Bilateral Laser In Situ Keratomileusis Research Articles

Acute-Onset Visual Snow Syndrome After LASIK

PURPOSE: To describe a case of acute-onset visual snow syndrome occurring after bilateral myopic laser in situ keratomileusis (LASIK). METHODS: Case report. RESULTS: A 38-year-old man presented with a 7-month history of constant positive visual disturbances involving his entire binocular visual field after bilateral LASIK. The patient described his symptoms as a “moving texture” present at all times in all lighting conditions that he noticed beginning the evening of the same day he had LASIK. The phenomenon was worse in low lighting and was in fact present in complete darkness, even when his eyes were closed. The patient also endorsed large halos, nyctalopia, and enhanced entoptic phenomena in both eyes, all of which had subjectively worsened after LASIK. Topography-guided customized ablation treatment enhancement had been performed to reduce the patient's symptoms without success. On presentation, uncorrected distance visual acuity was 20/16 in both eyes. Results of slit-lamp examination and corneal imaging were unremarkable in both eyes. The patient was eventually fit with scleral contact lenses, which reduced his halos at night but did not improve his visual snow symptoms. CONCLUSIONS: Although visual snow and visual snow syndrome have been known to present suddenly in a subset of cases, this is the first published case report of acute-onset visual snow syndrome immediately after refractive surgery. Visual snow syndrome has reportedly been preceded by specific events, including migraine attacks, medications, and trauma. Because the symptoms are non-ocular in origin, further refractive surgery enhancement is not indicated. [ Journal of Refractive Surgery Case Reports. 2022;2(3):e51–e54.]

Wavefront-guided myopic laser in situ keratomileusis with a high-resolution Hartmann-Shack aberrometer and a new nomogram.

To evaluate visual, refractive, aberrometric, and patient-reported outcomes of wavefront-guided (WFG) myopic laser in situ keratomileusis (LASIK) using a high-resolution Hartmann-Shack aberrometer (iDesign Advanced WaveScan system) with a new nomogram and to determine whether the new nomogram resolved the mild undercorrection that occurs with the manufacturer's default settings. Three private LASIK practices. Prospective, open-label, noncomparative, multicenter study. One hundred ninety eyes of 95 patients underwent bilateral WFG LASIK for the correction of myopia or myopic astigmatism. A new nomogram was used, which effectively adjusted the wavefront-measured refraction sphere up or down to equal the manifest refraction sphere. Patients were followed up for 6 months. Eighty-four patients completed the final follow up. At 6 months, 162 (96.4%) of 168 eyes achieved monocular uncorrected distance visual acuity of 20/20 or better. No eye lost 2 or more lines of corrected distance visual acuity. The safety and efficacy indices were 1.12 and 1.09, respectively; 164 (98%) of 168 eyes had manifest refraction spherical equivalent within ±0.50 diopters (D) of emmetropia, and 154 (92%) of 168 eyes had residual manifest refractive astigmatism of 0.50 D or less. Fewer patients experienced burning, stinging, soreness, and irritation postoperatively than preoperatively. Eighty-one (96%) of 84 patients reported improved quality of life. WFG myopic LASIK using a high-resolution Hartmann-Shack aberrometer and a new nomogram resolved the undercorrection with the manufacturer's default settings. The treatment was safe and effective with excellent visual and refractive outcomes, high patient satisfaction, and improved quality of life.

Case Report: Serial Topography Analysis After Acute Unilateral Diffuse Lamellar Keratitis

Abstract
 Significance: Diffuse lamellar keratitis (DLK) is a widely reported complication of laser in-situ keratomileusis (LASIK); however, serial topography tracking the resolution of the condition is sparse. This case illustrates the healing profile which may be expected following an episode of DLK, and the patient reassurances which may be appropriate.
 Purpose: To report the topography changes and refractive resolution associated with a case of acute unilateral diffuse lamellar keratitis following bilateral femtosecond-assisted hyperopic LASIK.
 Case Report: A healthy 53-year old male presented with grade two-plus diffuse lamellar keratitis (DLK) 11 days after undergoing successful bilateral wavefront optimized (Alcon, Fort Worth, USA), femtosecond-assisted hyperopic LASIK. Resolution of the DLK was achieved in three weeks with topical corticosteroids. Stabilization of the patient’s topography and refractive error was observed two months after the resolution of the DLK.
 Conclusions: This case suggests that improvements in corneal topography and refractive error can be expected long after the clinical signs of DLK have subsided. Corneal irregularities and residual refractive errors (usually hyperopia and astigmatism) which exist at the time of resolution on gross examination should be monitored regularly and patients may be reassured that improvements appear likely even after topical regimens have been completed.

