Intraoperative variability of corneal epithelium thickness in photorefractive keratectomy.

PURPOSE: To evaluate the intraoperative central corneal epithelial thickness (ET) as measured by optical coherence pachymetry (OCP) in myopic eyes undergoing alcohol-assisted photorefractive keratectomy (PRK). METHODS: A retrospective review of patients who underwent alcohol-assisted PRK was performed. Data were abstracted on age, gender, contact lens (CL) wear, preoperative refractive errors, keratometry, topographic and ultrasonic pachymetry, and intraoperative OCP measurements before and after epithelium removal. The central ET was calculated by subtracting OCP measurement after epithelium removal from the OCP measurement prior to epithelium removal. RESULTS: The study comprised of 162 consecutive eyes from 81 patients. Mean age was 26.73 ± 6.47 years, 50.6% were males. CL was used in 92 eyes (56.8%). The mean sphere and spherical equivalent were -3.60 ± 1.84 D and -3.26 ± 1.85D, respectively. The mean intraoperative ET was 58.22 ± 17.53 µm (range, 15-121µm). Fifty-five percent of the eyes had an ET measurement above or below the range of 40-60µm. ET was significantly higher in the second operated eye compared to the first operated eye (p = 0.006), and an association was found to CL-wear (p = 0.03). There was no significant difference in thickness between genders (p = 0.62), and no correlation to patient age (p = 0.45, rp = 0.06), refractive errors (p > 0.30,rp=-0.07-0.08), nor keratometry(p > 0.80, rp=-0.01- (-0.02)). CONCLUSION: The intraoperative assessment of ET in alcohol-assisted PRK showed a high variability of the central corneal epithelium, with a significant difference between the first and second operated eyes. This difference may have implications when the epithelium is not included in the surgical planning in surface ablation.

Ex Vivo Histological Analysis of Corneas with Manually Implanted Intracorneal Stromal Ring Segments.

Backgrond: Intracorneal ring segments (ICRSs) are utilized to correct refractive changes impacting visual acuity, commonly implanted via femtosecond laser but can also inserted manually. Corneal deposits alongside the ICRS channels are seen commonly. Methods: This study explores the histological characteristics of corneal deposits following manual ICRS implantation, comparing them to previously published articles describing femtosecond laser-assisted cases. Results: This is a retrospective analysis of three cases involving manual ICRS implantation, accumulation of whitish deposits and later explanation of the corneas due to penetrating keratoplasty (PKP). Patient demographics, ocular history, and surgical details were collected. Histological analysis employed Hematoxylin and Eosin (H&E) and Masson's trichrome staining. Whitish deposits along ICRS tracts were observed in all cases, with minimal fibroblastic transformation of keratocytes adjacent to the segments. Comparing these cases of manual to femtosecond laser-assisted ICRS implantation, in most cases, similar deposits were identified, indicating the deposits' association with the stromal tissue reaction to the ring segment and not to the surgical technique. Conclusions: This study contributes insights into the histopathology of manually implanted ICRS, emphasizing the shared nature of deposits in both insertion methods. The findings highlight the link between deposits and the stromal tissue reaction to the ring segment, irrespective of the insertion technique.

Intraoperative Assessment of the Stromal Ablation in Photorefractive Keratectomy.

