bluuebunny/crossref_metadata_2025_split huggingface dataset:
Arcuate Keratotomy for the Correction of Spherical Hyperopia in Human Cadaver Eyes
Authors: Vrabec Michael P , Durrie Daniel S , Hunkeler John D 
Published: April 2021

ABSTRACT
BACKGROUND: A new experimental surgical technique to correct spherical hyperopia by steepening of the central corneal curvature was performed on human cadaver eyes.
METHODS: Ten eyes were used in the study. All were pretreated with glycerin to ensure a uniform corneal thickness between .55 and .65 mm on ultrasonic pachometry. A constant intraocular pressure of approximately 30 to 40 mm Hg was maintained in each eye by the injection of saline into the vitreous cavity. This was verified by pneumotonometry. A vertical blade diamond knife was set at 100% of the thinnest of four paracentral readings. Each eye underwent preoperative computed topography. One set of five eyes had 12 incisions made following a 5.75-millimeter diameter Mendez hexagonal marker that included unconnected T incisions at each junction (ie, "Hex T" pattern). The other set of five eyes had four arcuate incisions made following a 6-millimeter diameter zone marker; each incision was 60° in arc. Immediately after surgery, computed topography was repeated.
RESULTS: The hexagonal keratotomy set of eyes had an average steepening of the cornea of 0.80 D with a range of -1.05 to +4.38 D. The arcuate keratotomy set had an average steepening of +2.12 D with a range of + 1.27 to +3.27 D.
CONCLUSIONS: This study suggests arcuate keratotomy may be a more effective procedure in the correction of spherical hyperopia when compared with hexagonal keratotomy. The amount of corneal steepening achieved in a cadaver eye model may not be the same as when performed in vivo. (Refract Corneal Surg 1993;9:388-391.)
Topical Diclofenac Treatment Prior to Excimer Laser Photorefractive Keratectomy in Rabbits
Authors: Szerenyi Karin , Wang Xun Wei , Lee Martha , McDonnell Peter J 
Published: April 2021

ABSTRACT
PURPOSE: This study sought to determine whether pre- and posttreatment with topical diclofenac sodium 0.1% eye drops suppresses corneal inflammation after 193-nanometer excimer laser corneal ablation more effectively than does posttreatment alone.
METHODS: Eight rabbits were divided into four groups. Animals in group I were treated with topical diclofenac every half hour for 2 hours prior to photorefractive keratectomy; treatment was continued every hour for 3 hours after the ablation. Group Il animals, used as controls, were treated with the diclofenac vehicle according to the same schedule. The third group (III) received diclofenac topically only after the excimer laser ablation. The fourth group (IV) consisted of normal corneas from these same animals. At 3 hours after ablation, prostaglandin E? (PGE2) levels were measured in the corneas ana leukocytes were quantified.
RESULTS: Treatment with topical diclofenac significantly reduced levels of PGE2 compared to treatment with the vehicle (p = .024). Presurgical treatment with topical diclofenac did not result in greater suppression of PGE2 than did posttreatment alone (5.72 ± 0.91 pg/m L versus 5.79 ± 1.29 pg/mL). Similarly, there was a significant inhibition of leukocyte invasion in the diclofenac treated corneas (I vs II: ? = .019, ill vs II: ? = .024), but no statistically significant difference between pretreatment and posttreatment alone groups (I vs III: P = .72).
CONCLUSIONS: Topical administration of diclofenac reduces the release of PGE2 and the migration of polymorphonuclear leukocytes in the rabbit cornea 3 hours after 193-nanometer excimer laser ablation. However, pretreatmenf of the cornea, starting 2 hours prior to laser surgery, does not seem to offer advantages over postablation treatment in this animal model. Refract Corneal Surg. 1993;9:437-442.)
RÉSUMÉ
INTRODUCTION: Nous voulions étudier comparativement l'inflammation cornéenne dans les yeux traités avec diclofenac sodium avant et après kératectomie photorefractive au laser excimer 193 nm avec yeux traités uniquement en postopératoire.
MÉTHODES: Huit lapins furent divisés en 4 groupes. Les animaux du groupe I furent traités avec les gouttes de diclofenac toutes les 30 minutes pendant deux heures avant la kératectomie photorefractive et toutes les heures pendant trois heures post-opérativement. Le deuxième groupe servait de cas témoin, traité seulement avec le véhicule. Le troisième groupe recevait diclofenac uniquement en post-opératoire. Le quatrième groupe était constitué des cornées normales de ces animaux mêmes. Trois heures après la chirurgie, les niveaux de prostaglandin E2 (PGE2) furent mesurés et le nombre de leucocytes compté.
Arcuate Transverse Keratotomy for Astigmatism Followed by Subsequent Radial or Transverse Keratotomy
Authors: Price Francis W , Grene R Bruce , Marks Ronald G , Gonzales Jill S 
Published: April 2021

