Loss Of Best Spectacle-corrected Visual Acuity Research Articles

Foldable iris-fixated phakic intraocular lens implantation for the correction of myopia: Two years of follow-up

Purpose:To evaluate the safety, efficacy and potential risks of Artiflex foldable iris-fixated phakic intraocular lens (pIOL) implantation for the management of myopia.Materials and Methods:Seventy-eight eyes of 40 consecutive patients with a mean spherical refraction of –11.70 ± 3.77 diopters (D; range –5.50 to –17.5 D) were included in this prospective, noncomparative, interventional case series. Main parameters assessed were uncorrected visual acuity (UCVA), best-spectacle corrected visual acuity (BSCVA), corneal topography (Orbscan II, BauchandLomb, Rochester, NY, USA), manifest and cycloplegic refractive errors, endothelial cell density (ECD) and applanation tonometry.Results:After 2 years, BSCVA was 20/40 or better in 82% of the eyes and UCVA was 20/40 or better in 84% of the eyes. After 1 month, 1 year, and 2 years, 51.3% (37 of 72 eyes), 58.9% (46 of 78 eyes) and 76.0% (38 of 50 eyes) of eyes gained 1 line or more of BSCVA, respectively. Compared to preoperative values, the mean endothelial cell loss was 2.6% at 1 month, 4.9% at 1 year and 7.4% at 2 years. Pigmented or non-pigmented precipitates were observed in17 eyes (21.7%) which were treated with topical corticosteroids. At the second postoperative year, pigmented precipitates persisted in nine eyes. However, this was not associated with a loss of BSCVA.Conclusion:The implantation of Artiflex pIOL is an effective surgical option for the management of high myopia. The most common complication observed within 2 years of follow-up was accumulation of pigmented precipitates with no effect on the final BSCVA.

A Randomized Comparison of Pupil-Centered Versus Vertex-Centered Ablation in LASIK Correction of Hyperopia

To compare visual and optical outcomes of pupil-centered vs vertex-centered ablation in patients undergoing laser-assisted in situ keratomileusis (LASIK) for hyperopia. Randomized, double-masked, prospective, single-center trial. Institutional practice. Sixty eyes of 30 patients with low and moderate hyperopia. Intervention procedure: Eyes underwent LASIK (Allegretto excimer laser). In 30 eyes, the ablation was centered on the pupil, while in the 30 other eyes the ablation was centered on the corneal reflex. Primary outcome measure was the safety index. Main secondary outcome measures were efficacy index, manifest refraction, uncorrected visual acuity, best spectacle-corrected visual acuity (BCVA), and ocular high-order aberrations for a 6-mm pupil size. At 3 months postoperatively, the safety index was 0.99 ± 0.04 in the pupil-centered group and 0.99 ± 0.08 in the vertex-centered group (P = .97). The efficacy index was also similar for both groups: 0.96 ± 0.05 in pupil-centered eyes and 0.93 ± 0.09 in vertex-centered eyes (P = .31). Optical aberrations were similar for pupil-centered and vertex-centered eyes. Considering only eyes showing large pupil decentration, we found a tendency for better visual results in favor of pupil-centered eyes in terms of safety index and a slight but significant increase of coma in vertex-centered eyes. LASIK is an effective procedure for treatment of hyperopia. Pupil-centered and vertex-centered treatments provide similar visual and optical outcomes. However, in eyes showing large temporal pupil decentration, pupil-centered ablation seemed to produce a lower amount of coma and, as a consequence, a reduced loss of BCVA compared with vertex-centered patients.

Femtosecond Sub-Bowman Keratomileusis: A Prospective, Long-term, Intereye Comparison of Safety and Outcomes of 90- Versus 100-μm Flaps

