Presbyopia is an age-related condition that progressively decreases the ability to focus on near objects. Minimally invasive surgical techniques have been developed to improve near vision, including laser in situ keratomileuses (LASIK) and corneal inlay. Most have similar approaches using monovision or increasing the depth of focus. Monovision laser refractive surgery is a combination of conventional LASIK, LASIK which creates a multifocal cornea (central near or peripheral near) and aspheric micro-monovision LASIK with a special ablation profile, which develops spherical aberration. Conductive keratoplasty is a method that uses radiofrequency energy to shrink the mid-peripheral corneal stromal tissue. However, it is not used because of regression. A corneal inlay is a small device that is implanted in the corneal flap or pocket made by a femtosecond laser. It is inserted into the non-dominant eye. There are various inlays such as the Flexivue Microlens (refractive), Raindrop (corneal shape-changing), and KAMRA (small-aperture) inlays. However, the safety and effectiveness of these inlays have not been proven over a long follow-up period, so care is required when performing inlay implantation. All presbyopia treatments can improve near vision but also have limitations and side effects such as reduced far vision, contrast sensitivity, or increased glare. Therefore, it is essential to select patients carefully. Mechanisms associated with presbyopia are not fully understood, and presbyopia remains challenging for ophthalmologists.
Contrast Sensitivity ; Cornea ; Corneal Transplantation ; Follow-Up Studies ; Glare ; Humans ; Inlays ; Keratomileusis, Laser In Situ ; Methods ; Presbyopia ; Refractive Surgical Procedures ; Vision, Monocular

PURPOSE: To determine effectiveness of laser-assisted in situ keratomileusis (LASIK) in the treatment of astigmatism following penetrating keratoplasty (PK). METHODS: We performed a retrospective review of medical records of patients who underwent LASIK following PK and had over 1 year of follow-up data. RESULTS: Twenty-six patients (26 pairs of eyes) underwent LASIK following PK. Mean age of the patients at the time of LASIK was 40.7 years (range, 26 to 72 years). Following LASIK, the mean cylinder was reduced by 2.4 diopters and mean reduction of cylinder after LASIK was 65.4% from the preoperative values at the last follow-up visit. Uncorrected visual acuity became 20 / 50 or better in 69.2% of the eyes after LASIK. Best-corrected visual acuity became 20 / 50 or better in 73.1% of the eyes after LASIK. All of them were intolerable to contact lenses before LASIK. After LASIK, 6 pairs (23.1%) did not need to use contact lenses and 18 pairs (69.2%) were tolerable to using contact lenses or spectacles. There were no significant endothelial cell density changes 12 months after LASIK (p = 0.239). CONCLUSIONS: LASIK is effective in the treatment of astigmatism following PK and increases contact lens and spectacle tolerance.
Adult ; Aged ; Astigmatism/etiology/physiopathology/*surgery ; *Contact Lenses/utilization ; Corneal Topography ; Female ; Humans ; Keratomileusis, Laser In Situ/*methods ; Keratoplasty, Penetrating/*adverse effects ; Lasers, Excimer/*therapeutic use ; Male ; Middle Aged ; Refraction, Ocular/physiology ; Retrospective Studies ; Vision, Binocular/physiology ; Visual Acuity/physiology

