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ABSTRACT: This retrospective observational case series describes a clinical syndrome in laser refractive surgery. Five eyes of 4 patients with noninflammatory peripheral corneal opacification in the period immediately after photorefractive keratectomy or laser in situ keratomileusis were identified and the charts abstracted. Peripheral stromal opacification, localized corneal thinning, irregular astigmatism leading to a decrease in corrected visual acuity, and gradual clearing were characteristic findings. Gradual clearing occurred without treatment in all eyes over a period of 2 weeks to 12 months. This syndrome has similarities to central toxic keratopathy but occurs in the peripheral cornea. We refer to the syndrome as toxic peripheral keratopathy, the cause of which is unknown.
Journal of cataract and refractive surgery 09/2012; 38(9):1684-9. · 2.75 Impact Factor
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ABSTRACT: PURPOSE: We sought to prospectively compare postoperative symptoms of dry eye, visual fluctuations, and foreign body sensation in patients undergoing LASIK and photorefractive keratectomy (PRK). DESIGN: Randomized clinical trial. PARTICIPANTS: Sixty-eight eyes of 34 patients were treated with wavefront-guided LASIK and PRK. METHODS: One eye was treated with LASIK and the fellow eye was treated with PRK. Eyes were randomized by ocular dominance. Patients completed a questionnaire preoperatively and at each postoperative visit evaluating symptoms of dry eye, dry eye severity, vision fluctuations, and foreign body sensation. MAIN OUTCOME MEASURES: Change in self-reported dry eye with secondary outcome measure of visual fluctuations and foreign body sensation scores after LASIK and PRK. RESULTS: Both groups of eyes experienced significant increases in symptoms of dry eye, vision fluctuation, and foreign body sensation after LASIK and PRK at postoperative months 1, 3, and 6. However, by the 12-month postoperative visit, there was no increase in dry eye symptoms over the preoperative baseline levels in either group. Patients undergoing PRK experienced significantly higher levels of vision fluctuation at postoperative month 1 than those undergoing LASIK. CONCLUSIONS: Both LASIK and PRK caused an increase in dry eye symptoms and severity, vision fluctuations, and foreign body sensation over baseline in the early postoperative period. At postoperative month 1, PRK caused greater vision fluctuations than LASIK. By 1 year postoperatively, all symptoms of dry eye, vision fluctuations, and foreign body sensation returned to their baseline, preoperative levels. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any of the materials discussed in this article.
Ophthalmology 08/2012; · 5.45 Impact Factor
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Ophthalmology 04/2012; 119(4):884-5. · 5.45 Impact Factor
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ABSTRACT: To compare the safety and efficacy of wavefront-guided laser in situ keratomileusis (LASIK) vs photorefractive keratectomy (PRK) in a prospective randomized clinical trial.
A cohort of 68 eyes of 34 patients with -0.75 to -8.13 diopters (D) of myopia (spherical equivalent) were randomized to receive either wavefront-guided PRK or LASIK in the fellow eye using the VISX CustomVue laser. Patients were evaluated at 1 day, 1 week, and months 1, 3, 6, and 12.
At 1 month, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), 5% and 25% contrast sensitivity, induction of higher-order aberrations (HOAs), and subjective symptoms of vision clarity, vision fluctuation, ghosting, and overall self-assessment of vision were worse (P<0.05) in the PRK group. By 3 months, these differences had resolved (P>0.05). At 1 year, mean spherical equivalent was reduced 94% to -0.27 ± 0.31 D in the LASIK group and reduced 96% to -0.17 ± 0.41 D in the PRK group. At 1 year, 91% of eyes were within ±0.50 D and 97 % were within ±1.0 D in the PRK group. At 1 year, 88% of eyes were within ±0.50 D and 97% were within ±1.0 D in the LASIK group. At 1 year, 97% of eyes in the PRK group and 94% of eyes in the LASIK group achieved an UCVA of 20/20 or better (P=0.72). Refractive stability was achieved in both PRK and LASIK groups after 1 month. There were no intraoperative or postoperative flap complications in the LASIK group. There were no instances of corneal haze in the PRK group.
Wavefront-guided LASIK and PRK are safe and effective at reducing myopia. At 1 month postoperatively, LASIK demonstrates an advantage over PRK in UCVA, BSCVA, low-contrast acuity, induction of total HOAs, and several subjective symptoms. At postoperative month 3, these differences between PRK and LASIK results had resolved.
Transactions of the American Ophthalmological Society 12/2011; 109:201-20.