ABSTRACT
BACKGROUND: We studied the safety and efficacy of arcuate transverse keratotomy performed for the primary correction of naturally occurring corneal astigmatism.
METHODS: A multicenter, prospective evaluation of one-stage arcuate transverse keratotomy was conducted in 160 eyes with 1.00 to 6.00 diopters (D) of naturally occurring astigmatism. Vector analysis was used. After 1 month, those eyes that needed further refractive surgery received radial keratotomy for myopia and second- stage arcuate transverse keratotomy for residual astigmatism.
RESULTS: Mean preoperative refractive cylinder was 2.80 D. At 1 month, the vector-corrected change was 2.30 D. Eighty-eight (61%) eyes had at least 1.00 D of residual refractive cylinder and 24 (17%) had at least 2.00 D. Eyes undergoing a second surgery averaged 1.60 D of vector-corrected effect, for a total effect of 2.90 D from both surgeries, indicating the astigmatic refractive effects were not additive. Eyes that had radial keratotomy alone as the second surgery demonstrated a similar change in refractive cylinder as eyes that had both radial and transverse keratotomies. Two eyes lost two lines of spectacle-corrected visual acuity, 29 eyes lost one line, 84 showed no change, and 26 eyes improved one line.
CONCLUSION: Arcuate transverse keratotomy reduced refractive astigmatism. Both overcorrection and undercorrection were common. Complications were infrequent but occasionally caused significant irregular astigmatism. Arcuate transverse keratotomy appears to be a safe procedure with few complications. [J Refract Surg. 1996;12:68-76.]
Anterior Chamber Flare After Photorefractive Keratectomy
Authors: Tomas-Barberan Santiago , Fagerholm Per 
Published: April 2021

ABSTRACT
BACKGROUND: The inflammatory reaction produced after excimer photorefractive keratectomy (PRK) remains to be clarified. In this study, we measured flare in the anterior chamber after excimer PRK as an indirect sign of postoperative inflammation.
METHODS: Flare was measured in 25 eyes with a laser flare meter (Kowa FM 500) before and after excimer laser PRK. The eyes were divided in two groups: 1-week and 1-month follow-up groups. All eyes received topical 0.1% dexamethasone drops postoperatively.
RESULTS: The 95% confidence interval for the difference in flare between the operated and fellow eyes was 3.23 ± 1.81 at day 5 and 2.20 ± 2.02 at day 12 after surgery in the 1-month group and 6.50 ± 2.51 at day 2 and 2.12 ± 0.89 day 5 after the procedure in the 1-week group, thus showing a statistically significant elevation in flare after PRK (P<0.05 ). A statistically significant correlation between the depth of the stromal ablation and the flare elevation 12 days after PRK in the 1-month group was shown.
CONCLUSIONS: There was significant increase in anterior chamber flare after PRK, although considerable individual variation occurred. [J Refract Surg. 1996;12:103-107.]
Holmium:YAG Laser Thermokeratoplasty for Astigmatism in Rabbits
Authors: Lim Key Hwan , Kim Woo Jung , Wee Won Ryang , Shin Dong Eul , Lee Jin Hak , Chang Bong Leen 
Published: April 2021