To analyze the long-term safety profile, visual and refractive results, and incidence of complications between sub-Bowman keratomileusis with 90- and 100-μm flaps. Prospective, randomized, comparative clinical study. A total of 385 candidates (770 eyes) underwent bilateral, single-sitting, sub-Bowman keratomileusis, with flap creation (90 or 100 μm) on IntraLase 60-kHz (Abott Medical Optics) and ablation on Technolas 217z100 (Technolas PV) . Right and left eyes were randomized to undergo 90- or 100-μm flap procedures. Preoperative and postoperative assessment included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), refraction, and topographic analysis. All cases were followed up until 12 months after surgery. After excluding cases lost to follow-up, a final analysis of 368 patients was carried out (368 eyes in each of the 2 groups). The main outcome measures were BSCVA, UCVA, complication rates, and residual spherical equivalent refractive error. The mean preoperative values were: spherical equivalent, -6.08 ± 2.7 diopters (D; 90-μm group) and -5.99 ± 2.8 D (100-μm group; P = .7); and logarithm of the minimal angle of resolution BSCVA, 0.01 ± 0.03 (90-μm group) and 0.01 ± 0.04 (100-μm group: P = .8). Postoperative 12-month values were: spherical equivalent, -0.02 ± 0.4 D (90-μm group) and -0.01 ± 0.4 D (100-μm group; P = .8); logarithm of the minimal angle of resolution BSCVA, -0.05 ± 0.07 (90-μm group) and -0.04 ± 0.07 (100-μm group; P = .8); and logarithm of the minimal angle of resolution UCVA, 0.012 ± 0.01 (90-μm group) and 0.017 ± 0.02 (100-μm group; P = .2). No loss of BSCVA was seen in any case. The efficacy indices were 1.039 ± 0.21 (90-μm group) and 1.014 ± 0.24 (100-μm group; P = .2); safety indices were 1.163 ± 0.21 (90-μm group) and 1.158 ± 0.22 (100-μm group; P = .6); and vision difference indices were 0.09 ± 0.14 (90-μm group) and 0.10 ± 0.15 (100-μm group; P = .1). Both groups had a low but comparable incidence of diffuse lamellar keratitis and microstriae. However, the incidence of microstriae (although visually asymptomatic) was significantly higher in ablation with spherical equivalent of -9 D or more compared with lesser ablations (6.7% vs 0.8%; P < .001). The 1-year follow-up of femtosecond sub-Bowman keratomileusis with 90- and 100-μm flaps suggests that both the flap options have comparable outcomes.

Facteurs prédictifs de succès des anneaux intracornéens de Ferrara dans le kératocône

To define predictive factors after manual implantation of intrastromal corneal ring segments (Ferrara ring) for the management of keratoconus. Twenty-five eyes of 25 patients with keratoconus were implanted with Ferrara intracorneal ring segments using a mechanical procedure. We measured corneal ring implantation depth, best spectacle-corrected visual acuity (BSCVA), as well as refractive and keratometric outcomes. Patients were separated into two groups according to the gain of at least two lines of BSCVA ("good response") or the gain of only one line of BSCVA, no change, or the loss of lines of BSCVA ("poor response"). After a 6-month follow-up, 41% patients experienced a gain of at least two lines of BSCVA, 31.8% a gain of only one line, 13.6% no change, and 13.6% a loss of BSCVA. The sphere reduced from 4.39 to 2.34D (p<0.01), the cylinder from 4.19 to 2.77D (p<0.01), and the mean keratometry from 51.44 to 48.74D (p<0.02). As successful predictive factors, we found the asymmetry of keratoconus (p<0.01) in relation to the steepest meridian and patients implanted with a single ring (p<0.02). Defining preoperative successful predictive factors for Ferrara intracorneal ring segments is essential to enhance postoperative outcomes.

A Prospective Randomized Comparison of Four Femtosecond LASIK Flap Thicknesses

To evaluate the visual outcomes, predictability, and planarity of four types of 60-kHz femtosecond laser-assisted LASIK flaps: 90, 100, 110, and 120 microm. This randomized, prospective, interventional, comparative trial was performed at a tertiary care facility. Two hundred forty eyes with a calculated residual bed thickness >300 microm (at 120-microm flap thickness and subjective refraction) were randomized into four flap thickness groups to undergo femtosecond laser-assisted LASIK. Pre- and postoperative assessment included uncorrected visual acuity, best spectacle-corrected visual acuity (BSCVA), and refraction. Flap thickness was assessed by anterior segment optical coherence tomography on 28 points per flap at 1-month follow-up. Three new indices were devised to assess the predictability and planarity. The baseline parameters were matched. Postoperative vision and refractive outcome were similar in the four groups (P>.05, analysis of variance). The achieved flap thickness was different at each measured point among the groups (P<.05) with standard deviations ranging from +/-3.2 to +/-7.3 microm. The predictability and planarity were satisfactory in all four groups, although the indices were slightly better in the 110-microm and 120-microm groups. No loss of BSCVA or flap complications occurred in the four groups. The study demonstrated that all four flap thicknesses are relatively uniform in predictability and clinical outcomes.

