bluuebunny/crossref_metadata_2025_split huggingface dataset:
Automated Lamellar Keratomileusis In Situ for Myopia
Authors: Price Francis W , Whitson William E , Gonzales Jill S , Gonzales Celedon R , Smith Jocelyn 
Published: April 2021

ABSTRACT
BACKGROUND: Keratomileusis in situ, particularly automated lamellar keratoplasty, is a commonly performed technique of keratomileusis in the United States.
METHODS: A single center consecutive series of 152 eyes undergoing keratomileusis in situ for myopia was analyzed. Spherical equivalent refractions were compared before and after surgery. The standard nomogram supplied with the automatic corneal shaper (Chiron Vision Corp, Irvine, Calif) was used. The mean of preoperative myopia treated was -9.30 ± 3.10 diopters (D) (range, -5.12 to -22.75 D).
RESULTS: Of the 144 eyes with 1 month follow up, 30 (21%) were within 0.50 D of the planned correction at 1 month, 54 (38%) were within 1.00 D, and 97 (67%) were within 2.00 D. At 6 or more months follow up, 51 of 68 eyes (75%) achieved uncorrected visual acuity of 20/40 or better and 13 of 68 (19%) 20/20 or better when eyes with macular degeneration and amblyopia were removed. Forty-six of 78 eyes (59%) with 6 months or greater follow up required retreatment procedures to correct residual myopia or astigmatism. Multiple regression analysis explained 40% of the variation between attempted correction and postoperative results. An overall 5% shift of refraction in the myopic direction occurred between 1 and 6 months. Of the 110 eyes with both 1- and 3-month examinations, the spherical equivalent refraction changed between these time intervals by 1.00 D or more in 54 (49%) eyes; and 11 (31%) eyes changed by 1.00 D or more between the 3- and 6-month examinations. Although 6% of eyes lost 2 or more lines of spectacle-corrected visual acuity, 11% gained 2 or more lines.
CONCLUSION: Myopic keratomileusis in situ using the automated lamellar keratoplasty technique appears to be a safe and most effective procedure to reduce moderate to high myopia. However, the predictability of the procedure needs improvement. [J Refract Surg. 1996;12:29-35.]
Radial Keratotomy for Myopia From 5.00 to 13.00 Diopters Two Years After Surgery
Authors: Percival S Piers B , Vyas Ashok V 
Published: April 2021

ABSTRACT
BACKGROUND: Radial keratotomy for low myopia can produce good results with few side effects. For higher myopia, predictability becomes less accurate and side effects more common.
METHODS: A retrospective study of 111 eyes of 76 patients were divided into two groups. Group I had 79 eyes with myopia of -5.00 to -8.00 diopters (D); group II had 32 eyes with myopia -8.25 D to -13.00 D. One hundred eleven eyes were followed for 1 year and 90 eyes were followed for 2 years.
RESULTS: Sixty-seven (84.8%) eyes in group I and 12 (37.5%) eyes in group II achieved a refraction within the range of -1.00 D and +1.00 D. Ninety-two percent of group I and 44% of group II achieved an uncorrected visual acuity of 20/40 or better. Three percent lost spectacle-corrected visual acuity. Four eyes developed a hyperopic shift of 1.00 D or more between 2 months and 2 years. Seven other eyes developed a hyperopic shift of 1.00 D or more between 2 months and 5 years.
CONCLUSIONS: Eight-incision radial keratotomy is an attractive option for treatment of myopia up to -8.00 D. For levels above -8.00 D, the results are poorer; there may be a variable period before refraction stabilizes. [J Refract Surg. 1996;12:86-90.]
Multicomponent Intraocular Lens
Authors: Werblin Theodore P 
Published: April 2021

ABSTRACT
BACKGROUND: Refractive surgery for any form of ametropia, including postoperative cataract rehabilitation, should have as its refractive goal an accuracy comparable to non-surgical modalities such as contact lenses and spectacles. To date, all refractive procedures fall significantly short of this goal because of poor predictability, significant instability, and annoying optical side effects. The multicomponent intraocular lens is being developed to further refine the accuracy of conventional IOL surgery by making the initial refractive result adjustable.
METHODS: The multicomponent intraocular lens has three optical elements. The spherical base lens looks much like an ordinary PC-IOL. Attached to it are two exchangeable optical elements-a toric sandwich lens and a spherical or multifocal cap lens. The exchangeable elements allow the surgeon to refine the initial refractive result during a second, optional operative procedure.
RESULTS: To date, prototype lenses have been fabricated from polymethylmethacrylate. These lenses have been assembled and disassembled both in vitro and in cat eyes to demonstrate the feasibility of this new concept.
CONCLUSION: The multicomponent intraocular lens concept is a major departure from conventional IOL technology because it allows enhancement, or fine tuning, of an already fairly accurate refractive procedure, IOL surgery. [J Refract Surg. 1996;12:187-189.]
Successful Phototherapeutic Keratectomy for Recurrent Erosions in Bullous Keratopathy
Authors: Thomann Urs , Niesen Ulrike , Schipper lsaak 
Published: April 2021