ABSTRACT
BACKGROUND: Holmium:YAG laser thermokeratoplasty has generated considerable interest as a technique for correcting hyperopia. In this study, the effect of holmium:YAG laser on inducing astigmatism according to application patterns was evaluated.
METHODS: An experimental study based on the results of astigmatic holmium:YAG laser thermokeratoplasty using the Summit OmniMed laser system (Summit Technology Inc, Waltham, Mass) in 36 rabbit eyes is presented. We divided the rabbits into four groups: arcuate, reverse arcuate, linear, and control group according to application patterns. All rabbits were followed for 3 months and cycloplegic refractive measurements were carried out.
RESULTS: The average surgically induced astigmatism was 1.86 diopters (D) for the arcuate group, 2.93 D for the reverse arcuate group, and 1.31 D for the linear group. No significant complications related to the operation were noted.
CONCLUSION: The reverse arcuate pattern of holmium:YAG laser thermokeratoplasty is most effective in inducing astigmatism in rabbits. [J Refract Surg. 1996;12:190-193.]
Tracker-Assisted Photorefractive Keratectomy for Myopia of -1 to -6 Diopters
Authors: Pallikaris loannis , McDonald Marguerite B , Siganos Dimitrios , Klonos Gregory , Detorakis Stathis , Frey Randy , Downes Richard , Gauthier Charline A 
Published: April 2021

ABSTRACT
BACKGROUND: The Autonomous Technologies T-PRK® (Tracker-assisted Photorefractive Keratectomy) excimer laser system uses a small beam scanner that allows flexibility in the ablation pattern that is applied to the cornea and incorporates a sophisticated LADARVision® eye tracker that is capable of following saccadic movements. This paper describes the first clinical results on sighted eyes for the correction of low myopia.
METHODS: Forty-two normal sighted eyes of 42 patients were treated for spherical myopia between -1.00 diopters (D) and -6.00 D with 6 mm ablations. Visual acuity, refractive error, contrast sensitivity (with and without glare), corneal haze, endothelial cell density, and patient satisfaction were measured.
RESULTS: Mean manifest refraction was -0.39 D ± 0.68 D at 1 month with regression to -0.94 D at 3 months and -1.05 D at 6 months. At 6 months, 5 (20%) eyes were ± 0.50 D and 14 (56%) eyes were ± 1.00 D. Consistent with this undercorrection and regression, uncorrected visual acuity (UCVA) of 20/20 and 20/40 or better was achieved by 10 (40%) and 34 (85%) eyes at 3 months and 16 (40%) and 17 (68%) eyes at 6 months. None of the eyes lost 2 or more lines of spectacle corrected visual acuity. Corneal haze was graded as 1/2 trace or less in 89% to 100% of eyes at all intervals. There was no loss of endothelial cells (mean ± SD cell density centrally: preop 3115 ± 322 and 6 months 3220 ± 333) and contrast sensitivity recovered to baseline levels at 3 months.
CONCLUSIONS: The Autonomous Technologies T-PRK® excimer laser system is safe and effective for the reduction or correction of myopia from -1.00 D or -6.00 D. The refractive results may be improved by adjusting the calibration to reduce the undercorrection and by instituting use of topical corticosteroids on an individual basis for those who regress. [J Refract Surg. 1996;12:240-247.]
Double Zone PRK for High Myopia
Authors: Aktunç Turgay , Aktunç Rengin , Bahçecioglu Halil 
Published: April 2021

