bluuebunny/crossref_metadata_2025_split huggingface dataset:
Traumatic Aphakia Treated with an Iris Prosthesis/Intraocular Lens or Epikeratophakia
Authors: Uusitalo Risto J , Uusitalo Hannu M 
Published: April 2021

ABSTRACT
OBJECTIVE: We retrospectively analyzed the visual results and postoperative complications associated with severely traumatized eyes in which aphakia was corrected with epikeratophakia or a sutured iris prosthesis/intraocular lens (IOL).
METHODS: Fourteen eyes (14 patients) with traumatic aphakia and severe anterior segment complications were corrected either with epikeratophakia or a sutured iris prosthesis/IOL. AU eyes lacked lens capsule or iris support for an IOL. The surgical technique of implanting an iris prosthesis/IOL employed transcleral suturing in the ciliary sulcus combined with penetrating keratoplasty.
RESULTS: In the eight eyes treated with epikeratophakia, four (50%) had spectacle-corrected visual acuity of 20/40 or better. Almost all of these eyes lost one or two Snellen lines of baseline spectacle-corrected visual acuity. .Few complications occurred after epikeratophakia; none were severe. Of six eyes with penetrating keratoplasty and a sutured iris prosthesis/IOL or a sutured posterior chamber IOL, two (33%) achieved a visual acuity of 20/40 or better. In the IOL group, severe complications occurred, including posterior dislocation of the lens and secondary glaucoma.
CONCLUSIONS: The surgical correction of aphakia in severely traumatized eyes requires specialized surgical techniques. Epikeratophakia is a low-risk operation that can be performed in eyes in which an IOL is contraindicated. The iris prosthesis/IOL technique results in good cosmetic results; however, due to complications, this technique should be used with caution. [J Refract Surg 1997;13:382-387]
Laser in situ Keratomileusis for Myopia of -1 to -3.50 Diopters
Authors: Pirzada W A , Kalaawry Hassan 
Published: April 2021

ABSTRACT
BACKGROUND: Laser in situ keratomileusis (LASIK) is the procedure of choice for high myopia. We present a study of 85 eyes undergoing LASIK for myopia between -1.00 and -3.50 diopters (D) and assess the safety and efficacy of the procedure for treatment of low myopia.
METHODS: Eighty-five eyes of 47 patients with a mean age of 29 years, (range, 18 to 56 yrs) underwent LASDX using the Chiron microkeratome and the Nidek EC-5000 excimer laser. Mean preoperative myopia was -2.09 D and mean astigmatism was 0.86 D. All other ocular pathology was ruled out before surgery. Mean follow-up was 48 days (range, 1 day to 13 mo).
RESULTS: Uncorrected visual acuity of 6/9 or better at 1 week was achieved in 44 eyes (52%); at 1 month in 68 eyes (80%); and at 6 months in 70 eyes (93%). Pain score was minimal with the majority of patients having no postoperative pain. One eye suffered a serious postoperative complication of corneal abscess which resolved with treatment, but left a corneal scar and visual acuity of 6/60.
CONCLUSION: LASDX is a safe and effective procedure for low amounts of myopia; it also provides early visual rehabilitation and markedly reduced pain and discomfort to patients undergoing refractive surgery. [J Refract Surg 1997;13(suppl):S425S426]
Treatment of Irregular Astigmatism with a Broad Beam Excimer Laser
Authors: Buzard Kurt A , Fundingsland Bradley R 
Published: April 2021

