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PubMedDate not supplied

Astigmatic refractive errors associated with limbal dermoids.

A retrospective review of 17 patients with limbal dermoids revealed that 13 (76%) had astigmatism of 1.00 diopter or greater in the involved eye. In all but one patient, the minus cylinder axis of the astigmatism coincided with the location of the dermoid. Thirteen patients had surgery to remove the dermoids at ages ranging from 8 months to 15 years. The preoperative astigmatism persisted postoperatively with little change in its orientation or amount regardless of age at the time of surgery.

Adolescent↗
PubMedDate not supplied

The effect of spherical photorefractive keratectomy on myopic astigmatism.

The aim of this report is to present the effects of spherical photorefractive keratectomy (PRK) by excimer laser on myopic astigmatism. Spherical PRK was performed in 96 eyes with myopia associated with astigmatism of between 0.75 and 2.00 diopters (D) using the Summit excimer laser. The reduction both in sphere and in cylinder was found to be highly statistically significant (P < 0.0001 for both). The mean reduction of cylinder was 46%. Astigmatic error of less than 2.00 D can be corrected significantly by spherical PRK.

Adult↗
PubMedDate not supplied

Holmium:YAG laser thermokeratoplasty for correction of astigmatism.

The effect of astigmatic Holmium:YAG laser thermokeratoplasty in three eyes with previous surgery (extracapsular cataract extraction, penetrating keratoplasty and failed extracapsular cataract extractionntric photorefractive keratectomy 1 to 7 years previously) was evaluated. In the extracapsular cataract extraction eye the effect of a four-spot laser thermokeratoplasty regressed to almost zero within 1 week. In the penetrating keratoplasty and photorefractive keratectomy eyes an eight-spot laser thermokeratoplasty produced an enormous overshoot in astigmatic power of about 15.00 diopters (D), decreasing within 5 months to almost zero in the eye with penetrating keratoplasty and to 4.00 to 5.00 D corneal astigmatic power in the photorefractive keratectomy eye after 8 months of observation.

Adult↗
PubMedDate not supplied

Retrephination keratoplasty for high astigmatism after penetrating keratoplasty.

PURPOSE: We report preliminary results of a new procedure for correcting high astigmatism after penetrating keratoplasty. METHODS: The procedure entails full-thickness trephination along the original donor-recipient junction with careful suturing in a combined interrupted and running fashion. Four eyes of four patients with severe astigmatism and myopia after penetrating keratoplasty underwent the procedure. RESULTS: High preoperative cylinder ranging from 4.50 to 16.00 D (mean 9.00 D) was reduced to 0.50 to 3.50 D (mean 1.90 D) at the last examination (between 3 to 6 months). Spherical equivalent myopia ranging from -2.00 to -10.25 D (mean -4.90 D) was essentially unchanged at plano to -9.00 D (-4.70 D) at the last examination. Overall, there was a mean refractive cylinder reduction of 7.10 D (79%). CONCLUSION: Retrephination after penetrating keratoplasty appears to be an acceptable alternative for correcting high astigmatism, and had only a small effect on the level of myopia.

Astigmatism↗
PubMedDate not supplied

Laser in situ keratomileusis for astigmatism and myopia after penetrating keratoplasty.

BACKGROUND: After penetrating keratoplasty, many patients have high ametropia, which is difficult to correct with contact lenses. We used excimer laser in situ keratomileusis (LASIK) on four eyes of four consecutive patients that had previous penetrating keratoplasty in an attempt to correct myopia and astigmatism. METHODS: We used an automated microkeratome to make a lamellar flap and a Chiron Technolas 193-nm argon fluoride excimer laser. The laser was programmed for the desired myopic and astigmatic correction and a multizone ablation was applied to the central stroma. The corneal flap was placed back into position without sutures. RESULTS: After surgery, all corneas remained clear with no dislocation of the flap, and the edge of the flap was difficult to visualize after a few days. The average preoperative spherical equivalent was -10.75 diopters (D) (range -5.00 to -14.25 D) which decreased to an average -2.37 D (range -0.75 to -5.00 D) at a mean follow-up of 7 months (range 6 to 10.5 mos). The average preoperative astigmatism was -2.87 D (range -1.00 to -5.00 D) which changed to an average of -3.50 D. Uncorrected visual acuity was improved and spectacle-corrected visual acuity was preserved without changes. CONCLUSION: LASIK can effectively reduce myopia after penetrating keratoplasty.

