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At least 1,153 records · Page 64Linked to original sources
PubMed2001

Customized ablation for asymmetrical corneal astigmatism.

PURPOSE: To evaluate laser in situ keratomileusis (LASIK) cases in which a customized ablation assisted by corneal topography was performed. SETTING: Instituto de la Visión, Buenos Aires, Argentina. METHODS: The study group comprised 23 cases with asymmetrical corneas; 17 had myopia and 6, hyperopia. Visual acuity, spherical equivalent (SE), and cylinder vectorial change measurements, along with keratometry and corneal topography, were performed in all cases preoperatively and postoperatively. RESULTS: In the myopic cases, the mean preoperative SE was -4.92 diopters (D) +/- 2.46 (SD); it was -0.38 +/- 0.66 D after a mean follow-up of 4.41 +/- 2.32 months. In the hyperopic cases, the preoperative SE was +3.54 +/- 1.57 D; it was +0.33 +/- 0.50 D after a mean follow-up of 3.42 +/- 3.23 months. Cylinder vectorial change, visual acuity, and the number of visual acuity lines gained or lost were also evaluated in both groups. CONCLUSION: Although some features of our algorithm for corneal-topography-assisted customized ablations should be modified, the results of our treatment of cases with asymmetrical astigmatism were encouraging.

Adult↗
PubMed2003

Corneal ectasia detected 32 months after LASIK for correction of myopia and asymmetric astigmatism.

We report a case of corneal ectasia detected 32 months after laser in situ keratomileusis (LASIK) for correction of -4.25 diopters (D) of myopia associated with -2.00 D of regular but slight asymmetric astigmatism. The patient retained stable visual acuity for 15 months postoperatively. The preoperative corneal thickness was 540 microm, and the postablation untouched stroma was assumed to be 290 microm. Although a rare complication of LASIK, corneal ectasia can occur, and there is no consensus regarding how much stroma should be left intact to avoid it. Until we have a better understanding of corneal strength, we think surface photorefractive keratectomy or laser-assisted subepithelial keratectomy ablations should be considered instead of LASIK in borderline cases.

Astigmatism↗
PubMed2003

Implantation of a custom intraocular lens with a 30-diopter torus for the correction of high astigmatism after penetrating keratoplasty.

We present a 62-year-old woman who had implantation of an intraocular lens (IOL) with a torus of 30.0 diopters (D) in an eye after penetrating keratoplasty. The patient presented with cataract and a best corrected visual acuity of 20/400. Penetrating keratoplasty was performed in 1975 because of decompensated keratoconus. With a clear but inferiorly decentered corneal graft, visual acuity was limited because of keratoplasty-related high corneal astigmatism of 22.5@156 that could not be successfully treated with spectacles or contact lenses. A custom toric IOL with -30.0 D of cylindrical power was implanted in the capsular bag via a sclerocorneal tunnel incision. Additionally, a spherical IOL of -15.0 D sphere was implanted in the ciliary sulcus. Six months after implantation, the IOLs were still well centered and the uncorrected visual acuity was 20/60.

Astigmatism↗
PubMed1993

Spontaneous fistula formation as a complication of relaxing incisions with suture placement for postkeratoplasty high astigmatism.

A 39-year-old man had a corneal relaxing incision with corneal compression suture placement to correct more than 10 diopters of corneal astigmatism. A permanent fistula formed from the compression suture, resulting in a localized corneal pocket of aqueous that broke through the surface. The aqueous drained into the tear film, requiring major surgical repair.

Adult↗
PubMed1994

Astigmatic decay following small incision, self-sealing cataract surgery.

A series of 22 consecutive patients had phacoemulsification using a small (3.5 to 4.0 mm), self-sealing incision. Preoperative keratometric analysis was performed using the EyeSys photokeratoscope. Results of this analysis were compared with keratometric data obtained at one week and at one month postoperatively. These comparisons were evaluated for surgery-induced cylinder and astigmatic decay at the 3, 5, and 7 mm corneal zones. At one week postoperatively, there was only mild against-the-rule change in cylinder at each corneal zone, and these changes showed minimal decay at the one month follow-up visit.

Aged↗
PubMed1995

Correcting simple myopic astigmatism with the excimer laser.