ABSTRACT
BACKGROUND: Four basic types of irregular astigmatism are described: central elevation, central flat area, eccentric elevation, and eccentric flat area.
METHODS: The importance of the Munnerlyn formula is shown for the treatment of irregular astigmatism. A new diagnostic entity is described, the steep/flat ratio, modeled on the inferior/superior ratio described previously in keratoconus. Calculation of the steep/flat ratio is described using the cross sectional view of videokeratography, leading to specific treatments for the four types of irregular astigmatism. Surgical technique using the VISX Star excimer laser for repeated laser in situ keratomileusis (LASDÎ) is described.
RESULTS: Case studies are given for each of the forms of irregular astigmatism showing improved topographic appearance and indicating treatment parameters. In each case, improvement of both uncorrected and spectacle-corrected visual acuity is demonstrated.
CONCLUSIONS: Irregular astigmatism is an important complication of refractive surgery. Four basic forms of irregular astigmatism can be treated with a broad beam excimer laser. [J Refract Surg 1997;13:624-636]
Comparison of Laser in situ Keratomileusis and Automated Lamellar Keratoplasty for the Treatment of Myopia
Authors: Esquenazi Salomon 
Published: April 2021

ABSTRACT
BACKGROUND: Automated lamellar keratoplasty (ALK) and laser in situ keratomileusis (LASIK) are surgical procedures used to correct high myopia, although their differences in effectiveness and long-term stability have not been sufficiently documented. Little information exists about the results of the two procedures in the hands of the same surgeon.
METHODS: To assess long-term stability of refractive results of ALK and LASEK, a retrospective study of 260 eyes that received ALK and 308 eyes that received LASBK was undertaken. The mean followup was 1.8 years for ALK and 1.4 years for LASEK.
RESULTS: The mean baseline spherical equivalent refraction in ALK eyes was -14.30 ± 2.05 D (range -5 to -25 D) and in LASDK eyes was -8.50 ± 1.75 D (range -3 to -26 D). At 3 months after surgery, 65 ALK eyes (25%) were within ±1.00 D of intended correction compared with 269 LASEK eyes (87.5%). At 1 year, only 31 ALK eyes (16%) were within ±1.00 D of intended correction, compared with 224 eyes (82%) in the LASEK group. At 3 months after surgery, the mean spherical equivalent refraction was -2.64 D in ALK eyes; at 1 year it was -4.60 D, and at 2 years it increased to -5.50 D. In contrast, the mean spherical equivalent refraction in the LASIK eyes at 3 months after surgery was -0.22 D and remained nearly stable until 1.5 years after surgery, when it was -0.50 D. More regression occurred when a large amount of corneal stromal tissue was removed. One out of four eyes that had more than 25% of its corneal tissue removed lost correction after 6 months for both ALK and LASIK. No ALK or LASEK eyes with a remaining corneal thickness of 310 µm or more had regression of the refractive result after 6 months.
CONCLUSIONS: Both ALK and LASIK can reduce moderate and high myopia. The safety and longterm stability of LASIK is better than that for ALK. Although both procedures take advantage of lamellar keratoplasty techniques, the LASEK technique minimizes the depth of ablation while maximizing optical zone size which results in more accurate correction and better long-term stability, the latter depending primarily on the amount of corneal stromal tissue removed. [J Refract Surg 1997;13:637-643]
Accuracy of Topcon CM-1000 Videokeratoscope on Spherical Test Surfaces
Authors: Pérez-Yern Elías , Fimia-Gil Antonio , Mateos Felipe , Carretero Luis 
Published: April 2021

ABSTRACT
BACKGROUND: Many videokeratoscopes use mathematical formulas to calculate corneal radii; calculations depend on slope, curvature, coordinate position, or focal properties of the surface. Accuracy of each type of videokeratoscope must be evaluated. A controversy exists about whether axial or tangential methods best provide a precise description of corneal shape; therefore results with the Topcon CM-1000 using both methods were evaluated.
METHODS: Measurements were done on black polymethylmethacrylate (PMMA) spherical calibrated surfaces. Lenses were first aligned and measured and then misaligned in different directions and measured. Results for each position were compared with the zero or alignment position.
RESULTS: Accuracy of the CM-1000 was high even under extreme misalignment conditions. Tolerance to misalignment was high (about 300 mm). Misalignment-induced variations in the output results were small (usually less than 0.05 mm). However, important variations (more than 1.00 diopter [D]) were found for the lowest measured radius (6 mm). In some cases, small differences between axial and tangential radii for the same point could be found.
CONCLUSION: With the exception of extremely low radii of curvature, the CM-1000 was accurate for measuring spherical surfaces. Further investigation remains to be done on aspheric surfaces and in clinical practice. [J Refract Surg 1997;13:663-6681
Bivariate Polar Value Analysis of Surgically Induced Astigmatism
Authors: Naeser Kristian , Knudsen Ellen Birthe , Hansen Mette Kaas 
Published: April 2021