PURPOSE: To investigate the effect of macrophage migration inhibitory factor (MIF) on corneal sensitivity after laser in situ keratomileusis (LASIK) surgery. METHODS: New Zealand white rabbits were used in this study. A hinged corneal flap (160-microm thick) was created with a microkeratome, and -3.0 diopter excimer laser ablation was performed. Expressions of MIF mRNA in the corneal epithelial cells and surrounding inflammatory cells were analyzed using reverse transcription polymerase chain reaction at 48 hours after LASIK. After LASIK surgery, the rabbits were topically given either 1) a balanced salt solution (BSS), 2) MIF (100 ng/mL) alone, or 3) a combination of nerve growth factor (NGF, 100 ug/mL), neurotrophine-3 (NT-3, 100 ng/mL), interleukin-6 (IL-6, 5 ng/mL), and leukemia inhibitory factor (LIF, 5 ng/mL) four times a day for three days. Preoperative and postoperative corneal sensitivity at two weeks and at 10 weeks were assessed using the Cochet-Bonnet esthesiometer. RESULTS: Expression of MIF mRNA was 2.5-fold upregulated in the corneal epithelium and 1.5-fold upregulated in the surrounding inflammatory cells as compared with the control eyes. Preoperative baseline corneal sensitivity was 40.56 +/- 2.36 mm. At two weeks after LASIK, corneal sensitivity was 9.17 +/- 5.57 mm in the BSS treated group, 21.92 +/- 2.44 mm in the MIF treated group, and 22.42 +/- 1.59 mm in the neuronal growth factors-treated group (MIF vs. BSS, p < 0.0001; neuronal growth factors vs. BSS, p < 0.0001; MIF vs. neuronal growth factors, p = 0.815). At 10 weeks after LASIK, corneal sensitivity was 15.00 +/- 9.65, 35.00 +/- 5.48, and 29.58 +/- 4.31 mm respectively (MIF vs. BSS, p = 0.0001; neuronal growth factors vs. BSS, p = 0.002; MIF vs. neuronal growth factors, p = 0.192). Treatment with MIF alone could achieve as much of an effect on recovery of corneal sensation as treatment with combination of NGF, NT-3, IL-6, and LIF. CONCLUSIONS: Topically administered MIF plays a significant role in the early recovery of corneal sensitivity after LASIK in the experimental animal model.
Animals ; Epithelium, Corneal/*drug effects/innervation/physiology ; Female ; Humans ; Interleukin-6/pharmacology ; Keratomileusis, Laser In Situ/*methods ; Leukemia Inhibitory Factor/pharmacology ; Macrophage Migration-Inhibitory Factors/genetics/*pharmacology ; Models, Animal ; Nerve Growth Factor/pharmacology ; Nerve Regeneration/*drug effects/physiology ; Neurotrophin 3/pharmacology ; RNA, Messenger/metabolism ; Rabbits ; Recovery of Function/*drug effects/physiology ; Sensation/*drug effects/physiology

Adult ; Anti-Bacterial Agents ; therapeutic use ; Conjunctiva ; drug effects ; microbiology ; Female ; Humans ; Keratomileusis, Laser In Situ ; adverse effects ; methods ; Levofloxacin ; therapeutic use ; Male ; Povidone-Iodine ; therapeutic use ; Prospective Studies

OBJECTIVETo observe the influence of flap-on or flap-off Epipolis laser in situ keratomileusis (epi-LASIK) on the release of transforming growth factor-β1 (TGF-β1) in tear fluid and corneal haze formation.

METHODSThirty patients (60 eyes) with myopia underwent epi-LASIK surgery with epithelial flap repositioning (flap-on) in the right eyes and epithelial flap removal (flap-off) in the left eyes. The level of TGF-β1 in tears was measured preoperatively and on days 1, 3, and 7 postoperatively. Corneal haze was graded at 1, 3 and 6 months after surgery.

RESULTSThe mean preoperative spherical equivalent refraction was -4.98∓2.28 D (-2.50 to -7.25 D) in flap-on group and -5.20∓4.02 D (-1.75 to -7.00 D) in flap-off group, showing no significant difference between the two groups (P=0.80). TGF-β1 levels in the tear fluid were similar in the two groups preoperatively (P=0.11) and at 1, 3, and 7 days postoperatively (P=0.55, 0.45, 0.19, respectively). TGF-β1 levels in tears gradually decreased after the first postoperative day in both groups, but were still higher than the preoperative value till the 7th postoperative day. Corneal haze scores in the two groups were similar at 1 month (P=0.98), 3 months (P=0.52), and 6 months (P=0.72) after the operation.

CONCLUSIONFlap-on and flap-off epi-LASIK surgeries do not differ significantly in postoperative TGF-β1 levels in the tear fluid or in the postoperative haze scores. TGF-β1 may play a role in corneal wound healing.