For one year we followed 46 eyes that had photoastigmatic refractive keratectomy with an excimer laser to correct simple myopic astigmatism. Mean preoperative cylinder was -2.50 +/- 0.70 diopters (D); mean preoperative best corrected visual acuity was 20/25 +/- 1 Snellen line. Mean postoperative refraction one year after surgery was -0.5 +/- 0.2, and mean uncorrected visual acuity was 20/25 +/- 1 Snellen line. In all eyes, the final axis of the residual cylinder was +/- 5 degrees around the preoperative axis. Uncorrected visual acuity equaled best preoperative acuity in 24 eyes. Eight eyes gained one line of best corrected visual acuity, six gained more than one line, and eight lost one line. No patient lost more than one line of uncorrected visual acuity. No significant complications such as haze, halos, eccentric ablation, or hypercorrection were observed.

Adolescent↗
PubMed1995

Effect of age and astigmatism on the AMO Array multifocal intraocular lens.

Multifocal intraocular lenses (MIOLs) have been designed to provide better uncorrected near visual acuity than monofocal IOLs. However, the increase in depth of focus is combined with a significant decrease in contrast sensitivity and glare. We implanted a new zonal-progressive MIOL (AMO Array) in 31 eyes of 25 patients whose mean age was 60.8 +/- 13.5 years. At 12.1 +/- 2.4 months postoperatively, the uncorrected visual acuity averaged 0.56 +/- 0.09 (20/32) for distance and 0.54 +/- 0.12 (20/40) for near focus. Seventy-five percent of patients achieved a best corrected distance visual acuity of > or = 0.9 (20/22). With distance correction only, mean near visual acuity was 0.72 +/- 0.17 (20/25). Best corrected near acuity reached 0.89 +/- 0.11 (20/22), requiring an additional near add of +1.0 to +2.0 diopters (D). We observed an age-dependent difference in the depth of focus. In younger patients (46 +/- 6 years), the pseudoaccommodation range was 6.25 D; acuity attained was > or = 0.4 (20/50). In older patients (71 +/- 7 years), visual acuity at the near focus was substantially reduced (two lines). Regan contrast sensitivity was lower for MIOL patients at all contrast levels, but the difference was statistically significant only at very low contrast (11%). Contrast sensitivity and glare were dependent on the patient's age but did not change with the amount of postoperative astigmatism. Younger patients were very satisfied with the results of MIOL implantation, and the small loss of contrast sensitivity was counterbalanced by the advantage of improved depth of focus and uncorrected near visual acuity.

Accommodation, Ocular↗
PubMed1994

Toric intraocular lenses: correcting astigmatism while controlling axis shift.

We evaluated the efficacy of toric intraocular lenses (IOLs) implanted in the eyes of 47 patients who had preoperative against-the -rule astigmatism. The lenses, which had a cylinder power of 2.00 diopters (D) (n = 26) or 3.00 D (n = 21), were implanted through a 5.7 mm incision after cataract extraction by phacoemulsification. Best corrected visual acuity three months postoperatively was 20/25 or better in 77% of eyes. The 3.00 D IOLs resulted in better correction than the 2.00 D IOLs when the axis shift of the lens was less than 30 degrees. A negative effect occurred in some eyes in which the lens axis rotated more than 30 degrees. The maximum acceptable axis shift seems to be less than 30 degrees.

Aged↗
PubMed1993

Topographic analysis of early changes in corneal astigmatism after cataract surgery.

Using the Topographic Modeling System (TMS), we studied the early changes in anterior corneal curvature following cataract surgery. Thirty patients who had planned extracapsular cataract extraction (p-ECCE) or phacoemulsification were evaluated with TMS at three days, and one, two, three, and five weeks postoperatively. After p-ECCE, the upper part of the cornea which corresponded to the wound and the lower cornea markedly steepened and showed a bow-tie pattern of astigmatism. Eight (57%) of 14 cases showed little reduction in the corneal steepening at five weeks postoperatively. In five cases (36%) the steepening in the lower cornea was less than the minimal change in the upper cornea. After phacoemulsification, corneal steepening was much less than it was after p-ECCE; three cases (17%) showed almost no surgically induced alteration of the cornea. In eight phacoemulsification cases (61%), postoperative corneal steepening decreased rapidly and the corneal shape recovered within five weeks. Our topographic analysis clearly demonstrated that a smaller wound in phacoemulsification surgery produced less corneal steepening and stabilized more rapidly than a larger wound in p-ECCE.