ABSTRACT
PURPOSE: To demonstrate the use of bivariate polar value analysis of surgically induced astigmatism following various cataract incisions.
METHODS: In a prospective study, we investigated surgically induced astigmatism following cataract surgery through 9.0-mm, 5.5-mm, and 4.0-mm superior corneal incisions. Autokeratometry was performed preoperatively and during the first year. All net astigmatisms were converted to polar values with reference to the 90? meridian. Univariate and bivariate polar value analyses were performed.
RESULTS: After 1 year, univariate polar value analysis disclosed flattening averaging 1.02 D for 9.0-mm incisions, 0.71 D for 5.5-mm incisions, and 0.64 D for 4.0-mm incisions. The induced torque was 0.46 D counterclockwise for the 9-mm incision and close to zero for the 5.5 and 4-mm incisions. Bivariate polar value analysis disclosed a statistically significant (P<.05) difference in surgically induced astigmatism between the 9.0-mm incisions and the two smaller incisions at all follow-up points.
CONCLUSION: Univariate polar value analysis demonstrated the surgically induced steepening and torque. Bivariate analysis demonstrated the joint variation in these entities and therefore always yielded the correct result. Univariate and bivariate polar values may be used for analysis of surgically induced astigmatism following cataract surgery in any meridian. [J Refract Surg 2002;18: 72-78]
Laser in situ Keratomileusis for Correction of Hyperopia and Hyperopic Astigmatism With the Technolas 117C
Authors: Lian Jingcai , Ye Wen , Zhou Deyou , Wang Kangsun 
Published: April 2021

ABSTRACT
PURPOSE: To evaluate the effectiveness, predictability, and safety of laser in situ keratomileusis (LASIK) for correction of hyperopia and hyperopic astigmatism.
METHODS: Fifty-four hyperopic eyes of 35 patients with a spherical equivalent refraction between +1.00 and +6.00 D were followed for at least 12 months following LASLK. AU surgery was performed with the scanning Chiron Technolas Keracor 117C excimer laser. Data on uncorrected and spectacle-corrected visual acuity, predictability, stability of refraction, and complications were analyzed.
RESULTS: At 12 months, the average residual refraction was +0.29 ? 0.78 D; 83.3% of eyes (45 eyes) were in the range of ?1.00 D and 61.1% of eyes (33 eyes) were within ?0.50 D of emmetropia. Fifty eyes (92.6%) had uncorrected visual acuity of 20/40 or better and 34 (63.0%) eyes had 20/20 or better. One eye (1.9%) lost two lines of best spectaclecorrected visual acuity and two eyes (3.7%) gained two or more lines. Two patients (two eyes, 3.7%) had complaints of halos and one patient (one eye, 1.9%) had glare at 12 months after LASLK for hyperopia.
CONCLUSIONS: LASLK was used to treat hyperopia from +1.00 to +6.00 D with good predictability and safety. Primary and second hyperopia require different nomograms, according to our experience. [J Refract Surg 2002;18:435-438]
Factors That Affect Corneal Flap Thickness With the Hansatome Microkeratome
Authors: Gailitis Raymond P , Lagzdins Mara 
Published: April 2021