ABSTRACT
INTRODUCTION: Although excimer laser PRK is our operation of choice for treating myopia, the correction of myopia exceeding -8.00 dpt is still a challenge as this procedure requires a deeper keratectomy. Therefore a double zone treatment may be beneficial to reduce ablation depth.
METHODS: Twenty-one eyes with myopia between -8.00 dpt and -14.00 dpt were included in this study. Twelve eyes were treated 60% of myopia by 5 mm zone and the remaining 40% in a 4 mm zone in the same session (Group 1).
RESULTS: Nine eyes achieved 60% of the desired correction treated with a 4 mm zone whereas 40% correction was achieved in a 5 mm zone (Group 2). No significant difference in postoperative healing, pain, hyperopic shift, myopic regression and haze was observed at the end of the mean follow-up time (10.4 months) but photophobic complaints were less in Group 2. Best corrected visual acuity did not decrease significantly.
CONCLUSIONS: Double zone treatment seems to be an interesting method for treating moderate to high myopia. [J Refract Surg. 1996;12:S271-S273.]
Excimer Laser Phototherapeutic Keratectomy for Corneal Opacities and Recurrent Erosion
Authors: Kozobolis Vasilios P , Siganos Dimitrios S , Meladakis George S , Pallikaris Ioannis G 
Published: April 2021

ABSTRACT
BACKGROUND: Phototherapeutic keratectomy (PTK) has been used to treat superficial corneal opacities, as well as the recurrent corneal erosion syndrome.
METHODS: We performed PTK 6 eyes of 6 patients to treat corneal opacities, and in one eye of another patient to treat recurrent corneal erosion syndrome. Opacities were caused by a healed corneal ulcer, herpetic keratitis, band keratopathy, corneal burn, corneal dystrophy, and an excised pterygium. The follow-up period ranged from 2 to 6 months.
RESULTS: Corneal clarity improved to variable degrees in all eyes with corneal opacities. There was no recurrence in the Recurrent Corneal Erosion Syndrome. A hyperopic shift was observed in 2 eyes.
CONCLUSIONS: PTK appears to be an effective alternative to penetrating keratoplasty in patients with selected anterior stromal opacities can treat the Recurrent Corneal Erosion Syndrome. [J Refract Surg. 1996;12:S288-S290.]
Arcuate Transverse Keratotomy With a Mechanical Arcutome Based on Videokeratography
Authors: Pallikaris Ioannis G , Xirafis Michael E , Naoumidis Leonidas P , Siganos Dimitrios S 
Published: April 2021

ABSTRACT
Corneal topographic hardware was used to develop software analysis for configuration and localization of relaxing astigmatic arcuate incisions. The software is based on the assessment of the results of corneal topographic measurements, performed by the EyeSys Corneal Analysis System. Data assessment includes: A) plotting the dioptric power curves along the circular zones that may be considered appropriate for the placement of arcuate cuts; B) determination of the astigmatic axes position in each selected arc; and C) finding the position of points with the mean dioptric power value between the neighboring astigmatic axes which determine the proposed placement of the arcuate incisions. The new instrument developed for arcuate astigmatic keratotomy includes the algorithm for incision(s) disposition, the software, and the arcutome. [J Refract Surg. 1996;12:S296-S299.]
Effect of Incision Direction on Refractive Outcome After Radial Keratotomy
Authors: Flanagan Gerald W , Binder Perry S 
Published: April 2021

ABSTRACT
PURPOSE: Radial keratotomy incisions can be made centripetally or centrifugally. The benefits and effects of both techniques have been disputed since American surgeons began performing RK in the late 1970s. We examined the RK database of a single surgeon to determine if incision direction was associated with refractive outcome.
METHODS: Stepwise regression was employed to select the important predictors of refraction change in the population. In addition to incision direction, variables eligible for entry into the model were optic clear zone diameter, incision number, patient age, corneal curvature and planned incision depth.
RESULTS: All variables except for planned incision depth and corneal power entered the model.
CONCLUSIONS: The results were consistent with previous investigations that found incision number, optic clear zone diameter and patient age important predictors of outcome. We also found incision direction to be a significant predictive variable with centripetal incisions decreasing myopia 0.6 diopters more than centrifugal incisions. [J Refract Surg. 1996;12:S299-S301.]
A New Scleral Suction Trephine for Retrieval of Corneoscleral Donor Tissue
Authors: Vrabec Michael P , Fan Nancy I , Dahl Patricia , Florakis George J 
Published: April 2021