Ultra B2 - Promoção de ligações covalentes do colágeno corneal (Corneal cross-linking) no tratamento de ceratocone: resultados preliminares

To present early visual and keratometric results for corneal cross-linking with riboflavin and UV irradiation in patients with progressive keratoconus. Twenty-five eyes of twenty patients (15 males and 5 females) with a progressive keratoconus in the previous 6 months were followed. Unaided visual acuity (UVA), best spectacle corrected visual acuity (BSCVA), spherical equivalent (SEQ), manifest cylinder, and maximal corneal curvature (max K) values were followed at 1, 3 and 6 months. All patients were submitted to corneal cross-linking using riboflavin (vitamin B2) as the photosensitizer and ultraviolet light (UV, wavelength 370 nm). Epithelium was removed with 20% alcohol, cornea was soaked with vitamin B2 for 15 min, and then irradiated with UV light for 30 min, after which a bandage contact lens (BCL) was placed. UVA increased after one month (from 0.15 +/- 0.15 to 0.23 +/- 0.20), and went on increasing at 3 and 6 months, reaching statistical significance (p=0.025 e p=0.037, respectively). BSCVA increased from 0.41 +/- 0.27 to 0.49 +/- 0.29 at month six, without reaching statistical significance at any time point. Progression of keratoconus stopped in all patients, in contrast with progression in all of them in the six-month period prior to the surgery. Max K decreased by more than 2 D (from 53.02 +/- 8.42 to 50.88 +/- 6.05 D), SEQ less that 1 D (from -3.27 +/- 4.08 to -2.68 +/- 3.02 D), while refractive cylinder decreased less than 0.5 D (from -2.29 +/- 1.77 to -1.86 +/- 0.92 D), without reaching a statistically significant difference. None of the eyes lost any line of BSCVA, 12 maintained the preoperative BSCVA, 7 gained one line, 5 gained two lines, and 1 patient gained three lines of BSCVA. Corneal cross-linking with riboflavin and UV light seems to be a safe (no loss of BSCVA) and effective (anatomical and optical properties maintained) procedure, which has shown to stop the progression of the keratoconus: a reduction, although not statistically significant, of the corneal curvature, spherical equivalent and refractive cylinder took place in patients where previous progression of keratoconus had been described.

Anterior Subcapsular Opacities and Cataracts 5 Years After Surgery in the Visian Implantable Collamer Lens FDA Trial

&lt;H4&gt;PURPOSE&lt;/H4&gt; &lt;p&gt;To use the techniques of survival analysis to analyze the incidence of anterior subcapsular opacities (symptomatic and asymptomatic) and clinically significant cataract in the US Food and Drug Administration clinical trial of the Visian Implantable Collamer Lens (ICL).&lt;/p&gt; &lt;H4&gt;METHODS&lt;/H4&gt; &lt;p&gt;Five hundred twenty-six eyes were followed for an average of 4.7 years; 89% (468 eyes), 73% (384 eyes), and 59% (311 eyes) were seen at 3, 4, and 5 years or later, respectively. Anterior subcapsular opacities were defined as trace or more (&lt;u&gt;&gt;&lt;/u&gt;0.6 LOCS III opacity). Clinically significant cataract required loss of 2 or more lines of best spectacle-corrected visual acuity (BSCVA), a significant increase in glare symptoms, or cataract extraction. Kaplan-Meier analyses of opacities and cataract were performed.&lt;/p&gt; &lt;H4&gt;RESULTS&lt;/H4&gt; &lt;p&gt;The Kaplan-Meier cumulative probability estimate for anterior subcapsular opacities over 7+ years of follow-up was 7% whereas 31 (5.9%) eyes were actually observed. Anterior subcapsular opacities generally occurred early with 58% seen in the first year, 68% in the first 2 years, and 74% in the first 3 years. The cumulative probability estimate for clinically significant cataracts over the 7+ years of follow-up was 2% whereas 7 (1.3%) were actually observed. The difference between the Kaplan-Meier estimate and the actual observed percentage is due to the fact that the former takes into account the differences in postoperative follow-up time of individual eyes. Preoperative myopia (&gt;12.00 diopters) and patient age (&gt;40 years) were significant factors in the development of cataract. No loss of BSCVA was observed in any eye following cataract extraction.&lt;/p&gt; &lt;H4&gt;CONCLUSIONS&lt;/H4&gt; &lt;p&gt;Approximately 6% to 7% of eyes develop anterior subcapsular opacities at 7+ years following ICL implantation but only 1% to 2% progress to clinically significant cataract during the same period, especially very high myopes and older patients. Visual outcome following cataract extraction was good. [&lt;cite&gt;J Refract Surg&lt;/cite&gt;. 2008;24:566-570.]&lt;/p&gt; &lt;h4&gt;ABOUT THE AUTHOR&lt;/h4&gt; &lt;p&gt;From the Center for Clinical Research, Elmhurst, Ill.&lt;/p&gt; &lt;p&gt;Dr Sanders is a consultant to STAAR Surgical Co, Monrovia, Calif.&lt;/p&gt; &lt;p&gt;Correspondence: Donald R. Sanders, MD, PhD, Center for Clinical Research, 242 N York Rd/Ste 102, Elmhurst, IL 60126. Phone: 630.530.9700 ext 12; Fax: 630.530.1636; E-mail: &lt;a href="mailto:drsmd@drsmd.com"&gt;drsmd@drsmd.com&lt;/a&gt;&lt;/p&gt; &lt;p&gt;Received: February 15, 2007&lt;/p&gt; &lt;p&gt;Accepted: May 9, 2007&lt;/p&gt; &lt;p&gt;&lt;b&gt;Posted online: December 28, 2007&lt;/b&gt;&lt;/p&gt;