ABSTRACT
PURPOSE: To evaluate factors that influence corneal flap thickness with the Hansatome microkeratome.
METHODS: One hundred thirty-two eyes of 70 patients underwent laser in situ keratomileusis (LASDX). Corneal flap thickness was measured by subtracting the intraoperative corneal bed pachymetry measurement from intraoperative total corneal pachymetry. Variables examined included plate thickness, ring size, blade use, temperature, humidity, barometric pressure, age, average keratometric power, and preoperative corneal thickness.
RESULTS: Mean flap thickness using a 180-jtm plate was 143 ? 19 /*m (range 61 to 207 /am). Mean flap thickness using a 160~/an plate was 119 ? 20 /an (range 83 to 159 ????). The difference was statistically significant (P<.05). Mean flap thickness using a 180-/im plate and the same blade on the right and left eye was 151 ? 21 ??\ (range 113 to 200 ?ta) and 137 ? 21 ?ta (range 91 to 191 ?ta), respectively. The 14-??? difference was statistically significant (P< .001). There was a slight negative correlation of flap thickness with humidity. There was a positive correlation with preoperative corneal thickness (pachymetry).
CONCLUSION: The Hansatome tended to cut thinner flaps than anticipated based on the plate used. Flaps cut on the first eye were thicker than the second eye using the same blade. Thicker corneas tended to lead to thicker flaps. There was no correlation between flap thickness and microkeratome ring size, temperature, barometric pressure, patient age, or average keratometric power. [J Refract Surg 2002;18:439-443]
Effect of Prophylactic Brimonidine or Bleeding Complications and Flap Adherence After Laser in situ Keratomileusis
Authors: Norden Richard A 
Published: April 2021

ABSTRACT
PURPOSE: Several authors have assessed the effect of prophylactic briomonidine on bleeding complications and flap adherence after laser in situ keratomileusis (LASIK). This study further evaluates these potential associations.
METHODS: We performed a prospective, doublemasked, single-surgeon study of 31 patients (61 eyes) who underwent LASIK with or without prophylactic brimonidine for primary myopia/ myopic astigmatism (59 eyes) or hyperopic astigmatism (2 eyes). Among myopes, mean preoperative sphere was -4.44 ± 2.21 D and mean cylinder was -1.04 ± 1.01 D. Thirty-three eyes (54%) had nasal hinges; 28 eyes (46%) had superior hinges.
RESULTS: Subconjunctival hemorrhage was observed in 22 of 61 eyes (36.1%). Three of these 22 eyes (13.6%) received prophylactic brimonidine; the remaining 19 eyes with subconjunctival hemorrhage (86.3%) did not receive brimonidine (P<0001). All but three eyes had some hyperemia; however, the amount of hyperemia was lower in the brimonidine group (P<.0001). Bleeding from the superior micropannus occurred in four of 61 eyes (6.6%). One of these four eyes received brimonidine. There was one case of flap slippage in a nonbrimonidine eye with a nasal hinge; no flap striae were observed after repositioning.
CONCLUSION: This study suggests that brimonidine administered before LASIK may significantly reduce subconjunctival hemorrhage and reduce the amount of hyperemia. [J Refract Surg 2002;18:468-471]
A New Intraocular Lens Design to Reduce Spherical Aberration of Pseudophakic Eyes
Authors: Holladay Jack T , Piers Patricia A , Koranyi Gabor , van der Mooren Marrie , Norrby N E Sverker 
Published: April 2021