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ABSTRACT: To prospectively compare intraoperative subtraction pachymetry flap thickness measurements and postoperative anterior segment optical coherence tomography (AS-OCT) flap thickness measurements in eyes that had laser in situ keratomileusis (LASIK) flap creation with a femtosecond laser or a mechanical microkeratome.
Stanford Eye Laser Center, Stanford University School of Medicine, Stanford, California, USA.
Comparative case series.
Each patient received wavefront-guided LASIK using an Intralase femtosecond laser in 1 eye and a Hansatome mechanical microkeratome in the fellow eye. Flap morphology was assessed with an ultrasound pachymeter intraoperatively and an AS-OCT system postoperatively at 1 year.
Thirty-six eyes (18 patients) were enrolled. Intraoperative subtraction pachymetry consistently underestimated mechanical microkeratome flap thickness compared with postoperative AS-OCT (P<.001). There was no significant difference between intraoperative subtraction pachymetry and postoperative AS-OCT measurements for femtosecond flaps (P=.38). The overall mean variation in flap thickness (ie, mean deviation from targeted flap thickness) was 2.6 μm (range 3 to 11 μm) with the femtosecond laser and 14.2 μm (range 17 to 52 μm) with the mechanical microkeratome (P<.001). Postoperative AS-OCT measurements showed femtosecond flaps had a planar configuration and mechanical microkeratome flaps had a meniscus-shaped configuration.
The femtosecond laser created more uniformly planar flaps than the mechanical microkeratome as measured by intraoperative subtraction pachymetry and postoperative AS-OCT. Postoperative AS-OCT measurements varied less than intraoperative subtraction pachymetry measurements for mechanical microkeratome flaps.
Neither author has a financial or proprietary interest in any material or method mentioned.
Journal of cataract and refractive surgery 08/2011; 37(10):1879-83. · 2.75 Impact Factor
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ABSTRACT: The use of systemic steroids has been established as a risk factor for the development of posterior subcapsular cataracts. In recent decades, the use of nasal topical steroids has increased in an effort to decrease systemic side effects. Current evidence of an association between nasal steroid use and cataract formation is contradictory. We present a case of rapid-onset bilateral posterior subcapsular cataracts in a young healthy patient with a history of long-term nasal steroid use.
Journal of cataract and refractive surgery 08/2011; 37(8):1555-8. · 2.75 Impact Factor
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ABSTRACT: To prospectively compare dry-eye symptoms after laser in situ keratomileusis (LASIK) with mechanical keratome-created flaps and femtosecond laser keratome-created flaps.
Department of Ophthalmology, Stanford University School of Medicine, Stanford, California, USA.
Randomized clinical trial.
Fellow eyes were prospectively randomized to the mechanical keratome group and femtosecond laser keratome group. Patients had wavefront-guided LASIK using a mechanical keratome in 1 eye and a femtosecond laser keratome in the fellow eye. They completed dry-eye questionnaires preoperatively and 1, 3, 6, and 12 months postoperatively. The effect of laser ablation depth, sex, age, and flap thickness on dry-eye symptoms was also analyzed.
The study enrolled 51 patients. There was no statistically significant change in dry-eye symptoms except in the femtosecond group 1 month postoperatively (mean increase 1.08) (P=.03). There were no significant differences in symptoms between the 2 groups (P=.7). The dry-eye score was 1.3 points lower in women than in men (P=.01). Central ablation depth, flap thickness, and age did not significantly affect the reported dryness.
There appeared to be no statistically significant difference in self-reported dry-eye symptoms between the mechanical keratome group and the femtosecond laser keratome group.
Journal of cataract and refractive surgery 06/2011; 37(8):1476-80. · 2.75 Impact Factor
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ABSTRACT: To report a case of bilateral late onset anterior cortical cataract following implantation of an iris-fixated phakic intraocular lens (pIOL).
Single observational case report.
Three and a half years following uncomplicated consecutive implantation of iris-fixated pIOL in both eyes, anterior cortical cataract changes inferiorly emanating from the site of enclavation of the lens in the right eye were noted. By 7 years after implantation, anterior cortical cataract changes were seen emanating from the enclavation sites superiorly and inferiorly in both eyes. These cataracts did not cause any loss of corrected distance visual acuity.
This case demonstrates that a potential complication of an iris-fixated pIOL is late onset secondary cataract formation.
Journal of refractive surgery (Thorofare, N.J.: 1995) 04/2011; 27(4):305-8. · 2.54 Impact Factor
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ABSTRACT: To evaluate the safety, efficacy, and clinical outcome of wavefront-guided photorefractive keratectomy (PRK) for the treatment of low to moderate and high myopia and compound myopic astigmatism.