Management of Irregular Astigmatism Following Rotationally Disoriented Free Cap After LASIK

To illustrate the challenges associated with a misaligned free flap (cap) and to report the outcome of applying wavefront-guided customized photorefractive keratectomy (PRK) followed by conventional PRK ablation to correct residual refractive error and aberrations after LASIK free cap complications. The clinical course and surgical interventions of two patients with free cap complications from LASIK surgery were reviewed. The first patient underwent a total of six interventions after the initial LASIK procedure, and the second patient underwent a total of five interventions. Interventions included cap lift, cap rotation, custom PRK, and conventional PRK enhancement with prophylactic topical mitomycin C (MMC). Customized PRK treatment and subsequent enhancements with prophylactic topical MMC led to the recovery of best spectacle-corrected visual acuity (BSCVA), neutralization of higher and lower order aberrations, and astigmatic neutrality. Symptoms related to higher order aberrations resolved in both patients. Wavefront-guided custom PRK for higher order aberrations followed by conventional PRK enhancement for residual lower order aberrations, both with topical MMC application, represents an efficacious strategy for treating patients with loss of BSCVA and visual symptoms due to LASIK free cap complications.

Femtosecond laser in situ keratomileusis for consecutive hyperopia after radial keratotomy

To assess the use of the femtosecond laser for laser in situ keratomileusis (LASIK) in eyes with consecutive hyperopia after radial keratotomy (RK). Private ambulatory surgical center, Valencia, Spain. This prospective noncomparative interventional case series study included 13 eyes of 9 patients with secondary hyperopia after previous RK. The patients were operated on with the IntraLase femtosecond laser (IntraLase Corp.) and the Star S2 excimer laser (Visx, Inc.). Postoperative uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, flap thickness, flap diameter, and complications were evaluated at 6 months. The mean spherical equivalent (SE) decreased from 2.00 diopters (D)+/-0.40 (SD) to -0.41+/-0.61 D, with 8 eyes (61.5%) within+/-0.50 D of the targeted refraction. Twelve eyes (92.3%) had a UCVA of 20/40 or better, and 3 eyes (23.1%) lost 1 line of BSCVA. A mean change in SE of 0.10 D was observed at the 6-month follow-up. The mean flap thickness and diameter were 117+/-14 microm and 9.18+/-0.12 mm, respectively. Most complications were in eyes with more than 8 RK incisions than in eyes with 8 RK incisions. These complications were multiple intraoperative incision openings (100% versus 28.6%, respectively), interface inflammation (66.6% versus 0%, respectively), haze (83.3% versus 14.3%, respectively), and loss of BSCVA (50% versus 0%, respectively). The femtosecond laser provided large, thin corneal flaps for hyperopic LASIK. However, the procedure should be avoided in eyes with more than 8 RK incisions because of the increased risk for multiple intraoperative incision openings, interface inflammation, haze, and loss of BSCVA.