ABSTRACT
PURPOSE: The aim of this study was to design and evaluate in the laboratory a new intraocular lena (IOL) intended to provide superior octtlar optical quality by reducing spherical aberration.
METHODS: Corneal topography measurements were performed on 71 cataract patients using an Orbscan I. The measured corneal surface shapes were used to determine the wavefront aberration of each cornea. A model cornea was then designed to reproduce the measured average spherical aberration. This model cornea was used to design IOLs having a fixed amount of negative spherical aberration that partially compensates for the average positive spherical aberration of the cornea. Theoretical and physical eye models were used to assess the expected improvement in optical quality of an eye implanted with this lens.
RESULTS: Measurements of optical quality provided evidence that if this modified prolate IOL was centered within 0.4 mm and tilted less than 7 degrees, it would exceed the optical performance of a conventional spherical IOL. This improvement occurred without an apparent loss in depth of focus.
CONCLUSION: A new IOL with a prolate anterior surface, designed to partially compensate for the average spherical aberration of the cornea, is intended to improve the ocular optical quality of Pseudophakie patients. [J Refract Surg 2002;18: 683-691]
Prospective Randomized Trial of an Anterior Surface Modified Prolate Intraocular Lens
Authors: Packer Mark , Fine I Howard , Hoffman Richard S , Piers Patricia A 
Published: April 2021

ABSTRACT
PURPOSE: We compare the contrast sensitivity obtained with an anterior surface modified prolate intraocular lens with the contrast sensitivity obtained with a standard spherical intraocular lens.
METHODS: Patients presenting for cataract surgery in one eye were randomized to receive either the Tecnis Z9000 intraocular lens (Pharmacia) or the AMO AR40e Opti-Edge intraocular lens (AMO). Sine wave grating contrast sensitivity testing under mesopic and photopic conditions served as the principal outcome measure.
RESULTS: The Tecnis Z9000 intraocular lens provided statistically significantly better contrast sensitivity at 1.5 and 3 cycles per degreee under mesopic conditions and at 6, 12 and 18 cycles per degree under photopic conditions.
CONCLUSION: The use of a modified prolate intraocular lens during cataract surgery has the potential to improve contrast sensitivity under both mesopic and photopic conditions. [J Refract Surg 2002;18:692-696]
Retinal Detachment in Myopic Eyes After Laser in situ Keratomileusis
Authors: Arevalo J Fernando , Ramirez Ernesto , Suarez Enrique , Cortez Rafael , Ramirez Gema , Yepez Juan B 
Published: April 2021

ABSTRACT
PURPOSE: To report the characteristics and surgical outcomes of rhegmatogenous retinal detachments in myopic eyes after laser in situ keratomileusis (LASIK).
METHODS: Clinical charts of patients that developed rhegmatogenous retinal detachment after LASIK were reviewed. Surgery to repair rhegmatogenous retinal detachment was performed in 31 eyes (mean follow-up of 14 months after vitreoretinal surgery).
RESULTS: A total of 38,823 eyes underwent surgical correction of myopia from -0.75 to -29.00 D (mean -6.00 D). Thirty-three eyes (27 patients; frequency .08%) developed rhegmatogenous retinal detachment after LASLK; detachments occurred between 12 days and 60 months (mean 16.3 mo) after LASIK. Eyes that developed a rhegmatogenous retinal detachment had a mean -8.75 D before LASLK. Most rhegmatogenous retinal detachment and retinal breaks occurred in the temporal quadrants (71.1%). Final best spectacle-corrected visual acuity (BSCVA) of 20/40 or better was obtained in 38.7% of the 31 eyes (two patients refused surgery). Poor final visual acuity (20/200 or worse) occurred in 22.6% of eyes. Information regarding visual acuity after LASIK and before the development of rhegmatogenous retinal detachment was available in 24 eyes; 45.8% (11/24 eyes) lost two or more lines of visual acuity after vitreo-retinal surgery. Reasons for poor visual acuity included the development of proliferative vitreo-retinopathy (n=5), epiretinal membrane (n=1), chronicity of rhegmatogenous retinal detachment (n=1), new breaks (n=1), displaced corneal flap (n=1), and cataract.
CONCLUSIONS: Rhegmatogenous retinal detachment after LASLK for myopia is a serious complication. Final visual acuity may be limited by myopic degeneration, amblyopia, or delayed surgical repair. [J Refract Surg 2002;18:708-714]
Effect of Microkeratome Suction Duration on Corneal Flap Thickness and Incision Angle
Authors: Seo Kyoung Yul , Wan Xiu H , Jang Jae W , Lee Jae Bum , Kim Moon J , Kim Eung Kweon 
Published: April 2021