Adult↗
PubMedDate not supplied

Laser in situ keratomileusis for low myopia and astigmatism with a scanning spot excimer laser.

PURPOSE: To determine the efficacy, predictability, safety, and short term stability of laser in situ keratomileusis (LASIK) in treating patients with low myopia and astigmatism using the Chiron Technolas Keracor 117 PlanoScan excimer laser. METHODS: We retrospectively studied the results of our initial 83 eyes with myopia ranging from -1.13 to -7.25 diopters (D) and astigmatism of no more than 4.00 D that underwent LASIK with the Chiron Technolas Keracor 117 PlanoScan. Follow-up was at 1 day, 1 month, and 3 to 6 months. RESULTS: Mean baseline spherical equivalent refraction was -3.54 +/- 1.41 D and cylinder -1.64 +/- 1.14 D. Mean postoperative spherical equivalent refraction was -0.52 +/- 0.50 D at 1 month and -0.65 +/- 0.62 D at 3 to 6 months; mean postoperative refractive cylinder was -0.45 +/- 0.54 D at 1 month and -0.50 +/- 0.63 D at 3 to 6 months. Fifty-three percent (44 eyes) achieved a spherical equivalent refraction within +/- 0.50 D and 81% (67 eyes) within +/- 1.00 D of emmetropia at the last examination. Fifty-seven percent (47 eyes) achieved a refractive cylinder of < or = 0.50 D, and 27% (22 eyes) had an undercorrection of their refractive cylinder at the last examination. An uncorrected visual acuity of 20/40 or better was achieved in 86% (71 eyes) of patients on postoperative day one, in 81% (67 eyes) at 1 month, and in 76% (63 eyes) at 3 to 6 months. Twenty-eight percent (23 eyes) saw 20/20 or better uncorrected at the last visit (41% [34 eyes] had a baseline spectacle-corrected visual acuity of 20/20). There was no statistically significant difference in the refractions or uncorrected visual acuities between the different postoperative examinations. No eye experienced a loss of spectacle-corrected visual acuity of more than one line at the last examination. CONCLUSION: LASIK with the Chiron PlanoScan excimer laser appears to be an effective, safe, and reasonably predictable means to reduce low myopia and astigmatism. Adjustment of computer algorithms is needed to decrease the number of under-corrections.

Adult↗
PubMedDate not supplied

Laser in situ keratomileusis for myopia from -5.50 to -11.50 diopters with astigmatism.

PURPOSE: To determine the efficacy, predictability, safety, and short-term stability of laser in situ keratomileusis (LASIK) in treating patients with high myopia and astigmatism. METHODS: We retrospectively studied the results of our initial 119 eyes with myopia ranging from -5.50 to -11.50 D and astigmatism less than 4.00 D that underwent LASIK with the Nidek EC-5000 excimer laser. Follow-up was at 1 day, 1 month, and 3 to 6 months; follow-up was 71% (84 eyes) at the 3 to 6 month visit (average 4.5 months). RESULTS: Of the 84 eyes with 3 to 6 months of follow-up, mean baseline spherical equivalent refraction was -8.62 +/- 1.27 D and mean cylinder was -1.84 +/- 1.02 D. Mean postoperative spherical equivalent refraction at the last examination was -0.61 +/- 0.84 D and mean cylinder was -0.39 +/- 0.38 D, with 83% (70 eyes) achieving a spherical equivalent refraction within +/-1.00 D of emmetropia, and 56% (47 eyes) within +/-0.50 D. Mean regression of spherical equivalent from 1 day to 1 month was less than -0.50 D and refractions were stable between 1 month and 3 to 6 months. An uncorrected visual acuity of 20/40 or better was noted in 84% (71 eyes) of these eyes on day 1 after surgery, in 75% (63 eyes) at 1 month, and in 77% (65 eyes) at 3 to 6 months. Twenty-two percent (18 eyes) of these eyes achieved 20/20 or better uncorrected visual acuity at 3 to 6 months; only 17% (14 eyes) had 20/20 or better spectacle-corrected visual acuity before surgery. One patient lost two or more lines of spectacle-corrected visual acuity at the last examination due to epidemic keratoconjunctivitis. CONCLUSION: LASIK with the Nidek EC-5000 excimer laser appears to be an effective and safe means for treating patients with high myopia and astigmatism. Studies with longer follow-up will help evaluate the long-term stability of the procedure and the possibility of late complications.