Aged↗
PubMed1992

Effect of small incision intraocular lens surgery on postoperative inflammation and astigmatism. A study of the AMO SI-18NB small incision lens.

A single center, single surgeon, randomized, prospective clinical trial was performed comparing the effectiveness of small (3.5 mm to 4.0 mm) incision intraocular lens surgery and a larger (6.0 mm) incision in improving uncorrected visual acuity and reducing post-operative inflammation and surgically induced astigmatism. One hundred twelve eligible unilateral cases were randomized to receive a 3.5 mm to 4.0 mm incision with implantation of an Allergan Medical Optics three-piece SI-18NB silicone lens (56 cases) or a 6.0 mm incision with implantation of a three-piece biconvex poly(methyl methacrylate) lens (56 cases). At one day after surgery, significantly (P less than .01) more patients with 3.5 mm incisions had 20/40 or better uncorrected visual acuity than patients with 6.0 mm incisions (45% vs 20%). Forty percent of patients with 6.0 mm incisions vs 14% of patients with 3.5 mm incisions had visual acuities of 20/100 or worse. At one day after surgery, the larger incision group had significantly higher (P less than .01) mean keratometric cylinder (2.28 diopters vs 1.28 diopters in the small incision group). The two groups were comparable by three months. Laser flare/cell meter measurements were taken for each group but showed no significant differences in mean flare or cell measurements between the groups.

Aged↗
PubMed1991

Astigmatically neutral sutured small incision.

The desire for rapid visual rehabilitation following phacoemulsification for cataract and intraocular lens implantation has stimulated a quest for an "astigmatically neutral" incision. We have evaluated an underemphasized aspect of wound closure technique for a small incision wound (5.1 mm). The essential element of the technique is reinflation of the anterior chamber after a nylon shoelace suture is placed and tied once but before the knot is finally secured. The resulting changes in corneal curvature are analyzed. Results are presented at two weeks and six weeks postoperatively. We have termed this technique post-suture inflation.

Astigmatism↗
PubMed1986

Temporal incision for astigmatic control in secondary implantation.

A small group of aphakic patients having secondary lens implantation had keratometry performed before and at four months after surgery. A temporally oriented scleral pocket incision and closure technique was used to place the incision in fresh tissue and in the steepest corneal meridian. The results demonstrated an overall reduction of corneal cylinder from modest flattening of the surgical axis. Placement of the scleral pocket incision in fresh temporal tissue for secondary lens implantation affords a watertight stable wound with astigmatic control.

Astigmatism↗
PubMed1989

Modified pocket incision: a simplified technique for astigmatism control and wound closure.

Advantages of small incision cataract surgery are widely known whether performed with phacoemulsification or manual fragmentation (phacofracture). A modified pocket incision technique that allows predictable astigmatism control without reliance on expensive intraoperative keratometers is described. This technique requires less dissection than the pocket incision and is less likely to bleed.

Astigmatism↗
PubMed1997

Predictability of excimer laser treatment of myopia and astigmatism by the VISX Twenty-Twenty. Melbourne Excimer Laser Group.

BACKGROUND: To determine the predictability of excimer laser photorefractive keratectomy (PRK) to correct myopia, astigmatism, or both between -1.00 and -19.00 diopters (D). SETTING: Royal Victorian Eye and Ear Hospital, East Melbourne, Australia. METHODS: This study comprised 1218 consecutive eyes treated with a VISX Twenty-Twenty excimer laser and followed prospectively for 12 months. Low myopia was treated with one ablation zone (6.0 mm), high myopia with two ablation zones (5.0 and 6.0 mm), and extreme myopia with three ablation zones (4.5, 5.0, and 6.0 mm). Maximum spherical treatment was 15.00 D at the corneal plane. Data were analyzed to determine the predictability of the postoperative outcomes by preoperative refraction. RESULTS: Nine hundred eighty eyes (80.5%) were available for the 12 month follow-up. The predictability of refraction and uncorrected and best corrected visual acuities progressively decreased with increasing myopia, although a comparable percentage of spherical correction was achieved at each diopter of myopia. The likelihood of losing lines of best corrected visual acuity and corneal haze increased with increasing myopia. CONCLUSION: These data can be used to counsel patients of likely outcomes of excimer laser PRK to correct myopia.