Purpose: To evaluate the difference between planned and measured central ablation depth (CAD) and compare the first and second operated eye in simultaneous bilateral myopic alcohol-assisted PRK. Methods: A retrospective review of patients was performed. Demographic and preoperative data was abstracted. Intraoperative assessment included environmental data, laser-planned algorithm of ablation (L-CAD), and optical coherence pachymetry (OCP) measurements. The true stromal ablation depth (O-CAD) was calculated by subtracting the immediate post-ablation OCP measurement from the OCP measurement before laser ablation. Deviation in pachymetry (DP) between O-CAD and L-CAD was also assessed. Results: The study comprised 140 eyes from 70 consecutive patients. The mean age was 26.91 ± 6.52 years, and 57.1% were females. O-CAD was significantly correlated to preoperative refractive errors and intraoperative laser settings. DP was not correlated to any of the pre- or intraoperative parameters. L-CAD showed a significant underestimation as compared to O-CAD (67.87 ± 25.42 µm and 77.05 ± 30.79 µm, respectively, p < 0.001), which was shown in 74.3% of the cases. A moderate agreement between the two methods was noted, with a mean deviation of 17%. This difference was maintained for each eye individually (p < 0.001). In addition, DP was significantly higher in the first operated eye as compared to the second operated eye (11.97 ± 16.3 µm and 6.38 ± 19.3 µm respectively, p = 0.04). Conclusion: The intraoperative assessment of stromal ablation showed significantly higher central ablation depth values compared to the laser-planned ablation algorithm. The deviation in pachymetry was higher in the first, compared to the second, operated eye. Awareness is warranted as to the discrepancy between preoperative planning and intraoperative assessment.

Differentiating highly asymmetric keratoconus eyes using a combined Scheimpflug/Placido device.

PURPOSE: To determine the ability to differentiate between normal eyes and clinically unaffected eyes of patients with highly asymmetric keratoconus (AKC) using a Scheimpflug/Placido device. SETTING: Tel Aviv Sourasky Medical Center and Enaim Medical Center, Israel. DESIGN: Retrospective case-control. METHODS: Imaging from a combined Scheimpflug/Placido device (Sirius, C.S.O.) was obtained from 26 clinically unaffected eyes of patients with frank keratoconus in the fellow eye, and 166 eyes from 166 patients with bilaterally normal corneal examinations that underwent uneventful corneal refractive surgery with at least 1 year of follow-up. Receiver operating characteristic curves were produced to calculate the area under the curve, sensitivity, and specificity of 60 metrics, and finally a logistic regression modeling was used to determine optimal variables to differentiate populations. RESULTS: The most predictive individual metric able to differentiate between 26 eyes in the case group to 166 eye in the control group was the posterior wall inferior-superior (I-S) ratio, with an receiver operating characteristics (ROC) of 0.862. A combination model of 4 metrics (posterior wall I-S ratio in the central 3 mm, thinnest pachymetry coordinate on the x horizontal axis, posterior asymmetry and asphericity index, corneal volume) yielded an ROC of 0.936, with a sensitivity/specificity pair of 92.3%/87%. Variables related to elevation were not found significant. CONCLUSIONS: Using a combination of metrics from a combined Scheimpflug/Placido device, a practical model for discrimination between clinically normal eyes of patients with highly AKC and normal eyes was constructed. Variables related to pachymetry and posterior cornea asymmetry were the most impactful.

Bioptics for high hyperopia with combined multifocal intraocular lens implantation and excimer ablation in young patients.

PURPOSE: To analyze the visual and refractive outcome of the bioptics procedure combining multifocal intraocular lens implantation and excimer laser surgery in young patients with high hyperopic eyes not suitable for a single surgical procedure. METHODS: This retrospective case series included 10 eyes of five patients (age range 18-30 years) with high hyperopia (spherical equivalent +8.51 ± 0.85 diopters (D)). They had been treated with serial multifocal intraocular lens implantation followed 6 weeks later by laser in situ keratomileusis for residual hyperopia. Uncorrected distance visual acuity, uncorrected near visual acuity, corrected distance visual acuity, corrected near visual acuity, and manifest refraction were evaluated before surgeries, after multifocal intraocular lens implantation, and 3 months post laser in situ keratomileusis. RESULTS: No patients were lost to follow-up (6 months). The mean spherical equivalent decreased to +2.05 ± 1.33 D after multifocal intraocular lens implantation and to -0.10 ± 0.58 D after the laser in situ keratomileusis procedure. Success of the procedures was determined by uncorrected visual acuity. LogMAR uncorrected distance visual acuity improved by a total of more than six lines from 1.05 ± 0.18 LogMAR to 0.46 ± 0.12 LogMAR post multifocal intraocular lens implantation and to 0.15 ± 0.06 LogMAR after both surgeries. The LogMAR uncorrected near visual acuity increased by 0.81 ± 0.82 LogMAR after lens implantation due to loss of accommodation, and all eyes reached a LogMAR of 0 at 1 month postoperatively following laser in situ keratomileusis. CONCLUSIONS: A bioptics approach involving multifocal intraocular lens followed 6 weeks later by a laser in situ keratomileusis procedure for the correction of very high hyperopia enabled the resolution of the residual refractive error in young very high hyperopic patients.

