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Results for “Keratotomy, Radial”

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At least 19 recordsLinked to original sources
PubMed1998

Analgesic efficacy and safety of nonpreserved ketorolac tromethamine ophthalmic solution following radial keratotomy. Ketorolac Radial Keratotomy Study Group.

PURPOSE: To compare the analgesic efficacy and safety of nonpreserved ketorolac tromethamine 0.5% with those of its vehicle in the treatment of postsurgical ocular pain following radial keratotomy. METHODS: This study employed a multicenter, double-masked, randomized, parallel-group design. Radial keratotomy patients were treated with either nonpreserved ketorolac tromethamine 0.5% or its vehicle four times daily for up to 3 days following surgery. Patients were provided with an escape medication (acetaminophen) for use only as needed for intolerable pain. RESULTS: Patients treated with ketorolac reported significantly greater pain relief (P < or =.023), less pain intensity (P < or =.047), less use of escape medication (P < or =.001), fewer symptoms of ocular discomfort (P=.024), and fewer sleep disturbances (P < or =.013) than did patients treated with vehicle. No treatment-related adverse events were reported in the ketorolac group, and only one treatment-related adverse event was reported in the vehicle group. Most other safety findings were equivalent in the two treatment groups except that there were significantly less eyelid erythema (P=.026) and eyelid edema (P < or =.001) in the ketorolac group. CONCLUSIONS: Nonpreserved ketorolac tromethamine 0.5% ophthalmic solution was significantly more effective than, and as safe as, vehicle in the treatment of postoperative pain associated with radial keratotomy. Therefore, topical ketorolac may be a valuable treatment option for the maintenance of patient comfort following refractive surgery.

Adult↗
PubMed1993

Excimer laser keratectomy after radial keratotomy.

Radial keratotomy to treat myopia has been characterized by a lack of predictability. Until recently, patients with undercorrected myopia who were unsatisfied with their visual outcome could only be offered secondary augmentation procedures, which were equally unpredictable. We performed excimer laser keratectomy in six eyes of five patients whose myopia was undercorrected after radial keratotomy. The average residual spherical equivalent refractive error after radial keratotomy was -2.40 diopters, and this was reduced to -0.48 diopters after laser treatment. Final uncorrected visual acuity ranged from 20/80 to 20/20, and visual acuity was corrected to within one line of the preoperative best-corrected value in all patients. Epithelialization of all eyes occurred within four to six days. There were no incidences of corneal neovascularization, including no vascularization of the radial keratotomy incisions. Our findings suggest excimer phototherapeutic keratectomy offers a safe and more controlled method of augmenting undercorrected myopia after radial keratotomy.

Adult↗
PubMedDate not supplied

Excimer photorefractive keratectomy after undercorrected radial keratotomy.

Radial keratotomy has been used for the treatment of myopia since 1979. Until recently, patients with undercorrected myopia had recourse only to repeated keratotomy. Now patients undercorrected after two or more radial keratotomy procedures can be treated with the excimer laser to reduce the residual myopia. Nineteen eyes of 17 patients with undercorrected myopia after repeated radial had excimer photoradial keratectomy performed. The mean residual spherical equivalent refractive error after radial keratotomy was -2.74 +/- 1.06 diopters (D). This was further reduced after PRK. Final uncorrected visual acuity ranged from 20/20 to 20/70. Excimer laser PRK offers a safe and more controlled method of treating residual after radial keratotomy.

Adolescent↗
PubMed1983

Predicting the results of radial keratotomy.

Radial keratotomy on 251 patient eyes was performed. Patients traversing the one-year gate after surgery have demonstrated a refractive change best predicted by the optical zone size, the number of incisions, the corneal dissymmetry, and the age of the patient. One year after surgery, a 16-incision radial keratotomy with 3.0-mm optical zone produced 4.66 diopters of refractive change if the limbus was traversed (N = 13), and 5.18 diopters of refractive change if all incisions remained in clear cornea (N = 39). An eight-incision, 3.0-mm optical zone radial keratotomy produced 5.21 diopters of refractive change at one year (N = 37). A 3.5-mm optical zone, eight-incision radial keratotomy produced 3.66 diopters of change at one year (N = 6). A 4.0-mm optical zone produced 2.67 diopters of change with 16 incisions (N = 8), and 3.45 diopters of change with eight incisions at one year (N = 9). Although older patients appear to have significantly greater refractive change with radial keratotomy at the three-month gate, this difference is not yet confirmed at one year after surgery. The shape of the cornea before surgery contributes to the predictability of the refractive results when the horizontal and vertical keratometer measurements are analyzed. Corneal dissymmetry produces greater refractive results with steeper horizontal K when against-the-rule astigmatism is present before surgery.

Adult↗
PubMedDate not supplied

Radial keratotomy.