ABSTRACT
BACKGROUND: Removal of donor corneo-scleral shell from a cadaver, leaving the remainder of the eye in place, has become a poplular technique. Manual removal can result in excessive trauma to the corneal endothelium or an uneven scleral rim.
METHODS: We describe a new technique for corneal retrieval using a sceral suction trephine.
RESULTS: The scleral suction trephine was cut evenly in our eyebank study. There was no additional trauma to the endothelium and the scleral rim was regular.
CONCLUSION: Suction trephination of the sclera in retrieval of corneal donor tissue appears to be safe and effective. [J Refract Surg. 1996;12:S302-s303.]
Closed-System Technique for Implantation of Iris-Supported Negative-Power Intraocular Lens
Authors: Krumeich Jorg H , Daniel Jan , Gast Robert 
Published: April 2021

ABSTRACT
BACKGROUND: The iris-supported claw lens can reversibly correct a wide range of ametropia and aniseikonia with excellent predictability and stability. However, concerns regarding its potential harm to the corneal endothelium have prevented its widespread use. Our experience with the closedsystem surgical technique and the spreader device used in 180 cases between 1987 and 1993 has led us to conclude that potential complications are more likely due to the technique of implantation rather than to the properties of the lens itself.
METHOD: We conducted a prospective study of 35 eyes of 20 consecutive patients (mean age, 38 years; range, 21 to 55 years) operated on between August 1993 and August 1994. Preoperative spherical equivalent refractions ranged from -6.00 to -21.25 diopters (D) (mean, -12.50 D). Follow up was 6 months (86% of eyes) to 1 year (57% of eyes). Spectacle-corrected visual acuity and endothelial cell density were measured prior to, and I1 6, and 12 months following lens implantation. All data were analyzed using the paired t-test.
RESULTS: Mean endothelial cell density dropped insignificantly (p>.10): by 1.22% at 1 month (n=34), by 2.25% at 6 months (n=27), and by 1.21% at 12 months (n=18).
Spectacle-corrected visual acuity increased significantly (p<.001): from a mean of 0.61 preoperatively to 0.77 at 1 month, 0.84 at 6 months, and 0.93 at 12 months postoperatively. At 12 months, 15 eyes (75%) had a refraction within ±0.50 D, 19 eyes (95%) within +1.00 D, and 20 eyes (100%) within +2.00 D of emmetropia.
CONCLUSIONS: Our results suggest that the closed-system approach using the spreader device allows safe implantation of the Worst iris-supported claw lens. [J Refract Surg. 1996;12:334-340.]
Photorefractive Keratectomy for Myopia With a 6-mm Beam Diameter
Authors: Shah Shetal I , Hersh Peter S 
Published: April 2021

ABSTRACT
BACKGROUND: Earlier studies have reported clinical outcomes for up to 2 years following photorefractive keratectomy (PRK) using a 5.0-mm treatment zone with the Summit excimer laser. We present results of PRK using a 6-mm ablation zone with the same laser.
METHODS: Forty-five eyes of 45 patients underwent excimer laser PRK for correction of myopia using a 6-mm excimer laser beam diameter. Attempted corrections ranged from 1.50 diopters (D) to 6.00 D. Data on outcomes of uncorrected visual acuity, spectacle-corrected visual acuity, predictability, corneal haze, subjective glare/halo effects, and patient satisfaction with the procedure were analyzed over a follow-up period of 6 months.
RESULTS: All patients obtained a postoperative uncorrected visual acuity of at least 20/40; 28 eyes (62%) achieved at least 20/20. Postoperative spectacle-corrected visual acuity was at least 20/20 in all patients; no patients lost more than one Snellen line of spectacle-corrected visual acuity. Twentyeight patients (62.2%) achieved within ±0.50 D of the attempted correction; 40 patients (84.4%) achieved within +1.00 D. Mean spherical equivalent refraction was -4.99 D preoperatively and +0.44 D at 1 month, +0.04 D at 3 months, and +0.09 D at 6 months. At 6 months, 40 eyes (88.9%) were graded as clear, 4 eyes (8.9%) as having trace subepithelial haze, and 1 eye (2.2%) as having mild subepithelial haze. The mean glare/halo index for all of the patients was 0.59 on a scale of 0 to 5. Mean subjective patient satisfaction was 4.68 (on the same scale).
CONCLUSIONS: Clinical outcomes following excimer laser PRK for myopia using a 6-mm treatment zone are encouraging. Postoperative subjective glare/halo were minimal, suggesting an optical advantage in using the larger ablation zone. [J Refract Surg. 1996;12:341-346.]
Corneal Asphericity and Its Implications for Photorefractive Keratectomy: a Mathematical Model
Authors: Patel Sudi , Marshall John 
Published: April 2021