ABSTRACT
BACKGROUND: The treatment of patients with recurrent erosions due to bullous keratopathy is disappointing in cases when penetrating keratoplasty cannot be performed. A trial has been made to prevent recurrent erosions through the smoothing of the cornea with the excimer laser.
METHODS: Excimer laser phototherapeutic keratectomy (PTK) was performed after removal of the epithelium.
RESULTS: Sixteen patients (17 eyes) with recurrent erosions due to bullous keratopathy were treated. The mean follow-up period was 17.2 months (range: 3 to 32 months). All patients responded well to the treatment; their pain subsided after a few weeks. In four cases, a second treatment was necessary because areas with loose epithelium remained, which resulted in recurrent erosions. No complications have been seen so far.
CONCLUSION: Excimer laser PTK is an effective, easy to perform treatment of bullous keratopathy. [J Refract Surg. 1996;12:S290-S292.]
Corneal Topography, Arcuate Keratotomy, and Compression Sutures for Astigmatism After Penetrating Keratoplasty
Authors: Koffler Bruce H , Smith Vivien M 
Published: April 2021

ABSTRACT
BACKGROUND: Twenty (20) patients with postpenetrating keratoplasty (PKP) (21 eyes) and excessive corneal astigmatism were studied using corneal topography to determine placement of arcuate incisions and compression sutures for astigmatism reduction.
METHODS: Keratoplasty wounds and compression sutures were placed asymmetrically based on corneal topography only. Incisions were at the donor-host junction at a depth of 500 microns.
RESULTS: A 56% reduction in corneal astigmatism was accomplished with an average cylinder reduction of 5.3 D. Keratometry readings were reduced in 18 of 20 (90%) of eyes and refractive cylinder was reduced in 15 of 20 (75%) of eyes. Corrected visual acuity improved in 15 of 20 (75%) declined in 15%, and did not change in 10%.
CONCLUSION: Visual acuity can be improved by manipulating the astigmatism after penetrating keratoplasty using corneal topography maps to determine placement of arcuate incisions and compression sutures. [J Refract Surg. 1996;12:S306-S309.]
Acute Tissue Deformation of the Human Cornea After Radial Keratotomy
Authors: Hjortdal Jesper Ø , Ehlers Niels 
Published: April 2021

ABSTRACTPURPOSE: The regional deformation pattern of the cornea after radial keratotomy, which is essential for understanding the mode of action of the procedure, has not previously been studied in detail.METHODS: Up to 90 tiny mercury droplets were placed from center to limbus on the epithelial and endothelial corneal surfaces of eight eviscerated human donor eyes with four radial keratotomies (depth 100% of central corneal thickness, 3.5-mm clear zone). From digital images obtained under pressure loads ranging from 2 to 100 mm Hg, the distances between the fixed droplets were measured with an accuracy of 1 µ??. After transforming the data to polar coordinates, regional meridional and circumferential strain patterns were calculated. Regional meridional and circumferential radii of curvatures were calculated from corneal profile images obtained at different pressure loads before and after keratotomy.RESULTS: Increasing the intraocular pressure from 2 to 100 mm Hg induced: an epithelial side wound gape of 44 mm; epithelial side circumferential tissue compression between incisions; considerable epithelial side meridional tissue elongation at and between incisions; little endothelial side circumferential strain across incisions; and little endothelial side meridional strain at and between incisions.The radial keratotomy induced 2.30 diopters (D) of central corneal flattening at an intraocular pressure of 2 mm Hg. The degree of central flattening correlated linearly with the amount of wound gape. In the physiological pressure range of the central cornea flattened 0.05 D for each millimeter-of-mercury increment in intraocular pressure. Pronounced meridional steepening was induced corresponding to the middle and peripheral parts of the keratotomy incisions.CONCLUSIONS: Our study suggests that the peripheral "tissue addition" seen after radial keratotomy is a net result of wound gape and circumferential tissue compression. Local bending of intact stromal tissue below the incisions plays an important role for the generation of the wound gape at the corneal surface. These data may help verify finite-element computer models of the human cornea. [J Refract Surg. 1996;12:391-400.]
Photorefractive Keratectomy for Compound Myopic Astigmatism With an Eye Cup Erodible Mask Delivery System
Authors: Brancato Rosario , Carones Francesco , Venturi Elisabetta , Morico Alessandro , Gobbi Pier Giorgio 
Published: April 2021