Correction ratio and vector analysis of femtosecond laser arcuate keratotomy for the correction of post-mushroom profile keratoplasty astigmatism.

PURPOSE: To evaluate the refractive and keratometric effect of arcuate keratotomy using femtosecond technology in patients with high post-keratoplasty astigmatism with a mushroom profile. SETTING: Enaim Refractive Center, Tel-Aviv, Israel. DESIGN: Noncomparative prospective interventional case series. METHODS: The arcuate depth incision was set to 80% of the minimal graft thickness, with a 60-degree angle. The mean diameter was 5.79 mm ± 0.32 (SD) according to the graft size. Patient evaluation included logMAR corrected distance visual acuity (CDVA), refraction, keratometry (K), and a complete eye examination. RESULTS: Twenty-seven eyes of 27 patients after keratoplasty surgery were included. Both uncorrected distance visual acuity and logMAR CDVA improved after surgery. The preoperative mean logMAR CDVA was 0.29 ± 0.37 (SD), which improved by 1 line (to 0.19 ± 0.10; P = .01). The mean refractive astigmatism was -8.43 ± 2.80 diopters (D) (range -4.5 to -15 D), and it declined at the 3-month postsurgical follow-up to -4.31 ± 0.23 D (P < .001) and remained stable until the end of follow-up (-3.31 ± 1.39 D; P = 1.00). The K value decreased by 1.18 D (P < .001). There were no complications or adverse effects during the follow-up period. CONCLUSIONS: Arcuate keratotomies performed with the femtosecond laser showed good results. There was a more than 50% decrease in post-mushroom profile keratoplasty astigmatism as well as stability of the results over 1 year. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Air-pulse corneal applanation signal curve parameters for characterization of astigmatic corneas.

PURPOSE: The aim of this study was to test the 42 parameters of the ocular response analyzer for distinguishing between the biomechanical properties of emmetropic eyes with normal topography and eyes with moderate-to-high with-the-rule astigmatism (WTA) and against-the-rule astigmatism (ATA) that have symmetric bowtie topography. METHODS: This retrospective case series study included 37 patients (37 studied eyes) with WTA astigmatism and 35 patients (35 studied eyes) with ATA astigmatism. The control group consisted of 70 patients with emmetropia (70 studied eyes) with normal topography. We first tested correlations of the parameters that describe the applanation curve during ocular response analyzer measurements with the maximum keratometry values and the corneal thickness in all 3 groups. We then evaluated the significant parameters among them in search of any group differences in the biomechanical properties of the cornea. RESULTS: Fifteen parameters correlated with Kmax reading values or corneal thickness values. The correlation coefficients (r) were low. The best correlated parameters were p1area, p2area, h1, dive1, p2area1, h11, h2, and h21. The ATA group had the highest number of parameters (n = 6) with significant differences compared with the control group. Only p2area was predictive for ATA. In contrast, the WTA group had only 1 parameter (p2area1) that was found to be significantly different compared with the control group. CONCLUSIONS: Some of the new waveform parameters can distinguish between patients with ATA and WTA and normal topography patterns and may delineate the differences in biomechanical properties between these groups that may predict the risk of corneal ectasia after laser in situ keratomileusis.

Topical 0.03% tacrolimus for subepithelial infiltrates secondary to adenoviral keratoconjunctivitis.