Does Pregnancy Affect Refractive and Corneal Stability or Corneal Epithelial Remodeling After Myopic LASIK?

To investigate possible refractive changes in pregnant women who have previously undergone myopic laser in situ keratomileusis (LASIK). This prospective study included 64 pregnant women (128 eyes) who had previously undergone bilateral myopic LASIK. Uncorrected distance visual acuity (UDVA), spherical equivalent, corneal keratometry, topography and tomography, and epithelial mapping were evaluated before LASIK, 12 months after LASIK, during the third trimester of pregnancy, and 1 year postpartum. The average age at the time of recruitment was 32.5 ± 5 years (range: 24.5 to 39.5 years). The evaluation during pregnancy was at an average 55 months (range: 12 to 108 months) from the initial LASIK procedure. The preoperative mean refractive error was -6.72 ± 2.96 diopters (D) (range: -1.00 to -11.00 D). Comparing 12-month refractive data after the original LASIK procedure to the those within the third trimester of the subsequent pregnancy, the average UDVA was 20/18, the residual refractive error was -0.63 ± 1.00 to -0.51 ± 0.82 D, the steepest keratometry value was 40.85 ± 1.89 to 40.88 ± 2.84 D, and the central epithelial thickness was 56.4 ± 3.89 to 57.38 ± 5.04 µm, respectively. In this study, pregnancy did not affect the refractive stability of LASIK. Pregnancy-related changes in refractive error, corneal stability, and total corneal and epithelial thickness in women after LASIK were not found to be statistically significant. [J Refract Surg. 2022;36(2):118-122.].

Long-term course of contrast sensitivity in eyes after laser-assisted in-situ keratomileusis for myopia.

Purpose:To evaluate the long-term contrast sensitivity (CS) after laser in-situ keratomileusis (LASIK) for myopia.Methods:This retrospective, single-center, cohort study involved 190 eyes of 95 patients who underwent bilateral LASIK between January 2001 and October 2007. This study includes patients who underwent CS and higher-order aberration (HOA) measurements in a five-year postoperative period. For all enrolled patients, visual acuity, refractive error (RE) in diopters (D), CS at 3-, 6-, 12-, and 18-cycles per degree (cpd), and HOA in a 4 mm area of the dilated pupil were measured before surgery and 6 months, 1 year, and 5 years after it.Results:The mean RE measured before the surgery and after 6 months, 1 year, and 5 years after was - 6.08 ± 2.50D, −0.26 ± 0.65D, −0.28 ± 0.65D, and −0.48 ± 0.80D, respectively. There were no clinically significant changes between preoperative results and the measures taken 6 months, 1 year, and 5 years after surgery. The slight increase in HOA had little effect on CS over the mid to long-term postoperative period.Conclusion:Our findings show that CS does not clinically change post LASIK. Although we were unable to identify the specific mechanism, we theorize that after LASIK there is a possibility for the compensation of HOA.

Prospective, Randomized, Contralateral Eye Comparison of Wavefront-Guided and Wavefront-Optimized Laser in Situ Keratomileusis