ABSTRACT
PURPOSE: To determine the effect of suction duration on corneal flap thickness and incision angle of the cut margin created by a microkeratome in a porcine eye.
METHODS: Thirty porcine eyes were randomly assigned to three groups according to different suction duration: group 1 (10 sec), group 2 (35 sec), and group 3 (60 sec). The Hansatome microkeratome with a #160 plate and 8.5-mm-diameter suction ring was used to create a corneal flap with a diameter of 8.5 millimeters. Corneal flap thickness was measured by automated ultrasonic pachymetry, and the incision angle was assessed by measuring the angle of a sagittal section of the cornea using image analysis software.
RESULTS: Mean corneal flap thickness in groups 1 (10 sec), 2 (35 sec), and 3 (60 sec) was 87.8 ± 22.0 µm, 116.0 ± 7.0 µm, and 127.2 ± 16.8 µm, respectively. There was a statistically significant difference between groups 1 (10 sec) and 2 (35 sec) (P=.005) and groups 1 and 3 (P=.004). The mean incision angle in groups 1, 2, and 3 was 34.8 ± 9.0°, 44.4 ± 16.1°, and 48.24 ± 15.3°, respectively. A statistically significant difference was found between groups 1 (10 sec) and 2 (35 sec) (P=.044) and groups 1 (10 sec) and 3 (60 sec) (P<.001).
CONCLUSION: In laser in situ keratomileusis in porcine eyes, an increase in suction duration resulted in a thicker flap and greater incision angle. [J Refract Surg 2002;18:715-719]
Intraoperative Arcuate Transverse Keratotomy With Phacoemulsification
Authors: Titiyal Jeewan S , Baidya Krishna P , Sinha Rajesh , Ray Manotosh , Sharma Namrata , Vajpayee Rasik B , Dada Vijay K 
Published: April 2021

ABSTRACT
PURPOSE: To evaluate the efficacy of paired intraoperative arcuate transverse keratotomy at a 7- mm- diameter zone along with a 3.5-mm clear corneal phaco tunnel in the steeper axis to correct pre-existing astigmatism.
METHODS: A prospective randomized case-control study was conducted on 34 eyes of 28 patients with immature senile cataract. They were divided into two groups; in one group (17 eyes) intraoperative arcuate keratotomy was coupled with phacoemulsification in the steeper meridian (arcuate keratotomy group; mean preoperative astigmatism 2.28 ± 0.89 D) and the other group (17 eyes) phacoemulsification was performed in the steeper meridian without arcuate keratotomy (control group; mean preoperative astigmatism 2.04 ± 0.50 D). The patients were examined at 1 day, and 1, 4, and 8 weeks postoperatively. Correction of keratometric astigmatism, surgically induced refractive changes, magnitude and axis of cylinder, spherical equivalent refraction, with and against the wound change, and coupling ratio were evaluated.
RESULTS: Mean reduction in keratometric astigmatism in the keratotomy group was 1.26 ± 0.54 D (P = .0067) and in the control group was 0.48 ± 0.60 D (P = .0423). The difference in reduction of keratometric astigmatism between the two groups was statistically significant (P = .0296). Surgically induced refractive change at 8 weeks follow-up was 2.15 ± 1.13 D in the keratotomy group and 1.50 ± 1.32 D in the control group (P = .046). Coupling ratio was -1.10 ± 0.43 in the keratotomy group at 8 weeks after surgery while the control group was -0.82 ± 0.38.
CONCLUSION: A combination of intraoperative arcuate keratotomy with steep axis phacoemulsification incision is more effective than steep axis phacoemulsification incision alone in reducing pre-existing astigmatism. IJ Refract Surg 2002; 18: 725-730]