris atrophy and iridocyclitis after routine surgery for exotropia. Both the clinical picture and fluorescein angiogram indicated anterior segment ischemia. It is postulated that this was related to hyperviscosity of the blood caused by a high white blood cell count (114,000/cu mm).
The possibility of anterior segment ischemia should be kept in mind when contemplating strabismus or retinal detachment surgery in the presence of hematologic disorders likely to increase blood viscosity. I ? these cases a minimal amount of surgery should be done with proper supportive therapy. Strabismus surgery should be done in stages allowing for hemodynamic compensation between procedures.
Iridectomy in Rubeosis Iridis
Authors: Hersh Stanley B , Kass Michael A 
Published: April 2021

SUMMARY
Creating an iridectomy in the face of rubeosis iridis carries a significant risk of hyphema. A technique is described utilizing a bipolar micro-cautery to cauterize iris vessels under direct observation before cutting iris tissue. This allows the iridectomy to be performed with less risk of intraocular bleeding.
Intravitreous Air Injection and the Custodis Procedure
Authors: O'Connor Patrick A 
Published: April 2021

SUMMARY
Occasional failure follows any form of retinal detachment surgery. Most of these persistent detachments are due to inadequate closure of a known retinal tear by scleral buckling. Avoidance of major reconstructive surgery may be accomplished by the judicious application of an intravitreous air injection under local anesthesia at bedside. Although technically precise, this singular maneuver was found safe and reliable. Its use is suggested as an alternative to classical reoperative procedures.