ABSTRACT
BACKGROUND: Several clinical trials investigating myopic excimer laser photorefractive keratectomy (PRK) report an initial change in refraction from myopia to hyperopia, followed by a gradual regression toward emmetropia and occasionally to recurrent myopia. We examined the effect of corneal shape on refraction following PRK for myopia using a mathematical model.
METHODS: We calculated the volume of corneal tissue removed by PRK for -3.00-diopter (D) and -6.00-D corrections with ablation diameters of 5 mm and 6 mm. For all the operating algorithms» the central region of the cornea was considered spherical. Mathematical models were developed based on calculations of the apical radius of the ablated cornea and the final refraction for a range of corneal asphericities. Baker's equation was used to model corneal asphericity.
RESULTS: The smaller both the ablation size and desired correction, the smaller the effect of corneal asphericity on the refractive outcome. While corneal asphericity can influence the immediate refraction after PRK, the maximum effect is unlikely to be greater than +0.75 D.
CONCLUSIONS: Corneal asphericity marginally affects the initial outcome of PRK. The effect will probably be offset by the healing response of the cornea. [J Refract Surg. 1996;12:347-351.]
Pilocarpine in the Management of Overcorrection After Radial Keratotomy
Authors: Laranjeira Eduardo , Buzard Kurt A 
Published: April 2021

ABSTRACT
BACKGROUND: Induced hyperopia is a potential complication of radial keratotomy with few effective treatments. We report the results of a retrospective study to evaluate the effectiveness of pilocarpine in the treatment of eyes overcorrected by radial keratotomy.
METHODS: Sixteen eyes of 14 patients, from a consecutive pool of 200 eyes who underwent radial keratotomy, had hyperopia. The patients were subsequently treated with topical pilocarpine. The patients were treated from 3 to 14 weeks (mean, 8.2 weeks).
RESULTS: The mean time of diagnosis of hyperopia was 3 weeks after the surgery (range, 1 to 12 weeks). The mean spherical equivalent of the manifest (fogging) refraction was +1.92 diopters (D) (range, +0.75 D to +5.00 D) and the keratometric power ranged from 31.25 D to 41.00 D (mean, 36.05 D). Mean uncorrected visual acuity before the treatment with pilocarpine was 20/50. After the treatment with pilocarpine, the mean spherical equivalent refraction was -0.31 D (range, -1.75 D to +0.50 D). The mean keratometric power was 38.32 D (range, 34.87 D to 43.12 D), with a mean uncorrected visual acuity at 20/25. The patients were followed for 8 to 49 weeks after treatment without pilocarpine (mean, 21 weeks). The mean spherical equivalent refraction and keratometric readings after that period were -0.71 D (range, -2.25 D to +0.25 D) and 38.33 D (range, 36.12 D to 43.12 D), respectively. All eyes in this study had more than 1.00 D of reduction of hyperopia at the conclusion of the study.
CONCLUSION: Pilocarpine effectively reduced overcorrections after radial keratotomy. After termination of treatment, the steepening of corneal curvature was maintained. [J Refract Surg. 1996; 12:382-390.]