To compare outcomes in wavefront-optimized (WFO) laser insitu keratomileusis (LASIK) to high-resolution wavefront-guided (WFG) LASIK. Randomized, fellow eye controlled, clinical trial. A total of 200 eyes of 100 patients with myopia or compound myopic astigmatism undergoing bilateral LASIK between October 2015 and February 2017 underwent wavefront-optimized (WFO) LASIK in 1 eye and wavefront-guided (WFG) LASIK in the fellow eye. Each eye was evaluated for uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), contrast sensitivity, refractive error, and wavefront aberrometry. Outcome measurement primarily UDVA at 12months. Secondary outcomes were safety, predictability, stability, refractive error, CDVA, contrast sensitivity, and higher-order aberrations at 12months. WFG LASIK had higher levels of supervision and better contrast sensitivity compared to WFO. Both types had excellent postoperative UDVA results, without a significant difference in either mean UDVA or frequency of achieving a specified UDVA, for example, 20/16 or better (all P > 0.05). The mean gain in lines of CDVA was significantly higher in the WFG than in the WFO group (0.80 ± 0.75 vs 0.62 ±0.72, respectively; P= 0.04). The WFG cohort had significantly better contrast sensitivity for mean and frequency of achieving >20/40 for <5% low-contrast sensitivity (37.1%; 95% confidence interval [CI], 27.5-46.7 vs 24.7%; 95% CI, 16.2-33.3, respectively; P=0.01) and >20/32 for <25% low-contrast sensitivity (10.3%; 95% CI, 4.3-16.4 vs 4%, respectively; 95% CI, 0.0-8.1, respectively; P= 0.04). The WFO group had a significantly higher frequency of <0.25 diopters (D) of refractive astigmatism at 12months (82.5%; 95% CI, 75.0-90.0; vs 72.1%, respectively; 95% CI, 63.2-81.2; P= 0.02) but not <0.50 D (95.6%; 95% CI, 91.9-99.8; vs 96.9, respectively; 95% CI, 93.5-100; P= 0.61). The WFG group was significantly closer to emmetropia for both sphere and spherical equivalents at all time points. Trefoil was significantly lower in the WFG group and was also significantly lower than preoperative measurements. Wavefront-optimized and high-resolution wavefront-guided LASIK achieve excellent visual outcomes. Nonetheless, treatments based on a high-resolution aberrometer appear to offer superior results in some regards.

Patient-reported vision-related quality of life after bilateral wavefront-guided laser in situ keratomileusis

To evaluate functional vision and quality-of-life outcomes after bilateral wavefront-guided laser insitu keratomileusis (LASIK). Byers Eye Institute, Stanford University School of Medicine, Palo Alto, California, USA. Prospective case series. Visual acuity, refractive error, and aberrometric measurements were obtained preoperatively and 1, 6, and 12months after bilateral wavefront-guided LASIK. The Refractive Status and Vision Profile questionnaire scores were completed at each timepoint and compared with baseline scores. The study comprised 84 eyes of 42 patients (aged 24 to 47years). At 1year, 76 eyes (90.5%) had an uncorrected distance visual acuity of 20/20 or better and 88.1% of patients were satisfied with their vision without correction. Total refractive status and vision profile scores improved significantly from a mean of 30.9 points at baseline to 20.7 points 1year postoperatively (P<.001). The visual function, perceptions, and problems with corrective lenses subscales statistically significantly improved from preoperatively to postoperatively (all P<.001). In contrast, the driving (P=.286) and visual symptoms subscales (P=.199) did not show significant changes from baseline to 1year. Wavefront-guided LASIK not only afforded clinically measurable improvements in vision but also significant improvements in subjective functional vision and vision-related quality of life 1year after surgery.

Case Studies of &amp;lt;i&amp;gt;Mycobacterium abscess&amp;lt;/i&amp;gt; Infection after Laser in Situ Keratomileusis

Background: Infectious keratitis after refractive surgery is uncommon, and mycobacterium abscess has never been observed in corneal infections in China. Purpose: To propose an unusual presentation of two cases about Mycobacterium abscess infection after laser in situ keratomileusis (LASIK). Participants: Both cases 1 and 2 were females who exhibited a corneal ulceration after LASIK in the same hospital. Methods: The first patient in the study was a 28-year-old woman who underwent Epi-LASIK surgery in both eyes. She developed an infectious corneal ulcer in one eye after 50 days post-surgery. She was referred to our out-patient clinic 3 months post-surgery with corneal perforation, and was treated with a therapeutic penetrating keratoplasty. The second patient was a 27-year-old woman who developed infectious keratitis in one eye after 2 months after bilateral LASIK and was referred to us 3 months later. Results: Cultures in both the cases were identified as a Mycobacterium abscess, and case 1 was treated with penetrating keratoplasty eventually, while case 2 recovered after sensitive treatment. Conclusions: Infectious keratitis after refractive surgery is uncommon, and Mycobacterium abscess has never been observed in corneal infections. An accurate diagnosis and identification of the causative agent is very important.