Adolescent↗
PubMedDate not supplied

Photoastigmatic refractive keratectomy for correction of astigmatism after keratoplasty.

BACKGROUND: The efficacy and safety of photoastigmatic refractive keratectomy (PARK) to correct astigmatism after keratoplasty was evaluated. METHODS: PARK was performed using the Nidek EC-5000 excimer laser in 10 eyes of 10 patients (mean age: 49.5 +/- 11.5 years) with astigmatism after keratoplasty. RESULTS: The refractive cylinder decreased from 5.80 to 3.20 D, whereas at 6 months, topographic cylinder decreased from 7.40 to 5.90 D post-operatively. Five eyes (50%) had uncorrected visual acuity of 20/60 or better at 3 months. Stromal haze increased from 3 to 6 months postoperatively, and at 6 months, 5 eyes (50%) had a haze score of greater than or equal to 2.0. CONCLUSION: PARK is a moderately effective method of correcting astigmatism after keratoplasty.

Astigmatism↗
PubMedDate not supplied

Intraocular lens implantation and laser in situ keratomileusis (bioptics) to correct high myopia and hyperopia with astigmatism.

PURPOSE: To analyze the refractive outcome of moderate to high myopic and hyperopic patients with astigmatism who underwent programmed refractive surgery; first lens phacoemulsification with intraocular lens implantation and 3 months later, laser in situ keratomileusis (LASIK). METHODS: Four men and eight women (22 eyes) with a mean age 47.3 years (range, 38 to 75 yr), and an average spherical equivalent refraction of -11.76 D and +5.22 D and (range, -17.50 to +8.50 D) underwent two refractive procedures. First, phacoemulsification of the lens with a self-sealing incision through clear cornea on the steepest topographic axis and implant of a monofocal intraocular lens in the bag was performed by two experienced surgeons. Second, LASIK was performed with the Nidek EC-5000 excimer laser and the Moria LSK-One microkeratome, by one surgeon. Eyes were divided into two different groups. In the first group, the IOL implanted was calculated to leave the eye slightly myopic, with final correction to be achieved with LASIK. In the second group, the IOL implanted was calculated to achieve emmetropia, correcting any residual refractive error with the laser. RESULTS: After surgery, mean spherical equivalent refraction was +0.26 D (range, -0.375 to +1.50 D). Predictability of refractive outcome: 0 to -1.00 D, 63.63%; +0.25 to +1.00 D, 31.80%; +1.25 to +2.00 D, 4.54%. Mean residual refractive astigmatism was 0.30 D (range, 0 to 1.50 D). Uncorrected visual acuity of 20/20 or better was achieved in 18.3% of eyes; 20/40 or better in 81.8%. No eyes lost two or more Snellen lines of visual acuity and no adverse effects were observed. CONCLUSIONS: Bioptics (phacoemulsification with IOL implantation followed 3 months later by LASIK with the Nidek EC-5000 excimer laser) for correction of moderate to high myopia and hyperopia, with astigmatism, enabled us to treat the total refractive error and adjust final outcomes.

Adult↗
PubMedDate not supplied

Laser in situ keratomileusis for hyperopia and hyperopic astigmatism with the Nidek EC-5000 Excimer laser.

PURPOSE: We evaluated the efficacy, predictability, stability, and safety of laser in situ keratomileusis (LASIK) for hyperopia and hyperopic astigmatism. METHODS: A retrospective study was performed for 92 eyes of 62 consecutive patients to evaluate uncorrected (UCVA) and best spectacle-corrected visual acuity (BSCVA) and manifest refraction before and 3 and 6 months after LASIK (Moria LSK-ONE microkeratome, Nidek EC-5000 excimer laser). Eyes were divided into groups: Group 1 (low hyperopia) for spherical correction of +1.00 to +3.00 D (22 eyes), Group 2 (low hyperopic astigmatism) for toric correction with spherical equivalent refraction of +1.00 to +3.00 D (18 eyes), Group 3 (moderate hyperopia) for spherical correction of +3.25 to +6.00 D (10 eyes), and Group 4 (moderate hyperopic astigmatism) for toric correction with spherical equivalent refraction between +3.25 and +6.00 D (18 eyes). RESULTS: At 3 and 6 months after LASIK, 68 eyes (73.9%) were available for follow-up examination. Percentage of eyes with a spherical equivalent refraction within +/-0.50 D of emmetropia for Group 1 was 54.5% (12 eyes); Group 2, 50% (9 eyes); Group 3, 40% (4 eyes), and Group 4, 38.8% (7 eyes). UCVA > or =20/20 in Group 1 was 14% and in Groups 2, 3, and 4, 0%. One eye (5.5%) lost two lines of BSCVA. CONCLUSION: LASIK with the Moria LSK-ONE microkeratome and the Nidek EC-5000 excimer laser reduced low and moderate hyperopia and was within +/-0.50 D of target outcome in approximately 50% of eyes. Undercorrection was evident in all groups. The procedure was safe.