Adult ; Cornea ; surgery ; Epithelium, Corneal ; pathology ; surgery ; Female ; Humans ; Keratomileusis, Laser In Situ ; methods ; Male ; Postoperative Period ; Surgical Flaps ; Tears ; metabolism ; Transforming Growth Factor beta1 ; metabolism ; Young Adult

BACKGROUNDThin-flap laser in situ keratomileusis (LASIK) is the new trend of refractive error correction surgery, the formation of corneal flap is crucial for a success of LASIK surgery. This study aimed to assess and compare the variations of LASIK flap created by the IntraLase femtosecond laser, Moria One Use-Plus SBK and Moria M2 Single-Use 90 µm-head microkeratome using Anterior segment optical coherence tomography (Visante OCT).

METHODSOne hundred and sixty-one eyes of 81 consecutive patients were enrolled in this prospective study and randomly divided into three groups depending on the flap creation method: flap creation with the the IntraLase femtosecond laser (IntraLase group, 59 eyes), flap creation with the Moria One Use-Plus SBK (SBK group, 44 eyes), and flap creation with the Moria M2 Single-Use 90 µm-head microkeratome (M2SU90 group, 58 eyes). The nominal flap thickness was 110 µm for all patients and for the three devices. One month after surgery, Visante OCT was used to measure the flap thickness at 20 locations on each cornea and the results were assessed for uniformity, regularity, and accuracy.

RESULTSAt 1 month after surgery, the mean central flap thickness was (111 ± 3) µm in the IntraLase group, (114 ± 8) µm in the SBK group, and (118 ± 13) µm in the M2SU90 group respectively. The flaps in the IntraLase group and the SBK group were more regular, showing an almost planar configuration, than the meniscus-shaped flaps in the M2SU90 group. The maximum deviation from the intended flap thickness (110 µm) was 6 µm in the IntraLase group, 10 µm in the SBK group, and 20 µm in the M2SU90 group respectively. A difference greater than 20 µm was observed in 0.42% of measurements in the IntraLase group; 2.95% of the measurements in the SBK group and 21.12% of measurements in the M2SU90 group.

CONCLUSIONSThe flaps created by the IntraLase femtosecond laser and Moria One Use-Plus SBK are more uniform; more regular, and more accurate than those created by the Moria M2 Single-Use 90 µm-head microkeratome. The first two methods can make precise flaps for Sub-Bowman Keratomileusis.

Adolescent ; Adult ; Humans ; Keratomileusis, Laser In Situ ; methods ; Surgical Flaps ; Tomography, Optical Coherence

PURPOSE: The corneal change induced by refractive procedures influence both the postoperative refractive status and the ocular spherical aberration (SA). We evaluated changes in corneal SA after three types of surface ablation: phototherapeutic keratectomy (PTK), myopic photorefractive keratectomy (PRK), and myopic wavefront-guided laser epithelial keratomileusis (LASEK). METHODS: Twenty-six eyes (25 patients) were subjected to PTK 26 eyes (14 patients) to PRK, and 34 eyes (17 patients) to wavefront-guided LASEK. Corneal SA was measured with the iTrace in all patients both preoperatively and 6 months postoperatively. RESULTS: Six months after surgery, mean corneal SA was -0.173 +/- 0.171 micrometer in the PTK group, 0.672 +/- 0.200 micrometer in the PRK group, and 0.143 +/- 0.136 micrometer in the wavefront-guided LASEK group. The mean difference between the preoperative and postoperative corneal SA (DeltaSA) was -0.475 micrometer in the PTK group, 0.402 micrometer in the PRK group, and -0.143 micrometer in the wavefront-guided LASEK group. CONCLUSIONS: Surgically induced changes in corneal SA vary with procedure. The prediction of the pattern of SA change induced by various surface ablation procedures may be helpful for developing future surgical procedures.
Adult ; Aged ; Corneal Dystrophies, Hereditary/*surgery ; Corneal Wavefront Aberration/*surgery ; Female ; Follow-Up Studies ; Humans ; Keratomileusis, Laser In Situ/*methods ; Male ; Middle Aged ; Myopia/*surgery ; Photorefractive Keratectomy/*methods ; Prospective Studies ; Treatment Outcome