OBJECTIVE: To determine the safety and efficacy of topical 0.03% tacrolimus ointment treatment for subepithelial corneal infiltrates (SEIs). METHODS: This prospective non-controlled interventional case series included patients with SEIs who had been previously treated with topical corticosteroids with either no improvement or the medication being withdrawn due to associated intraocular pressure (IOP) elevation. The patients were treated with 0.03% tacrolimus ointment twice daily for 22 weeks (including a 1-month washout). The objective data were best-corrected Snellen visual acuity (BCVA), IOP, and full ocular examination results, including SEI severity and the Schirmer test. The subjective data were the patients' responses to a questionnaire at all follow-up visits. RESULTS: The patients consisted of five males (45%) and six females (55%) (mean age 50 ± 11 years) who were followed up for an average of 22 weeks. The mean BCVA (logarithm of the minimum angle of resolution [logMAR]) before and after treatment was 0.34 ± 0.09 and 0.08 ± 0.04 respectively (p = 0.042). All the patients evidenced significant objective clinical improvement, and none had a severe degree of SEI at the end of the treatment. The patients reported considerable reduction in the severity of their symptoms (foreign body sensation, glare, etc.). Three patients were excluded due to side-effects (one had severe dizziness and discomfort), and their data were excluded from the study. CONCLUSION: Topical tacrolimus 0.03% is a safe and effective alternative treatment in patients with SEIs who do not respond to other treatment modalities or have untoward side-effects from topical steroids.

Monovision surgery in myopic presbyopes: visual function and satisfaction.

PURPOSE: To describe our experience with monovision excimer laser correction in individuals with myopic presbyopia. METHODS: This prospective interventional case series was conducted in a private refractive surgery center on 40 patients with presbyopia aged 40 years and older, who were treated with monovision refractive surgery between 2010 and 2011. The dominant eye was corrected for distance vision and the nondominant eye was corrected for near vision, with anisometropia of ≥1.00 diopters (D). All patients underwent comprehensive objective and subjective visual assessments, including a questionnaire that was filled out preoperatively and at 6 and 12 months postoperatively. The primary outcomes were preoperative and postoperative refraction, binocular visual acuity, stereopsis, contrast sensitivity, glare, and questionnaire results. RESULTS: The 1-year follow-up was completed by 38 patients (95%). Preoperative and 1-year postoperative refraction of the distance eye spherical equivalent (SE), anisometropia SE, and uncorrected visual acuity were -4.05 ± 1.94 and -0.01 ± 0.22 D, 0.45 ± 0.50 and 1.73 ± 0.56 D, and 0.87 ± 0.2 and 0.09 ± 0.11 logMAR, respectively. Best-corrected visual acuity was unchanged. Both mean distance and near stereopsis decreased, from 52 to 142 seconds of arc and from 54 to 57 seconds of arc, respectively. Contrast sensitivity and glare decreased significantly. Patient satisfaction improved from 41.5 ± 30.4% to 85.2 ± 5.0% (range, 40 to 100%) at the 1-year follow-up. CONCLUSIONS: Monovision excimer laser correction provides both effective and satisfactory results and should be considered as an option for individuals with myopic presbyopia suitable for, and interested in, refractive surgery.

Simultaneous wavefront-guided photorefractive keratectomy and corneal collagen crosslinking after intrastromal corneal ring segment implantation for keratoconus.

