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At least 991 records · Page 55Linked to original sources
PubMed2001

200 Hz flying-spot technology of the LaserSight LSX excimer laser in the treatment of myopic astigmatism: six and 12 month outcomes of laser in situ keratomileusis and photorefractive keratectomy.

PURPOSE: To evaluate safety, efficacy, predictability, and stability in the treatment of myopic astigmatism with laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) using the 200 Hz flying-spot technology of the LaserSight LSX excimer laser. SETTING: SynsLaser Clinic, Tromsø, Norway. METHODS: This retrospective study included 110 eyes treated with LASIK and 87 eyes treated with PRK that were available for evaluation at 6 and 12 months, respectively. The mean preoperative spherical equivalent (SE) was -5.35 diopters (D) +/- 2.50 (SD) (range -1.13 to -11.88 D) in the LASIK eyes and -4.72 +/- 2.82 D (range -1.00 to -15.50 D) in the PRK eyes. The treated cylinder was 4.00 D in both groups. Eleven (8.5%) LASIK eyes and 8 (7.4%) PRK eyes had secondary surgical procedures before 6 and 12 months, respectively, and were excluded when the 6 and 12 month outcomes were analyzed. RESULTS: None of the eyes lost 2 or more lines of best spectacle-corrected visual acuity. Seventy-seven percent of the LASIK eyes and 78% of the PRK eyes achieved an uncorrected visual acuity of 20/20 or better; 98% in both groups achieved 20/40 or better. The SE was within +/-0.5 D of the desired refraction in 83% of the LASIK eyes and 77% of the PRK eyes; it was within +/-1.0 D in 97% and 98%, respectively. The cylinder correction had a mean magnitude of error of 0.04 +/- 0.31 D (range -0.96 to +0.85 D) in the LASIK eyes and 0.02 +/- 0.37 D (range -1.44 to +0.72 D) in the PRK eyes. Refractive stability was achieved at 1 month and beyond in the LASIK eyes and at 3 months and beyond in the PRK eyes. CONCLUSION: The outcomes of this study are comparable to those achieved with lasers that use small-beam technology with a lower frequency, as well as with other types of delivery systems. They suggest that the 200 Hz technology used in the LaserSight LSX excimer laser is safe, effective, and predictable and that with LASIK and PRK the results are stable when treating low to moderate myopia and astigmatism up to 4.0 D.

Adult↗
PubMed2002

Selective argon laser suturelysis versus needle suturelysis to treat induced corneal astigmatism after cataract surgery.

PURPOSE: To compare the complications and subjective experience of patients having argon laser suturelysis (LS) with those of patients having needle suturelysis (NS) for corneal astigmatism after extracapsular cataract extraction (ECCE). SETTING: Department of Ophthalmology, Tan Tock Seng Hospital, Singapore. METHODS: This prospective study comprised 30 patients (30 eyes) with more than 3.00 diopters of with-the-rule astigmatism after ECCE. A minimum of 5 weeks after surgery, 2 sutures along the steepest meridian were lysed by the same surgeon, 1 by a needle and the other by laser using a Hoskins lens. Patients were randomized to receive NS first followed by LS or LS followed by NS. The complications were recorded. The patients subjectively graded their fear and discomfort/pain during suturelysis using a scale from 0 to 10. Patient preference for either procedure was also recorded. RESULTS: The complications of NS were conjunctival epithelial defect (17/30), subconjunctival hemorrhage (13/30), and corneal abrasion (4/30) and of LS, minor conjunctival burn (1/30) and conjunctival epithelial defect (1/30). The mean subjective fear and discomfort/pain scores in the NS group were significantly higher than in the LS group (P =.0010 and P =.0014, respectively). Nineteen patients preferred LS, 3 preferred NS, and 8 had no preference for either procedure. CONCLUSION: Argon laser suturelysis was associated with fewer complications than NS and was preferred by patients.

Aged↗
PubMed2002

Cyclotorsion: a possible cause of residual astigmatism in refractive surgery.

PURPOSE: To determine whether cyclotorsion occurs when a subject changes from binocular to monocular fixation and to assess positionally induced cyclotorsion. SETTING: Clinics of the Rotterdam Eye Hospital, Rotterdam, The Netherlands. METHODS: The axis of astigmatism was measured with the Nidek handheld keratometer in 15 normal subjects under monocular and binocular fixation and in seated and supine positions. The limits of agreement for the repeatability of measurements with the Nidek keratometer were used to identify subjects with statistically significant cyclotorsion. RESULTS: Two subjects (13%) showed statistically significant excyclotorsion when changing from binocular to monocular fixation in a seated position. In a supine position, 3 subjects (20%) showed excyclotorsion when the fixation changed. Body position itself had no influence on ocular torsion. CONCLUSIONS: Significant cyclotorsion may occur under monocular viewing conditions. If monocular photorefractive keratectomy procedures are based on binocular keratometry readings, an undercorrection of myopic astigmatism may result. Individuals at risk should be identified before refractive keratectomy is performed.