Adult↗
PubMedDate not supplied

Soft contact lenses for irregular astigmatism after laser in situ keratomileusis.

PURPOSE: To investigate soft contact lenses for managing irregular astigmatism after laser in situ keratomileusis (LASIK). The prevailing notion has been that soft contacts conform to corneal surface irregularities and have a limited role for managing LASIK-induced irregular astigmatism. METHODS: A 41-year-old man with bilateral central steep islands following LASIK had best spectacle-corrected visual acuity of 20/40(+1) in the right eye and 20/70+2 in the left eye, despite 20/20 acuity in each eye with rigid contact lenses. Three soft lenses made of etafilcon A (58% H2O) in different center thicknesses were placed sequentially on each eye. All lenses were -2.00 D sphere, in the flatter of the two available base curves. With each lens, corneal topography, spherical over-refraction, and the resulting visual acuity were recorded. RESULTS: In all instances, corneal topography showed reduced surface irregularity although at least some irregularity still transmitted through the lenses. Each spherical over-refraction gave better visual acuity than the corresponding best spectacle-corrected visual acuity. The right eye achieved 20/20 with the thickest lens and spherical over-refraction. The left eye achieved 20/25 with the lens of intermediate thickness and spherical overrefraction. The patient reported functional vision and good comfort with these lenses. CONCLUSIONS: Disposable soft contact lenses can modestly mask irregular astigmatism caused by excimer laser ablation.

Adult↗
PubMedDate not supplied

Laser in situ keratomileusus for mixed and simple myopic astigmatism with the Nidek EC-5000 Laser.

PURPOSE: To evaluate the visual and refractive results of laser in situ keratomileusis (LASIK) for mixed and simple myopic astigmatism using bitoric ablation. METHODS: A retrospective study was performed in 65 eyes of 38 consecutive patients to evaluate uncorrected (UCVA) and best spectacle-corrected visual acuity (BSCVA) and cyclopegic and manifest refraction, before and 3 and 6 months after LASIK (Moria LSK-ONE microkeratome, Nidek EC-5000 excimer laser). RESULTS: At 3 and 6 months after LASIK, 40 eyes of 24 patients (64.5%) were available for follow-up examination. Mean age was 25.9 +/- 6.6 years (range 18 to 43 yr). Mean preoperative manifest spherical equivalent refraction was -1.40 +/- 0.80 D (range -3.80 to +0.50 D) mean preoperative cylinder was -3.30 +/- 1.30 D (range -1.00 to -6.00 D). At 6 months follow-up, mean manifest spherical equivalent refraction was +0.30 +/- 0.46 D (range -0.38 to +1.88 D), mean cylinder was -0.73 +/- 0.61 D (range -2.25 to 0 D). There was a 77.8% decrease in astigmatism magnitude. According to vector analysis, mean achieved vector magnitude was 80% of intended. Fifty percent (20 eyes) had a cylinder within +/- 0.50 D of emmetropia. Twenty-three eyes (57.5%) had a spherical component within +/- 0.50 D. Eighty-five percent (34 eyes) had postoperative UCVA of 20/40 or better. Ten percent (four eyes) lost two lines of Snellen BSCVA, whereas 35% (14 eyes) gained one or more lines. CONCLUSIONS: Bitoric LASIK with the Moria LSK-ONE microkeratome and Nidek EC-5000 excimer laser was effective and safe for the reduction of cylinder in mixed and simple myopic astigmatism. Moderate undercorrection of the cylinder was evident.

Adolescent↗
PubMedDate not supplied

Conductive keratoplasty to correct hyperopic astigmatism.