PURPOSE: To study the results of simultaneous photorefractive keratectomy (PRK) and corneal collagen crosslinking (CXL) in keratoconus after previous intrastromal corneal ring segment (ICRS) implantation. SETTING: Enaim Laser Center, Jerusalem, Israel. DESIGN: Case series. METHODS: This study comprised patients with moderate keratoconus who had previous Intacs ICRS implantation with the Intralase laser at least 6 months before PRK-CXL. Wavefront-guided PRK and ultraviolet-A CXL were performed simultaneously. Refraction, uncorrected (UDVA) and corrected (CDVA) distance visual acuities, keratometry (K) values, endothelial cell count (ECC), pachymetry, corneal resistance factor (CRF), and corneal hysteresis (CH) were assessed 3, 6, and 12 months postoperatively. RESULTS: Twelve months after PRK-CXL, the mean decimal UDVA improved significantly from 0.20 ± 0.12 (SD) to 0.55 ± 0.15 (P<.01). The mean decimal CDVA improved from 0.58 ± 0.13 to 0.77 ± 0.17 (P=.01). The mean cylinder decreased from -3.60 ± 1.70 to -1.30 ± 1.10 diopters (D) (P<.001). The mean apex K decreased from 50.91 ± 5.50 D to 46.61 ± 4.52 D (P<.005). The other corneal parameters did not change significantly after treatment. No significant difference was found between the 6-month and 12-month results. No patient lost lines of CDVA. Mild haze remained in 11.1% of eyes 12 months after treatment. CONCLUSIONS: Simultaneous wavefront-guided PRK and CXL for keratoconus after ICRS implantation was safe and effective. It significantly improved the UDVA, CDVA, and central K value, and consequently the visual function, of patients with moderate keratoconus.

Contamination of contact lens storage cases of asymptomatic refractive surgery candidates.

PURPOSE: To examine the rates of contamination of contact lens storage cases of refractive surgery candidates and compare the growth yields of the traditional method of culturing and a broth-based method. METHODS: Thirty contact lens storage cases of 16 asymptomatic refractive surgery candidates were studied. Samples from the lens storage case fluid were inoculated into Bactec Peds Plus F broth (Becton Dickinson) and also directly onto blood agar, chocolate agar, and Sabouraud dextrose agar ("traditional method"). Another sample was processed for amoebal contamination. The rate of contamination of cases and the types of pathogens were evaluated for the broth-based and traditional culturing methods. Correlation between right and left storage cases of the same patient was defined as contamination of the two compartments with the same pathogen or pathogens. To avoid statistical bias, only one compartment was included in the study for these patients. RESULTS: Four storage cases were omitted due to growth correlation between right and left storage cases. Of the remaining 26 storage cases, 16 (61.5%) were found to be contaminated using the broth-based method and 10 (38.5%) using the traditional method (P=.011). High contamination rates were observed regardless of the type of disinfecting solution or type of contact lens used. CONCLUSIONS: The broth-based method had significantly greater culture yield than the traditional method. The high rates of contamination of contact lens storage cases of refractive surgery patients may put this cohort at greater risk than non-contact lens wearing candidates for developing postoperative infections.

Femtosecond thin-flap LASIK for the correction of ametropia after penetrating keratoplasty.

PURPOSE: To evaluate the outcomes of LASIK with thin femtosecond laser flaps for the treatment of refractive errors after penetrating keratoplasty (PK). METHODS: Eleven consecutive eyes underwent femtosecond thin-flap LASIK 51.6+/-42.1 months (range: 13 to 156 months) after the initial PK. A full ophthalmic assessment was performed before femtosecond LASIK and 6 months after surgery. Postoperative retreatments were also noted. RESULTS: No intra- or postoperative complications were observed. The outcomes of nine eyes that completed at least 6 months' follow-up and had no retreatment during that period were evaluated. Mean preoperative myopia decreased from -3.60+/-1.60 diopters (D) to +1.00+/-2.70 D 6 months after surgery, and mean hyperopia decreased from +3.50+/-1.30 D preoperatively to +0.30+/-0.70 D 6 months after surgery. Mean preoperative astigmatism decreased from -6.60+/-3.60 D to -2.90+/-2.00 D 6 months after surgery. At 6 months, the mean preoperative myopic spherical equivalent refraction (SE) decreased from -6.40+/-2.00 D to -0.02+/-2.20 D, and mean hyperopic SE from +0.80+/-2.80 D to -0.60+/-0.60 D. At 6 months postoperatively, 67% (6/9) of eyes were within 1 line of preoperative best spectacle-corrected visual acuity and 33% (3/9) gained > or =2 lines. CONCLUSIONS: Femtosecond thin-flap LASIK is a safe procedure in eyes with previous PK. This procedure is reasonably predictable, especially for the spherical component of the refraction. Creating the flap with the femtosecond laser and performing excimer laser ablation within the corneal graft limits without involving the graft-host junction provides the advantage of performing the entire procedure in one step.