Early recovery of quality of vision and optical performance after refractive surgery: Small-incision lenticule extraction versus laser in situ keratomileusis

To assess the early time course of the visual function after small-incision lenticule extraction (SMILE) and laser insitu keratomileusis (LASIK). Quinze-Vingts National Ophthalmology Hospital, Paris, France. Prospective case series. Patients scheduled for bilateral small-incision lenticule extraction or LASIK were consecutively enrolled. In addition to standard refraction and visual acuity, contrast sensitivity, aberrometry, and patient-reported quality of vision and overall satisfaction were measured 1day, 7days, and 1month postoperatively. Each group comprised 23 patients (46 eyes). The postoperative contrast sensitivity was better in the LASIK group at 1day (P=.014) and 7days (P=.001) but not at 1month. No significant differences in visual acuity, efficacy, or safety were found between the 2 groups throughout the follow-up. The objective scatter index assessed by double-pass aberrometry was better after LASIK 1day postoperatively (P=.036) but was not statistically different thereafter. The patient-reported quality of vision was significantly worse in the small-incision lenticule extraction group than in the LASIK group at 7days (P=.010). Global satisfaction did not differ between groups throughout the study. Significant correlations were found between contrast sensitivity and aberrometry in both groups at all examinations. Targeted analysis of early quality of vision through objective and subjective methods suggested that compared with LASIK, a slight delay in corneal optical recovery after small-incision lenticule extraction might lead to reduced contrast sensitivity and specific patient-reported visual disturbance during the first postoperative week with no effect on overall patient satisfaction.

Retreatment Rate Following Supracor Treatment of Hyperopic Presbyopia

Objective: To report the retreatment rate and safety of presbyopia treatment using the corneal laser in situ keratomileusis (LASIK) procedure, Supracor. Methods: In this case series, bilateral LASIK using the Supracor algorithm was performed on consecutive hyperopic presbyopic patients. All patients were followed for a minimum of six months postoperatively. The principal outcome measures were retreatment rate, safety, efficacy in terms of uncorrected distance visual acuity (UDVA) and uncorrected reading ability (vocational reading test), patient satisfaction, stability and predictability. Results: 76 eyes of 38 patients were treated. 42% of patients (16 patients) that were treated required at least one re-treatment. The mean preoperative manifest refractive spherical equivalent (MRSE) was +1.90 D ± 1.01 D. The mean MRSE following all treatments was -0.24 D ± 0.62 D. The UDVA was 20/20 or better in 38%, and was 20/30 or better in 91% of eyes following all treatments. 12% of eyes lost 1 line of Snellen corrected distance visual acuity (CDVA), and 3% lost 3 lines of Snellen CDVA following the primary treatment. 14% of eyes had lost 1 line of Snellen CDVA, and 4% of eyes had lost 3 lines of Snellen CDVA following all treatments. 92% of patients had uncorrected binocular near reading of J5 or better following the primary treatment. 97% of eyes had uncorrected binocular near reading of J5 or better following all treatments. Following all treatments, 82% of patients that underwent Supracor were pleased they had had the procedure performed. The mean follow-up period of patients in the study was twelve months. Conclusion: While there was a high level of near vision spectacle independence, the high retreatment rate with reduced CDVA in some cases is a cause for concern. The high retreatment rate with potentially reduced CDVA following Supracor may be due to a combination of blend zone, centration, and hyperpositive central zone issues.