PURPOSE: The corneal change induced by refractive procedures influence both the postoperative refractive status and the ocular spherical aberration (SA). We evaluated changes in corneal SA after three types of surface ablation: phototherapeutic keratectomy (PTK), myopic photorefractive keratectomy (PRK), and myopic wavefront-guided laser epithelial keratomileusis (LASEK). METHODS: Twenty-six eyes (25 patients) were subjected to PTK 26 eyes (14 patients) to PRK, and 34 eyes (17 patients) to wavefront-guided LASEK. Corneal SA was measured with the iTrace in all patients both preoperatively and 6 months postoperatively. RESULTS: Six months after surgery, mean corneal SA was -0.173 +/- 0.171 micrometer in the PTK group, 0.672 +/- 0.200 micrometer in the PRK group, and 0.143 +/- 0.136 micrometer in the wavefront-guided LASEK group. The mean difference between the preoperative and postoperative corneal SA (DeltaSA) was -0.475 micrometer in the PTK group, 0.402 micrometer in the PRK group, and -0.143 micrometer in the wavefront-guided LASEK group. CONCLUSIONS: Surgically induced changes in corneal SA vary with procedure. The prediction of the pattern of SA change induced by various surface ablation procedures may be helpful for developing future surgical procedures.
Adult ; Aged ; Corneal Dystrophies, Hereditary/*surgery ; Corneal Wavefront Aberration/*surgery ; Female ; Follow-Up Studies ; Humans ; Keratomileusis, Laser In Situ/*methods ; Male ; Middle Aged ; Myopia/*surgery ; Photorefractive Keratectomy/*methods ; Prospective Studies ; Treatment Outcome

PURPOSE: To compare the changes in posterior corneal curvature using scanning slit topography (Orbscan II) and Scheimpflug imaging (Pentacam) before and after Epi-laser in situ keratomileusis (LASIK) for myopia. METHODS: In a prospective observational case-series study, 20 myopic patients having undergone Epi-LASIK were examined serially with two different devices, Orbscan II and Pentacam, preoperatively and one month postoperatively. Posterior central elevation (PCE) and posterior maximal elevation (PME) were compared between the two devices, and the changes in parameters after Epi-LASIK were analyzed using a difference map. RESULTS: All parameters (preoperative and postoperative PCE and preoperative and postoperative PME) that were measured using the Orbscan II were significantly greater compared to those of the Pentacam (for all p < 0.001). PCE and PME were significantly increased one month postoperatively in the Orbscan II measurements (p < 0.05) but were not significantly increased in the Pentacam measurements. Also, DeltaPCE and DeltaPME, in the difference map obtained by each serial scanning, were significantly greater in the Orbscan II measurements than with the Pentacam (p = 0.012, p = 0.016). CONCLUSIONS: The Pentacam measurements displayed significantly reduced values in all parameters related to posterior corneal elevation compared to those of the Orbscan II. The Pentacam showed no significant change in posterior corneal curvature after Epi-LASIK, based on the difference map.
Adult ; Corneal Topography/*methods ; Female ; Humans ; Keratomileusis, Laser In Situ/*methods ; Male ; Myopia/*surgery ; Prospective Studies ; Treatment Outcome

A 38-year-old woman developed diffusely distributed opacities with crystalline materials in the laser in situ keratomileusis (LASIK) interface of her eye after she was scratched by a sprig during mountain climbing. No sign of flap displacement was noted. Despite two days of topical and systemic antibiotics therapy, the corneal infiltration with interface opacities persisted. The following day, the distribution of the crystalline materials had rotated in a counterclockwise direction. Flap lifting and foreign body removal using sufficient irrigation were performed. One month after surgery, the patient's postoperative uncorrected visual acuity was 0.8 with cleared interface. No signs of epithelial ingrowth or flap striae were noted. Mild traumatic corneal scratching without flap displacement may threaten the integrity of the LASIK interface. If foreign bodies are suspected to be the cause of inflammation, early flap lifting with irrigation is imperative for successful treatment.
Adult ; Cornea/*injuries/pathology/surgery ; Eye Injuries/*complications/diagnosis/surgery ; Female ; Follow-Up Studies ; Humans ; Keratomileusis, Laser In Situ/*methods ; Myopia/surgery ; *Surgical Flaps ; Surgical Wound Dehiscence/diagnosis/*etiology/surgery ; Wounds, Nonpenetrating/*complications/diagnosis/surgery