Toxic anterior segment syndrome following iris-supported phakic IOL implantation with viscoelastic Multivisc BD.

PURPOSE: To report on the association between Multivisc BD and toxic anterior segment syndrome (TASS) post phakic intraocular lens (IOL) implantation. METHODS: Two patients developed severe toxic anterior chamber inflammation following implantation of phakic iris fixated IOL with Multivisc BD viscoelastic. Anterior chamber washout was performed with intracameral antibiotic injection. Local antibiotics were continued until cultures were found to be negative. Thereafter, intensive local and systemic steroids were initiated and gradually tapered down. RESULTS: The inflammatory reaction disappeared completely and the visual acuity improved from hand motion to 6/9 without correction within 1 week. CONCLUSIONS: Any viscoelastic material may be contaminated by heat-stable bacterial endotoxic as it is prepared by gene-coded bacteria. It is suggested that Multivisc BD was the etiologic factor of TASS. Refractive surgeons should be aware of this rare complication of phakic IOL implantation whenever they use a new viscoelastic material.

Effect of thin femtosecond LASIK flaps on corneal sensitivity and tear function.

PURPOSE: To evaluate changes in comeal sensitivity and tear function following myopic LASIK with thin femtosecond flaps. METHODS: A retrospective study was performed to compare corneal sensitivity (filament), tear breakup time, and anesthetized Schirmer test preoperatively and at 1 week and 2 and 6 months postoperatively. RESULTS: Seventy-two eyes of 38 consecutive patients (20 women and 18 men) who underwent LASIK for myopia or myopic astigmatism with thin femtosecond flaps (IntraLase femtosecond laser system and Technolas 217 PlanoScan V2.9992 or wavefront-guided Zyoptix 3.1 excimer laser) were evaluated. Preoperative mean corneal sensitivity was 5.3+/-1.5 mm, which decreased to 4.6+/-1.7 mm at 1 week, increased to 5.0+/-1.3 mm at 2 months, and returned to baseline values at 6 months postoperatively. Mean Schirmer score was 13.7+/-5.7 mm preoperatively and 12.1+/-5.1, 13.1+/-4.8, and 13.0+/-5.1 mm at 1 week and 2 and 6 months postoperatively, respectively. Mean tear breakup time was 7.7+/-2.6 seconds preoperatively and 7.8+/-3.5, 9.2+/-4.6, and 8.8+/-4.5 seconds at 1 week and 2 and 6 months postoperatively, respectively. No significant increase in fluorescein staining was observed throughout follow-up. CONCLUSIONS: Reductions in corneal sensitivity and tear function tests were minimal after myopic LASIK with thin femtosecond flaps. Despite the relatively narrow hinge, the thin, uniform femtosecond flap does not appear to have an adverse effect on corneal sensitivity and dry eye signs at 6 months postoperatively.

Intacs adjustment surgery for keratoconus.

PURPOSE: To describe the visual outcome of keratoconic eyes managed with Intacs (Addition Technology, Inc.) that required additional Intacs surgery (defined as any combination of removal, exchange, addition, or shifting of an Intacs segment). SETTING: Private refractive surgery center, Jerusalem, Israel. METHODS: This retrospective noncomparative interventional consecutive small case series studied all eyes of a cohort of 58 keratoconic eyes managed with Intacs that had additional Intacs surgery. The uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity, manifest refraction, videokeratography, and patient questionnaires on visual function were assessed. These outcome measures were compared before Intacs implantation, before Intacs adjustment, and 1 year after the final Intacs adjustment. Eyes having any intervention other than Intacs surgery were excluded. RESULTS: Of 58 keratoconic eyes managed with Intacs, 7 had additional Intacs surgery. After the initial Intacs surgery, 6 of these eyes had UCVA < or =20/100 and 1 had UCVA of 20/50. After the final Intacs adjustment, 3 eyes achieved UCVA > or =20/40, 5 achieved UCVA > or =20/70, and 2 remained <20/200. The indications for Intacs adjustments were increased astigmatism in 4 eyes, induced hyperopia (overcorrection) in 3, and undercorrection in 1. One eye had both surgically induced astigmatism and hyperopia. Induced astigmatism and hyperopia were most often managed by removing the superior segment. The undercorrected eye, having initially received a single inferior segment, was treated by implanting a superior segment. CONCLUSIONS: Approximately 10% of keratoconic eyes managed with Intacs may require Intacs adjustment surgery, which often has a good outcome.