Visual outcomes after femtosecond laser in situ keratomileusis flap complications

To compare visual outcomes in normal and complicated laser in situ keratomileusis (LASIK) flaps constructed with a femtosecond laser. Wilford Hall Ambulatory Surgical Center, San Antonio, Texas. Retrospective chart review. The main outcome measures were uncorrected distance visual acuity (UDVA) and best-corrected distance visual acuity (CDVA) at 1 month post-surgery, which were compared in patients with and without complications during flap creation. This retrospective chart review identified 586 eyes of 293 consecutive patients who had bilateral simultaneous femtosecond LASIK for myopia. A normal flap was attained in 539 (91.8%) of patients. At 1 month postoperatively, the mean UDVA was 20/19.1, and the CDVA was 20/16.8. 3 (0.51%) of patients experienced an incomplete side cut or intraoperative flap tear (the mean 1-month uncorrected distance visual acuity [UDVA] was 20/17.5 and the corrected distance visual acuity [CDVA] was 20/16.9 in both groups). Microstriae were seen in 28 (4.8%) of patients (mean 1-month UDVA, 20/21.7; CDVA, 20/17.4). Diffuse lamellar keratitis appeared in 4 (0.68%) of patients (mean 1-month UDVA, 20/21.7; CDVA, 20/15.6). Epithelial ingrowth developed in 9 (1.5%) of patients (mean 1-month UDVA, 20/18.7; CDVA, 20/16.9). There was no statistically significant difference in UDVA or CDVA at 1 month postoperatively between complicated and uncomplicated flaps (P > .05), and complicated flaps did not lose a statistically significant amount of CDVA or low-contrast acuity (CDVA 5%) compared to preoperative values. Intraoperative and postoperative complications of LASIK flaps created with the femtosecond laser were rare, and their visual outcomes were equivalent to those of normal flaps. Charles D. Reilly is a consultant to Alcon Labs and Abbott Medical Optics at present, but was not at the time of the study. For the remaining authors none are declared.

Standardization of laser in situ keratomileusis surgical technique evaluated by comparison of procedure time between 2 experienced surgeons

To evaluate the concordance of surgical step pacing between 2 experienced surgeons following a standardized surgical protocol for bilateral laser in situ keratomileusis (LASIK). London Vision Clinic, London, United Kingdom. Retrospective comparative case series. This was a video review comprising an equal number of consecutive bilateral LASIK patients for 2 surgeons following a standardized surgical protocol using the Visumax femtosecond laser and MEL 80 excimer laser. Timestamps were recorded for flap creation, flap lift, excimer laser ablation, and flap replacement. Total surgery time was defined with the endpoints of speculum insertion and removal. Each surgeon performed bilateral LASIK on 30 patients. The mean total surgery time was 11 minutes 17 seconds ± 1 minute 46 seconds (SD) for surgeon 1 and 12 minutes 13 seconds ± 1 minute 37 seconds for surgeon 2. The mean bilateral flap creation time was 3 minutes 5 seconds ± 24 seconds and 3 minutes 42 seconds ± 25 seconds, respectively. The mean suction time for an individual eye was 26 seconds ± 4 seconds for surgeon 1 and 23 seconds ± 1 second for surgeon 2. The difference in timing was accounted for by differences in the length of surgeon conversation with patients rather than by physical surgical steps. Bilateral LASIK procedure time was highly concordant within and between surgeons using a standardized surgical protocol. Use of a standardized surgical protocol can optimize the efficiency of corneal suction time as well as total surgical time while providing the expected equivalency in visual outcomes between surgeons.

Effect of a hyperosmotic agent on epithelial disruptions during laser in situ keratomileusis

To evaluate the incidence of epithelial disruptions during primary laser in situ keratomileusis (LASIK) with the use of a preoperative hyperosmotic treatment comprising sodium chloride 5% ophthalmic ointment (Muro-128) and to identify the incidence of epithelial disruptions in various demographic populations. TLC Laser Eye Center, McLean, Virginia, USA. Comparative case series. Using a matched-pair design, hyperosmotic treatment was randomized to 1 eye of patients having bilateral LASIK. The primary outcome measure, epithelial integrity, was assessed in each eye. Epithelial integrity was evaluated in groups defined by characteristics that included age, sex, ethnicity, skin type, presence or absence of rosacea, eye color, and hair color. The study evaluated 496 eyes of 248 patients. The preoperative hyperosmotic treatment was associated with significantly less corneal epithelial disruption, as indicated by an epithelial integrity score. Compared with control eyes, the rate of corneal epithelial disruptions in the population of treated eyes decreased by 40% (relative risk, 0.60; 95% confidence interval [CI], 0.38-0.95). Among the characteristics studied, age was the best predictor of corneal epithelial disruptions; every 1-year increase in age was associated with a 9.0% increase in the risk for corneal epithelial disruptions (odds ratio [OR], 1.09; 95% CI, 1.05-1.13). Eyes of patients older than 34 years had a 4.4 times greater odds of being associated with epithelial disturbances than eyes of patients 34 years or younger. The preoperative use of hyperosmotic agents can reduce the risk for intraoperative epithelial disruptions during LASIK. An increase in epithelial disruptions was associated with increasing age.