Reduced Best Spectacle-corrected Visual Acuity from Inserting a Thicker Intacs Above and Thinner Intacs Below in Keratoconus

To report a case of decreased best spectacle-corrected visual acuity (BSCVA) 2 months after Intacs implantation. A 33-year-old woman with keratoconus and contact lens intolerance underwent Intacs surgery in the left eye at another institution. Two segments were used--a thinner one (0.25 mm) below the cone and a thicker one (0.35 mm) above the cone. Two months postoperatively, the patient presented to our practice with BSCVA reduced from 20/20 to 20/30. The superior Intacs segment was explanted, the inferior segment was exchanged for a thicker one (0.35 mm), and collagen cross-linking with riboflavin treatment was performed. This resulted in visual, topographic, and refractive improvement with BSCVA returning to 20/20. Single inferior segment Intacs may be more appropriate for paracentral and peripheral cones. Collagen cross-linking may help cause further flattening. Using asymmetrical segments, with the thicker segment above the cone, may increase distortions and result in loss of BSCVA.

Hyperopic LASIK Retreatments With the Technolas Laser

To evaluate the safety, efficacy, and predictability of hyperopic LASIK retreatments. This retrospective, consecutive, non-comparative, observational study included 85 eyes that underwent hyperopic LASIK retreatment with 1-year follow-up. Complete ophthalmic examination included distance uncorrected (UCVA) and best spectacle-corrected visual acuity (BSCVA), cycloplegic refraction, and pachymetry. Patients were divided into two groups according to the preoperative spherical equivalent refraction: group 1, < or = +3.9 diopters (D) and group 2, > or = +4.0 D. The UCVA improved from 0.31 +/- 0.2 to 0.7 +/- 0.2 in group 1 and from 0.2 +/- 0.2 to 0.6 +/- 0.2 in group 2 following retreatment. Mean spherical equivalent refraction improved from +2.8 +/- 0.85 to +0.2 +/- 0.9 in group 1 and from +5.3 +/- 0.9 to +0.3 +/- 1.3 in group 2 after retreatment. In group 1, 32 (72.7%) of 44 eyes had BSCVA > or = 20/25, and in group 2, 24 (58.5%) of 41 eyes had BSCVA > or = 20/25. After primary hyperopic LASIK, 25 (56.8%) of 44 eyes in group 1 and 19 (46.3%) of 41 eyes in group 2 maintained BSCVA or gained > or = 1 lines postoperatively in contrast to 21 (47.7%) of 44 eyes in group 1 and 22 (53.9%) of 41 eyes in group 2 after retreatment. In group 1, 11 (25%) of 44 eyes lost > or = 2 lines of BSCVA after initial hyperopic LASIK compared to 14 (31.8%) of 44 eyes after retreatment. In group 2, 10 (24.4%) of 41 eyes lost > or = 2 lines of BSCVA after initial hyperopic LASIK compared to 12 (29.2%) of 41 eyes after retreatment. After hyperopic LASIK retreatment, 31 (70.5%) of 44 eyes in group 1 and 19 (46.4%) of 41 eyes in group 2 were within +/- 0.5 D of emmetropia. Safety was 0.9 in both groups and efficacy was 0.8 and 0.7 in groups 1 and 2, respectively. Complications included epithelial ingrowth of 1 to 3 mm (30%) and flap edge melting (2%). Hyperopic LASIK retreatment improved the refractive results of initial hyperopic LASIK surgery with 20% to 30% of eyes gaining > or = 1 lines of BSCVA. The loss of BSCVA was greater after primary hyperopic LASIK than after retreatment.

Correction of Presbyopia by Technovision Central Multifocal LASIK (PresbyLASIK)

To investigate central multifocal presbyLASIK based on the creation of a central hyperpositive area. Twenty-five patients (50 eyes) underwent presbyLASlK in an open-label, prospective, non-comparative pilot study. Mean patient age was 58 years (range: 51 to 68 years), mean preoperative spherical equivalent refraction was +1.6 +/- 0.63 diopters (D) (range: +0.50 to +3.00 D), and mean spectacle near addition was +2.27 +/- 0.37 D (range: +1.75 to +3.00 D). The ablation pattern was performed with proprietary software from Technovision using an H. Eye Tech. excimer laser platform. Mean postoperative spherical equivalent refraction was -0.37 +/- 0.55 D (range: -1.50 to + 1.00 D) and mean spectacle near addition was +1.72 +/- 0.34 D (range: +1.25 to +2.25 D). After 6 months, 16 (64%) patients achieved a distance uncorrected visual acuity (UCVA) of > or = 20/20 and 18 (72%) patients achieved a near UCVA of > or = 20/40. Seven (28%) patients lost a maximum of 2 lines of best spectacle-corrected visual acuity (BSCVA). The safety index for distance was 0.98 binocular and for near was 0.99 binocular. After 6 months, no significant change was noted in contrast sensitivity at 1.5 cycles/degree. A significant mean reduction was found at spatial frequencies of 3, 6, 12, and 18 cycles/degree (P<.001). There was a significant change in corneal aberrations after surgery. The coefficients for coma increased and the coefficients for spherical aberrations decreased. A significant decrease was noted in point spread function values (P=.0018). Central presbyLASIK may be used to provide improvement in functional near vision in patients with presbyopia associated with low and moderate hyperopia. However, factors involved in the loss of BSCVA in some cases and loss in vision quality should be further clarified prior to its general use.