Laser in situ keratomileusis in myopic patients with congenital nystagmus.

PURPOSE: To evaluate the results of laser in situ keratomileusis (LASIK) and IntraLASIK in the treatment of myopic patients with nystagmus. METHODS: Eight patients with congenital nystagmus (16 eyes), aged 23 to 49 years, had LASIK surgery. Corneal flaps were created using the Bausch & Lomb Hansatome microkeratome or the IntraLase femtosecond laser. The ablations were performed with the Bausch & Lomb excimer laser with an active tracking system. In some patients, the eyes were fixated with forceps or a fixation ring during laser ablation. RESULTS: The refractive errors were corrected in all cases. There was no decentration or loss of best corrected visual acuity greater than 1 line. In 56% of the eyes, the postoperative uncorrected visual acuity was better than the best spectacle-corrected visual acuity (BSCVA). The BSCVA improved in 62.5% of the eyes. The overall visual performance improved in all patients. One patient who did not drive before surgery became eligible for a driver's license after surgery. CONCLUSIONS: Selected patients with myopia and congenital nystagmus may benefit from laser refractive surgery. Laser refractive surgery may be safely and accurately performed using the Hansatome microkeratome or the IntraLase femtosecond laser and an active tracking system with or without mechanical fixation. The BSCVA may improve in certain patients postoperatively.

[Wavefront-guided lasek after intacs in eyes with stable keratoconus].

BACKGROUND: Keratoconus is a non-inflammatory, progressive thinning disorder of the cornea, resulting in a typical protrusion and in refractive errors and low visual acuity. Many of the patients with stable keratoconus encounter difficulties wearing glasses or contact lenses. PURPOSE: To evaluate the results of wave-front guided laser assisted subepithelial keratectomy (LASEK) for the correction of residual spherical and spherocylindrical myopia after INTACS insertion in patients with stable keratoconus. METHODS: Four eyes of keratoconus patents were treated with Zyoptix wavefront-guided LASEK for correction of residual myopia and astigmatism after insertion of INTACS. The refraction after insertion of INTACS was stable at least six months before the Zyoptix-LASEK. The mean pre-INTACS refraction was myopia of -2.37 D (range 0 to - 5.00 D) and astigmatism of -3.93 D (range -1.00 to -7.5 D). The mean refraction prior to Zyoptix-LASEK was myopia of -0.2 D and astigmatism of -2.71 D. The mean follow-up period after the Zyoptix LASEK was 8 months. RESULTS: Initially, prior to both surgeries, the mean uncorrected visual acuity was 6/240 (range count-fingers to 6/60) and at the final postoperative visit 6/12 (range 6/10 to 6/ 18). The preoperative mean best spectacle corrected visual acuity was 6/15 (range 6/10 to 6/24) and at the final postoperative follow-up visit 6/9 (range 6/8.5 to 6/12). CONCLUSION: Zyoptix wavefront-guided LASEK for correction of residual myopia and astigmatism in keratoconus patients after INTACS insertion and stable refraction provided excellent visual outcome, with no loss of visual acuity and no complications.

[Lasik in myopic patients with congenital nystagmus].