ABSTRACT
BACKGROUND: The erodible mask is a new energy delivery system for the 193-nm argon fluoride excimer laser. It consists of a polymethylmethacrylate button, whose profile is transferred by photoablation onto the corneal surface. We present the 6- and 12-month results of this technique in the correction of compound myopic astigmatism.
METHODS: We performed the mask procedure on 21 eyes of 16 subjects (mean age, 30.7 years; range, 24 to 46) to correct combined myopia and astigmatism. Attempted myopic correction ranged between -1.50 diopters (D) and -10.00 D (mean, -7.07 D). Attempted astigmatic correction ranged between -1.50 D and -4.00 D (mean, -2.46 D).
RESULTS: Mean procedure error was: sphere +0.74 D (range, -3.00/+5.00), cylinder -1.41 D (range, -3.50/0.00) at 1 month after surgery; sphere +0.18 D (range, -2.50/+3.50), cylinder -1.56 D (range, -4.00/0.00) at 6 months; and sphere -1.30 D (range, -3.00/0.00), cylinder was -1.25 D (range, -2.00/-0.50) at 12 months (10 eyes). During follow up, haze values were never higher than 1, except for one case of haze 2 that regressed to 0 during follow up. Postoperative uncorrected visual acuity improved in all eyes where emmetropia was envisaged; none of the eyes lost spectacle-corrected visual acuity lines 6 or 12 months after surgery.
CONCLUSIONS: The erodible mask proved effective and fairly predictable mainly in the correction of the spherical component of refractive error, while the correction of astigmatism revealed greater unpredictability, with a constant trend to undercorrection. [J Refract Surg. 1996;12:501-511.]
Autologous Keratophakia for the Correction of Consecutive Hyperopia After Automated Lamellar Keratoplasty for Myopia
Authors: Chan Wing-Kwong , Maloney Robert K 
Published: April 2021

ABSTRACT
PURPOSE: Consecutive hyperopia occurs if too much corneal tissue is resected during automated lamellar keratoplasty for myopia. We report what are, to our knowledge, the first two cases of consecutive hyperopia after automated lamellar keratoplasty that were treated by keratophakia with autologous corneal tissue.
METHODS: The patient in case 1 had a spherical equivalent refraction of +3.38 diopters (D) and the patient in case 2 a refraction of +3.63 D in each eye after automated lamellar keratoplasty for myopia. Corneal tissue from the contralateral eye of each patient was obtained with an automated microkeratome and transferred to the overcorrected eye in an autologous keratophakia procedure.
RESULTS: The patient in case 1 had an unaided visual acuity of 20/20, with a spherical equivalent refraction of +0.63 D 4 months after the autologous keratophakia. The patient in case 2 had an unaided visual acuity of 20/60, with a spherical equivalent refraction of -2.25 D 2.5 months postoperatively.
CONCLUSION: These two cases illustrate the use of simultaneous contralateral myopic automated lamellar keratoplasty with autologous keratophakia to treat eyes overcorrected following previous automated lamellar keratoplasty for myopia. [J Refract Surg. 1996;12:514-516.]
Epithelial Inclusion Cysts Following Epikeratoplasty
Authors: Al-Rajhi Ali A , Al-Kharashi Soliman A 
Published: April 2021

ABSTRACT
BACKGROUND: Epikeratoplasty for keratoglobus performed to tectonically support the thin globular cornea may have complications such as interface opacities.
METHODS: We report the case of a patient with persistent interface opacities and epithelial cysts following epikeratoplasty for keratoglobus that were treated primarily by washouts and repeated argon laser photocoagulation.
RESULTS: Interface opacities led to massive epithelial inclusion cysts. Direct removal of these cysts and placement of a new lamellar graft resulted in a favorable outcome.
CONCLUSION: Massive epithelial inclusion cysts may develop in the lamellar interface after epikeratoplasty. Direct surgical removal was successful. [J Refract Surg. 1996;12:517-520.]
Ultrastructure of Picosecond Laser Intrastromal Photodisruption
Authors: Krueger Ronald R , Quantock Andrew J , Juhasz Tibor , Ito Mitsutoshi , Assil Kerry K , Schanzlin David J 
Published: April 2021