Safety and efficacy of a hydrogel inlay with laser in situ keratomileusis to improve vision in myopic presbyopic patients: One-year results

To study the safety and efficacy of implanting a hydrogel corneal inlay (Raindrop Near Vision Inlay) concurrently with performing laser in situ keratomileusis (LASIK) to treat myopic presbyopia and to compare the results with results of the same treatment in emmetropic and hyperopic patients. Two private clinics, Tijuana and Monterrey, Mexico. Prospective nonrandomized clinical trial. Bilateral myopic LASIK was performed and a corneal inlay was concurrently implanted in the nondominant eye under a flap created using a femtosecond laser. Primary safety outcomes were the retention of corrected distance (CDVA) and near (CNVA) visual acuities. Efficacy was evaluated on the basis of uncorrected near (UNVA), intermediate (UIVA), and distance (UDVA) visual acuities. A patient questionnaire was used to assess the preoperative and postoperative incidence of visual symptoms, the ability to perform common tasks with no correction, and patient satisfaction with vision. Thirty eyes were enrolled. At each postoperative visit, the mean CDVA and CNVA were within one half line of preoperative measurements and no eye lost 2 or more lines of CDVA. The mean binocular UDVA, UIVA, and UNVA were better than 20/25 Snellen at all postoperative visits. By 6months, 93% of patients had a binocular Snellen acuity of 20/25 or better across all visual ranges. According to patient questionnaires, 1year after surgery, visual symptoms were at preoperative levels, 98% of all visual tasks could be easily performed without correction, and 90% of patients were satisfied or very satisfied with their overall vision. A hydrogel corneal inlay with concurrent LASIK was safe and effective for treating myopic presbyopia. Drs. Garza and Chayet are consultants to and investigators for Revision Optics, Inc.

Two target locations for corneal inlay implantation combined with laser in situ keratomileusis

To compare the visual acuity outcomes between 2 target locations for corneal inlay implantation with concurrent laser in situ keratomileusis (LASIK) to compensate for presbyopia. Shinagawa LASIK Center, Tokyo, Japan. Retrospective cohort study. Bilateral LASIK was performed simultaneously with inlay implantation in the nondominant eye. The preoperative and 6-month postoperative uncorrected distance (UDVA) and uncorrected near (UNVA) visual acuities were evaluated. Patients were divided into the following 2 groups based on the pupil center to Purkinje reflex distance (Pp-Pk): small (≤300 μm) and large (>300 μm). Each group was divided into subgroups according to the distance of the inlay center to the Purkinje reflex (I-Pk) or to the midpoint between the pupil center and Purkinje reflex (I-M). The inlay position was classified as 0 to 100 μm, 101 to 200 μm, 201 to 300 μm, and 301 to 400 μm from the Purkinje reflex and from the midpoint. Of 1008 patients, 992 were available for postoperative follow-up. The UDVA and UNVA improved in both subgroups with all inlay positions (P < .0001). There were no statistically significant differences in UDVA or UNVA within or between the small Pp-Pk group and the large Pp-Pk group (P > .05). The Spearman rank-order correlation showed weak associations between the inlay distance and visual acuity. The amount of inlay decentration had no influence on postoperative visual acuity. Dr. Tomita is a consultant to Acufocus, Inc. No other author has a financial or proprietary interest in any material or method mentioned.

Femtosecond laser versus mechanical microkeratome-assisted flap creation for LASIK: a prospective, randomized, paired-eye study.