Radial keratotomy has always produced ambivalent feelings in the Ophthalmologist. The severe complications produced by the Sato procedure has been an unforgettable episode. The work of Fyodorov and Durney (1979) and their American counterparts, Bores (1981) and Hoffer (1981) have done a great service to radial keratotomy in having it established as an acceptable procedure. The controversy really only abated with the work of the National Institute of Health Funded Prospective Evaluation of Radial Keratotomy (PERK) study which suggested that the procedure has a low initial risk and was effective in decreasing myopic correction. Over the last 3 years a series of cases where evaluated and followed up in detail in an effort to gain a perspective on the one problem which has bugged the radial keratotomy programme from the beginning-its predict-ability.

Adolescent↗
PubMed1985

Slit-lamp microscopic appearance of corneal wound healing after radial keratotomy.

Radial keratotomy offers a unique opportunity to study corneal wound healing because the corneas are normal, the fine knife blades disrupt adjacent tissue minimally, no sutures are used, there is minimal inflammation, and few postoperative drugs are administered. We studied corneal wounds with a slit-lamp microscope as they healed from two weeks to three years after radial keratotomy in 84 eyes of 51 consecutive patients enrolled in the Prospective Evaluation of Radial Keratotomy (PERK) Study. One day after surgery, the incisions were surrounded by edema. At two weeks, a dense, gray, diffusely marginated opacity occupied 0.1 mm on both sides of the incision. At three months, the area adjacent to the incision was filled with discrete, fine, gray spicules that protruded at right angles from the incision. At six months, the gray cloudiness had completely disappeared, and the individual spicules were more prominent. By one year, the spicules were disappearing from the anterior portion of the incision and were concentrated primarily in the posterior part of the incisions. At two and three years, the incision scar was fainter and the spicules had disappeared from all but the deep posterior part of the wound. We believe that these spicules correspond to the reorganization of the stroma along the edges of the corneal incision. The persistence of the spicules suggests that wound healing in radial keratotomy may not be complete until two years or more after surgery.

Cicatrix↗
PubMed1988

Four incision radial keratotomy.

Radial keratotomy is a constantly evolving procedure. This paper investigates the value of four incision radial keratotomy. The possible advantages of fewer incisions include increased corneal stability, lower risk of perforation, less potential of endothelial cell loss, decreased chance of overcorrection, and simplification of the procedure. We evaluated the results of four incision radial keratotomy in 55 eyes of 31 patients. Follow-up ranged from one to 18 months. Results in low myopia (-2.00 to -3.12 diopters) show 93% of the patients were 20/40 or better, 90% were within +/- 1 diopter of emmetropia, and no patients were overcorrected greater than 1 diopter. In moderate myopia (-3.25 to -4.37 diopters), 84% of the patients were 20/40 or better, 92% were within +/- 1 diopter of emmetropia, and no patients were overcorrected greater than 1 diopter. Regression analysis was performed and it was determined that the postoperative result was equal to .262 + [1.293 x preop spherical equivalent] - [1.166 x optical zone] + [0.56 x depth] + [.038 x age], R = .87.

Follow-Up Studies↗
PubMed1987

Investigation of contrast sensitivity following radial keratotomy.

Radial keratotomy is a surgical procedure for the correction of myopia in which the cornea is flattened by partial-thickness radial incisions. While postoperative visual acuity is usually good, measurements of acuity are of only limited value and do not describe visual performance for a variety of spatial frequencies and contrasts. In the present study, the effect of radial keratotomy on the contrast-sensitivity function was examined. Six spatial frequencies were tested (0.5, 1.0, 3.0, 6.0, 11.4, and 22.8 cycles/degree) using the Nicolet CS 2000 with patients wearing corrective lenses. The results revealed that, at least for the conditions tested, radial keratotomy does not produce a statistically significant decline in contrast sensitivity.

Humans↗
PubMed1992

Corneal topographic changes over time after radial keratotomy.

Radial keratotomy flattens the cornea, but in a nonuniform fashion. We used computer-assisted topographic analysis to examine curvature changes in different regions of the cornea. Within 45 days after surgery in human eyes, the central and midperipheral cornea flattens and the periphery steepens. Shortly after surgery, the central cornea (within 1-1.5 mm of the corneal light reflex) is steeper than the adjacent midperipheral cornea (1.5-3 mm peripheral to the light reflex). With time, however, the central cornea flattens more than the midperiphery, such that it is no longer relatively steeper. This regional variability in corneal curvature after radial keratotomy helps explain phenomena such as multifocal lens effect after radial keratotomy, and the changes with time account for the conflicting results observed clinically in human corneas and experimentally in human eye bank eyes.

Adult↗
PubMed1986

What patients should know about radial keratotomy.