This retrospective study included 174 eyes of 102 patients with low to moderate (-0.125 to <-6.50 diopters [D]) and high (≥-6.50 D) myopia treated with wavefront-guided PRK using the VISX CustomVue S4 IR (Abbott Medical Optics) excimer laser. Eyes were analyzed preoperatively and at 1, 3, 6, and 12 months postoperatively. At 3 months, 174 eyes of 102 patients were evaluated, and at 12 months, 146 eyes of 75 patients were evaluated. No eyes were retreated in the study.
Mean patient age was 38.3±8.76 years (range: 20 to 66 years), and mean preoperative manifest refraction spherical equivalent (MRSE) was -5.60±2.58 D (range: -0.13 to -10.50 D). At 12 months postoperative, MRSE was -0.16±0.45 D (range: -1.50 to 1.38 D); 96.6% of eyes were within ±1.00 D of intended correction, whereas 81.5% were within ±0.50 D of intended correction. For all eyes, the safety and efficacy indexes were 1.01 and 1.02, respectively.
These data support the safety and efficacy for the correction of low to moderate and high myopia and compound myopic astigmatism using wavefront-guided PRK.
Journal of refractive surgery (Thorofare, N.J.: 1995) 03/2011; 27(3):173-80. · 2.54 Impact Factor
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ABSTRACT: To evaluate the effect of preoperative pupil size on quality of vision after wavefront-guided LASIK.
Prospective study.
One hundred two eyes.
LASIK for mild to moderate myopia or astigmatism (preoperative manifest spherical equivalent, -3.99±1.42 diopters).
Questionnaires evaluating specific visual symptoms before and after surgery. Each eye was evaluated before surgery, and 1 week and 1, 3, 6, and 12 months postoperatively. Pupils were stratified according to size: small (≤5.5 mm), medium (5.6-6.4 mm), or large (≥6.5 mm). Mesopic pupil size and preoperative and postoperative variables were evaluated using an analysis of variance. A regression model was also performed to determine the correlation between mean spherical equivalent and cylinder and visual symptoms.
In the early postoperative period, there was no difference between the 3 groups with regard to any of the symptoms. At the final 12-month postoperative visit, patients with medium pupils experienced less glare at night than small pupils (P = 0.02), medium pupils had less halos than small or large pupils (P = 0.001 and P = 0.02, respectively), and medium pupils experienced greater satisfaction in visual improvement than small pupils (P = 0.014).
Twelve months after wavefront-guided LASIK surgery, large pupil size does not positively correlate with any postoperative visual symptoms.
Ophthalmology 11/2010; 118(4):736-41. · 5.45 Impact Factor
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ABSTRACT: Photorefractive keratectomy (PRK) with the adjunctive use of mitomycin-C (MMC) for the treatment of residual refractive error after laser in situ keratomileusis (LASIK) has been shown to be safe and effective, with no occurrences of visually significant postoperative haze reported. We report a case of visually significant haze after PRK with MMC for residual myopia following LASIK.
Journal of cataract and refractive surgery 09/2010; 36(9):1599-601. · 2.75 Impact Factor
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ABSTRACT: Long-term stability of intrastromal corneal ring segments is important in maintaining patients' corrected distance visual acuity and avoiding injury to the local tissues. We report a case of traumatic shattering of intrastromal segments due to blunt trauma, with successful removal of the fragments.
Journal of cataract and refractive surgery 06/2010; 36(6):1042-4. · 2.75 Impact Factor
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ABSTRACT: Long-term stability of the position of phakic intraocular lenses (pIOLs) is important in maintaining visual acuity as well as avoiding injury to the local tissues. We report a case of late nontraumatic dislocation of an iris-fixated pIOL, with subsequent successful repositioning.
Journal of cataract and refractive surgery 05/2010; 36(5):854-6. · 2.75 Impact Factor
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ABSTRACT: The authors report anterior segment optical coherence tomography (OCT) imaging findings in a case of central toxic keratopathy following laser in situ keratomileusis (LASIK) surgery for low hyperopia. OCT imaging 1 month after surgery demonstrates that the flap thickness is maintained and the location of stromal tissue loss is just posterior to the flap in the stromal bed in the affected area. This corresponds to the clinical observation of interface opacity extending posteriorly into the stroma as first described by Sonmez and Maloney1 in their initial description of the syndrome. Follow-up OCT imaging 3 months later revealed interval decrease in stromal thinning. The etiology of this syndrome is unknown.
Ophthalmic Surgery Lasers and Imaging 04/2010; · 0.62 Impact Factor
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ABSTRACT: To evaluate the long-term efficacy and stability of conductive keratoplasty (CK) for low to moderate hyperopia.