ABSTRACT
PURPOSE: To investigate the ultrastructure of the corneal stroma after picosecond intrastromal photodisruption with a neodymium-doped yttriumlithium-fluoride (Nd:YLF) laser.
METHODS: We performed picosecond intrastromal photodisruption on six human eye-bank eyes using a lamellar technique. Thirty picosecond pulses at 1000 Hz and 20 to 25 mj per pulse were placed in an expanding spiral pattern, the pulses separated by 15 um. Three layers were placed in the anterior stroma, separated from each other by 15 uni. In addition, intrastromal radial and arcuate incisions were generated in two living rabbit eyes in a plane perpendicular to the corneal surface. After the procedure, the corneas were processed for scanning and transmission electron microscopy.
RESULTS: Scanning electron microscopy of the eye-bank eyes demonstrated multiple, coalescing intrastromal cavities forming a layer oriented parallel to the corneal surface. These cavities had smooth inner walls. Transmission electron microscopy demonstrated tissue loss surrounding some cavities, with the terminated ends of collagen fibrils clearly evident. Other cavities were formed by separation of lamellae, with little evidence of tissue loss. A pseudomembrane was present along the margin of some cavities. Although there was occasional underlying tissue disruption along the border of a cavity, there was no evidence of thermal damage or tissue necrosis. The perpendicular photodisruptions demonstrated intrastromal cleavage of corneal collagen similar to diamond-knife incisions, with the exception of intact overlying Bowman's and epithelial layers.
CONCLUSION: Intrastromal photodisruption with a Nd:YLF picosecond laser induced no thermal necrosis or coagulative change in the region of tiesue interaction. Lamellar intrastromal photodisruption demonstrated both tissue loss and lamellar separation when performed with the current treatment parameters, possibly limiting ablation efficiency and predictability. [J Refract Surg. 1996;12:607-612.]
Corneal Wound Healing and Nerve Morphology after Excimer Laser In Situ Keratomileusis in Human Eyes
Authors: Latvala Terho , Barraquer-Coll Carmen , Tervo Kaarina , Tervo Timo 
Published: April 2021

ABSTRACT
BACKGROUND; Our aim was to describe wound healing and nerve regeneration in the human cornea after excimer laser in situ keratomileusis.
METHODS: Excimer laser in situ keratomileusis was done in three human eyes 8 days, 54 days, and 4 months prior to enucleation. Acetylcholinesterase reaction was used to histochemically demonstrate the corneal nerves. Immunohistochemical methods were used to demonstrate the following wound healing proteins: cellular fibronectin, tenascin, transforming growth factor-ßl, and a-smooth muscle actin.
RESULTS: All corneas healed without complication. No epithelial hyperplasia appeared and the Bowman's layer was smooth and acellular. An epithelial plug extending up to 100-300 µ?? under the flap margins was seen in all specimens. Regenerative nerve fiber bundles emerging from sharply cut anterior stromal nerves were observed, but the deeper nerves were normal. Restricted expression of fibronectin and tenascin was found at the wound area. All corneal cell types were positive for transforming growth factor-ßl antibody. Cells lining the limbal vessels were positive for a-smooth muscle actin antibody whereas the corneal cells were negative.
CONCLUSIONS: The nerve morphology showed only a few abnormalities, especially in deep stromal nerves. Epithelial plugs at the flap margins may maintain a delayed wound healing process for several months but otherwise the process remained active for a relatively short time. [J Refract Surg 1996;12:677-683]
Histopathological Comparison of Photorefractive Keratectomy and Laser In Situ Keratomileusis in Rabbits
Authors: Amm Marita , Wetzel Wolfgang , Winter Martin , Uthoff Detler , Duncker Gernot I W 
Published: April 2021