Radial keratotomy is a relatively new, widely advertised procedure that promises patients with myopia 20/20 vision without corrective lenses. However, radial keratotomy sometimes does not fulfill this promise. New studies have reported numerous cases in which patients were not helped or were actually harmed by radial keratotomy. Also, its long-term effects are unknown. Family physicians should advise patients to approach the procedure with caution.

Cornea↗
PubMed1981

Precision standardization of radial keratotomy.

Radial keratotomy is an experimental surgical procedure being performed in increasingly large numbers, often without carefully designed protocols which meet accepted methodology for clinical research. This paper presents an instrumentation system which makes it possible to have precise control of the length, depth, and spacing of radial keratotomy incisions. This is not a paper in favor of radial keratotomy. It raises the need for rigid standardization of the technique with evaluation of the results according to carefully controlled and accepted clinical trial methodology.

Animals↗
PubMed1997

Rhegmatogenous retinal detachment operation after radial keratotomy.

Radial keratotomy has recently been introduced for the correction of myopia. This procedure does not hinder progression of the pathophysiological changes in the myopic eye. We hereby describe a case of rhegmatogenous retinal detachment operation after radial keratotomy and present the operative considerations and refractive results.

Cornea↗
PubMed1988

Binocular vision complications after radial keratotomy.

Radial keratotomy (RK), a popular procedure for reducing myopia, does not always have a successful outcome. Of the adverse effects reported in the literature, there have been few reports of undesirable disturbances of binocular vision. Four representative cases are reviewed which presented clinically with varying binocular problems induced by RK. The treatment considerations and final solutions for each are discussed. In the presence of RK-induced anisometropia, aniseikonia can be a particularly debilitating binocular vision problem for some patients.

Adult↗
PubMed1990

Radial keratotomy.

Radial keratotomy is effective for correcting low-grade myopia. The predictability is best for myopia that is less than 4 diopters. If the procedure is well performed, the rate of complications remains low. There is not always good correlation between refraction and keratometric changes because of correction errors, which are the main complication. Glare and fluctuating vision are common in the weeks following surgery. Wound healing may be delayed. Histological studies have shown that the epithelial plug is sometimes not eliminated after 4 years, which explains the long-term changes in refraction and corneal fragility after trauma. Incision ruptures can occur many years after surgery. The long-term evolution after 10 years is not known, and the indications are still controversial because it is a surgical procedure that modifies the visual function of a healthy eye.

Humans↗
PubMedDate not supplied

Inflammatory cell responses to radial keratotomy.

Radial keratotomy stimulates the influx of polymorphonuclear cells (PMNs) into the tear film and stroma. These cells do not degranulate and are gone in four days. Incisions fill with persistent epithelial plugs, and extracellular matrix (ECM) replacement does not occur. In contrast, a thermal burn stimulates a prolonged influx of PMNs into the tear film and stroma, where they degranulate and remove damaged tissue. ECM replacement in a few weeks suggests that factors released by activated PMNs may stimulate normal wound healing in the cornea.

Animals↗
PubMed1995

[A study on five-year postoperative results of radial keratotomy].

Radial keratotomy was performed on 285 myopic eyes (155 cases) with a mean of -5.48D. 1-2 pairs of flag-shaped transverse incisions were also made to correct corneal astigmatism over 1.00D. After a postoperative follow-up of 4-5 years, the mean keratometric corneal refractive power, corneal astigmatism and spherical equivalent refraction of the eyes were reduced by 3.98D, 0.36D and -4.74D, respectively. The rates of emmetropia, overcorrection and undercorrection were 70.7%, 15.5% and 13.8%, respectively. The decrease of the best corrected visual acuity by over two lines occurred in 3.4% of the eyes. The percentage of eyes with postoperative uncorrected visual acuity > or = 1.0 was 63.8% and that > or = 0.6, 89.7%. The complications included corneal microperforation in 4.6%, visual fluctuation in 34.1% and glare in 8.8% which decreased to 1.8% after postoperative 6 months. The mean rate of endothelial cell loss at the central optical zone was 6.2% in the postoperative 1-2 years.

Adolescent↗
PubMed1995

Astigmatism analysis after radial keratotomy.

Radial keratotomy without T-cutting was performed on 245 eyes of 124 patients with 6-8 months of post-operative follow-up. The results showed that post-operatively astigmatism was increased in 74 eyes (30.2%) with the increased range from +0.50 to +3.50DC, decreased in 27 eyes (11.0%) and not changed in 144 eyes (58.8%). The main causes of astigmatic change included microperforations, irregular incisions, incisions across the central optical zone and various depths of incisions, etc.

Adolescent↗
PubMed1987

An improved radial marker for radial keratotomy.

Radial marks on the peripheral cornea in radial keratotomy can lead to confusion during incision placement. I have designed and successfully used a small radial marker that indicates the starting position for each incision, but does not mark the peripheral cornea.

Humans↗