Department of Ophthalmology, Stanford University School of Medicine, Stanford, California, USA.
In this prospective nonrandomized noncontrolled clinical trial, performed as part of a U.S. Food and Drug Administration pivotal trial, patients with +0.75 to +3.00 diopters (D) of hyperopia and 0.75 D or less cylinder were initially treated with CK. The postoperative uncorrected and corrected Snellen visual acuities and refractions over time were evaluated. The main outcome measures were differences in refraction and uncorrected visual acuity postoperatively.
Nine patients (16 eyes) of a subset of 14 consecutive patients (25 eyes) originally enrolled between 1999 and 2000 were available for long-term follow-up. Preoperatively, the mean manifest refraction spherical equivalent (MRSE) in the subset with long-term follow-up was +1.45 D. Postoperatively, the mean MRSE was +0.295 D. at 23 months, regressing to +1.00 D at 48 months and +1.394 D at the final follow-up (mean 73 months), indicating significant regression of effect. No eye lost more than 1 line of corrected Snellen visual acuity as a result of CK. The rate of regression was linear and calculated at +0.0184 D per month after 6 months postoperatively. Keratometric regression appeared to be similar to MRSE regression.
Conductive keratoplasty led to significant regression of refractive and keratometric effects over extended follow-up. Patients should be counseled that this refractive procedure is not permanent.
Journal of cataract and refractive surgery 10/2009; 35(9):1591-6. · 2.75 Impact Factor
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ABSTRACT: To compare clinical outcomes between fellow eyes randomized to femtosecond laser-created flaps (femtosecond group) or mechanical keratome-created flaps (mechanical group) during wavefront-guided laser in situ keratomileusis.
Prospective, randomized, comparative clinical study.
Efficacy, safety, predictability, stability, changes in corneal optical aberrations, and low-contrast visual acuity before and 1 week and 1, 3, 6, and 12 months after surgery.
Forty-three patients underwent evaluation in this study. One month after surgery, the mean (SD) spherical equivalent was -0.15 (0.30) diopters (D) for the femtosecond group and -0.12 (0.29) D for the mechanical group (differences were not statistically significant). Twelve months after surgery, 39 eyes (98%) in the femtosecond group had uncorrected visual acuity of 20/20 or better compared with 37 (95%) in the mechanical group. The femtosecond group had fewer high-order, spherical, and coma aberrations and more trefoil aberrations than the mechanical group at 1 month (P = .55), 3 months (P = .05), 6 months (P = .33), and 12 months (P = .48) after surgery. At 25% contrast, the femtosecond group had gains at 1 month (P = .01) and 6 months (P = .008) after surgery.
Twelve months after keratomileusis, clinical outcomes were similar for both groups.
Archives of ophthalmology 12/2008; 126(11):1484-90. · 3.86 Impact Factor
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ABSTRACT: To evaluate the efficacy, predictability, and safety of wavefront-guided laser in situ keratomileusis (LASIK) using the Visx CustomVue excimer laser (Advanced Medical Optics) in eyes with consecutive hyperopia and compound hyperopic astigmatism after LASIK.
Stanford University School of Medicine, Department of Ophthalmology, Stanford, California, USA.
This retrospective analysis included 19 eyes of 16 patients who had wavefront-guided LASIK for consecutive hyperopia and compound hyperopic astigmatism after initial LASIK surgery. Primary outcome variables, including uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), higher-order aberration (HOA) analysis, and spherical equivalence, were evaluated at 1 and 3 months. Nine eyes of 7 patients were available for all visits.
The mean patient age was 51.7 years +/- 3.77 (SD) (range 44 to 55 years). The mean preoperative manifest refractive spherical equivalent (MRSE) was 0.99 +/- 0.32 diopters (D) (range 0.50 to 1.50 D) and the mean 3-month postoperative MRSE, -0.04 +/- 0.66 D (range -1.50 to 0.75 D). At 1 month, 57.9% of eyes had a UCVA of 20/20 or better and 78.9% of 20/25 or better; 84.2% were within +/-1.00 D of emmetropia. At 3 months, 66.7% of eyes had a UCVA of 20/20 or better and 88.9% of 20/25 or better; 88.9% were within +/-1.00 D of emmetropia. No eye lost 2 or more lines of BSCVA at 1 or 3 months.
Wavefront-guided LASIK was an effective, predictable, and safe procedure for consecutive hyperopia and compound hyperopic astigmatism after LASIK.
Journal of Cataract [?] Refractive Surgery 08/2008; 34(8):1260-6. · 2.26 Impact Factor
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ABSTRACT: To evaluate the safety, efficacy, predictability, and long-term stability of the Artisan Phakic Intraocular Lens (Ophtec BV, Groningen, the Netherlands) for the correction of high myopia.