Wavefront-guided Enhancements Using the WaveLight Excimer Laser in Symptomatic Eyes Previously Treated With LASIK

To describe our clinical experience in wavefront-guided LASIK enhancements using the WaveLight ALLEGRETTO system (WaveLight Technologie AG, Erlangen, Germany) for symptomatic eyes previously treated with standard LASIK. Twenty-six eyes of 20 patients with residual myopia, hyperopia, or mixed astigmatism and/or night vision symptoms after primary standard LASIK were considered for wavefront-guided customized retreatment using the WaveLight ALLEGRETTO WAVE 200 Hz excimer laser system (model 106). Preoperative best spectacle-corrected visual acuity (BSCVA), uncorrected visual acuity, topography with the ALLEGRETTO Topolyzer, wavefront analysis using the ALLEGRETTO WAVE Tscherning Analyzer, and contrast sensitivity were compared to postoperative (enhancement) measurements. Twenty-two of the original 26 eyes underwent wavefront-guided enhancement, 4 were excluded because they did not meet wavefront-guided treatment inclusion guidelines of this study. Mean follow-up was 8 months (range: 6 to 13 months, standard deviation [SD] 2). All patients were within +/- 0.50 diopters (manifest refraction) of intended postoperative refraction. The mean preoperative BSCVA improved from 20/25 (SD +/- 0.12) to 20/18 (SD +/- 0.1) postoperatively. All patients gained at least one line of BSCVA, and a maximum of three lines. There was no loss of BSCVA in any patient. The total amount of high order aberrations (RMSH) decreased from an average of 1.04 (SD +/- 0.22) to 0.46 (SD +/- 0.14) microm. Patients also had a mean improvement in low contrast sensitivity of 59%. Based on this small series, customized wavefront-guided enhancements using the WaveLight ALLEGRETTO system in patients who underwent previous LASIK appear to be safe and effective in correcting residual refractive error, reducing high order aberrations, and improving visual symptoms when reliable and reproducible measurements are achieved.

Laser in situ keratomileusis in patients with corneal guttata and family history of Fuchs' endothelial dystrophy

To report 1-year results of laser in situ keratomileusis (LASIK) in 7 eyes with corneal endothelial guttata and a family history of Fuchs' endothelial dystrophy. John Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. A retrospective chart review was performed of 4 patients (7 eyes) who had trace to 1+endothelial guttata and a family history of Fuchs dystrophy and then had uneventful LASIK for the correction of myopia and myopic astigmatism. Preoperative and postoperative measurements included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), corneal pachymetry, endothelial cell density (ECD), manifest refraction, and spherical equivalent. The changes in ECD, pachymetry, and spherical equivalent after LASIK were subjected to statistical analysis using a paired Student t test to determine significance. Transient corneal edema was noted in the early postoperative period in 3 eyes of 2 patients. At 1 year, 6 of the 7 (86%) eyes had lost > or =2 lines of BSCVA. A statistically significant decrease in ECD of 12.4% +/- 2.7% was observed at 1 year compared with baseline (P < .001). An increase in corneal thickness (P = .006) and a statistically significant myopic shift in spherical equivalent (P = .017) was also noted at 1 year compared with 3 months. Patients with mild corneal guttata and a family history of Fuchs' dystrophy are prone to transient corneal edema, loss of BSCVA, endothelial cell loss, and myopic regression after uneventful LASIK for correction of myopia and myopic astigmatism.