PurposeTo compare a femtosecond laser with a microkeratome for flap creation during laser in situ keratomileusis (LASIK) in terms of flap thickness predictability and visual outcomes.Patients and methodsThis was a prospective, randomized, masked, paired-eye study. Forty-four patients (34 females) who received bilateral LASIK were included. Patients were stratified by ocular dominance, and they then underwent randomization of flap creation using the femtosecond laser on one eye and undergoing the microkeratome procedure on the other one. The visual outcome differences between the corrected distance visual acuity (CDVA) at baseline and the uncorrected distance visual acuity (UDVA) on the first day postoperatively were set as the efficiency index for both groups. All visual acuity outcome results and the deviation of flap thickness were evaluated. P-values <0.05 were considered statistically significant.ResultsThe index of efficiency regarding the postoperative visual outcomes in the microkeratome group was lower (P<0.0001). This result was correlated with the difference between intended and achieved flap thickness (P=0.038; r=0.28), and a negative relationship in the regression analysis was confirmed (P<0.04; R2=0.1428). The UDVA in the microkeratome group improved significantly by the end of the first month (P<0.0271) in comparison to the baseline CDVA. The deviation between intended and postoperative flap thickness using either optical coherence pachymetry or Heidelberg Retinal Tomography II confocal microscopy was statistically significant (paired t-test; P<0.001) between the groups. The flap thickness deviation in the microkeratome group was higher. In the femtosecond laser group, the efficiency index was stable postoperatively (P=0.64) The UDVA improved significantly by the end of the first postoperative week (P=0.0043) in comparison to the baseline CDVA. Six months after surgery, improvement in the UDVA was significant in both groups (all P<0.001; one way analysis of variance).ConclusionFemtosecond laser was superior to microkeratome-assisted LASIK in terms of flap thickness predictability and the speed of visual acuity recovery. A negative relationship in the regression analysis between increasing flap thickness deviation and visual acuity recovery was confirmed.

In vivo confocal laser microscopy of morphologic changes after simultaneous LASIK and accelerated collagen crosslinking for myopia: One-year results

To evaluate the safety of corneal collagen crosslinking (CXL) combined with laser in situ keratomileusis (LASIK). Shinagawa LASIK Center, Tokyo, Japan. Case series. Bilateral myopic LASIK patients had unilateral accelerated CXL (KXL System) in the nondominant eye. After LASIK, riboflavin 0.1% was instilled in the residual stromal bed for 60 seconds. After the riboflavin was washed out and the flap placed in its original position, ultraviolet-A light (30 mW/cm(2)) was administered for 60 seconds. The LASIK-CXL eyes and the LASIK-only eyes were compared. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, manifest refraction spherical equivalent (MRSE), keratometry values, endothelial cell density (ECD), pachymetry, optical coherence tomography (OCT), corneal hysteresis (CH), corneal resistance factor (CRF), keratoconus match index (KMI), and 37 parameters from a dynamic bidirectional applanation device (Ocular Response Analyzer) were analyzed. Morphologic changes were evaluated using confocal microscopy. No significant differences in UDVA, CDVA, MRSE, ECD, dynamic bidirectional applanation readings (eg, CH, CRF, KMI), or 37 additional parameters were found between the 2 groups (P>.05). Increased hyperreflectivity and a demarcation line similar to that seen after CXL were observed in the LASIK-CXL eyes. The demarcation line (mean depth 200.04 μm ± 27.01 [SD]; range 178 to 278 μm) was present in 23 eyes (95.8%); the line was well defined in 2 eyes (8.3%) and faint in 21 eyes (87.5%). Combined LASIK-CXL was safe, causing insignificant corneal biomechanical and morphologic changes similar to those with CXL treatment only. No author has a financial or proprietary interest in any material or method mentioned.