Adult↗
PubMedDate not supplied

Endophthalmitis after astigmatic myopic laser in situ keratomileusis.

A 36-year-old woman had uneventful astigmatic myopic laser in situ keratomileusis (LASIK) to correct -12.00 -1.50 x 70. Three days later, she developed a corneal abscess, hypopyon, and an intense vitreous cellular reaction-endophthalmitis. The patient was immediately given intravenous ciprofloxacin and topical vancomycin and ceftazidime. The infecting organism was Streptococcus pneumoniae. One day after therapy was instituted, the hypopyon resolved. Seven months later, best corrected visual acuity was 20/25 and refractive error, -4.00 diopters. A stromal scar (grade 2 haze) was causing a slight reduction in acuity. Endophthalmitis after LASIK, if treated promptly, need not lead to a permanent reduction in visual acuity.

Administration, Topical↗
PubMed1998

Keratitis complicated by endophthalmitis 3 years after astigmatic keratotomy.

Endophthalmitis after keratotomy is rare and usually occurs soon after surgery. A 56-year-old woman with mild dry-eye symptoms developed keratitis complicated by endophthalmitis 3 years after astigmatic keratotomy (AK). The keratitis lasted for less than 1 day in the upper keratotomy incision. Corneal cultures yielded. Pseudomonas aeruginosa. Keratitis progressed to endophthalmitis 1 day after the detection of keratitis. The inflammation was controlled with intravitreal, subconjunctival, topical, and systemic antibiotics. This case demonstrates the potential risk of endophthalmitis developing very shortly after late keratitis of AK incisions. Vigorous early treatment and close follow-up seem justifiable in any keratitis associated with a keratotomy incision.

Anti-Bacterial Agents↗
PubMed1999

Early- versus late-onset infectious keratitis after radial and astigmatic keratotomy: clinical spectrum in a referral practice.

PURPOSE: To compare the clinical characteristics of early- versus late-onset keratitis after radial keratotomy (RK) and astigmatic keratotomy (AK). SETTING: Referral subspecialty practice. METHODS: This retrospective review comprised 19 patients with infectious keratitis after RK and AK. Early- versus late-onset groups were analyzed for predisposing conditions; infiltrate location, size, and depth; microbiologic data; and final visual outcome. RESULTS: Ten patients in the early-onset group developed keratitis within a mean of 7.4 days after surgery (range 3 to 14 days). Nine patients in the late-onset group developed keratitis a mean of 5.4 years after surgery (range 1.5 to 15.0 years). Staphylococcus aureus was the predominant organism in the early-onset group and Pseudomonas aeruginosa in the late-onset group. In the early-onset group, most infiltrates occurred in the paracentral aspect of the RK incision and extended to the middle or posterior stroma. In the late-onset group, most infiltrates occurred in the peripheral portion of the RK incision and were localized to the superficial stroma. A hypopyon was present in 7 of 10 ulcers in the early group and in 1 of 9 in the late group. Two patients in the early group developed endophthalmitis. Most patients in the late-onset group had incisional pseudocysts; 2 had other risk factors for keratitis. Final visual acuity was 20/40 or better in 7 of 10 patients in the early group and in 8 of 9 patients in the late group. CONCLUSIONS: Early-onset corneal ulcers after incisional refractive keratotomy were usually paracentral and deep, whereas late-onset ulcers were usually peripheral and superficial. Despite the predominance of Staphylococcus and Pseudomonas in the early- and late-onset groups, respectively, a variety of organisms may be responsible for infections in keratotomy incisions.

Adult↗
PubMed1987

The correction of post-keratoplasty astigmatism.

The results of refractive surgery for post-keratoplasty astigmatism in 41 eyes are presented. Thirty-nine eyes regained a functional vision of 6/12 or better. Relieving incisions and compression sutures are the most useful procedures, but more than one operation may be required.

Adolescent↗