Six-year follow-up of laser in situ keratomileusis for moderate and extreme myopia using a first-generation excimer laser and microkeratome

Purpose To evaluate objectively and subjectively the long-term outcome of laser in situ keratomileusis (LASIK) in patients with high and very high myopia. Setting Department of Ophthalmology, Philipps University, Marburg, Germany. Methods Thirty-three eyes of 19 patients were followed for a mean of 76 months (range 50 to 84 months) after primary LASIK using the Keratom I excimer laser (Schwind) and the ALK microkeratome (Chiron). Refraction, glare, pachymetry, corneal topography, and tear-film secretion and stability were measured. At the last examination, patients also answered a 14-item questionnaire. Results Preoperatively, the mean spherical equivalent was –13.65 diopters (D). At 1 year, it was –0.25 D and after 6 years, –0.88 D. Fifteen percent of eyes lost ≥2 lines of best spectacle-corrected visual acuity (BSCVA), and 9% gained ≥2 Snellen lines. At the end of the study, 46% of eyes were within ±1.0 D of the attempted corrected and 88% were within ±3.0 D. There were 5 microkeratome-associated complications; 3 resulted in loss of BSCVA. The latest pachymetry showed a mean corneal thickness of 498.5 μm (range 396 to 552 μm). There were no cases of keratectasia. Seventy-five percent of patients noted an increase in their quality of life. Seventy-one percent were satisfied with their postoperative visual acuity; however, 75% noticed glare and halos at night. Conclusions Laser in situ keratomileusis correction of very high myopia did not cause keratectasia in the long term provided the corneal thickness was respected. A flap thickness setting of 130 μm with a first-generation microkeratome resulted in a high number of cut failures. Most patients were happy with the results despite a modest level of accuracy and glare.

Laser-assisted subepithelial keratectomy for the correction of myopia

Purpose: To evaluate the results of laser-assisted subepithelial keratectomy (LASEK) for spherical and spherocylindrical myopia. Setting: Indiana Eye Institute, South Bend, Indiana, USA. Methods: In a retrospective noncomparative single-surgeon interventional case series, outcomes in 222 consecutive eyes with myopia ranging from −1.25 to −11.25 diopters (D) and astigmatism up to +2.25 D treated with LASEK using a VISX Star S2 excimer laser were analyzed 4 days, 2 weeks, and 3, 6, and 12 months after surgery. Results: The uncorrected visual acuity (UCVA) was 20/40 or better in 84% of eyes at 4 days and in 98% at 2 weeks. At 12 months, in 84 eyes, the UCVA was 20/15 in 16 eyes (19.0%), 20/20 in 53 (63.1%), and 20/25 in 15 (17.9%). There was no loss of best spectacle-corrected visual acuity (BSCVA), and no eye required retreatment. Conclusion: Laser-assisted subepithelial keratectomy for myopia provided excellent refractive and visual results with no loss of BSCVA and no serious complications. Subjective results and other measures of visual function need further evaluation.

Two-year outcomes of intrastromal corneal ring segments for the correction of myopia

Objective To evaluate the safety and efficacy of Intrastromal Corneal Ring Segments (ICRS) for the correction of myopia. Design Nonrandomized, comparative trial. Participants Patients enrolled in the United States Food and Drug Administration phase II and phase III clinical trials of the ICRS had best spectacle-corrected visual acuity (BSCVA) of 20/20 or better, myopia of −1.00 to −3.50 diopters (D), and a cylindrical correction of 1.00 D or less as measured by manifest refraction. Intervention Surgical correction of myopia with an ICRS. Main outcome measures Efficacy was assessed by predictability of refractive outcome (deviation from predicted cycloplegic refraction spherical equivalent), stability of refractive effect, and postoperative uncorrected visual acuity. Safety was assessed by adverse events, maintenance or loss of preoperative BSCVA, and induced manifest refraction cylinder. Results Four hundred fifty-two patients were enrolled at 11 investigational sites in both studies. Of the 454 surgical attempts, 449 received an ICRS in one eye (0.25, 0.30, and 0.35 mm in 148, 151, and 150 eyes, respectively). First surgeries were attempted in 452 patients. An ICRS was successfully implanted in 447 initial eyes, and 5 surgeries were discontinued. Of the five discontinued surgeries, three patients subsequently exited from the study, and two patients went on to have the ICRS implanted in the second eye, bringing the total number of successful implants to 449 patient eyes. Month 24 postoperative follow-up was completed on 358 patients (80%). At month 24, 328 of 354 eyes (93%) were within ±1.00 D of predicted refractive outcome. Refraction changed by 1 D or less in 97% of eyes (421/435) between 3 and 6 months after implantation and in 99% (343/348) between months 18 and 24. Before surgery, 87% of eyes (390/448) saw worse than 20/40 uncorrected; 24 months after surgery, 55% of eyes (196/358) saw 20/16 or better, 76% (271/358) saw 20/20 or better, and 97% (346/358) saw 20/40 or better. Although two eyes (2/358; 0.5%) lost two or more lines of BSCVA at 24 months; visual acuity in both was 20/20 or better. Intraoperative complications included anterior corneal surface perforation (three eyes) and anterior chamber perforations (two eyes, one during an attempted exchange procedure); all healed spontaneously without suturing and without loss of BSCVA. The ICRS was repositioned in five eyes to increase correction. Postoperative complications in one eye each were infectious keratitis, shallow segment placement, and loss of two lines of BSCVA at two or more consecutive examinations (subsequently regained). Conclusions The ICRS safely, predictably, and effectively reduced or eliminated myopia of −1.00 to −3.50 D. The refractive effect was stable over time.