PURPOSE: To evaluate the efficacy of conductive keratoplasty in the treatment of pre-existing and surgically induced hyperopic astigmatism. METHODS: In this prospective, noncomparative case series, four eyes of four subjects, two female and two male (age 25 to 47 yr) were treated for hyperopia (up to +5.50 D) and hyperopic astigmatism (up to +5.75 D) with the Refractec ViewPoint conductive keratoplasty system. The follow-up period was 6 months. Uncorrected and spectacle-corrected visual acuity, manifest and cycloplegic refraction, and videokeratographs were obtained before and after surgery. We treated two patients who had already had LASIK, one of them with a decentered ablation and the other with flap striae, one patient after PRK, and one patient with keratoconus. RESULTS: No complications were observed. No eye lost lines of spectacle-corrected visual acuity. All eyes showed improvement of uncorrected visual acuity of 3 or more lines. Videokeratographs demonstrated improved centration and reduction in keratometric power readings. Each eye was analyzed separately, including a comparative analysis of the proposed nomograms and quality of vision after surgery. CONCLUSIONS: Conductive keratoplasty may be a minimally invasive solution for patients with irregular hyperopic astigmatism, offering improved quality of vision in instances of flap striae by tightening the central cornea.

Adult↗
PubMed2004

[Arcuate keratotomy to correct residual astigmatism after stromal herpetic keratitis].

CLINICAL CASE: A woman with a history of recurrent herpes simplex keratitis in the left eye developed endothelial and stromal keratitis after cataract extraction. Because of the resultant corneal distortion a high regular astigmatism appeared. An arcuate keratotomy was performed to improve her visual acuity. DISCUSSION: Corneal astigmatism can appear after herpetic keratitis. An arcuate keratotomy was effective in this case to decrease astigmatism and improve her vision. Keratitis reactivation is possible so antiviral prophylaxis is advisable. Our good results show that arcuate keratotomy can be a useful technique for these patients.

Acyclovir↗
PubMed1997

[Photorefractive keratectomy to correct myopic astigmatism].

The VISX 20/20 excimer laser was used to treat 260 eyes with myopia and myopic astigmatism of 166 patients. All patients were followed up for one year. The diopter of preoperative astigmatism was from -0.25-(- 4.00 D (-1.00 +/- 0.62 D). The diopter was lowered to -0.07 +/- 0.40 D at 6 months postoperatively (P < 0.05) and -0.06 +/- 0.39 D at 12 months postoperatively (P < 0.01). Photorefractive keratectomy (PRK) is effective and safe for myopic astigmatism.

Adolescent↗
PubMed2000

Management of irregular astigmatism with rigid gas permeable contact lenses.

PURPOSE: The purpose of this study was to measure improvement in best corrected visual acuity with rigid gas permeable (RGP) contact lenses compared to best corrected spectacle visual acuity for patients with irregular astigmatism. METHODS: We compared best corrected visual acuity obtained with spectacle correction to best corrected visual acuity obtained with rigid gas permeable contact lenses for forty-eight eyes of 29 patients with irregular astigmatism. RESULTS: Patients with 20/20 spectacle visual acuity achieved, on average, no improvement in visual acuity with RGP contact lenses. Patients with 20/25-20/30 spectacle visual acuity achieved a one line average improvement. Patients with 20/40 spectacle visual acuity achieved a two line average improvement. Patients with 20/50-20/200 spectacle visual acuity achieved a four line average improvement and patients with spectacle visual acuity of 20/400, a six line average improvement. CONCLUSIONS: RGP contact lenses can provide a significant improvement in visual acuity compared to spectacle correction for patients with irregular astigmatism.

Astigmatism↗
PubMedDate not supplied

[Peripheral chorioretinal dystrophy and astigmatism of myopic eyes: statistical evaluation, relationship and clinical significance].

A clinically significant relationship between the myopic eye astigmatism and manifestation of peripheral chorioretinal dystrophies in them in young patients is described. A simple and effective method for predicting peripheral vascular chorioretinal dystrophies in myopic patients is proposed, based on the presence and severity of astigmatism. The incidence of various dystrophies in spherical and aspherical myopia is 32 and 78%, respectively. Dystrophies fraught with retinal detachment occur three times more often in astigmatic eyes, which are characterized by a more flat lens.

Adolescent↗