Prospective analysis of 26 eyes from 15 patients who underwent placement of the Artisan lens for the correction of high and extreme myopia. The mean (SD) preoperative spherical equivalent was - 12.30 (2.69) diopters (D) (range, - 17.25 to - 8.25 D).
At 5 years, the mean (SD) manifest refraction was - 0.37 (0.69) D, with 95% of eyes within 1 D of attempted correction and 74% of eyes within 0.5 D of the attempted correction. Ninety-five percent of eyes achieved an uncorrected visual acuity of 20/40 or better and 74% achieved an uncorrected visual acuity of 20/20 or better. No eyes experienced a loss of 1 or more lines of best-corrected visual acuity. Sixteen percent of eyes gained 2 or more lines of best-corrected visual acuity. From preoperative measurements, the mean endothelial cell density decreased by 14.05% at 5 years postoperatively.
Placement of the Artisan lens is predictable, stable, and effective at reducing high and extreme myopia 5 years after implantation. The rate of endothelial cell loss was significantly higher than has been reported in previous studies.
Archives of ophthalmology 07/2008; 126(6):775-81. · 3.86 Impact Factor
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ABSTRACT: To prospectively evaluate the safety, efficacy, predictability, and long-term stability of hyperopic laser in situ keratomileusis (LASIK) using the Star S2 excimer laser (Visx).
Department of Ophthalmology, Stanford University School of Medicine, Stanford, California, USA.
This study evaluated 41 eyes of 27 patients who had LASIK for the correction of spherical hyperopia. Patients were divided into 3 groups based on preoperative cycloplegic refraction: low hyperopia (less than +2.00 diopters [D]), medium hyperopia (+2.00 to +4.00 D), and high hyperopia (more than +4.00 D).
In all eyes, the mean preoperative spherical equivalent (SE) was +2.53 D (range +0.75 to +5.25 D) and the mean attempted SE was +2.58 D (range +0.75 to +5.25 D). At the last visit (mean 5.29 years), the mean SE was +0.44 D +/- 0.69 (SD) in the low hyperopia group, +0.58 +/- 0.56 D in the medium hyperopia group, and +0.59 +/- 1.18 D in the high hyperopia group. The percentage of eyes within +/-1.00 D of emmetropia was 82.4%, 75.0%, and 66.7%, respectively (68.9% overall). The uncorrected visual acuity was 20/40 or better in 100% of eyes in the low hyperopia group, 91.7% in the medium hyperopia group, and 66.7% in the high hyperopia group (87.8% overall). The hyperopic shift between 1 year and the last visit was +0.18 D, +0.30 D, and +0.55 D, respectively (+0.40 D overall; range -1.25 to +2.63 D).
Hyperopic LASIK using the Star S2 excimer laser was safe, effective, and predictable for hyperopia up to +4.10 D (mean of high group). A mild regression of the refractive effect was seen over the 5-year follow-up.
Journal of Cataract [?] Refractive Surgery 03/2008; 34(2):232-7. · 2.26 Impact Factor
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ABSTRACT: To evaluate the safety, efficacy, and clinical outcomes of wavefront-guided laser in situ keratomileusis (LASIK) surgery for the treatment of moderate to high myopia and compound myopic astigmatism.
Stanford University School of Medicine, Department of Ophthalmology, Stanford, California, USA.
This retrospective study included patients with moderate (-6.0 to -8.0 diopters [D]) and high (greater than -8.00) myopia treated with wavefront-guided LASIK using the WaveScan linked to the CustomVue system (AMO USA, Inc.). Eyes were analyzed preoperatively and 1, 3, and 12 months postoperatively.
The mean patient age was 38.4 years +/- 7.14 (SD). Eighty-nine eyes of 45 patients were evaluated at 3 months and 50 eyes of 25 patients at 12 months. No eye was retreated during the study. The mean manifest refraction spherical equivalent was -8.10 +/- 0.98 D (range -6.00 to -10.63 D) preoperatively and -0.33 +/- 0.55 D (range -1.625 to 1.375 D) 12 months postoperatively. Ninety percent of the eyes were within +/-1.00 D of the intended correction and 64.0%, within +/-0.50 D. For all eyes, the safety index was 1.00 and the efficacy index, 1.18.
The data support the safety and efficacy of correcting moderate to high myopia and compound myopic astigmatism using wavefront-guided LASIK.
Journal of Cataract [?] Refractive Surgery 02/2008; 34(1):21-7. · 2.26 Impact Factor