Complications of laser in situ keratomileusis for the correction of myopia

Objective To determine the incidence and severity of complications from laser in situ keratomileusis (LASIK) for the correction of myopia by experienced and inexperienced surgeons. Design Prospective, observational clinical study. Participants Fourteen surgeons and 1062 eyes of 574 myopic patients who desired surgical correction of myopia ranging from −2.00 to −22.50 diopters (D; mean, −7.57 D) and astigmatism no greater than 4.00 D participated in this study. Intervention Myopia was corrected with LASIK. Astigmatism was corrected with arcuate keratotomy at the same time as the initial procedure or subsequently. Main outcome measures Primary outcome measures were change in best spectacle-corrected visual acuity (BSCVA) and the incidence of complications. Results Eyes were followed for a mean of 9.5 months after their last surgical procedure (range, 2 weeks–21 months). Three hundred eighty-one eyes (36%) underwent 468 enhancement procedures 3 months or more after the initial treatment. There were 27 (2.1%) intraoperative and 40 (3.1%) postoperative complications. Laser ablation was not performed during the initial treatment of 17 (1.6%) eyes because of intraoperative complications. Seventy-four eyes gained 2 or more lines of BSCVA, while 50 eyes lost 2 or more lines of BSCVA. Only three eyes lost two or more lines of BSCVA to a level worse than 20/40. One eye with a flap buttonhole (BSCVA 20/50) also had an epiretinal membrane. The second eye (BSCVA 20/60) had a flap buttonhole that may have been related to a previous corneal transplant. The third eye (−22.50 D before surgery) had a rhegmatogenous retinal detachment develop, reducing BSCVA from 20/60 to 20/200. The incidence of intraoperative complications decreased from 3.1% during the first 3 months to 0.7% during the last 9 months of the study ( P = 0.02). Conclusions LASIK is acceptably safe for the correction of myopia. Although complications occur in approximately 5% of cases, these rarely lead to visual loss of more than two Snellen lines and postoperative acuity below 20/40. Flap buttonholes were more likely to cause loss of BSCVA than free or incomplete flaps ( P = 0.02); flap buttonholes may be more likely in eyes that have undergone previous surgery. Complication rates can be reduced as the surgical team gains experience.

Excimer Laser Phototherapeutic Keratectomy

The objective of this study was to evaluate the safety and efficacy of excimer laser phototherapeutic keratectomy in the treatment of anterior corneal pathology in a group of 45 patients. Forty-five patients were treated with the Visx Excimer Laser System for various types of anterior corneal pathology including postinflammatory and postsurgical scars, stromal dystrophies, surface degenerations, pterygia, and epithelial basement membrane dystrophies. Excimer laser phototherapeutic keratectomy (PTK) has been used to treat anteriorly located corneal pathology since 1990; however, most published studies thus far have been composed of small numbers of patients with limited duration of follow-up. The present study is one of the largest domestic PTK series with one of the longest mean follow-ups. Forty patients were followed for > or = 6 months with a mean follow-up of just less than 1 year (11.25 months). Statistically significant improvement was achieved in irritative symptoms and visual acuity. Best spectacle corrected visual acuity (BSCVA) improved a mean of two lines (range, -3 to +7) with 20/50 or better BSCVA present in 29% of patients preoperatively improving to 60% postoperatively. Refractive changes were unpredictable. Mean spherical equivalent underwent a hyperopic shift of 2.81 diopters (D). Fifty percent of patients developed > or = 1 D of refractive astigmatism. Complications occurred in six patients with loss of BSCVA, three patients with topical corticosteroid associated increased intraocular pressure, and three patients with recurrent herpes simplex stromal keratouveitis. Excimer laser phototherapeutic keratectomy can consistently achieve a modest to a more substantial improvement in irritative ocular symptoms and/or visual acuity with significant potential for adverse results that appear to be less severe than the complications associated with alternative treatment by keratoplasty.