Astigmatism↗
PubMed1992

Use of grafts smaller than the opening for keratoconic myopia and astigmatism. A prospective study.

A prospective study was conducted on 15 consecutive keratoconic eyes to evaluate the use of grafts smaller than the opening in keratoconic myopia and astigmatism. All surgeries were performed by the senior author. Average age of the patients was 41.1 years. Average follow-up was 1.6 years. After all sutures were removed, results showed an average decrease in myopia of 13.24 diopters (D) (range 1.75 to 23.25) principally from corneal flattening and a small reduction in axial length. Average postoperative spherical equivalent was -2.17 D (range +1.50 to -7.25). The average postoperative astigmatism was 3.78 D (range 1.75 to 6.00). This study and a previous retrospective study suggest that the use of grafts 0.25 mm smaller than the opening, i.e., 7.50/7.75 mm, for penetrating keratoplasty in keratoconus is justified.

Adult↗
PubMed1995

Keratolenticuloplasty: arcuate keratotomy for cataract surgery and astigmatism.

Cataract surgery has evolved into a procedure in which pre-existing refractive errors can be corrected simultaneously to improve uncorrected visual acuity following surgery. This paper describes keratolenticuloplasty, a new technique of clear corneal arcuate keratotomy for cataract surgery that corrects pre-existing astigmatic errors at the time of cataract extraction. This technique uses topical anesthesia, a single pair of arcuate corneal incisions placed on the steepest axis of astigmatism, one-step capsulorhexis, hydrodissection, intercapsular phacoemulsification, and injection of an elastic intraocular lens within the capsular bag. The technique has been used in over 1,000 patients with follow-up of 24 months. Uncorrected visual acuity of 20/40 or better with no associated complications was achieved in 96% of patients.

Anesthesia, Local↗
PubMed1995

Correcting myopic astigmatism with an areal 193 nm excimer laser ablation.

A new system to correct symmetric bow-tie myopic astigmatism with the excimer laser using oval apertures for toric ablations is described. Initial results in two patients who had -5.0 and -5.5 diopters of astigmatism after surgery with six-months follow-up showed a reduction of up to 85% with a minimal axial error of two degrees.

Aged↗
PubMed1992

Effect of suture material on postoperative astigmatism.

Two hundred patients were enrolled in a randomized, prospective clinical trial comparing the use of 10-0 nylon, 10-0 polypropylene (Prolene), 11-0 polyester (Mersilene), and 10-0 polyethylene (Novafil) suture materials on the amount and decay curves of surgically induced astigmatism following intraocular lens (IOL) surgery. Patients with Mersilene and nylon sutures had the highest amounts of induced with-the-rule (WTR) cylinder (significantly more than Prolene) at one day after surgery. However, the WTR cylinder decayed rapidly for nylon during the first three months but more slowly for Mersilene because of its lack of stretchability. The Prolene group had the lowest level of induced WTR cylinder at one day, but against-the-rule (ATR) drift occurred, leaving cases with ATR astigmatism by a year. The nylon group had the second highest amount of induced WTR cylinder at one day, which had decayed to ATR cylinder by five months. Between one and two years postoperatively, the nylon group experienced a significant ATR shift. The amount of early induced WTR cylinder seemed to be related to the knot-tying technique and tissue gripping characteristics, whereas the shape of the decay curve was related to the material characteristics of the suture.

Adult↗
PubMed1995

Astigmatism after cataract surgery: nylon versus Mersilene. Five-year data.

This is a follow-up of a previous study that evaluated astigmatism after cataract surgery. In that study with a six-month follow-up, there was no statistically significant difference in astigmatism between eyes with nylon sutures and those with polyester fiber (Mersilene) sutures. This article reports the five-year data on this series of eyes.

Astigmatism↗
PubMed1995

Long-term astigmatic changes after phacoemulsification with single-stitch, horizontal suture closure.

We analyzed postoperative corneal astigmatism in 32 eyes followed for three years after small incision phacoemulsification with a 4 mm scleral tunnel incision and a single-stitch, horizontal suture technique. Sutures were left intact postoperatively. Mean surgically induced cylinder was 0.63 diopters (D) at one day postoperatively, -0.01 D at one year, and -0.07 D at three years. A significant number of eyes showed an initial shift toward with-the-rule astigmatism. At one year, the axis had nearly returned to preoperative orientation without further against-the-rule shift after three years. An uncorrected visual acuity of 20/40 or better was found in 43.8% of the patients at one week postoperatively and in 62.5% at one and three years. Best corrected visual acuity of 20/40 or better was found in 62.5%, 90.6%, and 93.7%, respectively.