Spontaneous Resolution of Delayed Epithelial Ingrowth After LASIK

Epithelial ingrowth is a known complication after laser in situ keratomileusis (LASIK), with a high incidence after repeat surgery or trauma. The authors report the occurrence of epithelial ingrowth 23 months after primary LASIK and its subsequent spontaneous resolution over the following 6 months. A 35-year-old man underwent bilateral uneventful microkeratome-assisted LASIK in June 2008. The patient presented 23 months later after noticing a "white spot" in his left eye. Examination of the left eye showed an oval patch of epithelial growth in the superonasal quadrant. Uncorrected distance visual acuity (UDVA) was 1.0 OD and 0.6 OS. Topical fluorometholone 0.1% eye drops were prescribed four times a day. Over the next 2 weeks, the UDVA improved to 1.0 and the size of the interface opacities decreased slightly. However, no further change was observed with continuation of corticosteroid eye drops over the next 2 weeks. All treatment was stopped. Three months later, the epithelial ingrowth expanded toward the visual axis. An option of surgical intervention was refused by the patient. Subsequent monthly follow-ups over another 3 months showed gradual decrease in the size of epithelial growth. Final slit-lamp examination showed complete clearance of the epithelial cells from the interface. The UDVA returned to 1.0 in the left eye. Epithelial ingrowth can occur after a long interval after primary LASIK. In our case, the epithelial cells disappeared without any surgical intervention over a period of 6 months.

Simultaneous corneal inlay implantation and laser in situ keratomileusis for presbyopia in patients with hyperopia, myopia, or emmetropia: Six-month results

To evaluate the safety and efficacy of simultaneous Kamra corneal inlay implantation and laser in situ keratomileusis (LASIK) for the treatment of presbyopia in emmetropic, hyperopic, or myopic patients. Private center, Tokyo, Japan. Cohort study. Patients had bilateral LASIK with simultaneous implantation of a corneal inlay in the nondominant eye to treat presbyopia and ametropia between September 2009 and April 2010. The efficacy and safety were determined by the spherical equivalent (SE) in the eye with the inlay. The study enrolled 360 eyes of 180 patients with a mean age of 52.4 years ± 5.1 (SD) (range 41 to 65 years). Sixty-four patients were available for the 6-month postoperative examination. The mean logMAR uncorrected near visual acuity in the eye with the inlay improved 7 lines in hyperopic eyes, 6 lines in emmetropic eyes, and 2 lines in myopic eyes. The mean logMAR uncorrected distance visual acuity improved by 3 lines, 1 line, and 10 lines, respectively. Simultaneous intracorneal inlay implantation and LASIK to treat presbyopia with emmetropia, hyperopia, or myopia was clinically safe and effective, yielding improvement in distance and near visual acuity. Patients were satisfied with decreased dependence on reading glasses regardless of the preoperative SE range. However, postoperative symptoms, such as dry eyes, halo, glare, or night-vision disturbances, occurred occasionally. Dr. Waring has a financial interest in and is world surgical monitor for Acufocus. No other author has a financial or proprietary interest in any material or method mentioned.

Patient-perceived pain during laser in situ keratomileusis: Comparison of fellow eyes

To compare pain scores during laser in situ keratomileusis (LASIK) between first-eye surgery and second-eye surgery. Private practice, Beirut, Lebanon. Cohort study. Sequential bilateral LASIK was performed between January 2010 and January 2011 by the same surgeon using a Schwind Amaris excimer laser. Hemodynamics and intraocular pressure (IOP) were monitored intraoperatively. Patients graded their pain perception on a 4-point scale after the completion of each eye's surgery. The study enrolled 154 patients. The first surgery was performed in the right eye in 106 patients and in the left eye in 48 patients. Patients reported discomfort during suction (mean pain score 0.80 ± 0.56 [SD]). More pain was reported during second-eye surgery by 74% of patients; 2% reported more pain in the first eye, and 24% reported equal pain in both eyes. The mean pain score was 0.63 ± 0.35 in the first eye and 0.93 ± 0.51 in the second eye (P=.01). Pain was higher during second-eye surgery whether the procedure was started in the right eye or in the left eye. Systolic blood pressure was also higher during second-eye surgery (P=.001). There was no statistically significant difference in diastolic blood pressure, heart rate, IOP, or suction-ring pressure. Patients had more pain during second-eye LASIK for reasons that are not clear. A psychological explanation or regional sensitization processes are potential factors and should be studied. No author has a financial or proprietary interest in any material or method mentioned.