ABSTRACT
BACKGROUND: After 193 nm excimer laser photorefractive keratectomy (PRK) for myopia, superficial opacities in the ablation zone and regression of refractive results can occur. Clinical studies have emphasized that corneal clarity and early refractive stability can be achieved with laser in situ keratomileusis (LASDX). We present clinical and histological results that compare PRK and LASIK for the treatment of myopia in rabbits.
MATERIALS AND METHODS: We treated 12 New Zealand white rabbits with PRK and 12 with LASLK using a 193-nm excimer laser (Aesculap Meditec). In both techniques, the identical excimer software and ablation parameters of -10 D treatment depth were used. Six months after surgery, all eyes were removed and prepared for light, fluorescence and transmission electron microscopy.
RESULTS: At the time of enucleation, nine eyes in the PRK group had a moderate to high degree of haze (grade 2 to 3), whereas after LASIK, all corneas showed an almost clear interface in the ablation zone. Correspondingly, all histological investigations after LASIK showed a regular stromal architecture, in contrast to the obvious anterior stromal disorganization after PRK.
CONCLUSION: The preserved integrity of the superficial corneal layers after LASLK ensures quick wound healing with minimal tissue proliferation, resulting in a transparent corneal interface. This technique appears especially suitable for correcting high myopia. [J Refract Surg 1996;12:758-766]
Photorefractive Keratectomy after Radial Keratotomy
Authors: Al-Rajhi Ali A , Risco J Miguel , Badr Ihsan A , Teichmann Klaus D 
Published: April 2021

ABSTRACT
BACKGROUND: Twenty-three eyes of 22 patients remained undercorrected 5 to 49 months after radial keratotomy, either alone or in combination with transverse keratotomy.
METHOD: We attempted to correct the residual myopia ranging from -1.25 to -5.75 diopters (D) (with astigmatism of 0 to 1.25 D) with photorefractive keratectomy. The mean age of patients was 26 years (range 22 to 40 years).
RESULTS: After photorefractive keratectomy (follow-up 6 to 17 months) uncorrected visual acuity was equal to or better than 20/20 in 39% (9 eyes), better than 20/25 in 65% (15 eyes), and better than 20/40 in 74% (17 eyes). Spectacle-corrected visual acuity was equal or better than 20/40 in all eyes; one eye (4%) lost two lines of spectacle-corrected visual acuity. Refractive error was within ±0.50 D in 48% (11 eyes) and within ±1.00 D in 65% (15 eyes). Undercorrections of more than 1.00 D occurred in 22% (5 eyes) and overcorrections of more than 1.00 D occurred in 13% (3 eyes). No or minimal haze was present in 57% (13 eyes), mild haze in 39% (9 eyes) and moderate haze in 4% (1 eye). Final uncorrected visual acuity was better (p=0.0002) and haze was less (p=0.003) in the group with less than -3.00 D than in the group with greater than or equal to -3.00 D.
CONCLUSION: Photorefractive keratectomy after radial keratotomy is safe but less effective and less predictable in eyes with greater than or equal to -3.00 D compared to those with less than -3.00 D. [J Refract Surg 1996;12:801-805]
Intraocular Lens Power Calculation for Cataract Surgery after Photorefractive Keratectomy for High Myopia
Authors: Kalski Richard S , Danjoux Jean-Pierre , Fraenkel Graham E , Lawless Michael A , Rogers Christopher 
Published: April 2021

ABSTRACT
OBJECTIVE: To assess intraocular lens (IOL) power calculations in patients undergoing cataract surgery after excimer laser photorefractive keratectomy (PRK) for myopia.
METHODS: Four eyes of two patients underwent phacoemulsification with IOL implantation after PRK for myopia. The estimated refractive error that would have been induced had the IOL predicted for emmetropia been implanted was calculated using SRK-n, SBKfT, Holladay, and Binkhorst formulas. Manual keratometry and videokeratography-simulated keratometry values measured before surgery were used. Keratometry values calculated by subtracting the refractive change induced by the excimer laser PRK from the manual keratometry or videokeratography-simulated keratometry values measured before PRK were also used. Both spectacle and corneal plane calculations were performed.
RESULTS: Manual keratometry and videokeratography-simulated keratometry values underpredieted the IOL power. Corneal plane manual or videokeratography refraction-derived keratometry calculations were most accurate using the SRKT formula, while spectacle plane calculations were most accurate using the SRK-II formula. In both methods the calculated refractive error was within 0.52 diopters (D) for the emmetropic lens power predicted. Statistical analysis was not performed.
CONCLUSIONS: Refraction-derived keratometric values provided the most accuracy in calculating IOL powers. Our results suggest the SRK/T formula was the most accurate for corneal plane calculations, while the SRK-II formula was the most accurate for spectacle plane calculations. [J Refract Surg 1997;13:362-366]