PURPOSE: To present the results of IntraLASIK treatment in myopic patients with nystagmus. METHODS: Four patients, ranging in age from 25 to 49 years, with congenital nystagmus (8 eyes), underwent IntraLASIK surgery. Corneal flaps were made by Intralase femtosecond laser. In some patients, the eyes were fixated with forceps or a fixation ring during the laser ablation. In all patients, the effect of involuntary eye movements was neutralized by an active tracking system. RESULTS: The refractive errors were corrected in all cases. There was no decentration or loss of best corrected visual acuity by more than 1 line. In 3 of 8 eyes, the post-operative uncorrected visual acuity (UCVA) was equal or better than the best spectacles corrected visual acuity (BSCVA) preoperatively. Four of the 8 eyes retained or improved their BSCVA. CONCLUSIONS: Some patients with myopia and nystagmus may benefit from laser refractive surgery. By using the Intralase femtosecond laser and an active tracking system with or without mechanical fixation, laser refractive surgery may be safely and accurately performed in selected cases of nystagmus. Certain patients improve their BSCVA postoperatively.

Keratoconus managed with intacs: one-year results.

OBJECTIVES: To describe the visual outcome of keratoconus managed with Intacs implantation (Addition Technology Inc, Fremont, Calif) and to define criteria that predict good outcome. METHODS: This retrospective, nonrandomized, comparative, consecutive case series studied 58 eyes of 43 patients with keratoconus managed by Intacs implantation. The outcome measures were analyzed pre-Intacs and 1 year post-Intacs. Preoperative parameters were correlated with outcome. MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, videokeratography, and patient questionnaires. RESULTS: Intacs were implanted in all eyes with no intraoperative complications. Six eyes underwent additional Intacs surgery. Post-Intacs, the mean +/- SD UCVA improved from less than 20/200 +/- 0.1 line to 20/50(-3) +/- 3.1 lines, the mean +/- SD BSCVA was unchanged at 20/32 +/- 2.0 lines, the mean +/- SD spherical equivalent improved from -3.88 +/- 1.64 to -1.04 +/- 1.51 diopters (D), and the mean +/- SD astigmatism improved from 3.34 +/- 2.23 to 1.97 +/- 1.51 D. Twenty-five eyes had a good outcome (UCVA> or =20/40). Multiple regression selected BSCVA, astigmatism, and spherical myopia as the preoperative predictors of outcome. CONCLUSIONS: Intacs improve myopia and regular astigmatism in keratoconus. Milder keratoconus (BSCVA>20/32(-2) and astigmatism<3.50 D) and significant spherical myopia (>-1.75) predict better outcome.

Laser in situ keratomileusis for correction of myopia in eyes after retinal detachment surgery.

PURPOSE: To evaluate the safety and efficacy of laser in situ keratomileusis (LASIK) for correction of myopia in eyes with previous retinal detachment surgery. METHODS: A retrospective review was conducted of all consecutive eyes that underwent LASIK after retinal detachment surgery. Data was collected regarding previous ocular surgery and its time prior to LASIK, intra- and postoperative complications, and visual outcome measures pre- and postoperatively. RESULTS: Ten eyes with previous retinal detachment surgery were scheduled for LASIK. One eye was excluded from data analysis as LASIK was aborted due to inadequate microkeratome suction because of conjunctival scarring. Nine eyes underwent an uneventful LASIK procedure. On average, LASIK was performed 130+/-123 months following retinal detachment surgery. Postoperative LASIK follow-up was 14.8+/-12.5 months. No significant intraoperative, postoperative, or retinal complications were observed. The mean preoperative spherical equivalent refraction was -9.00+/-3.00 diopters (D), uncorrected visual acuity (UCVA) was 0.06+/-0.02, and best spectacle-corrected visual acuity (BSCVA) was 0.64+/-0.16. At the end of follow-up, the mean spherical equivalent refraction was 0.65+/-0.88 D, mean UCVA was 0.57+/-0.14, and mean BSCVA was 0.72+/-0.19. Differences between BSCVA before and after LASIK were statistically significant (P=.038). At final follow-up, the safety index was 1.22 and efficacy index was 1.01. CONCLUSIONS: Laser in situ keratomileusis was found to be a safe and efficient option for treating refractive errors in eyes with previous retinal detachment surgery.