Aged↗
PubMed1995

Astigmatic decay following small incision, self-sealing cataract surgery: one-year follow-up.

Twenty patients who had phacoemulsification using a small, self-sealing incision were evaluated one year after surgery for astigmatic changes. Keratometric analysis was performed using the EyeSys photokeratoscope, and data for the 3 mm corneal zone for each patient were recorded. Results were compared with those reported for the one-week and one-month postoperative periods. From one month to one year, a minimal amount of additional against-the-rule change in cylinder occurred. Because the range of changes was broad, it was difficult to predict the direction of astigmatic change (i.e., against the rule versus with the rule) that would occur over time for a given patient.

Aged↗
PubMed1993

One year postoperative astigmatic comparison of sutured and unsutured 4.0 mm scleral pocket incisions.

The postoperative astigmatic course of unsutured and sutured 4.0 mm scleral pocket incisions was followed for one year in a small pilot study. Initially, with-the-rule changes were noted only in the sutured group; eventually both groups demonstrated a small against-the-rule change that did not differ clinically or statistically. At one year after surgery the group without suture closure developed a -0.45 diopter (D) shift while a -0.34 D change was noted in the group closed with the anchor suture method. The unsutured group of eyes demonstrated physical stability as did those eyes with suture closure; no cases developed wound leaks, hypotony, or filtration blebs. Mean intraocular pressure was statistically unchanged from preoperative levels at one day after surgery for both groups. No case demonstrated postoperative endophthalmitis. Properly performed no-stitch corneal valve incisions provide physical and astigmatic stability that is indistinguishable from sutured incisions.

Astigmatism↗
PubMed1994

Astigmatic changes after cataract surgery with 5.1 mm and 3.5 mm sutureless incisions.

We evaluated postoperative keratometric astigmatism in 80 eyes that had phacoemulsification and intraocular lens implantation through sutureless corneal incisions. The eyes were separated into two groups based on the use of rigid ovoid or foldable silicone lenses inserted through 5.1 mm corneal lip incisions or 3.5 mm lip incisions, respectively. In the early postoperative period (one to three months), vector analysis showed less induced astigmatism in the 3.5 mm group than in the 5.1 mm group. Uncorrected visual acuity during the postoperative period was also better in the smaller incision group.

Adult↗
PubMed1991

Comparison of postoperative astigmatism with incisions of varying length closed with horizontal sutures and with no sutures.

Four groups of cataract patients having phacoemulsification with a scleral tunnel incision were studied. Three groups had incision lengths of 5.0, 6.0, and 6.5 mm closed with a single horizontal suture. The fourth group of patients had 5.0 mm incisions without suture closure. We found no statistical difference between these groups in the vector astigmatic changes over a four week period and subsequently over a 6.9 +/- 3.7 week period. The patients in all groups returned to their preoperative astigmatic values within one to two weeks within the statistical significance achieved in this study.

Astigmatism↗
PubMed1991

Use of small incisions to control induced astigmatism and inflammation following cataract surgery.

A series of 55 small incision (3 mm) silicone-implanted cataract cases closed with horizontal sutures and a concurrent series of 48 6 mm to 7 mm incision poly(methyl methacrylate)-implanted cases closed with radial incisions were compared retrospectively for surgically induced astigmatism. At two to three weeks after surgery, the mean surgically induced astigmatism in the poly(methyl methacrylate) group was more than twice as high as in the silicone group (2.27 D vs 1.07 D, P less than .01). In addition, a series of 41 small incision cases and a concurrent series of 61 cases with 6 mm to 7 mm incisions were compared for inflammation as measured by an FC-1000 laser flare/cell meter. The larger incision cases had significantly higher average cell counts at one day and one week postoperatively (P = .005 and P = .03, respectively) and had significantly higher average flare measurement at one day (P = .01) than the smaller incision cases.

Aged↗
PubMed1989

Paired transverse relaxing keratotomy: a combined technique for reducing astigmatism.

Phacoemulsification, posterior chamber intraocular lens implantation, and corneal relaxing incisions were performed as a combined procedure in 75 eyes with preexisting with-the-rule or against-the-rule astigmatism. The results of this study confirm that this technique can safely reduce preexisting low and moderate astigmatism with a greater likelihood of achieving excellent uncorrected visual acuity.

Astigmatism↗
PubMed1989

Correction of preexisting astigmatism at the time of small incision cataract surgery.

To reduce preexisting astigmatism in patients having cataract surgery, paired keratotomy incisions of graded lengths were performed at the time of cataract extraction. Small incisions, made possible by foldable silicone implants, were used to make the correction more accurate. The results obtained in 48 patients are analyzed. It appears that this technique is safe, quick, and helpful in reducing preexisting astigmatism.

Astigmatism↗